Mehrfache „Click” Reaktionen an Porphyrinen · MELDAL as well as SHARPLESS proposed a stepwise mechanism for the Cu(I)- catalyzed cycloaddition [10, 20] in their first publication

Multiple “Click” Reactions on Porphyrins

Mehrfache „Click” Reaktionen an Porphyrinen

Der Naturwissenschaftlichen Fakultät

der Friedrich-Alexander-Universität Erlangen-Nürnberg zur

Erlangung des Doktorgrades Dr. rer. nat.

vorgelegt von Nina Lang

aus Bamberg

Als Dissertation genehmigt von der Naturwissenschaftlichen Fakultät der Friedrich-

Alexander-Universität Erlangen-Nürnberg

Tag der mündlichen Prüfung: 04. Juni 2010

Versitzender der Prüfungskommission: Prof. Dr. Eberhard Bänsch

Erstberichterstatter: Priv.-Doz. Dr. Norbert Jux

Zweitberichterstatter: Prof. Dr. Jürgen Schatz

Die vorliegende Arbeit entstand in der Zeit von Mai 2006 bis April 2010 am Institut für

Organische Chemie der Friedrich-Alexander-Universität Erlangen-Nürnberg. Mein

besonderer Dank gilt hierbei meinem Doktorvater PD Dr. Norbert Jux für die

Unterstützung und das Interesse am Fortgang meiner Arbeit.

For my family

"We all want to believe in impossible things, I suppose, to persuade ourselves that miracles can happen."

Paul Auster (The Book of Illusions)

TABLE OF CONTENTS

1 “CLICK“ CHEMISTRY - A NEW SYNTHETIC PHILOSOPHY 1

1.1 1,3-DIPOLAR CYCLOADDITION - REACTION AND MECHANISM 2 1.2 CONDITIONS FOR CU(I)-CATALYZED 1,3-DIPOLAR CYCLOADDITION 5 1.3 APPLICATIONS OF THE CU(I)-CATALYZED 1,3-DIPOLAR CYCLOADDITION 8 1.3.1 Bioconjugation ........................................................................................................................................................... 8 1.3.2 Material science ....................................................................................................................................................... 11

1.3.3 Drug Design ............................................................................................................................................................. 15

1.4 “CLICK” CHEMISTRY ON PORPHYRINS 17

2 PROPOSAL 23

3 RESULTS AND DISCUSSION 25

3.1 FUNDAMENTAL PORPHYRIN BUILDING BLOCKS 25 3.2 FIRST STEPS IN APPLYING THE 1,3-DIPOLAR “CLICK” CYCLOADDITION 31 3.3 SYNTHESIS OF FERROCENE-PORPHYRIN CONJUGATES 41 3.4 SYNTHESIS OF DENDRITIC FERROCENE-PORPHYRIN CONJUGATES 51 3.5 WATER-SOLUBLE FERROCENE-PORPHYRIN SYSTEMS 60 3.5.1 Highly-Substituted Conjugates ................................................................................................................................. 60

3.5.2 Bis-Substituted Water-Soluble Ferrocene-Porphyrin Conjugates .............................................................................. 61

3.6 METALATION OF THE FERROCENE-PORPHYRIN CONJUGATES WITH NICKEL, COPPER, MANGANESE AND IRON 65 3.7 THE “CLICK” ROUTE TO “CAPPED” PORPHYRINS 75 3.7.1 Ferrocene-Bridged Porphyrins ................................................................................................................................. 75 3.7.2 Porphyrins Bridged with Dendritic Systems .............................................................................................................. 83 3.7.3 Cyclic Voltammetry of the Bridged Porphyrins .......................................................................................................... 86

3.8 CREATING OLIGOMERIC FERROCENE-PORPHYRIN CONJUGATES 89 3.8.1 Di- and Trimeric Ferrocene-Porphyrin Conjugates .................................................................................................... 89 3.8.2 Synthesis of a Porphyrin-Triad formed of a new AB2C-Porphyrin ............................................................................. 93

3.9 SYNTHESIS OF A NOVEL A2B2-PORPHYRIN-SYSTEM AND ITS FUNCTIONALIZATION BY “CLICK” CHEMISTRY 100 3.9.1 Dendritic Functionalization of Bispropargyl Porphyrin 112 ...................................................................................... 102

3.9.2 Ferrocene Conjugates Generated from the Novel A2B2-Porphyrin .......................................................................... 104

3.10 DIMERS, TRIMERS AND TETRAMERS EXCLUSIVELY CONSTITUTED OF PORPHYRINS 106 3.10.1 Synthesis of Two Different Acetylene Porphyrins ................................................................................................... 106 3.10.2 Combining Acetylene and Azidoporphyrins to Oligomers ....................................................................................... 108

3.11 SIDE-SELECTIVE MODIFICATION OF PORPHYRINS 114

4 CONCLUSION AND HIGHLIGHTS 120

5 ZUSAMMENFASSUNG 123

6 EXPERIMENTAL SECTION 126

6.1 CHEMICALS, METHODS AND EQUIPMENT 126 6.2 SYNTHETIC PROCEDURES 129

7 REFERENCES 211

Abbreviations

AChE acetylcholinesterase

AFM atomic force microscopy

Ar aryl

ATR attenuated total reflection

ATRP atom transfer radical polymerization

β-H β-pyrrolic protons (labeling in the depicted NMR spectra)

Boc t-butoxycarbonyl

bpy bispyridin

Bu butyl

COSY correlation spectroscopy

CV cyclic voltammetry

d day(s)

d doublet

DCC dicylcohexylcarbodiimid

DCTB trans-2-(3-(4-t-butylphenyl)-

2-methyl-2-propenylidene)malononitrile

dd doublet of a doublet

DDQ 2,3-dichloro-5,6-dicyano-1,4-benzoquinone

DHB 2,5-dihydroxybenzoic acid

DIPEA diisopropylethylamine (Hünig‟s base)

DMAP N,N-dimethyl-4-aminopyridine

DMF dimethylformamide

E (E½) (half-wave) potential

EA elemental analysis

Epa, Epc anodic (cathodic) peak potential

eq equivalent(s)

et al. et alia

exc. excess(ive)

FAB fast atom bombardment

Fc ferrocene

Fc* decamethylferrocene

Fmoc fluorenylmethoxycarbonyl

GP general procedure

h hour(s)

HETCOR heteronuclear correlation

HIV human immunodeficiency virus

IR Infra-red

m multiplet

M molar

MALDI-TOF matrix assisted laser desorption ionization - time of flight

Me methyl

MS mass spectrometry

NBA nitrobenzyl alcohol

n-BuLi n-butyl lithium

NH2 [G1] NEWKOME dendron 1st generation

NH2 [G2] NEWKOME dendron 2nd

generation

nJ j-coupling (constant) with n indicating

the number of involved bonds

NMR nuclear magnetic resonance

NMRP nitroxide-mediated radical polymerization

Ox oxidation

PBS phosphate buffered saline

PM3 parameterized method No. 3

ppm parts per million

R substituent

RAFT reversible addition fragmentation chain transfer

Red reduction

ROMP ring-opening metathesis polymerization

rt room temperature

s singlet

SAM self-assembled monolayer

SCE standard calomel electrode

sin sinapic acid

SWNTs single-walled carbo nanotubes

t triplet

t tertiary

TBDPS t-butyldiphenylsilyl

TBTA tris(benzyltriazolylmethyl)amine

TCEP tris(2-chlorethyl)phosphate

TEM transmission electron microscopy

TFA trifluoro acetic acid

THF tetrahydrofuran

TLC thin layer chromatography

TPP tetraphenylporphyrin

UV ultraviolet

vis visual

λ wavelength

http://de.wikipedia.org/wiki/Tris(2-chlorethyl)phosphat

“Click“ Chemistry - A New Synthetic Philosophy

1

1 “Click“ Chemistry - A New Synthetic Philosophy

The search for new reaction types is still an important issue in organic chemistry and

in pharmacological researches. Above all, easy accomplishable and reliable

reactions that offer good yields and no by-products are worthwhile. In 2001 the term

of “click” chemistry was first coined by SHARPLESS[1] implying the idea that “all

searches must be restricted to molecules that are easy to make”. Actually, the goal

was to present new synthetic strategies for drug discovery that can be combined from

easy compounds. Only reactions that work modular, offer high yields, have a wide

scope and are stereospecific (but not necessarily enantioselective) match the criteria

of a “click” reaction. The required process should further take place under easy

reaction conditions, offer a simple isolation of the product and work with readily

available starting materials and reagents. Thus, a large new field of research has

opened up which had a dramatic impact in the recent years. This becomes apparent,

when the number of publications dealing with “click” chemistry is considered. The

amount of related publications has shown a nearly exponential growth since the

introduction in 2001.

A literature search via SciFinder Scholar®[6], performed on February 2nd of 2010,

revealed a total of 2338 publications containing the keyword “click chemistry” which

included journal articles, reviews, and patents. Publications in this area have quickly

increased over the past eight years. Five publications in 2002, from which four arose

in the SHARPLESS group, have grown up to 724 publications in 2008. The big success

Figure 1: “Click” chemistry on covers of chemical journals. [2-5]


2

started in 2006, when the publication number reaches 256. In comparison in the

years 2005, 2004 and 2003 alltogether only 139 papers have been published on that

issue. Even a set of books about click chemistry can be purchased today.[7, 8]

Four great reaction types that meet the criteria of “click” chemistry have been

identified to this day:[1, 9]

Cycloadditions; these primarily refer to 1,3-dipolar cycloadditions[10], but also

include hetero-DIELS-ALDER cycloadditions[11].

Nucleophilic ring-openings[12]; these refer to the opening of strained

heterocyclic electrophiles, such as aziridines, epoxides[13], cyclic sulfates,

aziridinium ions, episulfonium ions, etc.

Carbonyl chemistry of the non-aldol type:[1] examples include the formation of

ureas, thioureas, hydrazones, oxime ethers, amides, aromatic heterocycles,

etc. Carbonyl reactions of the aldol type generally have a low thermodynamic

driving force; thus they have longer reaction times and give side products, and

therefore cannot be considered as “click” reactions.

Additions to carbon-carbon[14], multiple bonds; examples include epoxidations,

aziridinations, dihydroxylations, sulfenyl halide additions, nitrosyl halide

additions, and certain MICHAEL additions.

All these processes have a high thermodynamic driving force, usually bigger than

20 kJ, what guarantees a rapid conversion and the high selectivity for only a single

product.[1] As a multitude of reactions has gained the “click” status, the use in many

application fields is only a corollary. The key areas where “click” chemistry has a

significant impact can be separated into three relevant categories[15]: bioconjugation,

material science and drug discovery, which are presented more in detail in

Chapter 1.3.

1.1 1,3-Dipolar Cycloaddition - Reaction and Mechanism

Of all the processes with “click” status the 1,3-dipolar HUISGEN[16] alkyne-azide

cycloaddition has become the most famous example of this class of reactions. This

reaction describes the formation of triazoles from azides and alkynes. Despite the

thermodynamic favorability of azide decomposition, kinetic factors allow aliphatic

azides to remain nearly chemically invisible until presented with a good dipolarophile.

In fact, this kinetic stability of alkynes and azides is directly responsible for their slow


3

cycloaddition, which generally requires elevated temperatures and long reaction

times. The original version of the HUISGEN 1,3-dipolar cycloaddition between an azide

and an alkyne furnishes a mixture of the 1,4- and the 1,5-regioisomer and this

requires further purification. The selective formation of only one of these regioisomers

has often been investigated[17-19] but didn‟t lead to acceptable results. In 2002

SHARPLESS[10] and MELDAL

[20] independently presented the Cu(I)-catalyzed way of the

1,3-dipolar-cycloaddition of alkynes and azides. This reaction normally occurs at

room temperature, proceeds with almost full conversion and shows a selectivity for

only the 1,4-regioisomer.

Moreover, this new process needs no protecting groups, works in all solvents and

does not need the exclusion of oxygen or water. These properties fit perfectly to the

new “click” philosophy and that is why “click” chemistry is often used as synonym for

this Cu(I)-catalyzed 1,3-dipolar cycloaddition. It should be mentioned that besides

Cu(I) salts, other metals that promote the dipolar cycloaddition reaction of terminal

acetylenes and azides have been reported recently.[21] Thus SHARPLESS and co-

workers found that a variety of Ru complexes, such as CpRuCl(PPh3), (Cp*RuCl2)2,

Cp*RuCl(NBD), and Cp*RuCl(COD), promote the azide/alkyne “click” reaction.

Interestingly, not only the 1,4-aduct is favored by some catalysts (i.e.,

Ru(OAc)2(PPh3)2), but also the 1,5-adduct can be formed exclusively by the use of

other Ru catalysts (e. g. Cp*RuCl(PPh3)2).[21] A catalytic cycle that relies on a

pathway similar to the one of the cyclotrimerization reaction of alkynes via a six-

membered cycle has been proposed. MATYJASZEWSKI and co-workers have recently

published the use of Ni, Pd, and Pt salts to catalyze this reaction, although a

mechanistic description has not been provided.[22]

Scheme 1: Thermal cycloaddition in comparison to the Cu(I)-catalyzed one.


4

MELDAL as well as SHARPLESS proposed a stepwise mechanism for the Cu(I)-

catalyzed cycloaddition[10, 20] in their first publication about that issue in 2002. This

was confirmed by later investigations especially by SHARPLESS and other researchers

at the Scripps Institute in La Jolla, California, USA based on calculations and kinetic

studies.[23, 24] Although the thermal cycloaddition occurs concerted, DFT studies on

monomeric copper acetylide complexes indicate the preference for a stepwise

mechanism. The concerted cycloaddition of the Cu(I) acetylide complex with azide

seems very unlike regarding the calculated activation barrier for this process. This

barrier for which 27 kJ/mol have been determined is even higher as the barrier for the

uncatalyzed reaction and does not correspond to the properties of this reaction. The

barrier found for the stepwise process, 11 kJ/mol, explains better the enormous rate

enhancement under Cu(I) catalysis. Kinetic calculations also show that a dynamically

exchange of different Cu(I) acetylide complexes is involved in the mechanism. A

broad outline is shown in Scheme 2.

The catalytic cycle begins with the formation of a copper(I) acetylide via π-complexes

and base-protonated proton abstraction of the alkyne. As it is already known for the

SONOGASHIRA coupling, this doesn‟t occur for internal alkynes.[25] The first step

involves π-complexation of a Cu(I) dimer 1 to the alkyne, followed by deprotonation

of the terminal hydrogen to give the copper acetylide 2. The copper π-coordination

lowers the pKa of the alkyne hydrogen up to nine orders of magnitude, which

normally allows the deprotonation without a base in aqueous solution. If a non-basic

solvent, such as acetonitrile, is used, then a base, such as 2,6-lutidine or N,N’-

diisopropylethylamine (DIPEA), must be added. Despite all, the nature of the copper

acetylene complex 2 has not become completely clear yet. The different reaction

Scheme 2: Proposed mechanism for the Cu(I)-catalyzed 1,3-dipolar cycloaddition of alkynes and azides.


5

orders found in dependence on the copper concentration indicate a change between

mono-, di- and polymeric complexes. An important role is assigned to a two-copper

core species 3, where one copper core is complexed to the acetylene unit and the

other copper atom activates the azide. Subsequent cyclization has been explored

only for monomeric copper species, but a similar process of dimeric copper

complexes can be proposed.[26] The complexation of the azide by the copper

acetylide activates the nucleophilic attack of the acetylide carbon to generate

metallocycle 4.[27] In the monomeric case ring contraction ensues from the

metallocycle intermediate with almost no barrier as calculations indicate. The

transformation to the triazole 5 should be just as fast, because the kinetic is only

changed slightly by changing the ring size. Protonation of triazole-copper derivative 6

in the 1,5-position followed by dissociation of the product ends the reaction and

regenerates the catalyst. Limited deuteration studies suggest that this protonation in

the 1,5-position occurs through interaction with an external base or solvent molecule

but further studies are needed to conclusively establish this theory.

1.2 Conditions for Cu(I)-catalyzed 1,3-dipolar Cycloaddition

The huge scope, the tolerance towards most functional groups and the easy working

procedure are the factors for the uniqueness of the Cu(I)-catalyzed cycloaddition.

Thus, arrays of different approaches of generating the active Cu(I) species have

been carried out in the last years. Most commonly, Cu(I) is generated in situ by using

Cu(SO)4∙5 H2O and sodium ascorbate in 3-10 fold excess as reducing agent. Other

reducing agents including hydrazine[22] or tris(2-carboxyethoxy)phosphine (TCEP)[28]

have also been used successfully. No inert atmosphere is required despite the

instability of Cu(I) towards oxygen. The typical solvent is a mixture of water and

tBuOH[29, 30], but also other solvents can be used if the reagents are not soluble in

this media. In that manner, mixtures of water and organic solvents provided just as

good results as it was shown for the synthesis of water-soluble calixarenes[31] 9, 10

and 11 shown in Scheme 3. An azido calixarene was converted with different alkyne

compounds which introduce the water-solubility by “click” reactions. In this approach

a mixture of THF, water and ethanol is used as solvent and the reaction is stirred at

60°C. The advantages of using water are the faster reaction times and, mostly, the

exclusion of an additional base. 6

5

4

3

2

1


6

Another way of generating Cu(I) in situ is the oxidation of Cu(0). Therefore copper

turnings are stirred with the alkyne and the azide in water/alcohol mixtures. The

copper(I) is obtained via comproportionation of the Cu(0)/Cu(II) couple[32] and

furnishes the corresponding triazole in good yields.[24] Cu(II) is obtained due to the

undesired oxidation of Cu(I). As the turnings do not offer a large reaction surface, this

reaction takes quiet long. First improvements on this process succeeded by the

addition of nanosize activated powder of Cu(0) instead of the turnings.[33] But in this

case a reaction only occurred by the addition of propargyl amine hydrochloride salt

instead of the free base. This may be due to the presence of an amine ligand and a

slightly acidic environment, which would presumably be ensured with the addition of

an amine hydrochloride salt, that might be required to generate the Cu(I) catalytic

species. Even better results can be achieved by the use of copper nanoparticles[34]

what further decreases the reaction time. The copper nanoclusters were prepared by

reducing cuprous chloride in solution with tetraoctyl ammoniumformate (TOAF). This

method gives a stable suspension that can be kept for months, with a narrow cluster

size distribution and is very easy to handle.[35]. This process is likely catalyzed by

Cu(I), which is built on the surface, than by Cu(I) ions that leach into the reaction

mixture.

Of course Cu(I) can also be added directly as copper salt, such as CuI or CuBr.[36]

This is usually performed in any organic solvent, without the addition of water, that

can destroy the active Cu(I) species. As water is mostly necessary as base to form

the Cu(I)-acetylide complex, in organic solvents often an additional base is required.

The tolerance to different functional groups is limited, thus propargyl alcohol does not

form the triazole in a few cases.[36] Another disadvantage is the extreme sensitivity

towards the reaction conditions. The use of triethylamine as base has furnished no

triazole in the reaction of 12 to 13 shown in Scheme 4, whereas DIPEA as base

Scheme 3: Synthesis of water-soluble calixarenes via “click” reactions. CuSO4∙5 H20 and sodium ascorbate is used as Cu(I)-source and a mixture of THF, water and ethanol as solvent.

8

9

10

11


7

brought a yield of 38%.[37] Furthermore, this reaction only worked well when toluene

is used as solvent. The performance of this reaction in MeCN did not lead to

satisfying results.

The Cu(I) oxidation state can be stabilized by special ligands that shield the metal

centre against degradation. The best performing ligands all share a similar structural

motif: They are oligotriazole derivatives derived from propargylamine cores (Figure

2).[38]

From these ligands, tris(benzyltriazolylmethyl)amine (TBTA) 14 shows very good

shielding properties. The Cu(I) core can be enclosed completely by the four nitrogen

centers of this ligand. The combination of the tertiary amine and the triazole units

may be the reason for the unique effectiveness: The former accelerates the catalysis

by providing additional electron density to the metal core while the latter supports the

formation of the copper acetylide complex. Adding amounts of one of these ligands to

the reaction mixture has the advantage, that on the one hand, the catalyst loading

can be reduced without any loss in yield and on the other hand, a reducing agent

Alkyne Base (1eq) CuI Solvent T [ C] Time [h] Yield [%][a]

5 eq None None None 80 24 89[b]

1 eq Et3N 2 eq MeCN rt 18 trace

1 eq DIPEA 2 eq MeCN rt 18 38

1 eq Et3N 0.1 eq toluene rt 18 65

1 eq DIPEA 0.1 eq toluene rt 18 85

1 eq None 0.1 eq toluene rt 3 52

1 eq None 0.1 eq toluene rt 7 61

Scheme 4: This example shows the extreme sensitivity of the CuI process towards the reaction conditions.

Figure 2: Different triazolylligands that can be used in the cycloaddition to stabilize the Cu(I) against oxidation.

12

13


8

isn‟t necessary.[39] Tristriazolyl ligands also inhibit the Cu(II)-catalyzed oxidative

coupling reactions of terminal alkynes to diynes under otherwise standard conditions,

what can occur as by-reaction.[40]

1.3 Applications of the Cu(I)-catalyzed 1,3-Dipolar Cycloaddition

Since its first appearance in 2001, “click” chemistry has stimulated an enormous

amount of interest in many different research fields ranging from microelectronics

over virus labeling to treatments for cancer. In the following sections, an in-depth look

will be taken at some of its applications which can be divided in three main

categories: bioconjuction, material science and drug discovery.[15] These different

areas are presented with the help of a few examples in the next sections.

1.3.1 Bioconjugation

The approach of bioconjugation can be considered as the link of chemistry and

biology. Synthetic labels are attached covalently to biological systems for studies of

biomolecular frameworks.[41] Fusing two proteins together, linking complex

carbohydrates with peptides or enclose small molecular probes (e. g. fluorescent

dyes, affinity tags) to a biopolymer are a few examples for this field. As biological

systems have a broad structural complexity, one has to find chemoselective reactions

that allow the coupling of two mutually and unique functional groups. This has to

occur under physiological conditions what means aqueous environment and the

presence of a lot of functional groups, as there are in natural systems. The Cu(I)-

catalyzed cycloaddition can be very helpful in that case as it offers two great

advantages: 1) the azide moiety is absent in almost all natural existing compounds

and 2) despite a high intrinsic reactivity, azides allow selective ligation with a very

limited set of reaction partners.[42]

The applicability of “click” reactions towards bioconjugation was first hinted in the

work of MELDAL et al.[20] in 2001. In this work, different peptide triazoles 15 were

prepared by solid phase techniques as shown in Scheme 5.

The mild reaction conditions, the compatibility to Fmoc and Boc protecting groups

and the stability of other functional groups like free amino groups or carboxylic acids

under these conditions are the major advantages of this process.


9

In another example, the “click” cycloaddition is used to attach proteins on a solid

surface in the preferred orientation. The immobilization of a protein onto a solid

surface in the correct orientation is essential for optimal interaction with other species

with which it should form a functional complex. Most current surface conjugation

schemes offer limited control over the three dimensional assembly of bound proteins

due to their reliance on functional groups that are often abundantly present within the

protein.[43]

To manage that problem, an alkyne-terminated PEGylated surface was provided for

the conjugation of azide-containing biomolecules via “click” chemistry, which

proceeded to completion at low temperature and in aqueous solvent. This process is

illustrated in Scheme 6.

The Cu(I) cycloaddition approach is also suitable for the synthesis of large bivalent

cyclic peptides, generated of peptide monomers with six residues or longer (JAGASAKI

et al.[44]). Peptide chains with a terminal alkyne and azide unit were prepared to be

converted in a Cu(I)-catalyzed cycloaddition[44] to give head to tail connected cycles.

Scheme 6: Immobilization of different biological substrates on a glas surface.

Scheme 5: The first peptide triazoles generated via Cu(I)-catalyzed cycloaddition by Meldal et al.

,,

,


10

By changing the reaction conditions, such as solvent, the analogue cyclic monomer

can be obtained. The combination of the right resin and solvent properties

guarantees the success of the cyclodimerisation. This is shown in Scheme 7, where

either a cyclic dimer or a cyclic monomer is built from the same resin.

Another striking application was reported by FINN et al.[45] in their studies on the

conjugation of fluorescein dye molecules onto the cowpea mosaic virus. The virus

itself resembles a cage-like molecule, formed from 60 identical copies of a two-

protein asymmetric unit, which surrounds the genetic information in the core. In initial

studies fluorescein is conjugated via a triazole unit to different functionalized virus

particles by the “click” reaction to give the conjugates 16 and 17. In conjugate 16, the

fluorescein dye features the azide unit, whereas in conjugate 17, it has the alkyne

unit as “click” component.

Some important conclusions were made from this work: First the use of ascorbate or

p-hydroquinone reductants led to substantial disassembly of the virus capsid and

second the triazole formation in the presence of Cu(II) led to virus decomposition

despite the virus being stable to Cu(I) alone. Tris(benzyltriazolylmethyl)amine as

ligand for the stabilization of Cu(I) could protect the virus from copper-triazole

induced disassembly. On this way, fluorescein dyes could be attached to the virus as

it is shown in Figure 3.

Scheme 7: Cyclodimerisation or cyclomonomerisation from the same peptide chain in dependence of the solvent.


11

In further research studies[46], the reaction conditions were even improved by this

group and various appendages were conjugated to the virus, including complex

sugars, peptides, poly(ethylene oxide) polymers and the iron carrier protein

transferrin.

1.3.2 Material science

The increasing need for materials with controlled structures will continue to fuel the

employment of synthetic organic concepts into material science. One powerful

example is the introduction of “click” chemistry by the material science community.

This new philosophy offers access to easy modification of already existing materials

or allows the development of new polymeric structures.

One example of material modification is the functionalization of single-walled carbon

nanotubes (SWNTs) with alkyne-substituted spacers via amine groups in the

research group of ADRONOV.[47]

Scheme 8: Functionalization of SWNTs with alkyne units in order to click the alkyne nanotubes to azide polystyrene.

Figure 3: Modification of the cowpea mosaic virus with a fluorescine dye.

17 16

18

O

NH2

O

ON3

O

n

isoamyl nitrit

60 C

1. EBiB, CuBr/Bpy

DMF, 110 C

2. NaN3, DMF, rt

Cu(I), DMF

+

PS = polystyrene


12

The use of click chemistry for chemical functionalization of SWNTs provides a new

access route to nanomaterials that were otherwise difficult to purify. The presence of

the alkyne groups did not interfere with the initial coupling, but enabled highly specific

post-synthesis modification, as demonstrated by subsequent reaction of alkynated

nanotubes with azide-terminated polystyrene to 18 (Scheme 8). This method

guarantees a greater level of control over the orientation and the density of the

polymer attached to the nanotube surface while reducing the risk of side reactions.

The value of “click” chemistry becomes most apparent in the work with polymers.

Recently, several reviews described the use of the Cu(I)-catalyzed HUISGEN

cycloadditions for the synthesis of dendritic, branched, linear, or cyclic co-

polymers.[48, 49]

HAWKER, SHARPLESS, FOKIN, and co-workers first introduced the HUISGEN

cycloreaction to polymer chemistry by using it for the synthesis of dendrimers.[50] In

their task, triazole-based dendrons were divergently synthesized using the “click”

cycloaddition as the actual generation-growth step. These dendritic building blocks

Figure 4: Dendritic system generated via “click” chemistry.


13

were then convergently anchored to a variety of polyacetylene cores to generate

dendrimers. One example is shown in Figure 4. Since then, this “click” HUISGEN

cycloaddition has been widely employed to synthesize or modify various dendrimers.

The combination of “click” chemistry with other living polymerization techniques, such

as ring-opening polymerization (ROP), ring-opening metathesis polymerization

(ROMP), cationic polymerization, nitroxide-mediated radical polymerization (NMRP),

atom transfer radical polymerization (ATRP) and reversible addition fragmentation

chain transfer polymerization (RAFT) (a few examples are shown in Figure 5) has

shown very good results.

Functional polymers with highly defined structures could be obtained in many of

these cases. The combination of “click” chemistry with one or more of these

polymerization methods provides easy access to a broad range of polymeric

materials that are otherwise very difficult to prepare.

One example is the formation of aliphatic polyesters, an important class of

biodegradable polymers that easily decompose during post-polymerization

modifications due to the labile nature of the backbone. The mild reaction conditions

required for “click” chemistry readily allowed its combination with ROP, leading to

pendant-group functionalized polyesters[51-53] 19 and 20. The efficient combination of

“click” chemistry with ROMP has also led to functional polymers with high functional-

group tolerance.[54] That synthetic approach was used to synthesize side-chain-

modified poly(oxynorbornene)s through pre- and post-polymerization modifications.

The most successful combination so far has been the “union” of “click” chemistry with

ATRP. Thus, the introduction of azide groups via the initiator, -

dihydroxypolystyrene furnishes polymer 21 in good yields.[55]

Figure 5: Examples of the combination of different polymerization techniques (ATRP, polyaddition and ROMP) and “click” chemistry.


14

By using “click” cycloadditions, different functional groups (e. g. carboxyl, olefin, and

amine) could be attached to the ends of polymers prepared by ATRP; also

biomolecules were further attached to the polymer chain ends. The “click” coupling of

telechelic polystyrene prepared by ATRP yielded a linear polystyrene 22 that

contained ester bonds in the backbone[56] rendering the polymer partially

biodegradable. Similar strategies were also applied to the synthesis of various block

copolymers,[57] star polymers,[58] miktoarm stars and mikto dendritic copolymers,[59]

and well-defined macromonomers[60] from building blocks prepared by ATRP.

Further important areas in material science are the functionalization of nanoparticles,

the generation of self-assembled monolayers (SAM) and liquid crystals (Scheme 9).

To attach different chemical groups on nanoparticles in technology reactions for the

introduction of functionalities on the already existing assembly on the surface are

required. Therefore the “click” chemistry offers good possibilities, as it has been

shown in the functionalization of alkynyl-terminated monolayers on gold nano

particles.[61, 62] To a reaction mixture containing the alkynyl-terminated gold

substrates in aqueous ethanol azido reagents and Cu(I) were added. This resulted in

good introduction of several different functionalities.

Figure 6: Futher examples of “click” chemistry in combination with different polymerisation techniques.

Scheme 9: Functionalization of Au-nanoparticles with different acetylene derivatives by 1,3-dipolar “click” cycloaddition.


15

An example of liquid crystals gained by “click” reactions has recently been reported

(Figure 7).[63, 64] The triazole compounds 23 and 24 could be obtained in good yields

(60-90%) by refluxing the azide and alkyne in aqueous ethanol with CuI and NEt3.

The melting point of these compounds can be controlled by the distance between the

core and the triazole unit.

1.3.3 Drug Design

The last big field of application in “click” chemistry is the development of new drugs,

as this is the actual aim declared by SHARPLESS in 2001.[1] The time consuming and

expensive traditional discovery process for new pharmaceutical drugs should be

replaced by a more efficient and faster way. The value of triazoles for pharmaceutical

needs has already been known, as triazole compounds are e. g. known for their anti-

HIV effect[65] or their activity against Gram positiv bacteria.[66]

Scheme 10: Formation of a HIV-1 protease inhibitor.

In this way HIV-1 protease inhibitors have been prepared successfully. In general,

protease inhibitors are a class of medications used to treat or to prevent viral

infections. HIV-1 protease inhibitors prevent viral replication by inhibiting the activity

of HIV-1 protease, an enzyme used by the viruses to cleave nascent proteins for final

assembly of new virons. Therefore alkyne 25 and azide 26 were added to the

protease, which acts itself as a template for the reaction and increases the formation

26 27 25

Figure 7: Triazole derivatives used as liquid crystals.

http://en.wikipedia.org/wiki/HIV-1_protease

http://en.wikipedia.org/wiki/Enzyme

http://en.wikipedia.org/wiki/Protein

http://en.wikipedia.org/wiki/Virons


16

of the 1,4-regioisomer.[67, 68] The 1,4-regioisomer 27 can act as an inhibitor for the

HIV-1 protease.

Another method of fighting against HIV and AIDS infection is the blockage of a viral

envelope protein to antigens in the host T-cell surface.[69] The modification of a

proline unit with 4-phenyl-1,4-disubstituted 1,2,3-triazole,[70] synthesized via “click”

reaction, led to a peptide that binds to the viral protein with an affinity two orders of

magnitude greater than that of the parent peptide and strongly disturbs the

interaction of this glycoprotein with the host cell surface.[70]

Also, other potent inhibitors were prepared using “click” chemistry: An inhibitor of the

human 1,3-fucosyltransferase was synthesized by LEE et al.[71] 1,3-

Fucosyltransferase VI is a pivotal enzyme which is involved in the catalysis of the

final glycosylation step in the biosynthesis and expression of many important

saccharides. Applying the “click” cycloaddition a library of 85 triazole compounds

could be synthesized in water without the need of protecting groups and no further

purification steps. Potential inhibitors could be idendified from that library.

The synthesis of resveratrol (28) analogues, a polyphenylic compound found in some

plants, such as the skin of red grapes,[72] has also been achieved via “click”

chemistry.[73]

This compound exhibits some benefical properties such as caesioprotective,

neuroprotective, antiviral, and antiinfallatory properties. Thus derivatives of

reserveratrol are of interest as biologically active compounds. A library of derivatives

29 that are shown in Figure 8 has been synthesized, in which the double bond has

been replaced by a triazole ring. According to that, analogues of other natural

compounds are of interest. One example is vitamin D equipped with a triazole ring[74]

to take advantage of the biological activities of this natural compound.

Figure 8: Resveratrol 28 and different derivatives of resveratrol 29 with the typical triazole unit.

29 28


17

The groups of SHARPLESS and FINN applied the azide-alkyne coupling in the parallel

synthesis of a highly active inhibitor of the enzyme acetylcholinesterase (AchE).[75]

For that purpose different alkyl azides and alkyl acetylenes (Figure 9) of varying

chain lengths were incubated in the presence of the enzyme Electrophorus AChE at

room temperature.

This enzyme can act as template so that the addition of Cu(I) is not necessary. Only

those building blocks which are involved in an interaction with the active site of the

enzyme are close enough together to react under these conditions. Mainly the 1,5-

regioisomer is built in that case. One of these formed triazoles turned out to be the

best non-covalent inhibitor of AChE that exists until now.

1.4 “Click” Chemistry on Porphyrins

The interest of the porphyrin community in “click” chemistry has grown very slowly.

The publications found to that issue derive from the years 2008 and 2009 and give

only attention to the “click” variant of the HUISGEN cycloaddition. Above all, this

variant has been used to build up porphyrin conjugates established from compounds

with a lot of reactions centers.

Due to the reliability of this reaction even with a lot of reaction centers, this process

was employed to generate dendritic systems with a porphyrin core. Dendritic

polyglycol-porpyhrin systems like compound 31 were prepared by ZIMMERMAN et

al.[76] This approach could be achieved by two ways: Either an octakisalkynyl

porphyrin and a polyglycol dendron with an azide focal point were brought to reaction

Figure 9: Inhibitors of the enzyme acetylcholinesterase (AChE) built up from different alkynes and azides.


18

or an octakisazidoporphyrin is converted with alkyne dendrons to conjugate 31 as it is

shown in Figure 10.

Polyglycerol dendrons, with eight or sixteen terminal alkene units and a single

TBDPS-protected alcohol can be synthesized in great amounts and good yields. The

alcohol was deprotected and converted into the corresponding alkyne or azide-cored

polyether dendrons. The azide-cored dendrons underwent the Cu(I)-catalyzed 1,3-

dipolar cycloaddition reaction with an octakisalkynyl tetraarylporphyrin (Figure 10) in

66% yield. The complementary way furnishes the corresponding dendritic system

with the same yield. Thereby, CuSO4∙5 H2O and sodium ascorbate seem to be the

best Cu(I) generating source.

Using this approach, dendritic porphyrins with molecular weights close to

16000 g/mol and 128 terminal alkene groups were synthesized. Those compounds

are likely to be particularly useful both for making biocompatible nanostructures and

for mono-molecular imprinting.

Furthermore, dendritic porphyrins, in which benzyl ether dendrons were linked to a

porphyrin core through 1,2,3-triazole units, were synthesized by KIMURA et al.[77]

which is illustrated in Figure 11. Alkaline mediated coupling of a

octylhydroxyporphyrin with propargyl bromide gave a multivalent porphyrin core,

Figure 10: Polyglycol dendrimer 31 with a porphyrin core.

31


19

which was metallated with Zn(OAc)2. The coupling of different dendritic azides to the

zinc porphyrin core was carried out in THF in the presence of the organo soluble

catalyst [(PPh3)3CuBr] and the desired dendritic porphyrins 32 or 33 were obtained

after further purification by flash chromatography.

The “click” approach has also been applied to generate fullerene-porphyrin hexakis-

adduct[78] 34 and bis fullerene-porphyrin dyad[79] 35 (Figure 12) in the working group

of NIERENGARTEN. The fullerene-porphyrin dyad was synthesized from the bisalkyne

porphyrin precursor und a fullerene bisadduct via a HUISGEN “click” cycloaddition in

64% yield. The optimized conditions for this reaction are using CuSO4∙5 H2O (0.1 eq)

and sodium ascorbate (0.3 eq) to give the active Cu(I) catalyst. As solvent a mixture

of CH2Cl2 and H2O was used. The product was finally isolated by flash

chromatography.

The synthesis of the hexakis fullerene adduct started with the reaction of a simple

bisazido malonate and C60. The approach of attaching first malonates with small

substituents to C60 and add the huge substituents in a second step seems well-

promising.[80]

But for the second step, it is important to have excellent working reactions, so that

even the conversion of many, in this case twelve, reaction centers offer an

Figure 11: Porphyrin dendrimers synthesized by KIMURA and co-workers.

32 33


20

acceptable yield. As this is a property of “click” reactions, it is perfectly suited for this

purpose. In this manner, the hexakis bismalonate can be converted in a cycloaddition

under the conditions already been mentioned above. Thus, the twelve alkyne

porphyrins can be attached to the C60 hexakismalonate in 78% yield. This formation

of hexakis fullerene adducts has also been investigated with other alkyne

components, e. g. ethynyl ferrocene or phenyl acetylene and furnishes good yields.

Two different porphyrin-cyclodextrin dyads 36 and 37 have been synthesized in order

to complex tetrasodium tetraphenylporphyrin tetrasulfonate and for the investigation

of the nanoarchitecture that is built up. The reaction of the tetraalkyne porphyrin with

the different cyclodextrins in THF/H2O afforded the different tetrakiscyclodextrin-

modified zinc porphyrins via “click” chemistry in good yields. In this example as well,

CuSO4∙5 H2O and sodium ascorbate were used and the reaction mixture was stirred

Figure 12: Fullerene-porphyrin dyads 34 and 35 generated by “click” chemistry.

34

35


21

for 48 hours at 50°C. The kind of network and nanorod aggregates can be

determined by AFM, SEM and TEM. From those comparative studies in different

solutions, the mechanisms that results in the transition of nanorods to network

aggregates can be elucidated.

A new approach to capped porphyrins was introduced by CROSSLEY[81] and his co-

workers. BALDWINS “capped” porphyrins[82, 83] 38 and 39 represented a landmark in

design and synthesis of functional molecules and established the paradigm for

molecular engineering. The “capped” porphyrin has great beauty and its iron chelate

mimics aspects of the oxygen-carrying function of myoglobin. These synthetic mimics

revealed insights not easily discerned by the study of natural systems; for example,

the means by which carbon monoxide binding can be reduced. These studies

focused their attention on the diverse and complex porphyrin-containing structures

found in nature like the light-harvesting complexes I and II, haemoglobin, myoglobin,

and proteins such as cytochrome C and P430.

The synthesis carried out by BALDWIN and co-workers was based on a tetraaldehyde

template, which was then condensed with pyrrole to furnish the “capped” porphyrin

after purification of the raw product. CROSSLEY and coworkers[81] synthesized a

tetraazidoporphyrin and capped it by 1,3-dipolar “click” cycloaddition with a benzene

derivative bearing four propargyl esters. They explored two different synthetic

pathways. The first method used standard conditions of catalytic Cu(II) sulfate with L-

ascorbic acid in H2O/THF (1:10) with four equivalents of NEt3. The reaction mixture

Figure 13: Porphyrin cyclodextrin conjugates 36 and 37 connected via click cycloaddition.

36 37


22

was heated at reflux for 30 hours and chromatography of the product over silica to

remove polymeric by-products, gave the capped porphyrin 40 in 19% yield.

The coupling was also carried out under anhydrous conditions using anhydrous DMF

as solvent in conjunction with four equivalents of NEt3 and catalytic Cu(I)

tetrakis(acetonitrile) hexafluorophosphate. The reaction was stirred at 70°C for 16

hours, affording the “capped” porphyrin 40 in 14% yield.

Figure 14: “Capped” porphyrins synthesized by BALDWIN and CROSSLEY; Different “capped” porphyrins: 38 and 39 via ether connection and 40 synthesized by click cycloaddition.

40 39 38

Proposal

23

2 Proposal

The aim of this work is to apply the 1,3-dipolar Cu(I)-catalyzed cycloaddition on the

ortho-benzylic substituted tetraphenylporphyrin systems that have been synthesized

by the JUX[84, 85] group in recent years. These basic porphyrins feature different

degrees of functionalization. The functionalized porphyrins can be transferred to the

corresponding porphyrin azides.[85] Based on these azido systems, new molecular

structures will be generated by applying “click” reactions. Therefore, the best

conditions for this process must be determined for the present azidoporphyrins. The

optimization of the reaction conditions is performed with phenyl acetylene as

dipolarophile. If this succeeds and offers the less often substituted porphyrin with only

one “click” center in good yield, this approach is carried out with the highly

functionalized systems. These systems are the tetra- and octa-substituted

porphyrins. Porphyrins with an environment containing aromatic units will be the

result of this approach. In addition, ferrocene derivatives should be utilized in this

process in order to get highly-substituted ferrocene-porphyrin conjugates. Those

conjugates can bear up to eight ferrocene units in their periphery and are interesting

because of their electrochemical behavior.

Another interesting approach is the synthesis of water-soluble ferrocene-porphyrin

conjugates. Therefore a suitable compound, which introduces water-solubility, bears

the ferrocene moiety and is able undergo “click” reactions, must be generated. If this

task is mastered, the corresponding water-soluble compounds will be synthesized.

Different metals can be inserted in those conjugates. These metalloporphyrins offer

interesting properties, as those metals are enclosed by up to eight ferrocene units.

Especially redox-active metals, such as iron or manganese in the porphyrin core are

well promising.

By creating suitable compounds with two anchor groups, different azidoporphyrins

can be bridged by a ferrocene moiety. In this manner, the porphyrins bearing two

azido units on one porphyrin plane can be converted, as the azide groups offer the

anchor point for the ferrocene bridge. The approach of capping porphyrins is also

interesting with other alkyne compounds, like bulky units, which protect the porphyrin

against attacks of e.g. solvents. The electrochemical properties of these systems will

be investigated.

Proposal

24

Furthermore, the basic azidoporphyrins can be transformed into oligomers, which are

connected via a ferrocene bridge. Therefore, a ferrocene bisalkyne compound must

be reacted with the porphyrins, which furnishes porphyrin dimers and trimers bridged

via a ferrocene moiety. Other ferrocene-porphyrin conjugates will be generated by

using other fundamental porphyrins, which bear different active reaction centers.

Thus, a cascade of “click” reactions can be performed after subsequently introducing

the “click” reaction centers. On this way, different dyads will be generated.

As the JUX group has tried for a long time to insert functional groups selectively on

one side of the porphyrin plane concerning the tetra- or octa-substituted porphyrins,

this approach will now be carried out via “click” chemistry. In this manner, different

hydrophilic and hydrophobic groups can be attached to give porphyrins with two

different polar spheres.

Results and Discussion

25

3 Results and Discussion

3.1 Fundamental Porphyrin Building Blocks

In a first overview, the synthesis of different porphyrin building blocks based on

monomethoxy aldehyde 44a and bismethoxy aldehyde 44b will be presented. Those

two aldehydes can be generated in a four step synthesis starting with the commercial

available 5-t-butyl-xylene, which is shown in Scheme 11.

In the starting step, 5-t-butyl-xylene is converted with bromine under Fe catalysis

furnishing 41 in good yield.[86-88] Next, 41 is reacted with bromine under light

irradiation with a halogen lamp in a radical reaction to functionalize the benzylic

position(s). The formation of 42a or 42b can be controlled by choosing the right

stoichiometric amount of bromine.[89] The bromo substituents are converted to the

methoxy groups in a nucleophilic substitution reaction with sodium methanolate

delivering 43a and 43b.[90] In the last step, the formulation of the aryl core to the

aldehydes 44a and 44b is achieved by a halogen-metal exchange of the bromine

with n-BuLi followed by the addition of DMF and finally hydrolysis with HCl.[84]

The corresponding dipyrromethanes 45a and 45b are generated according to slightly

modified LINDSEY[84, 85, 91] conditions under Lewis acid catalysis (BF3∙OEt2) and

40 equivalents pyrrole as reagent and as solvent.[92]

Scheme 11: Formation of the aldehydes 44a and 44b in a four step synthesis.

Scheme 12: Dipyrromethane (45a and 45b) synthesis under slightly modified LINDSEY conditions.


26

Purification of the raw product is achieved easily by “Kugelrohr distillation” to give the

pure products 45a and 45b in 64%[93] and 65%[94] yield.

The basic porphyrin building blocks 46-52 can be generated from these precursors

after modified LINDSEY conditions that have been developed in the JUX group in

recent years.[84, 95] Figure 15 shows the porphyrin substance library arising from those

precursors.

Monomethoxyporphyrin 46[93], bismethoxyporphyrin 47[95] and octakismethoxy-

porphyrin 51[95] are prepared from aldehyde 44a or 44b, 5-t-butylbenzaldehyde and

pyrrol according to literature procedures. For the synthesis of tetrakismethoxy-

porphyrin 50 the best results can be obtained by converting dipyrromethane 45b with

5-t-butylbenzaldehyde delivering only the porphyrin. No corrol as by-product is

Figure 15: Basic porphyrin building blocks with different symmetries generated from aldehyde 44a/44b or dipyrromethane 45a/45b.

C2h

C2v


27

formed, which simplifies the purification process.[95] The condensation of

monomethoxy dipyrromethane 45a with 5-t-butylbenzaldeyde affords two

bismethoxyporphyrins 48 and 49[93], a pair of atropisomers which can be separated

by flash chromatography. Because of the ortho-position of the methoxymethyl

groups, the rotation of the aryl ring is hindered enabling the synthesis of stable

atropisomers that even hold their geometry at higher temperatures. In that way,

substituents can be inserted only on one side of the porphyrin plane.

After porphyrin synthesis, the methoxy groups of the basic porphyrins 46-51 are

exchanged with bromides in order to obtain a highly reactive benzylic position for

nucleophilic substitution reactions. The bromination works very well with HBr (33% in

HOAc) in CH2Cl2 as solvent. The reaction is stirred for a few hours at room

temperature.[84] As the porphyrin gets protonated in the acidic environment, the color

turns green. For purification, the green reaction mixture is neutralized carefully with a

saturated NaHCO3-solution, which changes the color back to purple, followed by

washing the porphyrin solution with water. In that manner, the different methoxy

porphyrins 46-51 can be converted to the corresponding bromoporphyrins. This is

shown in Scheme 13 using the example of the octakismethoxy porphyrin 48. The

transformation proceeds quantitatively for the all basic porphyrin systems.

Further modification of the bromoporphyrins by nucleophilic substitution reactions can

now succeed easily due to the high reactivity of the benzylic bromides. Those

different bromoporphyrins can be considered as the basis for further chemistry on

those systems. Because of the well-known characterization and properties of these

porphyrins[84, 85] a discussion of that is set aside in the present work.

Scheme 13: Substitution of the methoxy groups by bromides furnishes the bromoporphyrin.

48 52


28

Thereby, other functional groups can be introduced by SN-reactions without acid

catalysis to give e. g. azidoporphyrin 55,[85] cyanoporphyrin 53[89] or cationic pyridine

porphyrin 54.[95] Those different substitution reactions that have recently been

performed in the JUX group are shown in Scheme 14 using again the example of the

octakisbromoporphyrin 52.

Those reactions proceed quantitatively even on the porphyrin with eight reaction

centers. Thus, the only loss in yield is due to the purification steps. A further

advantage of those processes is that they are easy to handle without concerning the

exclusion of oxygen or water.

In this case, special attention is paid to the azidoporphyrins, which are generated by

treating the bromoporphyrins in DMF with NaN3. The reaction mixture is stirred for

twelve hours at 50°C. Afterwards the solution is poured into a mixture of saturated

NH4Cl-solution and ice. The precipitate is filtered off, is redissolved in CH2Cl2 and the

pure azidoporphyrin is obtained after flash chromatography. The yields of this

Scheme 14: Different SN-reactions on octakisbromoporphyrin 52 proceeding with complete conversion.


29

reaction range between 70 and 90%. Sometimes no chromatography is necessary. In

this case, the work-up procedure only consists of washing the organic layer with

water.

Besides the already known reactions on those azidoporphyrins in the JUX group, like

the Staudinger reaction[85] or the ring closure reaction,[96] those azido groups can

react as dipolar component in a 1,3-dipolar cycloaddition. The Cu(I)-“click”

cycloaddition by SHARPLESS presented in the introduction would offer a good

possibility for further modification of the porphyrin periphery. For applying the Cu(I)-

catalyzed 1,3-dipolar cycloaddition on those systems, the porphyrin core has to be

protected against the insertion of copper. Thus, the zinc complexes are synthesized;

first, because the zinc insertion works easily and fast, and second, because the free

base can simply be regained by treating the zinc complex with acid.

For the metalation, the free base azidoporphyrins and Zn(OAc)2 are dissolved in THF

and stirred at reflux for twelve hours. Afterwards the solvent is removed under

reduced pressure; the precipitate is redissolved in CH2Cl2 and washed twice with

water. In most cases the zinc complex can be obtained in pure form without further

need of flash chromatography. The reaction of the bromo precursor 52 to the zinc

octakisazidoporphyrin 55 is shown in Scheme 15.

The metal can be inserted as well before the substitution of the bromide groups with

azide moieties, which makes no change in the total yield. The different zinc

azidoporphyrins 55-60 which are generated subsequently from the methoxy building

blocks 46-51 are highlighted in Figure 16. The yield after metalation and substitution

of the bromides with azides are documented in brackets.

Scheme 15: Synthesis of zinc azidoporphyrins serving as dipolars in the 1,3-dipolar cycoaddtion.


30

The characterization is not discussed in detail in this small overview, but the data is

documented in the experimental section. As the only modification towards the bromo

systems is the substitution of the bromides with azido groups as well as the insertion

of zinc into the N4-core, no significant change apart from the disappearance of the

NH-signals of the porphyrin core can be seen in the corresponding 1H/13C

NMR spectra. Small changes are the slight shifts of the methylene group signals to

higher field and the broadening of these signals due to the resonance of the azido

groups in close proximity.

The substitution with azido groups can be monitored in the IR spectra (Figure 17).

Figure 16: Synthesized azidoporphyrins with different substitution degrees and diferrent symmetries.

Figure 17: IR-spectra of azidoporphyrins; the typical azide band arises between 2090 and 2100 cm-1

.

3500 3000 2500 2000 1500 1000

wavenumber (cm-1 )

azide band

500

56

57

60

55


31

Azido compounds show a typical IR-band between 2120 and 2160 cm-1[97] that can

be seen clearly in the spectra of the porphyrins 56-61. The intensity of the azido band

increases with the substitution degree of the porphyrin, which is presented in Figure

17 for azido compounds 56, 57, 60 and 55.

3.2 First Steps in Applying the 1,3-Dipolar “Click” Cycloaddition

Since the zinc azidoporphyrins 56-61 are easily available from the methoxy

porphyrins, new reactions on that systems are of interest. Due to the success of

“click” chemistry in the last years, this reaction promises to open up new interesting

molecular structures based on those porphyrin building blocks. The different methods

for that process have been described in chapter 1.2; the challenge is to establish the

best conditions for the present zinc azidoporphyrin systems 56-61. This was done

with phenyl acetylene as dipolarophile and the simplest azidoporphyrin presented in

Chapter 3.1: zinc monoazidoporphyrin 56.

As the porphyrin is poorly soluble in the typical and most common reaction mixture

(tBuOH/H2O) for Cu(I)-catalyzed cycloadditions, other solvents or solvent mixtures in

which the reagents as well as the catalysts are soluble must be used. Thereby, either

solvents in which all reaction participants are soluble like DMF or THF or mixtures

consisting of an organic solvent and a polar co-solvent (such as alcohols or water)

can be considered. Different approaches were carried out in order to achieve the best

possible yields (see Table 1).

First, CuI was used as catalyst and DMF, THF, dioxane, CH2Cl2 or toluene were

applied as solvent, mostly variants that have already been described in literature.[26]

Scheme 16: 1,3 Dipolar Cu(I)-catalyzed cycloaddition of azidoporphyrin 56 and phenyl actylene.


32

The zinc monoazidoporphyrin 56 was dissolved and phenyl acetylene was added in a

small excess (1.5 equivalents). To ease the deprotonation of the terminal alkyne

proton, either DIPEA or 2,6-lutidine were added as base to the reaction mixture. The

reaction mixture was stirred overnight at 40°C in all cases, but mostly even after a

few hours no change on the TLC plate could be observed meaning that the reaction

is already finished. In half of the approaches no triazole porphyrin 61 was obtained,

in a few cases only small amounts of 61 were found (see Table 1). The success of

the reaction can be seen on the TLC plate before further purification. The educt 56

has a Rf value of 1 in CH2Cl2, whereas the desired product is more polar and

possesses a Rf value of 0.5 in the same solvent. The best results for CuI as Cu(I)-

source can be obtained in DMF using DIPEA as base, whereas the formation of 61

can be proved by spectroscopy.

Since the results using CuI as catalyst were not satisfying, CuSO4∙5 H2O and sodium

ascorbate were used in further attempts, whereby Cu(I) is generated in situ by the

reducing agent sodium ascorbate. At first, the reaction was carried out in pure

solvents in which the reagents as well as the catalyst are soluble (DMF, THF). Due to

only 20% yield in DMF, solvent mixtures were explored, in most cases mixtures

containing a small amount of water. Although a base is not forcefully necessary if

water is added to the reaction mixture, DIPEA or 2,6-lutidine were added. A solvent

mixture of CH2Cl2 and water turned out to work best after the addition of DIPEA.

Controlling that reaction via TLC, the spot expected to be the product spot was bigger

than the educt spot. Adding a small amount of EtOH to that mixture, the amount of

Table 1: Conditions for the SHARPLESS 1,3-dipolar cycloaddition in Scheme 17.

solvent base yield

THF DIPEA -

THF 2,6-lutidine -

toluene DIPEA, 2,6-lutidine 20%

CH2Cl2:EtOH; 5:1 DIPEA, 2,6-lutidine 10%

DMF DIPEA 20%

DMF 2,6-lutidine -

dioxane DIPEA -

solvent base yield

THF DIPEA -

THF:H2O; 9:1 no base 20%

THF:H2O 9:1 DIPEA -

THF 2,6-lutidine -

DMF DIPEA 20%

DMF:H2O; 4:1 2,6-lutidine -

dioxane DIPEA -

CH2Cl2:EtOH; 9:1 no base -

CH2Cl2:EtOH:H2O

10:1:2no base

15%

CH2Cl2:EtOH:H2O

10:1:2DIPEA

65%

CuI CuSO4 ∙5 H2O; sodium acorbate


33

product even seemed to increase. After purification a yield of 67% could be achieved.

Finally, after a lot of failed approaches, the best conditions for the Cu(I)-catalyzed

cycloaddition for azidoporphyrin 61 were determined. The best results are obtained

using azidoporphyrin 61 and phenyl acetylene in a ratio of 1:1.5. The catalyst

CuSO4∙5 H2O is added in 0.1 equivalents, the reducing agent sodium ascorbate in

0.2 equivalents and two equivalents DIPEA per alkyne. The reagents are dissolved in

CH2Cl2. Both salts are separately dissolved in water, first the CuSO4∙5 H2O solution,

second the sodium ascorbate solution and at last the according amount of ethanol

and DIPEA are added. The solvents CH2Cl2, EtOH and water should be kept in a

ratio of 10:2:1. The reaction is finished after stirring for five hours at 40°C, after that

period no further change can be observed via TLC. The reaction mixture must be

stirred vigorously to make sure that both layers get mixed. Otherwise, the Cu(I)-ions

solved in the water layer cannot react with the acetylene solved in the organic layer.

This optimized “click” cycloaddition reaction is also carried out with the free base

monoazidoporphyrin, whereas the formation of a by-product occurs. As expected, the

copper is inserted partly into the porphyrin core, which reduces the yield and

complicates the purification. The demetalation of copper works under harsh

conditions using H2SO4 and TFA[89] and should be prevented if possible.

Figure 18 shows the 1H NMR spectra of the zinc azidoporphyrin 56 compared to the

zinc mono(phenyltriazolyl)porphyrin 61. Both spectra show the typical splitting pattern

for AB3-porphyrin systems in the aromatic region. The β-pyrrolic protons close to the

annulated phenyl ring appear as two doublets. The other four pyrrolic protons appear

as a singlet in the spectrum of the zinc azidoporphyrin 56, while the spectrum of zinc

mono(phenyltriazolyl)porphyrin 61 shows the exact splitting pattern: two doublets that

overlap with each other. In the spectrum of 56, these two doublets are completely

melted to a singlet what may be due to the smaller azido substituent. The resonances

of the phenyl groups attached to the porphyrin core also show a clearer splitting

pattern in the spectrum of 61. Here, a difference between upper and lower side is

indicated, leading to two different ABCD-system for the protons of the phenyl ring:

one on the two phenyl rings (dark blue in Figure 18) closer to the substituted one and

another ABCD-system for the phenyl ring (light blue in Figure 18) on the opposite

side. In that manner, the ortho-phenyl protons as well as the meta-phenyl protons are

not chemically equivalent leading to two dd-signals with a 3J- and a 4J- coupling. The


34

signals of the phenyl ring (light blue) do not show a clear dd-structure as the

resonances of the two protons are shifted on top of each other. The resonance of the

protons of the phenyl ring attached to the triazole moiety is shifted to higher field

appearing as two triplets for the para- and the meta-protons and a doublet for the

ortho-proton.

The signal of the methylene protons is shifted to lower field after the triazole

formation and appears at 4.63 ppm (61) instead of 3.59 ppm (56). The triazole proton

can be detected at 5.94 ppm, compared to literature shifted around 2 ppm to higher

field. The chemical shift of the 1,4-protons of 1,2,3-triazole appears in general

between 7 and 8 ppm.[98] The highfield shift in this case is due to the proximity of the

triazole unit to the diamagnetic porphyrin ring that has already been observed in

earlier experimental publications on triazolylporphyrins.[77] Thereby, the cross-peak

for the triazole proton signal (5.94 ppm) can be detected in the HETCOR spectrum at

119.1 ppm (13C NMR spectrum) which is located in the typical region for triazole 1,4-

carbons.[98] All aromatic signals can be assigned by the HETCOR-spectrum shown in

Figure 20, in which the aromatic region is depicted.

Figure 18: 1H NMR spectra of azidoporphyrin 56 and mono(phenyltriazolyl)porphyrin 61 in comparison.

*

ortho

para

metatriazole-H

-CH2-

-CH3

b-H

ortho meta

- tBu

*

9 8 7 6 5 4 3 2 1 0ppm

N

N N

N

Zn

N

NN

-CH2--CH3

- tBu

61

56


35

The FAB mass spectrum shows the molecular peak at m/z = 1021 and another peak

at m/z = 927. The second peak can be assigned to a fragment, in which the

phenyltriazole ligand is split off completely. In contrast to that, the FAB mass

spectrum of the educt offers a fragment peak at m/z = 941 assigned to the loss of N2.

The conversion of the azide unit can be monitored by IR spectroscopy, where the

disappearance of the azido moiety can be detected. The typical azido band at

2092 cm-1, which has been shown in Figure 17, disappears in the spectrum of

porphyrin 61.

4000 3500 3000 2500 2000 1500 1000 500

wavenumber [cm-1]

no azide band

Figure 20: IR spectrum of mono(phenyltriazolyl)porphyrin 61.

Figure 19: HETCOR spectrum of 61; the signal of the triazole proton can excactly be determined.


36

Finally, after successfully optimizing the synthesis of the mono conjugate 61, the

reaction is carried out with the other five zinc azidoporphyrins 55 and 57-60 under the

conditions that have been worked out. The phenyl acetylene is added each in an

excess of 1.5 equivalents per azido unit attached to the porphyrin. The reaction

mixture is stirred for twelve hours at 40°C followed by working-up, which includes

washing the reaction mixture twice with water, drying the organic layer with MgSO4

and flash chromatography over silica.

For the zinc bisazidoporphyrins 57, 58 and 59, lower yields than for the zinc

monoazidoporphyrin 61 are obtained, which seems logical due to one more reaction

center. In each of these reactions, small amounts of zinc azidoporphyrin educt are

not converted and a by-product occurs. The by-product can be identified as the

porphyrin that is only converted on one azide unit. However, the purification does not

lead to complications delivering pure zinc bis(phenyltriazolyl)porphyrins 62, 63 and

Figure 21: Porphyrin conjugates generated by 1,3-dipolar “click” reaction of zinc azidoporphyrins with

phenyl acetylene; the corresponding yields are remarked in brackets.


37

64 after simple flash chromatography with a solvent mixture of CH2Cl2 and EtOAc as

eluent.

Surprisingly, the reaction of tetrakis- (60) and octakisazidoporphyrin (55) shows a

remarkable increase in yield. This can be observed on the TLC plate even before the

final purification. No azidoporphyrin remains unconverted and no by-products are

formed. After flash chromatography to remove excessive phenyl acetylene, pure

product can be obtained in a yield of 92 (60) and 89% (55). Consequently, the only

loss of product is due to the chromatography step, which is necessary to remove

excessive phenyl acetylene. An overview of the synthesized phenyltriazolyl

porphyrins 61-66 and the corresponding yields are shown in Figure 21.

The yield of the triazole formation for each azido reaction center increases with the

number of attached azides. Since only 67% is obtained for the single reaction center

of zinc monoazidoporphyrin 56, the yield for the formation of one triazole in the case

of the three different zinc bisazidoporphyrins 57-59 increases to 68-73%. For the zinc

tetrakis and zinc octakisazidoporphyrin 65-66 full conversion (98 and 99%) is

obtained for each reaction center.

The extreme increase in yield for the highly-functionalized systems is possibly

caused by some kind of autocatalysis and self activation in these cases. First, as

already described in Chapter 1.2, triazole ligands can stabilize the catalytically active

Cu(I)-species against decomposition.[38] The phenyltriazolyl porphyrin systems can

itself act as Cu(I)-protecting ligand which lowers the reaction time and raises the

product formation. This kind of autocatalysis works better the more triazole ligands

the porphyrin bears leading to extremely good yields for the formation of 65 and 66.

Moreover the mechanism proposed for the 1,3-dipolar Cu(I)-catalyzed cycloaddition

can give a clue for explaining this fact (see chapter 1.1).[10] This mechanism can be

proposed especially for the present azidoporphyrin systems as it is illustrated in

Scheme 17.

In the first step, phenyl acetylene forms the copper acetylide complex which

dynamically changes between the monomeric and dimeric species. An important role

is assigned to the two copper-core complex (A in Scheme 17) whereas one copper

core is bound to the alkyne unit and the other copper atom activates the azide group.

After the nucleophilic attack of nitrogen, intermediate B is built. Here, one copper is


38

bound to the double bond, but the other copper center can activate another azide unit

in close proximity. Thus, the next azide group is already activated for the 1,3-dipolar

cycloaddition by the last reaction resulting in a chain reaction. However, this gives an

explanation for the good yields for the zinc tetrakis- and zinc octakisazidoporphyrin

65 and 66 as there are four or two azide groups located on one porphyrin plane.

Having a closer look at the 1H NMR spectra for the differently substituted zinc

(phenyltriazolyl)porphyrins 61, 65 and 66 in Figure 22, the symmetry of the various

conjugates becomes clear due to the splitting pattern of the signals for the pyrrolic

and phenylic protons.

The resonances of the pyrrolic protons of 62 are monitored as four doublets, whereas

one is shifted upfield and overlaps with a signal of the phenylic protons. The doublets

of the pyrrolic protons have a coupling constant of 4.6 Hz, while the doublets of the

phenylic protons have a higher coupling constant of 8.3 Hz. The two lowfield shifted

doublets can be assigned to the pyrrolic protons on the opposite side of the

substituted phenyl ring and the upfield shifted one arises for the protons of the phenyl

Scheme 17: Mechanistical proposal for the activation of the highly-conjugated azidoporphyrins.

A B


39

ring next to the substituted aryl ring. Because of the rising symmetry from porphyrin

62 to porphyrin 66, the signal set decreases to two doublets (65) or to one singlet in

the spectrum of octakis(phenyltriazolyl)porphyrin 66. The same phenomena can be

observed for the resonances of the phenyl protons. The splitting pattern of the

unsubstituted phenyl rings of 65 shows doublets for the ortho- and meta-protons, one

singlet is observed for the protons of the substituted phenyl rings. As a result of the

D4h symmetry of 67 only one signal appears for the phenylic protons.

The resonances of the phenyl rings attached to the triazole units look all in all the

same way, of cause, the intensity of these signals rises with the substitution degree.

The triazole protons‟ signal is always monitored as singlet, whereby a lowfield shift

can be observed from 64 to 66. While this proton appears in the spectrum of 62 at

Figure 22: 1H NMR spectra of the zinc (phenyltriazolyl)porphyrins 64, 65 and 66.

62

65

66

*

*

-tBu

*

9 8 7 6 5 4 3 2 1 0

ppm

b-H

ortho meta

ortho

b-H

orthopara

meta

triazole-H

-CH2

b-H ortho meta

triazole-H

-CH2

b-H phenyl-H

-CH2

-tBu

-tBu

triazole-H


40

5.48 ppm, this signal is shifted towards lower field in the spectrum of 65 (6.34 ppm)

and an even higher shift is observed for the zinc octakis(phenyltriazolyl)porphyrin 66

(6.58 ppm).

This fact can be explained by the sterical demand of each phenyltriazolyl ligand

which leads to a larger distance between the porphyrin core and the triazole ring. The

effect of the diamagnetic porphyrin ring current on the triazole substituent is reduced

with higher interspace.


41

3.3 Synthesis of Ferrocene-Porphyrin Conjugates

The Cu(I)-catalyzed cycloaddition has turned out to be very valuable to generate

highly-substituted porphyrins. To take advantage of this fact, different acetylene

compounds can be attached to the basic azido building blocks 56-61. Due to the

interesting properties of ferrocene-porphyrin conjugates[99] ethynyl ferrocene is first

chosen as acetylene compound. The donor-acceptor complementary and the

electrochemical activities of those derivatives have especially been exploited to

investigate photoinduced electron transfer processes and to mimic photosynthesis

active sites. Moreover, their multiple redox active centers are also of great

importance for the development of molecular-based electronic devices[100, 101] or

molecular electrogenic sensors. Their ability to reversibly accept and/or release

several electrons at distinct potentials is utilized in multi-electron redox catalysis[102]

and can be used for multibit information storage at the molecular level.[103, 104]

To generate ferrocene-porphyrin conjugates 67-72, the azidoporphyrins are

converted with ethynyl ferrocene into the corresponding ferrocene porphyrins

(Scheme 18). As ethynyl ferrocene can be purchased and the zinc azidoporphyrins

56-61 can be prepared easily from the methoxy porphyrins 46-51, these two starting

materials are easily available.

Scheme 18: Synthesis of different ferrocene-porphyrin conjugates 67-72 via “click” chemistry.


42

The synthesized conjugates and the calculated space filling structures (PM3

calculation) are depicted in Figure 23.

Each conversion is carried out according to the optimized “click” conditions presented

in chapter 3.2 with an excess (1.5 eq) of ethynyl ferrocene with respect to the number

of azide units of the converted porphyrin. The emulsion is stirred for twelve hours at

Figure 23: Ferrocene-porphyrin conjugates and the calculated molecular structure (PM3 calculation).


43

40°C. After washing the reaction mixture with water and drying the organic layer over

MgSO4, the crude product is finally purified by flash chromatography obtaining the

corresponding ferrocenyltriazolyl products 67-72 in each case in the last fraction. As

mobile phase different solvent mixture of CHCl3 and EtOAc are used; the eluent has

to be more polar the more ferrocenyltriazolyl groups the porphyrin bears. For the

exact ratios see the experimental part.

According to the “click” cycloaddition with phenyl acetylene, the yields are

astonishingly good for the highly-substituted systems 71 and 72. In the case of

tetrakis(ferrocenyltriazolyl)porphyrin and octakis(ferrocenyltriazolyl)porphyrin,

complete conversion of the porphyrin educts can be observed leading only to the

desired products excluding the formation of by-products.

The yields of the less substituted bis(ferrocenyltriazolyl)porphyrins are approximately

50% (for exact values see Figure 23), whereas unconverted azidoporphyrin and a by-

product, mono-“clicked” porphyrin, occurs in this reaction. The reaction of the zinc

monoazidoporphyrin 56 furnishes the triazolyl derivative 67 in a yield of 66%. In this

case, no by-product is formed; non-converted starting material can be regained by

flash chromatography.

The characterization of 67 and 72 by 1H NMR spectroscopy can be seen in Figure

24. The aromatic region of the spectra shows the typical splitting pattern of

porphyrins with C2h and D4h symmetry. The signal of the triazole protons can be

detected at 6.34 and 6.54 ppm. The ferrocene protons of the substituted Cp-rings

appear as two signals with lower intensity at 4.05 and 3.93 ppm for 69 and at 4.13

and 4.09 ppm for 72. Those signals mostly show the splitting pattern of an apparent

triplet caused by an AA‟BB‟-systems for the protons of the Cp-rings. The protons of

the unsubstituted ferrocene rings can be detected at 3.75 ppm in the spectrum of 69

and at 3.72 ppm for 72 as a singlet with higher intensity. By comparing the spectra of

the different ferrocene porphyrins, the intensity of the ferrocene signals changes with

the substitution level. The resonances of the methylene groups are in comparison to

the azidoporphyrins shifted to lower field and can be found at 4.59 (69) and 5.14 ppm

(72). The t-butyl groups appear as two singlets at 1.66 and 1.57 ppm in the spectrum

of 69 and as one singlet at 1.61 ppm in the spectrum of 72.


44

Further investigations of these systems can be made by UV/Vis spectroscopy. The

absorbances of the systems are listed in Table 2.

Table 2: Gathered extinction coefficients (UV/vis spectra recorded in CH2Cl2) of the ferrocenylporphyrin

conjugates 67-71.

Ethynyl ferrocene itself features absorption bands in the UV/Vis spectra at 233, 270

and 451 nm. But the extinction coefficient of the absorption with the highest intensity

at 233 nm is only 17100 l∙cm-1∙mol-1 and is approximately 25 times smaller than the

overall extinction coefficient of the SORET band of azidoporphyrins. The band at

absorbance λ (ε [l·cm-1·mol-1]) λ (ε [l·cm-1·mol-1]) λ (ε [l·cm-1·mol-1]) λ (ε [l·cm-1·mol-1]) λ (ε [l·cm-1·mol-1])

67 230 (40700) 268 (23000) 421 (488200) 551 (20000) 594 (8600)

68 231 (43500) 271 (18800) 424 (420600) 552 (20500) 595 (9000)

69 230 (58000) 270 (24000) 425 (422100) 559 (8400) 596 (7100)

70 230 (63300) 270 (25400) 425 (421200) 560 (8500) 602 (3200)

71 233 (74600) 270 (28300) 432 (405100) 564 (12900) 605 (3800)

72 231 (178000) 268 (70400) 434 (453500) 564 (32100) 601 (19400)

Figure 24: 1H NMR spectra (400 MHz, CDCl3) of the different (ferrocenyltriazolyl)porphyrins 69 and 72, on

the top the bis-substituted conjugate 69 and below the octa-substituted one (72).

72

-CH2-

-CH3

-tBu

*

-FcHb-H

triazole-Hortho

meta

-FcH

* -CH2-

-tBu

b-Htriazole-H

phenyl-H

9 8 7 6 5 4 3 2 1 0

ppm

*69


45

450 nm has the lowest absorbance and vanishes completely under the huge SORET

absorption in the case of the ferrocenylporphyrin conjugates as it can be seen in

Figure 26. The UV/Vis spectra of the conjugates can be seen as the summation of

the UV/Vis spectra of the ferrocene and the porphyrin moiety. Thus, with increasing

functionalization degree, the highest absorption band of the ferrocene units at

254 ppm can be recognized better. As it is illustrated in Figure 25, the ferrocene band

increases with growing substitution degree.

Crystal structure of ferrocene porphyrin 72

The structure of octakis(ferrocenyltriazolyl)porphyrin 72 can be determined by x-ray

spectroscopy. A solution of 72 in CHCl3 is covered with pentane in a glass tube,

whereby crystals can be obtained after a few weeks.

This crystal structure is presented in Figure 26. The crystal is shown from the front in

this figure. Two water molecules are bound to the zinc ion in the porphyrin core. The

eight ferrocene moieties are all located above or below the porphyrin plane, leading

Figure 25: UV/Vis spectra (in CH2Cl2) of selected ferrocenylporphyrin conjugates in comparison to ethynyl ferrocene.

0

2

4

1

5

3

400 600500300l [nm]

e [

10

6·l

·cm

-1·m

ol-1

]

0

0.5

1.5

2

1

e [

10

5·l

·cm

-1·m

ol-

1]

400 600500300

l [nm]

67 68

72


46

to a sterical hindrance of those units. The distance between the iron ion of the

ferrocene moieties and the zinc ion in the porphyrin core ranges between 6.59 and

10.80 Å. The interspace of the 1,5-carbon of the triazole units to the porphyrin‟s zinc

center lies in between 5.05 and 6.19 Å, whereby the triazole rings take in different

conformations in the present crystal. Either the triazolylic nitrogens point to the

porphyrin center or they point outwards and have therefore the opposite position.

Furthermore, the torsion of the porphyrin plane can be seen clearly taking a closer

look at the porphyrin using the program Mercury.

The crystal packing of 72 features a monoclinic system with a P2(1)/n space group.

The unit cell possesses the following dimensions: a = 20.915(2) Å; α = 90°;

b = 15.7885(12) Å, β = 107.819(7)°, c = 26.913(2) Å, γ = 90°. The sterical

configuration is shown in Figure 27, where the view along the b axis of the unit cell is

shown. The ferrocene and porphyrin units are each in one layer leading to separated

layers of ferrocene and of porphyrins moieties. The position of the porphyrins is

slightly toppled to each other. The phenyl rings on the opposite sides of the porphyrin

Figure 26: ORTEP visuallized crystal structure of 72.


47

are positioned parallel to each other. Thereby, the t-butyl groups bound to the phenyl

rings are in a staggered position to each other.

Figure 27: Crystal packing of octakis(ferrocenyltriazolyl)porphyrin 72.


48

Investigation of the Ferrocene-Porphyrin Conjugates via Cyclic

Voltammetry (CV)

As the different conjugates are equipped with up to eight ferrocene units, the

electrochemical properties of these systems are of interest. Ferrocene can be

oxidized to the ferrocenium cation and the zinc porphyrin ring exhibits two reversible

oxidation as well as two reversible reduction processes.[105] CVs of different

substituted ferrocene porphyrin compounds are recorded in CH2Cl2 as solvent and

with tetra-n-butyl ammonium hexafluorophosphate as supporting electrolyte

(c = 1 mM). The experimental setup consists of an Ag/AgCl as reference electrode, a

gold disc electrode as working electrode and a platinum electrode as counter

electrode. The substances are used in an approximately 0.1 mM concentration in

CH2Cl2. The solution is at first flushed with nitrogen for five minutes before the CV

measurement is started. Besides the voltammograms of the pure substances,

another voltammogram referred to an internal standard must be recorded to compare

the values obtained for the half-wave potentials. Normally, ferrocene is used as

internal standard for the measurements of porphyrin CVs. In the present case, the

Fc/Fc+ oxidation wave overlaps with the first oxidation of the ferrocene porphyrin.

Thus, decamethylferrocene (Fc*) is chosen as internal standard for these CVs as this

compound has been determined to be a suitable reference.[106, 107] The CVs of

ferrocene derivatives found in literature are often measured vs. Fc*.[108] A

voltammogram of Fc* vs. Fc is recorded and is shown in Figure 28.

Figure 28: Cyclic voltammogram of Fc* vs Fc0/+

(E½ = 0.53 V); scan rate 0.1 V/s; Ag/AgCl reference

electrode.

-0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0

Fc*

Fc

E [V]

http://en.wikipedia.org/wiki/Working_electrode

http://en.wikipedia.org/wiki/Counter_electrode

http://en.wikipedia.org/wiki/Counter_electrode


49

The half-wave potential of Fc* is shifted to a lower value and can be determined at

-0.03 V vs. the Fc/Fc+ couple (half-wave potential is set to E½Ox = 0.53 V). This is in

accord to the values found in literature.[106] The voltammograms obtained for 67, 68,

71 and 72 are illustrated in Figure 29. These ferrocene porphyrins exhibit different

functionalization degrees, which are mirrored in the stronger CV wave which is

assigned to the ferrocene units.

The wave of the oxidation of the ferrocene linked to the ferrocene can be found

around 0.54 V which shows no significant change to the uncoupled ferrocene moiety.

In the case of 67, 68 and 71, the two one-electron oxidation steps of the porphyrin

ring can be detected clearly (exact values in Table 3). These two waves arise from

the one-electron oxidation to the π-cation radical and the subsequent oxidation to the

dication.[109] 72 shows only one clear wave for the porphyrin ring with a half-wave

potential of 1.09 V, a cathodic peak potential can be monitored after zooming in at

Figure 29: Cyclic voltammograms of the ferrocene-porphyrin conjugates 67, 68, 71 and 72 in dry CH2Cl2 vs Fc* (E½ = -0.03 V); scan rate 0.1 V/s; Ag/AgCl reference electrode.

-2 -1.8 -1.6 -1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8-2.1 -2 -1.8 -1.6 -1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8-2.1

EpcOx2

E [V]

67

68

71

72


50

1.38 V. The higher value for the first oxidation indicates that the porphyrin ring of 72

is harder to oxidize. Furthermore, the missing of a corresponding anionic peak

potential for the second oxidation shows that this step is irreversible. The reduction

processes emerge in the cathodic region and show the typical two reversible

reduction steps of the porphyrin ring. These waves arise from the one-electron

reduction to the π-anion radical and another one-electron oxidation to the dianion.[109]

These two one electron processes feature the half-wave potentials of approximately -

1.26 and -1.65 V for 67, 68 and 71. 72 exhibit higher values, meaning that this

reduction is easier to achieve. But in this case the waves do not have a clear shape.

The half-wave potentials for the redox processes of Zn(II)-TPP are: E½Ox1 = 1.09 V

E½Ox2 = +0.78 V, E½

Red1 = -1.32 V and E½Red2 = -1.71 V.[110]

Comparing the half-wave potentials which have been determined, a trend is

observed, that the more ferrocenes are bound to the porphyrin, the oxidation of the

porphyrin ring is more handicapped and the reduction of the porphyrin ring proceeds

easier. Given the fact that the ferrocenes are oxidized first, the oxidation of the

porphyrin core of 72 happens in the presence of eight cationic charges in close

proximity.

Table 3: Half-wave potentials of the porphyrin-ferrocene conjugates and half-wave potential of Zn(II)-TPP;

CVs recorded in dry CH2Cl2 (c 10-3

), scan rate 0.1 V/s, internal standard E½ [Fc*/Fc*+] = -0.03 V; Ag/AgCl

as reference electrode

porphyrin ring reduction porphyrin ring oxidation ferrocene oxidation

E1/2Red2 [V] ΔEp

Red2 [V] E1/2Red1 [V] ΔEp

Red1 [V] E1/2Ox1 [V] ΔEp

Ox1 [V] E1/2Ox2 [V] ΔEp

Ox2 [V] E1/2Ox [V] ΔEp

Ox [V]

67 -1,69 0,13 -1,26 0,06 0,82 0,08 1,19 0,11 0,55 0,08

68 -1,63 0,10 -1.28 0.10 0,86 0,09 1,21 0,08 0,55 0,09

71 -1,60 0,09 -1,25 -0,13 0.98 0,09 1,31 0,10 0,54 0,13

72 -1,45*) 0,09 -1,18*) 0,09 1,09 0,08 1.38a - 0,57 0,19

Zn-TPPb -1.71 0.07 -1.32 0.05 0.78 0.06 1.09 0.05 - -

*) weak CV wave

a: Epc-value (weak wave) no corresponding anionic potential foundb: values found in literarture [111]


51

3.4 Synthesis of Dendritic Ferrocene-Porphyrin Conjugates

The next task is to introduce water-solubility into the ferrocene-porphyrin conjugates.

Water-soluble porphyrins are of interest, because of their ability to form homonuclear

dimers as well as to form supermolecular aggregates or complexes with other

charged compounds.[95, 111] A plenitude of water-soluble porphyrins has been

synthesized within the framework of the PhD-thesis of BALBINOT[95] in the JUX group.

Those systems show good properties for layer by layer applications. In addition,

electrostatic complexes of these porphyrins and charged nanotubes show good

electron transfer behavior.[112]

The concept for this issue is shown in Figure 30 presenting the porphyrin enclosed by

two shells: the first one consists of the

ferrocene units and the second one of

the dendritic units. As dendritic moiety,

the NEWKOME dendron[113] of the 1st

generation is very suitable. The

synthesis of this molecule is quite easy

and the t-butyl ester can be cleaved

easily by treating the dendron with acid

leading to the free acids which introduce

the water-solubility into the porphyrins.

Thus, the ferrocene and NEWKOME

dendron 1st generation must be

connected and further an alkyne unit has

to be attached to apply the “click” chemistry. As capable compound for that purpose,

an asymmetric ferrocene derivative 75, with one acetylene unit and one dendritic unit

is chosen.

Figure 30: Concept to introduce water-solubility to the ferrocene-porphyrin conjugates.

Scheme 19: Synthesis of an asymmetrical ferrocene derivative 75 which can be employed for the 1,3-dipolar “click” cycloaddition.

Ferrporphyrin

ferrocene units

dendritic units


52

This compound can be synthesized from 1,1‟-ferrocene dicarboxylic acid 73 in an

asymmetric acid chloride coupling reaction with propargyl alcohol and the NEWKOME

dendron 1st generation. This ferrocene conjugate can afterwards react in a 1,3-

dipolar Cu(I)-catalyzed cycloaddition with the azidoporphyrins 56-61 delivering

dendritic ferrocene conjugates.

The synthesis of the asymmetric ferrocene derivative is carried out via the carboxylic

acid chloride. First oxalyl chloride is added to 1,1‟-ferrocene dicarboxylic acid, which

is dissolved in small amounts of EtOAc. The reaction mixture is heated for two hours

until the solution becomes clear. Excess of oxalyl chloride is removed under reduced

pressure. The residue is redissolved in dry CH2Cl2 followed by the addition of

propargyl alcohol, NEWKOME dendron 1st generation and pyridine. After stirring the

mixture for twelve hours, the solvent is evaporated off. The formation of three

ferrocene derivatives is observed via TLC (hexane/THF; 6:1). The first spot can be

identified as dipropargyl ferrocene dicarboxylate 74, the second spot as the desired

product 75 and the last spot as ferrocene derivative 76 bearing two dendritic units.

Purification can only be achieved by flash chromatography in a mixture of hexane

and THF (6:1). 75 can be obtained in a yield of 18% as light orange solid. The purity

can be proved via the 1H NMR spectrum in Figure 31.

Figure 31: 1H NMR spectrum (400 MHz, CDCl3) of the assymmetric ferrocene derivative 75.

*-NH-

-CH2- -FcH

-C≡C-H

-CH2-

-tBu

8 7 6 5 4 3 2 1 0

ppm


53

The synthesis route via STEGLICH coupling[114] does not lead to the formation of 75. In

first attempts, the reaction was performed with a stoichiometrically deficient

proportion of propargyl alcohol to form the mono-coupled ferrocene conjugate, that

should react in the next step with the other coupling agent (NEWKOME dendron 1st

generation). But only the double-coupled symmetric ferrocene conjugate 74 is

obtained due to solubility problems of the 1,1‟-ferrocene dicarboxylic acid in the

reaction solvents CH2Cl2 or EtOAc. As the mono-coupled ferrocene carboxylic acid

shows a better solubility, this compound is preferred for coupling. The replacement to

more polar solvents, such as THF or DMF, does not lead to the formation of the

mono-coupled ferrocene conjugate.

Moreover, several approaches were carried out to obtain 75 via STEGLICH coupling

reactions with a statistical mixture of propargyl alcohol and the NEWKOME dendrimer

1st generation. If the reaction is carried out with DMAP, DCC and HOBt, the only

asymmetrical ferrocene derivative that is obtained is 77, whereas the HOBt active

ester 77 does not undergo the final coupling step even after heating the mixture. If

the reaction is transformed without HOBt, the DCC active ester undergoes

rearrangement leading to asymmetrical ferrocene derivative 78. These undesired by-

products are presented in Figure 32.

The subsequent step of the synthesis of dendritic ferrocene-porphyrin conjugates is

shown in Scheme 20. To build up the dendritic ferrocene-porphyrin conjugates, an

excess (1.5 equivalents per azide unit) of 75 is added to the different azidoporphyrins

56-61 and CuSO4∙5 H2O and sodium ascorbate, each separately solved in water, are

added. After adding ethanol and DIPEA to the solution, the reaction is stirred for

twelve hours at 40°C. Afterwards the mixture is purified by flash chromatography. As

eluent, solvent mixtures of CH2Cl2 and EtOAc are used, whereas a gradient is

applied. A ratio of 1:1 has to be used to elute the octa-substituted derivative 84. The

Figure 32: By-products formed in the reaction to generate 75; 77 emerges in the Steglich coupling with DCC, DMAP and HOBt and 78 results in the Steglich coupling without the addition of HOBt.

77 78


54

yields are remarked in Scheme 20 behind each conjugate. For the highly-substituted

derivatives excellent yields can be obtained. That means that this “click” reaction

works even very well with sterical demanding dipolarophiles. For the less-substituted

conjugates 80-82 the single converted by-product occurs, but this represents no

problems in the work-up procedure.

84 has a molecular weight of 7020 g/mol and bears 24 t-butyl esters in its periphery.

The porphyrin is in the center of the dendritic environment, whereas two ferrocene

units are attached to each aryl ring. This very symmetric porphyrin is surrounded by

eight moieties of the NEWKOME dendron 1st generation. The complete structure and

an optimized space filling model (PM3 calculation performed with Spartan) are shown

in Figure 33.

As the water-solubility of these conjugates is achieved by free acid groups, these

motifs can be obtained after splitting off the t-butyl groups. Thus, the highly-

substituted porphyrins bear more carboxylic acids than the less-substituted ones.

Octakis porphyrin 84 or tetrakis porphyrin 83 would exhibit 24 or twelve carboxylic

Scheme 20: Synthesis of dendritic porphyrin ferrocene-systems 79-84 by Cu(I)-catalyzed 1,3-dipolar cycloaddition.


55

acids. This cleavage of the t-butyl esters can also be performed on the other dendritic

ferrocenylporphyrins 79-83, but as there are fewer charges, it is not for sure that

these compounds can also be dissolved in water.

The dendritic porphyrins 79-84 are first characterized by 1H NMR spectroscopy. The

NMR spectra are recorded in the standard solvent CDCl3. The spectra of 83 and 84

are presented in Figure 34 and look clear and well resolved.

Figure 33: Structure of 84 and optimized space filling modell of 84.

Figure 34: 1H NMR spectra (400 MHz, CDCl3) of 83 and 84.

83

84 *

9 8 7 6 5 4 3 2 1 0ppm

* -CH2--CH2-

b-Hortho meta

- tBu

triazole-H

-NH-

-FcH

triazole-H

-NH-

*

-FcH-CH2-

-CH2-

- tBu

b-H meta


56

The conversion of 60 or 61 with the ferrocene derivative 75 can be controlled by the

disappearance of the resonance of the acetylene proton and the occurrence of the

triazole proton signal at 6.33 and 7.29 ppm, respectively. As already mentioned in the

discussion of the spectra of the phenyltriazolyl porphyrins in Chapter 3.2, the triazole

proton‟s resonance is shifted to lower field with higher substitution degree. As shown

in Figure 34, the resonances of the triazole proton of 84 overlaps with the chloroform

signal but the singlet of the triazole proton in the spectrum of 83 can be detected

close to the NH-signal at 6.33 ppm. The signals of the ferrocene substituents arise in

four apparent triplets with a coupling constant of 2.0 Hz in the spectrum of 83. The

protons of the ferrocene rings represent an AA‟BB‟ system. However, these signals

turn up as broad singlets in the spectra of 84. The signals of the dendritic methylene

protons appear between 1.9 and 2.3 ppm and even more shifted upfield the

resonances of the t-butyl groups of the porphyrin and of the dendritic units can be

monitored. Due to 24 or twelve t-butyl groups in the dendritic unit, this intensity of the

signal surpasses all the other resonances.

Figure 35: 1H NMR spectra (400 MHz, THF-d8) of mono (79) and anti dendritic conjugate 82.

82

79

* *

-FcH-CH2-

-CH2-

-CH3

-NH-

-tria.-H

- tBu

b-H ortho meta

*

*

-CH2-

- tBu- tBu

-CH3

-NH-

-triazole-H

b-H

ortho meta

metaortho

-FcH

-CH2-

9 8 7 6 5 4 3 2 1 0

ppm

- tBu


57

The spectra of the less often substituted porphyrins 79-82 recorded in CDCl3 do not

show clear signals, rather a broadening of all signals. By changing the solvent to

THF-d8 good spectra with clearly resolved signals can be obtained (Figure 35). This

is well-grounded by aggregation of the zinc porphyrin conjugates in CDCl3. This

aggregation can be minimized by using coordinating solvents like THF, which

themselves can bind to the zinc ion and exclude the porphyrin stacking.

The aromatic region shows the typical splitting pattern of tetra- and octa-

functionalized porphyrin systems, which is expected due to their symmetries. The

triazole signal and the NH signal turn up between 6 and 7 ppm. The assignment of

the signal of the triazole protons succeeds by HETCOR spectra, whereas a cross-

peak to the carbon spectra at approximately 120 ppm can be detected. For the

proton resonance of the NH no cross-peak is detected, respectively. Between 3.8

and 4.7 ppm, the resonances of the protons of the ferrocene rings appear. These

protons turn up as four apparent triplets due to the asymmetric 1,1‟-functionalization

and the resulting AA‟BB‟-proton-system. In the upfield region the dendritic methylene

groups and the t-butyl groups can be detected. For the latter, two signals arise, one

results of the porphyrin‟s t-butyl groups and one of the dendritic units.


58

Cyclic Voltammetry of the Dendritic Ferrocene Porphyrins

The electrochemical behavior of the novel dendritic ferrocene porphyrins is

investigated by cyclic voltammograms. Figure 36 shows the voltammograms of the

conjugates with different substitution degrees. The experimental setup is described in

chapter 3.3 (p. 48).

In this case, ferrocene can be used as internal standard as the ferrocene ligand of

the porphyrin is detected at a higher potential (0.97 V) as ferrocene due to the ester

and amide bonds of the ferrocene system. On the top of the figure reside the CVs of

the less-substituted porphyrins 79 and 80 and below the CVs of the highly-

substituted systems 83 and 84 are shown. On the first sight, one can see that the

redox waves become more and more unclear the larger the conjugate is. The half-

wave potentials determined from these measurements are gathered in Table 4. The

reduction processes emerge in the cathodic region and show the typical two

reversible reduction steps of the porphyrin ring in the case of porphyrin 79, 80 and

83. These arise from the one-electron reduction to the π-anion radical and another

one-electron oxidation to the dianion.[109] The values for these one-electron reduction

steps are -1.62 and -1.28 V for porphyrin 80 and 83. The reduction of 79 occurs at

Figure 36: Cyclic voltammograms of 79, 80, 83 and 84; scan rate 0.1 V/s, Ag/AgCl as reference electrode.

79

80

83

84

* *-FcH-CH2-

-CH2-

-CH3

-NH--tria.-H

- tBu

b-H ortho meta

*

*

-CH2-

- tBu- tBu

-CH3

-NH-

-triazole-H

b-H

ortho meta

metaortho

-FcH

-CH2-

9 8 7 6 5 4 3 2 1 0

ppm

-2 -1.8 -1.6 -1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8-2 -1.8 -1.6 -1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8

E [V]


59

slightly lower potential (-1.69 and -1.32 V) indicating that the reduction of porphyrin

79 is harder to achieve. In the anionic region, the oxidation processes are monitored.

79 clearly shows three oxidation steps, whereby two oxidations can be assigned to

the two one-electron oxidations of the porphyrin ring.[109]

Furthermore the oxidation of the ferrocene moiety can be detected. As the CV wave

that occurs in the voltammograms of 79, 80 and 83 between 0.92 and 1.03 V

increases with the number of ferrocene units that are attached to the porphyrin, this

wave can be assigned to the ferrocene oxidation. Furthermore, a CV of the ferrocene

ligand is recorded vs. Fc showing the half-wave potential of the uncoupled ferrocene

ligand at 0.97 V. This also supports the assignment of the second oxidation wave to

the ferrocene moieties. 79 shows the three expected waves at 0.82, 1.03 and 1.31 V.

Assuming that the wave at 1.03 V arises from the bound ferrocene, the two one-

electron oxidation steps of the porphyrin ring to the π-cation radical and the dication

turn up at 0.82 and 1.31 V. Compared with ZnTPP (0.82 and 1.14 V)[105, 115] , the

second oxidation wave is shifted to higher values meaning that the oxidation of the

present systems is harder to achieve. With more ferrocene units that are attached to

the porphyrin, the first wave at approximately 0.95 V rises and covers the first

porphyrin oxidation wave like it is the case in the voltammograms of 80 and 83. 80

features the second one-electron oxidation at 1.28 V, this second oxidation is not

visible for 83 meaning that this oxidation is not possible in this system. Octa-

substituted system 84 exhibits no reversible redox processes.

Table 4: Half-wave potentials of the conjugates 79, 80, 83 and 84; CVs recorded in dry CH2Cl2 (cpor 10-3

M), scan rate 0.1 V/s, internal standard E½ [Fc/Fc

+] = 0.53 V; , Ag/AgCl as reference electrode.


E1/2Red2 [V] ΔEp





Ox [V]

79 -1.69 0.11 -1.32 0.08 0.82 0.07 1.31 0.13 1.03 0.16

80 -1.62 0.11 -1.28 0.10 *) - 1.28 0.10 0.92 0.17

83 -1.62 0.12 -1.28 0.11 *) - *) - 0.96 0.11

84 -1.48 0.02 -0.96a - *) - 1.43a - 0.56b -

*) no wave detected due to overlapping with anotherCV wave

a: Epc-value; no correspondinganionicpotential foundb: Epa-value; no corresponding cationicpotential found


60

3.5 Water-Soluble Ferrocene-Porphyrin Systems

3.5.1 Highly-Substituted Conjugates

Different potentially water-soluble conjugates 76-84 have been synthesized. Those

systems are converted to the corresponding carboxylic acid conjugates. The water-

solubility of those ferrocene porphyrin systems can be achieved by treating the t-butyl

protected carboxylic acids with formic acid. Therefore the purple powder is solved in

a small amount of formic acid, the solution is stirred for four hours and afterwards the

acid is evaporated under reduced pressure. To make sure, that all formic acid has

been removed, the residue is twice suspended or solved in toluene and again

distilled under reduced pressure in order to get rid of residual acid.

The residues are afterwards dissolved in buffered water at pH 9, whereby the

carboxylic acids are deprotonated. The deprotected derivatives of 83 and 84 (FA-83

and FA-84) are soluble in water (pH 9), but deprotection of the lower-functionalized

systems 79-82 does not offer good water-solubility to those compounds.

Therefore, higher generations of the NEWKOME dendrimer must be attached to the

ferrocene derivative to get more charges after cleavage. The NEWKOME dendron 2nd

generation should offer the right amount of solubilizing groups. The synthesis of

these water-soluble ferrocene porphyrins is described later (Chapter 3.5.2).

Figure 37: Anionic derivates obtained after treating 83 or 84 with formic acid; those systems are water-soluble in basic media.

FA (free acid) 83 FA (free acid) 84


61

UV/vis spectra of the water-soluble highly-substituted conjugate are recorded in

buffered water at pH 9. The UV/Vis spectrum of FA-84 shows a splitting of the SORET

band, which indicates the partly demetalation of this conjugate. Moreover, the

absorbances in the Q-band region increase, which is also an evidence for the

existence of the free base porphyrin.

The recorded NMR spectra in D2O (pH 9) do not show well resolved signals but

rather a broadening of the signals. The cleavage of the esters can be proved by the

vanishing of the t-butyl signals at around 1.25 ppm.

3.5.2 Bis-Substituted Water-Soluble Ferrocene-Porphyrin Conjugates

As mentioned above, the amount of carboxylic groups attached to the lower

conjugates (mono- and bis-substituted) is not enough to achieve water-solubility. In

place of the 1st generation NEWKOME dendron, the dendrimer 2nd generation is

coupled to the 1,1‟-ferrocene carboxylic acid 73 (Scheme 21). The 2nd generation

NEWKOME dendron possesses nine t-butyl protected carboxylic acids instead of three

in the case of the 1st generation. The reaction to obtain asymmetric ferrocene

derivative 85 is carried out with DCC, DMAP and HOBt in DMF and is stirred for two

Figure 38: UV/Vis spectra in CH2Cl2 and water of the porphyrin 84 and the deprotected conjugate FA-84.

0

0.4

0.6

1

0.2

0.8

400 600500300

l [nm ]

inte

ns

ity

[a. u

.]

R =R =

FA-8484


62

days at room temperature. Compound 85 can be obtained after flash

chromatography with CH2Cl2 and EtOAc (5:1) as eluent in a yield of 10%.

The 1H NMR spectrum of 85 is very similar to the NMR spectrum of the ferrocene

derivative 1st generation 75, besides the appearance of the signals of the methylene

groups of the 2nd generation. Furthermore, the intensity of the resonance of the t-

butyl groups is much higher.

In an alkyne-azide “click” cycloaddition with zinc synazidoporphyrin 58 and ferrocene

derivative 85 porphyrin 86 can be obtained applying the optimized conditions.

Scheme 21: Ferrocene derivative 85 featuring NEWKOME dendron 2nd

generation.

Figure 39: Porphyrin conjugate 86 bearing two ferrocene moieties and two 2nd

generation NEWKOME dendrons.

86


63

As expected, no complete conversion and the formation of the monotriazolyl by-

product is observed in that reaction. But nevertheless, purification is easily achieved

by flash chromatography.

The 1H NMR spectrum (Figure 40) clearly evidences the formation of 86. The

spectrum looks like the one of the lower dendritic system 81 except of the

appearance of the second signal pair of dendritic CH2-protons and the higher

intensity of the t-butyl groups‟ signal. The signals of the non-annulated phenyl rings

show the splitting pattern of an ABCD-system arising in four dd-signals. The

resonance of the triazole protons appears at 6.27 ppm and the signal of the NH

protons at 7.07 ppm. Moreover, for this system the NMR spectra can be recorded in

the standard solvent CDCl3, which is not possible for compound 81 since in this case

no clear signals can be obtained. The aggregation phenomenon that turned up for

the smaller conjugate 81 seems to be precluded by adding a larger dendritic rest.

The formation of 86 can be detected by MALDI-TOF mass-spectrometry, where the

molecular ion peak appears at m/z = 3554.

Figure 40: 1H NMR spectrum (400 MHz, CDCl3) of 86.

8 7 6 5 4 3 2 1 0

ppm

9

-CH2--NH-

-CH2-

-tBu

/-CH3

b-H

ortho

meta

-FcH

triazole-H

*


64

By treating 86 with formic acid, the conjugate with 18 carboxylic acids can be

obtained. This free acid conjugate FA-86 features a good water-solubility in buffer

solution at pH 9.

The corresponding UV/Vis spectra are depicted in Figure 42, showing the

appearance of four absorptions in the Q-band region for FA-86. Furthermore, the

SORET absorbance of the water-soluble system is broadened. These observations

suggest the partly demetalation of FA-86, as it has been observed for FA-84.

Figure 42: UV/Vis spectra of 86 (in CH2Cl2) and FA-86 (in water pH 9).

Figure 41: Water-soluble bis-substituted porphyrin FA-86.

0

0.4

0.6

1

0.2

0.8

400 600500300

l [nm ]

inte

ns

ity

[a. u

.]

R =R =

FA-8686

86: M = Zn

FA-86: M= 2H or Zn


65

3.6 Metalation of the Ferrocene-Porphyrin Conjugates with Nickel, Copper, Manganese and Iron

As porphyrins have the unique property to form complexes with every metal,[116, 117]

different metallo-complexes of octakisferrocenyl porphyrins and tetrakisferrocenyl

porphyrins are synthesized. The interest in this work is focused on iron and

manganese porphyrins bearing a redox active center in the core. Moreover, copper

and nickel complexes are synthesized. Despite of the different size of these metal

ions, the insertion can be carried out in every case clearly showing the qualification of

the present porphyrins for metalation processes. The synthetic procedures for those

metalation reactions on porphyrins are well-known and work without

complications.[118]

It has been mentioned in Chapter 3.2 that metallated porphyrins react best in the

Cu(I)-catalyzed Huisgen reaction. In first attempts, the desired metal was inserted

into the free base azidoporphyrins instead of zinc. But these conversions lead to lots

of products in the case of manganese(III) and iron(III) caused by decomposition of

the azido units by the metals. The nature of these decompositions has not been

analyzed.

Scheme 22: Metalation of octakis(ferrocenyltriazolyl)porphyrin 72.


66

Additionally, the azido anion can bind to the metal center as ligand and/or the

formation of µ-azido complexes is possible. Therefore, the zinc ferrocene-porphyrin

conjugates are generated first followed by demetalation and subsequent

complexation of other metals. This is illustrated in Scheme 22 using the example of

the zinc octakisazidoporphyrin 55. After the synthesis of the zinc

octakis(ferrocenyltriazolyl)porphyrin 72, the zinc ion in the porphyrin core can be

removed by treating the compound with acid. In general, the demetalation process is

carried out with half-concentrated HCl resulting in full conversion to the free base

porphyrin (2H-72). Therefore, the porphyrins are dissolved in CH2Cl2, stirred with

half-concentrated HCl for one hour and afterwards neutralized with saturated

NaHCO3-solution. The conversion of the dendritic porphyrins 83 and 84 to the free

base porphyrins 2H-83 and 2H-84 has to be performed with caution as the t-butyl

ester may cleave in a too acidic media. Thus, only 4 N HCl is applied leading to

complete demetalation but not to cleavage.

To obtain the iron or manganese porphyrins (Fe(III)Cl-71, 72, 83, 84; Mn(III)Cl-

71, 72, 83, 84), the free base porphyrins are treated with FeCl2 or MnCl2, one drop of

2,6-lutidine is added and the mixture is stirred at reflux for several hours.[119] The

metal dications are oxidized by air to the trivalent form and feature the oxidation

state (+III) with an anionic ligand as counter ion in the porphyrin core. By adding

catalytically amounts of 2,6-lutidine, the use of highly boiling solvents can be

precluded and the yields of metallated porphyrin can be increased. The obtained

metalloporphyrins are much more polar than the free base porphyrins. Therefore,

flash chromatography of the crude mixture delivers traces of the free base porphyrins

in the first fraction. The second fraction consisting of the metalloporphyrins can only

be eluted with addition of 10% MeOH to the eluent. Furthermore, a ligand exchange

of these metalloporphyrins can occur, as, e. g., a hydroxyl group can complex to the

metal center. Manganese porphyrins are typically green and iron porphyrins are

brownish in solution and in solid state.

The nickel porphyrins (Ni-71, 72, 83, 84) are obtained after heating the free base

porphyrins with Ni(acac)2 in toluene for five hours.[120, 121] The nickel porphyrins

exhibit a cherry-red color. The conversion works very well and leads to very high

yields (almost full conversion). The nickel ion is the smallest ion (rNi(II)=0.63 Å)

presented here and fits perfectly into the N4 core. The synthesis of the copper


67

conjugates works with Cu(OAc)2∙H2O in CH2Cl2/MeOH[118] and gives a red colored

porphyrin. Nickel and copper have the oxidation state (+II) in the porphyrin core. For

the exact metalation procedures see the experimental part, in which the reactions are

described in detail. Figure 43 shows an overview of the synthesized metallo-

conjugates.

The characterization of the metallo-conjugates by NMR-spectroscopy is challenging

because of the paramagnetism of the iron(III), manganese(III) and copper(II)

complexes. All those spectra show a broadening of the signals, so that an exact

Figure 43: Synthesized ferrocene metalloporphyrin conjugates of 83, 84, 71 and 72.


68

assignment is rather difficult. The appearance of the β-pyrrolic protons as a broad

signal between 75 and 85 ppm in the 1H NMR spectra is typical for iron porphyrins.

This broad signal can be detected for Fe(III)Cl-71, 72, 83 and 84. Further broad

signals between 3 and 5 ppm and 1 and 2 ppm emerges in all of the spectra of these

iron porphyrins. The β-pyrrolic protons of manganese porphyrins turn up in the

1H NMR spectra as a broad singlet at approximately -20 ppm. Due to the extreme

signal broadening, these signals cannot be assigned clearly for the present

manganese porphyrins. Arylic and aliphatic signals can be monitored between 1 and

5 ppm. In the spectra of the copper porphyrins, broad signals can also be observed

in the quite narrow area between 1 and 9 ppm, containing the resonances of the

arylic, ferrocenylic and aliphatic protons. For the β-pyrrolic protons no signals can be

observed at all. These signals are supposed to emerge around 40 ppm but known to

be “terribly” broadened (up to 48 kHz).[122]

Only the nickel porphyrins are diamagnetic and allow a full NMR spectroscopic

investigation. The spectra of the tetra-substituted porphyrins Ni(II)-83 and Ni(II)-71

are shown in Figure 44, for instance. Almost no change can be observed compared

to the zinc complexes 83 and 71. The signals of the ferrocene units show a different

splitting pattern in these two spectra due to the different substitution configuration of

the ferrocene in the two compounds. For this reason the resonances of the ferrocene

9 8 7 6 5 4 3 2 1 0

ppm

Ni(II)-83

Ni(II)-71

-CH2-b-H phenyl-H

b-H phenyl-H -CH2-

- tBu

-CH2-

triazole-H

triazole-H

-NH-

-FcH

-FcH

*

*

Figure 44: 1H NMR spectra (400 MHz, CDCl3) of the nickel ferrocene porphyrins Ni(II)-83 and Ni(II)-71.


69

rings turn up as four triplets for porphyrin Ni(II)-83, while two triplets and one singlet

can be seen in the spectrum of Ni(II)-71. Problems occur also upon MALDI-TOF

mass spectrometry for all those metalloporphyrin. The molecular peak for the radical

cation is not observed in every case. Sometimes, a very broad molecular peak can

be detected or, sometimes, no molecular peak at all can be monitored. Maybe, ESI

mass spectrometry is a better choice to investigate those metallo-conjugates;

however this method has not been available during the time of this work.

The investigation of the metalloporphyrins by UV/Vis spectroscopy shows

characteristic spectra for the conjugates (see Figure 45). Manganese and iron

porphyrins feature irregular porphyrin hyper spectra, meaning that additional bands

appear besides the SORET band and the typical bands in the Q-band region. These

additional bands arise from charge transfer transition from the π-orbitals of the

porphyrin ring to d-orbitals of the metal with suitable symmetry. The strongest

absorption in the spectrum of Mn(III)Cl-71 can be detected at 485 nm.

Hypsochromically shifted, three additional porphyrin absorptions at 386, 408 and

426 nm can be monitored. The spectrum of Fe(III)Cl-71 exhibits the strongest band

at 422 nm and an additional absorption at 386 nm.

Figure 45: UV/Vis spectra in CH2Cl2 of the metallo-conjugates of 71

400 600500300

l [nm]

Mn(III)Cl-71

Fe(III)Cl-71

420

418 432 nm

0

0.4

0.6

1

0.2

0.8

inte

ns

ity

[a. u

.]

400 600500300

l [nm]

Zn(II)-71

Ni(II)-71

Cu(II)-71

inte

ns

ity

[a. u

.]

0

0.4

0.6

1

0.2

0.8


70

The spectra of the copper and nickel complexes belong to the group of hypso

irregular porphyrins and consist of the SORET band in the blue region and two Q-band

absorptions in the red region of the spectra. The two Q-bands arise from the

transition to the lowest excited singlet state and from the transition to a higher excited

state. The SORET band has the biggest extinction coefficient and is affected by the

transition to the second excited singlet state. Figure 45 shows the UV/Vis spectra of

the metalloporphyrins of 71. On the left, the hyper spectra of the manganese and iron

porphyrin can be seen. On the right the spectra of the zinc, nickel and copper

conjugates are shown. The maximum of the SORET band of Zn(II)-71 appears at

432 nm, while the SORET absorption of Cu(II)-71 and Ni(II)-71 is hypsochromically

shifted and can be monitored at 418 and 420 nm. This observation is in accord with

GOUTERMAN‟s theory stating that, in a hypso spectrum, more electropositive metal

centers cause a more pronounced blue shift of the spectrum. Also the extinction

coefficients go in line with theory as the e values for the Q-band of lowest energy

increase with lowered EN.[123-125] As the EN decreases from nickel (1.91) to copper

(1.9) to zinc (1.78), the Q-band absorbance rises from 7600 (Ni(II)-71) to 8100 to

10800 lmol-1cm-1 (Zn(II)-71).

Looking at the UV/vis spectra of the manganese conjugates (Figure 46) the different

substitution degrees of the conjugates become clear. The absorption in the ferrocene

main absorption area between 230 and 270 nm differs, while the absorption of the

manganese porphyrin does not show significant changes.

Figure 46: UV/Vis spectra in CH2Cl2 of different manganese porphyrin conjugates.

400 600500300

l [nm ]

0

0.4

0.6

1

0.2

0.8

e [1

05·l

·cm

-1·m

ol-1

]

400 600500300

l [nm]

0

0.4

0.6

1

0.2

0.8

e [1

05·l

·cm

-1·m

ol-1

]

Mn(III)Cl-71

Mn(III)Cl-72

Mn(III)Cl-83

Mn(III)Cl-74


71

The absorptions of the ferrocene band rises with the number of ferrocenes that are

attached to the porphyrin. Due to the eight ferrocenes that are bound to Mn(III)-72

and Mn(III)Cl-84, a solution of these metalloporphyrins in CH2Cl2 does not show the

typical green color any more but adopt the brown color of the ferrocene units. This is

illustrated in Figure 47 which shows the samples for the quantitative UV/Vis spectra

of tetrakis conjugate Mn(III)Cl-83 and octakis conjugate Mn(III)Cl-84. A solution of

Mn(III)Cl-83 still features the green color while the solution of Mn(III)Cl-84 is nearly

brown.

The cleavage of the t-butyl ester to obtain water-soluble systems can also be

performed on the metallated dendritic porphyrins M-83 and M-84, whereby no

demetalation should occur. The trivalent iron and manganese porphyrins are stable

against acid.[126]

Figure 48: Water-soluble ferrocene metalloporphyrins of 83 and 84.

Mn(III)-84 Mn(III)-83

Figure 47: Different color of Mn(III)Cl-83

and Mn(III)Cl-84 in solution.


72

The stability of copper and nickel complexes towards formic acid is also known in

literature.[127]

This is carried out by stirring the complexes in formic acid, evaporation of the acid

and final suspension of the residue in toluene followed by distillation to remove

vestiges of the acid. In this way the conjugates FA-M-83 and FA-M-84 (M = Ni, Cu,

FeCl, MnCl) can be obtained that are soluble in water at pH 9.

The brown color of the manganese and iron porphyrins remains, respectively. This

can be proofed by the corresponding UV/Vis spectra that still show the typical

features of the hyper spectra of manganese or iron porphyrins. Figure 49 shows the

additional bands to the SORET band which would vanish if the metal is removed from

the core. When applying this deprotection approach on nickel and copper conjugates,

the corresponding UV/Vis spectra also prove that the metal is still complexed in the

porphyrin core. Both spectra show two absorptions in the Q-band region, which is in

accord with the existence of the metallated species.

Figure 49: UV/Vis spectra of Mn(III)Cl-84 and Fe(III)Cl-84 in water and in CH2Cl2.

R1 = R2 =

400 600

l (nm)500300

R1 in CH2Cl2

R2 in water pH 9

400 600

l(nm)

500300

R1 in CH2Cl2R2 in water pH 9

M = FeCl M = MnCl

0

0.4

0.6

1

0.2

0.8

inte

ns

ity

[a. u

.]

0

0.4

0.6

1

0.2

0.8

inte

ns

ity

[a. u

.]


73

Cyclic Voltammetry of the Metalloporphyrins of 71

The electrochemical properties of the ferrocene metalloporphyrins are investigated

via cyclic voltammetry according to the setting described in Chapter 3.3 (p. 48). The

metallo-conjugates of tetrakis(ferrocenyltriazolyl)porphyrin 71 are used for these

measurements. The obtained voltammograms are illustrated in Figure 50. The half-

wave potentials (Table 5) are determined vs. Fc* as internal standard as ferrocene

overlaps with the wave of the ferrocene units bound to the porphyrin.

The voltammograms of the nickel conjugate and the copper conjugate show the

clearest reversible redox processes. Cu(II)-71 features two reversible one-electron

reductions belonging to the porphyrin ring. In literature, the theoretical appearance of

a third reduction (with an even more negative potential), which can be assigned to

the formation of a Cu(I)-dianion, is reported.[115] This wave cannot be observed in this

case. One explanation may be that this reduction is beyond the measureable region

which is limited to -2 V in CH2Cl2. In a more negative area, the solvent decomposes.

Furthermore, this can be due to the shielding properties of the ferrocene units. The

Figure 50: Cyclic voltammograms for the metallo porphyrins of 71 in dry CH2Cl2 vs Fc*0/+

(E½ = -0.03 V); scan rate 0.1 V/s; Ag/AgCl reference electrode.

Cu(II)-71

Ni(II)-71

Mn(III)Cl71

Fe(III)Cl-71

-2 -1.8 -1.6 -1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2

E [V]


74

cathodic region of the CV of Cu(II)-71 shows two reversible oxidations arising from

the ferrocene and the porphyrin ring. For the porphyrin ring only one reversible

reduction process can be observed, the second cathodic peak potential found does

not feature a corresponding anodic peak potential.

The cyclic voltammogram of Ni(II)-71 is also depicted in Figure 50. Only one clear

reversible reduction can be detected at -1.25 V and two reversible oxidations at 0.53

and 1.31 V. The first oxidation wave belongs to the oxidation of the ferrocene

moieties. The origin of the other reduction and oxidation waves cannot be determined

completely.[115] In the anodic region, the oxidation to a Ni(III)-cationic species as well

as the formation of the Ni(II)-π-radical cation is discussed in literature.[115] But the

generation of the π-radical cation in this case is more likely as no coordinating

solvent, which stabilizes the Ni(III)-species, is used for these CV measurements.[128]

The reduction can occur on the porphyrin ring as well as on the metal center.[115] As

only one clear reduction is observed in this CV, one possible explanation for that is

the appearance of more reduction steps overlapping each other, resulting in no clear

wave that can be detected.

Table 5: Half-wave potential of selected metallo porphyrins of 71; CVs measured in dry CH2Cl2 vs Fc*0/+

(E1/2 = -0.03 V); scan rate 0.1 V/s; Ag/AgCl reference electrode.

The voltammograms of the iron and manganese conjugate do not show clear

reversible redox waves but more unresolved small processes. The only oxidation

process, which can be monitored appears at 0.53 V for both conjugates and belongs

to the Fc0/+-couple linked to the porphyrin. The weak waves which can be seen are

due to the high number of redox processes that take place. The anionic ligand bound

to the metal center also broadens the range of electrochemical processes.[115]


E1/2Red2 [V] ΔEp





Ox [V]

Cu(II)-71 -1,62 0,14 -1,16 0,09 1,11 0,11 1.41a - 0.53 0.11

Ni(II)-71 -1,67 0,11 -1,13 0,10 1,25 -0,04 - - 0,53 0,10

Mn(III)-71 *) *) *) *) *) *) *) *) 0.53 0.09

Fe(III)-71 *) *) *) *) *) *) *) *) 0.53 -

*) no clear wave detected

a: Epc-value; no correspondinganionicpotential found


75

3.7 The “Click” Route to “Capped” Porphyrins

3.7.1 Ferrocene-Bridged Porphyrins

Inspired by the beauty of bridged porphyrins that have been synthesized by BALDWIN

et al.[83] for instance (see p. 22), in this project zinc synazidoporphyrin 58 and zinc

tetrakisazidoporphyrin 60 are capped with different compounds. The azidoporphyrins

58 and 60 bear two azide units on one or on both side(s) of the porphyrin plane,

which can be used as anchor groups for the bridgework.

As shown in the previous chapter, ferrocene-porphyrin conjugates have very

interesting physical properties.[99] Porphyrins capped with ferrocene units are the next

challenge. Therefore, a suitable ferrocene bisalkyne derivative must be synthesized.

1,1‟-ferrocene dicarboxylic acid is reacted with propargyl alcohol under STEGLICH

conditions providing dipropargyl ferrocene dicarboxylate 74 in a yield of 93%

(Scheme 23). Although 1,1‟-ferrocene dicarboxylic acid does not show a good

solubility in CH2Cl2, it is slowly dissolved with on-going reaction time.

Flash chromatography is necessary to remove the coupling reagents and traces of

formed by-products. The product 74 elutes in the first fraction and can be separated

easily.

Dipropargyl ferrocene dicarboxylate 74 also occurs as by-product in the reaction

shown in Scheme 19, but can be synthesized selectively in a much better yield by the

method presented here.

Dipropargyl ferrocene dicarboxylate 74 is brought to reaction with zinc

synazidoporphyrin 58 under optimized “click” conditions. To reduce polymer

formation the concentration of the reactants is decreased by using 150 mL CH2Cl2 to

dissolve 100 mg porphyrin. 74 is added in equimolar amounts to the porphyrin

Scheme 23: Dipropargyl ferrocene dicarboxylate 74 formed in a Steglich coupling with propargyl alcohole.

73 74


76

followed by the addition of the “click” reagents. The mixture is stirred overnight at

40°C.

Polymerization is strongly suppressed in this procedure. TLC shows vestiges of educt

running with the solvent front (CHCl3) and a second porphyrin spot moving much

more slowly that can be identified as product. The crude mixture can be separated by

flash chromatography (CHCl3). The second spot can be identified as product after full

characterization.

The FAB mass spectrum shows the molecular ion peak of the product at m/z = 1390

and a fragment peak at m/z = 953. As the single-“clicked” porphyrin, in which the

ferrocene derivative 74 is only anchored to the porphyrin at one side, has the same

molecular mass, it is ensured by IR-spectroscopy that no azide group remains.

According to the detected spectrum (Figure 51), both azides have reacted in a 1,3-

dipoar cycloaddition to triazoles.

wavenumber [cm-1]

4000 3500 3000 2500 2000 1500 1000 500

no azide band

Scheme 24: Reaction scheme for the transformation of syn bisazidoporphyrin 58 with 74

Figure 51: IR-spectrum of capped porphyrin 88.


77

The double triazole formation can also be proofed by NMR spectroscopy, whereby

the higher symmetry of the desired product in contrast to the mono-“clicked”

compound is reflected in the 1H NMR-spectrum in Figure 52.

Because of the fixed position of the ferrocene on top of the diamagnetic ring current

of the porphyrin ring, the signal of the ferrocene rings are shifted to higher field and

can be monitored at 3.69 and 3.30 ppm. This phenomenon can also be observed for

the resonance of the two triazole protons which appear as a singlet at 4.00 ppm. The

typical splitting pattern for tetraphenylporphyrins with C2h symmetry can be observed

for the β-pyrrolic and the phenylic protons. Actually, capped porphyrin 88 possesses

C2-symmetry, but due to the flexibility of the ferrocene bridge above the porphyrin

plane a splitting pattern for porphyrins with C2h-symmetry appears. A discussion on

that point is added at the end of this chapter. The β-pyrrolic protons appear as two

doublets and the phenylic protons as four dd-signals and two singlets for the four

protons on the annulated rings. The signal of the methylene protons next to the ester

bonds emerges at 5.05 ppm. The resonance of the other methylene groups next to

the aryl rings is shifted lowfield to 4.16 ppm compared to the spectrum of the educt,

zinc synazidoporphyrin 58. In this case, these protons can be detected at 2.57 ppm.

The allocations of the signals to the different protons of 88 can be supported by the

HETCOR spectrum presented in Figure 53. The two enlargements which are

Figure 52: 1H NMR spectrum of capped porphyrin 88; the splitting pattern of the aryl signals proves the

formation of the double clicked system.

ppm9 8 7 6 5 4 3 2 1 0

*

-CH2-

-CH2-

-CH3

- tBu

β-H

ortho triazole-HFcH

meta


78

depicted in this figure show the aromatic region and the region between 2 and 6 ppm,

in which the signals of the ferrocene, methylene and triazole protons appear.

Figure 53: HETCOR spectrum (CDCl3) of capped porphyrin 88.


79

The phenylic protons can be assigned doubtlessly to the different meta- and ortho-

positions due to the splitting pattern and the integrals. The methylene resonances at

4.16 and 3.05 ppm correlate with the peaks at 56.4 and 53.2 ppm in the carbon

spectrum.

The ferrocene signals at 3.69 and 3.30 ppm exhibit a cross-peak to the peaks at 72.1

and 70.4 ppm in the 13C NMR spectrum. The correct assignment of the triazole signal

can also be proved due to the cross-peak in the 13C NMR spectrum that appears at

124.6 ppm.

As the yield for the bridged system 88 turned out to be good, the same approach is

carried out with zinc tetrakisazidoporphyrin 60 delivering the double-capped system

89. The outline is shown in Scheme 25 depicting the conversion of 60 with two

equivalents of 74 again using high dilution to prevent polymerization. 100 mg zinc

tetrakisazidoporphyrin 60 and 74 are dissolved in 150 mL CH2Cl2, followed by the

addition of the “click” reagents and stirring at 40°C for twelve hours.

Capped porphyrin 89 can be isolated and characterized. In this reaction a by-product

is formed, which has been isolated and is identified as the single-capped system with

two azides units unconverted on the other side of the porphyrin plane. Purification of

89 is more difficult than for the single bridged porphyrin, but succeeds finally after

repeated flash chromatography (CH2Cl2/EtOAc, 40:120:1).

Scheme 25: Transformation of zinc tetrakisazidoporphyrin 60 into a double-bridged ferrocene porphyrin 89 using the optimized “click” procedure.

74


80

The 1H NMR spectrum in Figure 54 does not show many differences compared to the

spectrum of the mono-bridged system 88. Of course, the symmetry of this system is

higher (D2h instead of C2h), which is mirrored in the splitting pattern in the arylic

region. In this case, the non-annulated phenyl rings show AB-coupling-systems

leading to two doublets instead of two dd-signals, which appear for the ABCD-

systems of single-capped system 88. As already observed in the spectrum of 88

(Figure 52), the ferrocene and triazole signals experience an upfield shift due to their

position above (or under) the porphyrin plane.

Discussion on the Conformers of the Ferrocene Compounds

As the ferrocene moiety can exhibit different positions above the porphyrin plane, this

may result in the formation of different isomers. Figure 55 shows the PM3 optimized

structure for capped porphyrin 88. The ferrocene rings are placed in a fixed angle

above the porphyrin plane leading to different interspaces between the different

ferrocene protons and the porphyrin. Thus, an ABCD-System on each ferrocene ring

should lead to four ferrocene signals which are expected in the 1H NMR spectrum of

this system.

Figure 54: 1H NMR (400 MHz, CDCl3) spectrum of double-bridged porphyrin 89.

ppm9 8 7 6 5 4 3 2 1 0

*

00

β-H

meta - tBuortho

-CH2-

-CH2-Fc-H

triazole-H

β-H


81

As only two signals for the ferrocene protons can be detected in the

1H NMR spectrum, the presumption can be made that a fast twist of the ferrocene

rings occurs. The position of the ferrocene moiety changes fast at room temperature.

Figure 56 shows two possible conformers that can exist and which arise because of

the different positions of the ferrocene above the porphyrin resulting in a set of

averaged signals. However, these isomers are not stable at room temperature and a

dynamical exchange between those isomers occurs.

Figure 55: PM3 optimized structure of 88 showing the position of the triazole ring and the arrangement of the ferrocene.

Figure 56: Two possible conformation of 88; the transition is very fast at room temperature according to the

1H NMR spectrum.


82

This dynamical process can be shown upon cooling. Therefore, low temperature

NMR measurements were performed. The rotation of the ferrocene ring is hindered

and more signals can be seen for the protons of the bridging unit.

Figure 57 shows the 1H NMR spectra measured at low temperatures with CDCl3 as

solvent. Further measurements in CD2Cl2 are also performed between -65 and

-85°C, however the signals become too broad, so that an analysis is not possible

anymore. The low temperature NMR spectra show the appearance of more signals at

-55°C indicating that in this case a fixed position of the ferrocene ring above the

porphyrin plane exists. At -5°C, the two resonances of the ferrocene unit which are

detected at 20°C (Figure 52) appear as one coalesced signal. A further coalescence

phenomenon can be seen at -35°C. At -55°C, a splitting of the signals is observed.

Thus, the protons on the side of the porphyrin plane and on the side away from the

porphyrin plane emerge at different chemical shifts.

Figure 57: Low temperature 1H NMR measurements (CDCl3, 400 MHz) performed on 88.

ppm

9 8 7 6 5 4 3 2 1 0

ppm

9 8 7 6 5 4 3 2 1 0

-5 C

-15 C

-25 C

-35 C

-45 C

-55 C

*

-CH2-

-CH2-

FcH

tria.-H

20 C


83

3.7.2 Porphyrins Bridged with Dendritic Systems

Other interesting bridges are bulky units that cover the porphyrin on one or both sides

and protect the porphyrin against solvent attacks or aggregation. A suitable

compound for that reaction is benzene derivative 93, whereas the phenyl ring acts as

connection point of two alkyne units and the bulky NEWKOME dendron 1st generation.

The alkyne units serve as connection to zinc azidoporphyrin 58 or 60, while the

dendron acts as coverage above the porphyrin as it can spread its branches over the

aromatic ring.

The synthesis is carried out according to Scheme 26, whereas intermediate 91 is

formed after treating 3,5-dihydroxy benzoic acid 90 with propargyl bromide. K2CO3 is

added as base and 18-crown-6 as phase-transfer catalyst. Pure 91 can be

recrystallized from EtOH. The subsequent saponification furnishing 3,5-

bis(propargyloxy)benzoic acid 92 works with NaOH in a mixture of THF and water.

The mixture is extracted with CH2Cl2 and washed with saturated NH4Cl-solution. After

evaporating of the solvent, the residue can be transferred in a STEGLICH coupling

reaction to compound 93. The reaction mixture is stirred for three days and is

afterwards purified by flash chromatography.

Benzene derivative 93 reacts with zinc synazidoporphyrin 58 and zinc

tetrakisazidoporphyrin 60 furnishing the single-capped (94) and double-capped

system 95. The reaction is carried out applying the same conditions as for the

ferrocene-bridged systems 88 and 89. Zinc synazidoporphyrin 58 reacts with one

equivalent 93 and zinc tetrakisazidoporphyrin 60 is brought to reaction with two

equivalents of 93, whereas both reactions are again performed under high dilution.

The reaction mixtures are stirred for twelve hours at 40°C, followed by flash

chromatography to separate unconverted starting material and by-products.

Scheme 26: Synthesis of 93 via intermediate 91 and 92.


84

The 1H NMR spectra depicted in Figure 59 are obtained. The aromatic region shows

the splitting pattern expected due to the symmetry of the present porphyrins.

Figure 58: Porphyrin bridged by benzene unit bearing Newkome dendron 1st

generation.

Figure 59: 1H NMR (CDCl3, 400 MHz) spectra of 94 and 95.

94 95

94

95

*

9 8 7 6 5 4 3 2 1 0

ppm

-CH2-

-CH3

b-H

ortho

meta

- tBu

triazole-H

-CH2-

*

triazole-H

-CH2-

- tBu

-CH2-

-CH2-

-CH2-

b-H

ortho

metaphenyl-H

-NH-

phenyl-H

-NH-

- tBu


85

The resonances of the phenylic protons of the bridged benzene ring are shifted to

higher field because of the position of this aromatic ring above the porphyrin plane. In

the spectrum of the mono-capped system 94 those resonances can be detected at

6.45 and 5.85 ppm and in the spectrum of the double-capped system 95 at 6.41 and

5.63 ppm, respectively. The triazole signal of 94 overlaps with the signal of the

methylene groups leading to a broad singlet at 5.21 ppm which has an integral of six

protons. In the spectrum of 95, two signals at 5.19 and 5.00 ppm can be seen for

those protons. The signals of the dendritic system appear as two triplets, one singlet

and a broad singlet for the NH proton. The triplets arise from the methylene protons

and are located at 2.07 and 1.88 ppm for 94 or at 2.03 and 1.85 ppm for 95. The NH

signal is shifted lowfield to 6.14 (93) and 6.18 ppm (95).

PM3-calculations on those dendron capped systems show that the t-butyl branches

cover the porphyrin plane; the calculated models are depicted in Figure 60.

Double-capped compound 95 is shown on the left and the mono-capped system 94

on the right.

Figure 60: PM3 optimized calculations on the single 94 and doubly capped system 95.

95 94


86

3.7.3 Cyclic Voltammetry of the Bridged Porphyrins

According to the procedure that has already been described in Chapter 3.3, cyclic

voltammograms of the porphyrins 88, 89, 94 and 95 are recorded. As internal

standard ferrocene (E½Ox = 0.53 V) can be used, as the ferrocene oxidation of the

ferrocene capped porphyrins is based on ferrocene dicarboxylic acid and thus, is

shifted more towards positive potential. The CVs of 88 and 89 are depicted in Figure

61.

The single ferrocene capped porphyrin 88 (red line) shows four CV waves in the

anionic region of the voltammogram, which means that an additional wave to the

expected three waves appears. The wave with a half-wave potential of 1.03 V can be

assigned to the oxidation of the bound ferrocene unit. Furthermore, two oxidations

can be assigned to the two one-electron oxidations to the π-cation radical and the

dication of the porphyrin ring. The origin of the third wave may be a fast follow-up

chemical reaction which forms an electro active species showing another oxidation

wave. This has already been observed in electrochemical studies of strained capped

porphyrins by BECKER et al.[129] Two full reversible reduction processes at -1.32 and -

1.70 V can be detected. These two reduction steps also appear in the voltammogram

of 89 (blue line) and exhibit approximately the same potentials (see Table 6).

Figure 61: CVs of ferrocene capped porphyrins 88 and 89 in dry CH2Cl2 vs Fc0/+

(E½ = 0.53 V); scan rate 0.1 V/s; Ag/AgCl reference electrode.

E [V]

-2 -1.8 -1.6 -1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8-2 -1.8 -1.6 -1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8

88

89


87

The oxidation of the bridged ferrocene unit of 89 occurs at 0.91 V in this case and

shows a stronger current as it can be seen for the mono-capped system 88 due to

the presence of two ferrocene moieties in its periphery. Two more one-electron

oxidations can be monitored at 1.19 and 1.58 V. The letter corresponds to the

oxidation at 1.61 V in the voltammogram of 88 and corresponds to the third observed

oxidation wave that has been mentioned above. The first one-electron oxidation to

the π-radical-cation cannot be monitored due to its overlap with the ferrocene wave.

The voltammograms of the dendritic capped systems 94 and 95 are presented in

Figure 62. Mono-capped system 94 again features three reversible oxidation

processes in the anodic region.

The half-wave potentials for those oxidations are determined to 0.84, 1.19 and

1.60 V. The third oxidation process has its origin in the strapped nature of the

porphyrin and may result due to the formation of an electro active species, which

Table 6: Half-wave potentials of the ferrocene-bridged systems 88 and 89 vs Fc0/+

(E½ = 0.53 V);

(scan rate 0.1 V/s); CVs are measured in dry CH2Cl2 and with Ag/AgCl as reference electrode.

Figure 62: Cyclic voltammograms for the dendritic systems 94 and 95 in dry CH2Cl2 vs Fc0/+

(E½ = 0.53 V); scan rate 0.1 V/s; Ag/AgCl reference electrode.

-2 -1.8 -1.6 -1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8-2.2-2 -1.8 -1.6 -1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8-2.2

94

95

E [V]


E1/2Red2 [V] ΔEp






Ox [V]

88 -1.70 0.13 -1.32 0.06 0.88 0.06 1.27 0.08 1.61 0.08 1.03 0.06

89 -1.72 0.12 -1.32 0.07 *) - 1.19 0.12 1.58 0.18 0.91 0.14

*) no wave detected due to overlapping with another CV wave


88

subsequently undergoes another oxidation. Two reductions can be monitored at -

1.31 and -1.85 V, which are shifted to lower potentials compared with TPP.

The clearly observed three oxidation structure of 94 vanishes for compound 95. The

double-capped system features only one reversible oxidation at 0.93 V. For a second

oxidation only an irreversible cathodic peak potential at 1.35 V can be seen. The two

one-electron reductions possess half-wave potentials of -1.63 and -1.15 V,

respectively.

Table 7: Half-wave potentials for 94 and 95 vs Fc0/+

(E½ = 0.53 V); (scan rate 0.1 V/s); CVs are measured in

dry CH2Cl2 and with Ag/AgCl as reference electrode.

porphyrin ring reduction porphyrin ring oxidation

E1/2Red2 [V] ΔEp





Ox2 [V]

94 -1.85*) - -1.31 0.02 0.84 0.07 1.19 0.16 1.60 0.10

95 -1.63 0.20 -1.15 0.27 0.93 0.07 1.35a - - -

*) irreversible process

a: Epc-value; no corresponding anionic potential found


89

3.8 Creating Oligomeric Ferrocene-Porphyrin Conjugates

3.8.1 Di- and Trimeric Ferrocene-Porphyrin Conjugates

Oligomeric conjugates can be formed by “click” chemistry with different alkyne

compounds as linker between the azidoporphyrin monomers. The synthesized

dipropargyl ferrocene dicarboxylate 74 can assume this linker function and connect

different azidoporphyrin monomers via a ferrocene bistriazole bridge. The simplest

example is the connection of two zinc monoazidoporphyrins 56 via dipropargyl

ferrocene dicarboxylate 74 furnishing dimeric conjugate 96.

This reaction is carried out with ½ equivalents of 74 under optimized “click”

conditions. The yield of 31% is quite satisfactory. The mono-“clicked” ferrocene

derivative occurs as by-product in this reaction, but can be separated and afterwards

identified by spectroscopic methods.

Figure 63: Porphyrin dimer 96 and porphyrin trimer 97 generated from the basic azidoporphyrin precursors and dipropargyl ferrocene dicarboxylate 74.

96 97


90

The synthetic route to the porphyrin trimer 97 is more challenging, as there are two

general routes that can be chosen (Figure 64). The first route starts with the

conversion of zinc bisazidoporphyrin 57 with dipropargyl ferrocene dicarboxylate 74

to generate a porphyrin bisferrocenyl conjugate 98 with two free alkyne units which is

afterwards reacted with zinc monoazidoporphyrin 56 to the final porphyrin trimer 97.

The disadvantage of this reaction is the possible formation of polymers in the first

step.

The alternative route begins with the reaction of zinc monoazidoporphyrin 56 and

dipropargyl ferrocene dicarboxylate74 leading to mono-“clicked” ferrocene-porphyrin

conjugate 99, which can again undergo a “click” reaction with zinc bisazidoporphyrin

57. As in this case a polymerization is not possible, this seems to be the better way.

The synthesis of monoferrocenyl porphyrin 99 is carried out with an excess of

dipropargyl ferrocene dicarboxylate 74. The process works smoothly and gives the

intermediate in a yield of 68%. The final step, the reaction of zinc bisazidoporphyrin

57 with the intermediate 99 leads to the mono-”clicked” porphyrin dimer and the

desired product 97 which can be separated by flash chromatography (CHCl3/EtOAc,

100:1).

97 can clearly be identified clearly by the 1H NMR-spectrum in Figure 66. The

aromatic region shows an overlap of the signals of the two different porphyrins. In the

alkylic region a set of two signals appears for each group, which is in accord with the

presumed structure. Two singlets for the triazole protons appear at 6.11 and

Figure 64: Two routes to create the trimeric porphyrin-ferrocene conjugate 97.

98

99

56

57

74

74

56


91

6.09 ppm, whereby each signal reflects two protons. The two different methylene

groups next two the aryl rings appear at 4.50 and 4.45 ppm and the two methylene

groups next to the ester bond can be detected at 4.98 and 4.91 ppm. The

resonances of the ferrocene moieties are monitored as four triplets at 3.99, 3.96, 3.68

and 3.66 ppm. Furthermore, only one resonance for the methyl groups exists in this

system emerging at 1.93 ppm. The porphyrin trimer 97 has six chemically different

t-butyl groups. This fact is reflected in the spectrum, where six signals are detected.

The integrals of these signals are in the ratio of 18:36:18:9:18:9.

Concluding this chapter, the synthesis of a cycle (100) consisting of two ferrocene

units and two porphyrins is presented.

Figure 66: 1H NMR spectrum (THF-d8, 400 MHz) of porphyrin trimer 97.

Figure 65: Porphyrin-cycle 100.

(H2O)

100

9 8 7 6 5 4 3 2 1 0ppm

**

*-CH2-

-CH3

b-pyrryl

phenyl-H

triazole-H

- tBu

-CH2-

-FcH


92

For this purpose, zinc bisazidoporphyrin 57 and dipropargyl ferrocene dicarboxylate

74 are added equimolar to a larger volume (100 mL for 100 mg porphyrin) of CH2Cl2.

The reaction is carried out under high dilution to avoid polymerization. After stirring

overnight, the TLC plate shows that the polymerization was not prevented

completely. But only a few polymeric by-products remain on the baseline, while one

spot additionally appears moving more slowly than the educt.

This compound can be separated by flash chromatography and is identified as the

porphyrin cycle 100. MALDI-TOF mass spectrometry shows the molecule peak at

m/z = 2725. Another peak at m/z = 1365 can be assigned to the porphyrin triazole

fragment after the splitting off the two triazole units. The obtained fragment consists

of one porphyrin and one bistriazolylferrocenyl moiety.

The 1H NMR spectrum is presented in Figure 67. The β-pyrrolic protons as well as

the phenylic protons show the splitting pattern of a porphyrin with C2v-symmetry. The

signal of the triazole protons turns up at 6.51 ppm. The ferrocene and methylene

signals overlap and appear between 4 and 5 ppm.

Figure 67: 1H NMR spectrum (400 MHz, CDCl3) of porphyrin cycle 100.

*

9 8 7 6 5 4 3 2 1 0

ppm

-CH2-

-FcH

b-H

phenyl-H

- tBu

triazole-H


93

3.8.2 Synthesis of a Porphyrin-Triad formed of a new AB2C-Porphyrin

In this project a new AB2C-porphyrin system 102 is synthesized. Firstly, it is equipped

with azide groups to connect ethinyl ferrocene and secondly, coupled to propargyl

alcohol to have another “click” reaction center for the formation of higher conjugates.

This porphyrin is generated by the condensation of t-butylbenzaldehyde, t-butyl-2-(4-

formylphenoxy)acetate 101 and bismethoxy dipyrromethane 45b under TFA catalysis

(Scheme 27). The reagents are dissolved in CH2Cl2, TFA is added and the reaction

mixture is stirred for one hour, followed by the addition of NEt3 and DDQ to oxidize

the formed porphyrinogens. In this case, the neutralization with NEt3 is important to

avoid the cleavage of the t-butyl esters by acid. The work-up procedure starts with

filtration over a silica plug in order to remove higher oligomers, polymers and

excessive DDQ.

Scheme 27: Synthesis of porphyrin 102 from bismethoxy dipyrromethane 45b, t-butylbenzaldehyde and

t-butyl 2-(4-formylphenoxy)acetate 101.

101

102

103 102 104

Figure 68: Porphyrins formed in the reaction shown in Scheme 27.

45b


94

Flash chromatography is employed to obtain the pure porphyrin 102. Three

porphyrins can be separeted from this reaction: in the first fraction, 103 can be

obtained, the next fraction contains the desired product 102 and the last fraction

contains porphyrin 104.

The different porphyrins are characterized by 1H NMR spectroscopy. The aromatic

region of the porphyrins 102-104 is depicted in Figure 69. The splitting pattern of the

aromatic signals mirrors the symmetry of the porphyrin. Both by-products 102 and

104 possess D2h symmetry, while the desired product features C2V symmetry. The

resonances of the pyrrolic protons of 102 appear as three doublets. In fact, it should

be four doublets, but two overlap and emerge as one signal at 8.66 ppm. The

resonances of the β-pyrrolic protons of 103 and 104 show only two doublets due to

the higher symmetry. The different arylic protons of the t-butyl phenyl ring and of the

t-butyl-phenoxyacetate can be monitored in four doublets. The four protons of the

bismethoxy annulated phenyl rings can be detected as a singlet. This resonance can

also be detected in the spectra of the by-products 103 and 104.

In contrast to that, the spectra of the by-products only show one doublet pair of the

non-annulated aryl rings with double intensity. The resonances of the protons of the

t-butyl-phenoxyacetate substituent are shifted upfield compared to the resonances of

the non-annulated t-butyl ring.

Figure 69: Details of the 1H NMR spectra recorded for the porphyrins of the synthesis in Scheme 27.

103

D2h

105

D2h

102

C2V

8.5 8.0 7.5

*

*

9

β-Hortho meta

meta

meta

ppm

ortho

ortho


95

Subsequently, porphyrin 104 is dissolved in CH2Cl2 and is treated with HBr (33% in

HOAc) for four hours. This procedure is performed in order to substitute the methoxy

groups with bromides as well as to cleave the t-butyl ester. The purple solution turns

into green after the addition of HBr due to the protonation of the core nitrogens, but

turns again to purple after neutralizing the reaction mixture after four hours with a

saturated NaHCO3-solution. Afterwards the solution is washed with water and dried

over MgSO4. No flash chromatography is necessary as the conversion proceeds

completely. The obtained porphyrin 105 features a much higher polarity as the educt

due to the deprotected carboxylic acid.

Afterwards compound 106 is prepared for the Cu(I)-catalyzed “click” reaction by

exchanging the bromides with azides and insertion of zinc into the porphyrin core.

These well-known procedures need purification by flash chromatography, which is

done with CH2Cl2 and MeOH (10:1) as eluent. Zinc tetrakisazidoporphyrin 106 can be

converted with ethynyl ferrocene to the triazole connected ferrocene-porphyrin

conjugate 107.

Scheme 28: Subsequent reaction sequence delivering zinc azidoporphyrin 106.

Scheme 29: Cascade leading to conjugate 108 equipped with an alkyne unit for further “click” reactions.

105 106 102

107 108 106


96

Therefore, 106 is reacted with six equivalents ethynyl ferrocene, CuSO4∙5 H2O,

sodium ascorbate and DIPEA in a CH2Cl2/EtOH/water mixture. Fortunately, full

conversion can be observed, simplifying the purification of the product. Flash

chromatography of this compound is challenging because of the high polarity of the

compound. Here, the excessive ethynyl ferrocene can be eluted with EtOAc and only

the product remains on the column. This can be flushed with EtOAc/MeOH (5:1)

delivering the pure product 107. Silica residues are removed by evaporation of the

solvent, redissolving the residue in CH2Cl2 and filtration over a frit (P4).

The acetylene functionalization can be attached by a STEGLICH coupling with

propargyl alcohol. The reaction is carried out with DCC and HOBt as coupling

reagents in CH2Cl2 at room temperature and is stirred for three days. Unconverted

porphyrin remains in the crude product which can be separated by flash

chromatography easily. Because of the decreasing polarity of coupled porphyrin 108

in contrast to porphyrin 107, only acetylene porphyrin 108 is eluted with pure EtOAc.

The 1H NMR spectrum of 108 is illustrated in Figure 70.

The resonances of the ferrocene protons can be detected as two triplets at 4.25 and

4.18 ppm and one singlet at 3.77 ppm. The proton signal of the terminal alkyne turns

Figure 70: 1H NMR spectrum (CDCl3, 400 MHz) of porphyrin 108.

9 8 7 6 5 4 3 2 1 0

*

triazole-H

Fc-H

-CH

-tBu

ppm

β-H

-CH2-

phenyl-H


97

up at 2.61 ppm and features a 4J-coupling (4J = 2.6 Hz) to the methylene unit at

4.96 ppm in close proximity.

After introducing the propargyl group to the porphyrin 107, this ferrocene-porphyrin

conjugate can be connected to another porphyrin to obtain the trimeric system 109.

The reaction is depicted in Scheme 30. Two molecules of 108 are “clicked” to zinc

synazidoporphyrin 58 under optimized “click” conditions.

Work-up can be done by flash chromatography providing the product in the third

fraction. As eluent, a mixture of hexane and THF (2:1) is chosen because otherwise

the starting material cannot be separated well. The first fraction contains non-

Scheme 30: Formation of the porphyrin-ferrocene triade 109 under optimized “click” conditions.


98

converted starting material. The second fraction contains the mono-“clicked” system

bearing one unconverted azide unit.

This by-product as well as the product is first characterized by mass spectrometry,

showing the mass peak as signal with the highest intensity. Figure 71 shows the

MALDI-TOF mass spectrum of the triad 109, where the mass peak can be detected

at m/z = 5075. Furthermore, two fragment peaks occur at m/z = 3015 and 2008 that

accrue after the abstraction of either the ferrocene porphyrin at the ester bond or the

abstraction of the ferrocene porphyrin and the synazidoporphyrin.

Problems occur for the measurement of the 1H NMR and 13C NMR spectra of 109.

The spectra are first measured with CHCl3 but clear signals can only be observed

with THF-d8. This fact is due to aggregate formation. The 1H NMR spectrum shown in

Figure 72 does not allow differentiation between the pyrrolic signals of the two

different porphyrins as the resonances are overlapping. The same occurs for the

resonances of the phenylic protons of both porphyrins. Only the signals of the eight

protons of the annulated phenyl rings of the outer porphyrins can be detected as one

singlet at 6.92 ppm. Two different resonances for the triazole protons emerge at 6.56

and 6.54 ppm; this signal set features an integral of 2:8 protons. The highfield shifted

signals of the methylene groups are monitored at 5.13, 5.11, 4.99 and 4.68 ppm.

Between 4.5 and 3.5 ppm the resonances of the ferrocene rings appear. The

[M]+

Figure 71: MALDI-TOF mass spectra of triad 109; the abstraction of two molecule parts leading to two different fragment peaks.


99

methylene signal at 5.13 ppm, which can be assigned to the methylene group next to

the triazole ferrocene units, as well as one ferrocene signal at 4.29 ppm exhibits a

splitting. This can be due to the orthogonal positions of the ferrocene porphyrin over

the plane of the center porphyrin. This results in a difference of the two sides of the

ferrocene porphyrin.

Figure 72: 1H NMR spectrum (THF-d8, 400 MHz) of porphyrin 109.

**

-CH2-

-Fc-H

-CH3

-tBu

triazole-H

-CH2-

phenyl-Hβ-H

9 8 7 6 5 4 3 2 1 0ppm


100

3.9 Synthesis of a Novel A2B2-Porphyrin-System and its Functional-

ization by “Click” Chemistry

For the selective introduction of structural elements to porphyrins, a porphyrin with

different functional groups must be prepared. Therefore, bismethoxy dipyrromethane

45b is converted with 4-hydroxybenzaldehyde under acid catalysis (TFA) to generate

porphyrin 110. The reagents are dissolved in CH2Cl2, TFA is added and the mixture

is stirred for one hour. Subsequently, NEt3 and one minute later DDQ are added and

the mixture is stirred for two more hours. The crude product can be separated from

excessive DDQ and higher oligomers by filtration though a silica plug. Pure porphyrin

110 is obtained by flash chromatography with CHCl3. CHCl3 turns out to be the better

solvent as CH2Cl2 because of the better solubility of 110 in CHCl3.

The removal of non-converted 4-hydroxybenzaldehyde leads to problems as it cannot

be separated completely by flash chromatography. Therefore, the product is washed

with MeOH, whereby the aldehyde is dissolved and can be rinsed off the porphyrin.

A few modifications are made on the synthesized porphyrin 110 which are illustrated

in Scheme 32. First, tetrakismethoxyporphyrin 110 is converted with HBr (33% in

HOAc) to introduce the bromo substituents as good leaving groups. This process is

followed by an ether forming reaction at the phenolic position with propargyl bromide.

K2CO3 is used as base and acetone as solvent. Propargyl bromide is used in a huge

excess in order to prevent the by-reaction of the porphyrin‟s bromide groups and the

hydroxyl groups of the porphyrin. After evaporating off the solvent, redissolving of the

residue in CHCl3, all was removed of K2CO3. The solution is washed twice with water

Scheme 31: Synthesis of A2B2-porphyrin 110.

110

45b

45b


101

and dried with MgSO4. Flash chromatography delivers pure free base porphyrin 112

in the first fraction. The second fraction is a by-product: the porphyrin connected to

only one propargyl ether.

Metalation with zinc is performed with Zn(OAc)2 in THF as solvent. Stirring the

solution at reflux for five hours delivers 112 after the usual work-up procedure.

The spectrum of this A2B2 system is illustrated in Figure 73.

The signal of the terminal protons of the acetylene groups can be monitored at

3.15 ppm and the resonances of the methylene groups next to the acetylene group at

-CH2- -CH

b-H

ortho

meta

- tBu

-CH2-

* *

9 8 7 6 5 4 3 2 1 0

ppm

Figure 73: 1H NMR spectrum (400 MHz, THF-d8) of bispropargyl porphyrin 112.

Scheme 32: Subsequent modification of porphyrin 110 to bispropargyl porphyrin 112.


102

5.05 ppm. Both signals show a splitting due to the coupling over four bonds which

shows a small coupling constant with 4J = 2.4 Hz.

3.9.1 Dendritic Functionalization of Bispropargyl Porphyrin 112

To apply Newkome dendrimer 1st generation in a “click” reaction, it has to exhibit an

azide unit. This azide can be introduced via a C4-spacer as it is shown in Scheme 33.

4-Bromobutyryl chloride 113 is converted with Newkome dendron 1st generation

furnishing dendritic system 114. This reaction is carried out in CH2Cl2 with an

equimolar amount of pyridine to bind the formed HCl. Pure 114 is obtained after flash

chromatography as white solid. The bromide-azide substitution reaction is performed

in DMF with NaN3 and the mixture is stirred for twelve hours at 50°C delivering 116.

At this point, this system can be used for “click” reactions. A2B2-porphyrin 112 and di-

t-butyl-4-(4-azidobutaneamido)-4-(3-t-butoxy-3-oxopropyl)heptanedioate 116 can

react arising in conjugate 117 (Scheme 34).

In every case when applying the “click” reaction on bis-annulated systems, the mono-

“clicked” system occurs as by-product. In this case, only traces of this by-product are

formed, which can be removed easily by flash chromatography. Substitution of the

bromides in porphyrin 117 with azide units is performed under complete conversion

with NaN3 in DMF. Thus, no flash chromatography is necessary for the work-up

procedure, the purification can be done in a few simple steps: After pouring the

reaction mixture into a mixture of ice and saturated NH4Cl-solution, the precipitate

can be filtered off. Then it is redissolved in CH2Cl2. After washing the organic layer

several times with water, drying with MgSO4 and distilling of the solvent under

reduced pressure, the pure porphyrin 118 is obtained. The spectrum of 118 after

purification is shown in Figure 74.

Scheme 33: Reaction cascade featuring the Newkome dendron 1st

generation with an azide.


103

The significant change in the spectrum, compared to the other spectra of triazole

porphyrins in this work, is the chemical shift of the resonance of the triazole protons,

which turns up at 8.12 ppm. This is caused by the different location of these triazole-

protons: they are in the para-position of the tetraphenylporphyrin and additionally an

OCH2-unit is interposed between the porphyrin and the triazole.

Thus, the diamagnetic ring current of the porphyrin has no influence on the chemical

shift of these triazole protons. The triazole resonance emerges in the aryl region and

Scheme 34: Synthesis of bromo conjugate 117 and azido conjugate 118.

Figure 74: 1H NMR spectrum (400 MHz, THF-d8) of azido conjugate 118.

9 8 7 6 5 4 3 2 1 0ppm

*-CH2- -CH2-

b-Hortho

meta

- tBu

*

- tBu

-NH-

triazole-H


104

overlaps with a doublet of the ortho-protons of the para-substituted aryl rings. The

resonances of the spacer protons appear in the same region as the dendritic protons

(0.5-2.5 ppm) and cannot be assigned clearly. The NH protons can be monitored as

broad singlets at 6.78 ppm. Two different t-butyl group signals turn up in the

spectrum, one for the dendritic moiety and one for the phenylic t-butyl groups.

3.9.2 Ferrocene Conjugates Generated from the Novel A2B2-Porphyrin

Compound 118 is reacted with ethynyl ferrocene furnishing the tetrakisferrocenyl

conjugate 119 as well as with dipropargyl ferrocene dicarboxylate 74 leading to the

double-bridged systems 120.

The synthesis of 120 is carried out with two equivalents of 74 under high dilution to

avoid polymerization. The product turns out to be quite polar and the purification can

be achieved by repeated flash chromatography with a mixture of CHCl3 and EtOAc

(2:1) as eluent. Finally, only small amounts of 120 can be obtained purely.

Formation and preliminary purification of the tetrakisferrocenyl conjugate 119 works

better, because 119 is the only product that is formed in that reaction. The flash

chromatography is started with CHCl3 as eluent, whereas excessive ethynyl

ferrocene can be removed followed by successive addition of MeOH to the eluent

until the product can be obtained.

Figure 75: Different conjugates formed of 118 by “click” reactions.

119

120


105

The formation of the two conjugates can be proved by the 1H NMR spectra depicted

in Figure 76. Both spectra show two different triazole signals; one emerging from the

triazole linkage to the dendrons and one resulting of the triazole rings connected to

the ferrocene moieties. In the case of 119 those two signals can be detected at 8.05

and 6.28 ppm. The other system shows those two triazole signals at 7.44 and

3.75 ppm. In each case, the signal which is shifted more lowfield can be assigned to

the triazole units connected to the dendritic spacer. Moreover, the resonances of the

ferrocene rings of 120 are again shifted to higher field due to the higher influence of

the porphyrin ring current.

The signals of the different methylene groups are overlapping and are detected

between 1 and 2.5 ppm as multiplets. One signal of a methylene group is shifted

lowfield in both spectra: the resonance of the CH2-group next to the ester bond. This

signal can be detected at 4.45 (120) and 3.14 ppm (119).

Figure 76: 1H NMR spectra (400 MHz, CDCl3) of 119 and 120.

119

120

β-H phenyl-H

triazole-H

-CH2-

Fc-H

NH

-tBu

-CH2-

triazole-H

-CH2- -CH2-

-tBu

*

9 8 7 6 5 4 3 2 1 0

*

β-H

triazole-H

Fc-H

-CH2- -CH2-

-tBu

phenyl-H

ppm


106

3.10 Dimers, Trimers and Tetramers Exclusively Constituted of Porphyrins

3.10.1 Synthesis of Two Different Acetylene Porphyrins

Among the plethora of new compounds that have been presented in this work, “click”

chemistry can also be applied to simply connect two or more porphyrins. Based on

the basic porphyrins 56, 57 and 59 and two different acetylene porphyrins 124 and

125, several multiple porphyrin-core-systems are prepared.

4-Propargyloxybenzaldehyde 126 is synthesized from 4-hydroxybenzaldehyde and

propargyl bromide according to a literature procedure.[130] This aldehyde reacts with

pyrrole to A4-porphyrin 124 (Scheme 36) or with t-butylbenzaldehyde and pyrrole to

AB3-porphyrin system 125 (Scheme 35).

Synthesis of 125 works under modified LINDSEY conditions with one equivalent of

4-porpargyloxybenzaldehyde 126, three equivalents of t-butylbenzaldehyde and four

equivalents of pyrrole. As catalyst, BF3∙OEt2 is used. For the work up, the crude-

product is pre-purified by filtration over a silica plug, whereby the formed TTBPP is

partly separated. Final purification is achieved by flash chromatography. The

metalation reaction with zinc is carried out according to the common synthetic

protocol proceeding under full conversion.

A4-porphyrin 124 is synthesized of one equivalent 4-porpargyloxybenzaldehyde 126

and one equivalent of pyrrole furnishing only the porphyrin and no corrol. The work-

up procedure starts with a silica plug and finishes with flash chromatography. The

Scheme 35: Formation of the AB3-acetylene porphyrin 125.


107

free base porphyrin is metallated subsequently with zinc to obtain porphyrin 124 that

is suitable for a “click” reaction.

The 1H NMR spectra depicted in Figure 77 reflect the different symmetries (D4h and

Cs). The β-pyrrolic protons of 124 turn up as one singlet while the β-pyrrolic protons

of 125 appear as one singlet and two doublets. The arylic signals of 124 can be

monitored as two doublets. These protons engender more resonances in the spectra

of 125 and appear as four doublets, whereby two signals overlap.

Scheme 36: Porphyrin synthesis generating A4-system 124.

Figure 77: 1H NMR spectra (CDCl3, 400 MHz) of the acetylene porphyrins 124 and 125

-CH2-

-CH2--CH

-CH

- tBu

*

*

9 8 7 6 5 4 3 2 1 0

ppm

*

*

-CH

-tBu-CH

-CH2-

-CH2-

b-H

b-H

phenyl-H

phenyl-H

125

126


108

3.10.2 Combining Acetylene and Azidoporphyrins to Oligomers

The presented porphyrins 124 and 125 can be converted to different porphyrin

oligomers by applying the 1,3-dipolar Cu(I)-catalyzed cycloaddition.

Monoacetylene porphyrin 125 can be attached to various zinc azidoporphyrins. For

instance, dimeric conjugate 128 is obtained by the reaction of zinc

monazidoporphyrin 56 with 125.

The “click” reaction is carried out under optimized “click” conditions, but complete

conversion is not obtained. Small amounts of both educts still remain in the crude

product even after 48 hours reaction time. After flash chromatography (CH2Cl2), both

educts can be recovered and the desired dimer can be isolated.

Due to aggregation phenomena, no clear spectra can be obtained using CDCl3 as

solvent. Adding one drop of pyridine-d5, the spectrum becomes clearer. Because of

the great amount of signals in the aromatic region it is still challenging to allocate

every signal to a definite proton.

Scheme 37: Dimer formation by “click” reaction.


109

Higher substituted azidoporphyrins also react with acetylene porphyrin, resulting in

larger conjugates. Zinc bisazidoporphyrin 57 and zinc antiazidoporphyrin 59 are used

as starting material for this approach; these porphyrins are converted with a threefold

excess of alkyne porphyrin 125.

The synthesis is carried out according to the optimized “click” procedure presented in

Chapter 3.2. In both cases, a by-product is formed that can be identified as the

mono-“clicked” porphyrin dimer.

Flash chromatography is used in order to separate the different porphyrins, whereby

the trimeric porphyrins can be obtained in 50% (127) and 45% (126) yield.

The products can be characterized by FAB mass spectrometry, whereby only the

mass peak is detected in both cases. Porphyrin trimer 126 shows the highest peak at

m/z = 2841 and porphyrin trimer 127 at m/z = 2813.

Well-resolved NMR spectra can be recorded in CDCl3 after the addition of one drop

of pyridine-d5. The spectra of both trimers are presented in Figure 79. Due to the

amount of different signals in the arylic region and the low symmetry, a clear

assignment of all signals is rarely possible. Also, the corresponding HETCOR-, Cosy-

and DEPT NMR spectra cannot solve this problem completely.

-CH2-

-CH2--CH

-CH

- tBu

*

*

9 8 7 6 5 4 3 2 1 0

ppm

*

*

-CH

-tBu-CH

-CH2-

-CH2-

b -H

b -H

phenyl-H

phenyl-H

Figure 78: Trimeric compounds generated of zinc azidoporphyrin 57 or 59 with 125.

126 127


110

In addition, triazole linked pentamers can be obtained based on the presented basic

building blocks in two ways (Figure 80): A4-alkyne porphyrin is converted with zinc

monoazidoporphyrin 56 or zinc tetrakisazidoporphyrin 60 with zinc

monoacetyleneporphyrin 124.

Both reactions are carried out with a six fold excess of the monoazido or monoalkyne

porphyrin. The reaction proceeds according to the optimized “click”-conditions and

each reaction mixture is checked via TLC after stirring for twelve hours. The crude

product of the reaction leading to pentamer 128 shows four spots on the TLC plate

N3

N3 N3

N3

N3

N3

Figure 79: 1H NMR spectra (400 MHz, CDCl3, pyridine-d5) of 126 and 127.

128 129

126

127

Figure 80: Two possibilities to build up a triazole linked pentamer.

9 8 7 6 5 4 3 2 1 0

ppm

-CH2-

-CH2-

- tBu

-CH3

- tBu

*

*

*

*

b-H

phenyl-H

b-H

phenyl-H

-triazole-H

-triazole-H


111

(silica, CH2Cl2/EtOAc; 50:1): beside not converted educt, a few by-products occur in

this process.

The TLC plate (toluene) of the second reaction to pentamer 129 shows only two

spots: one spot of unconverted (this component was added in excess) zinc alkyne

porphyrin is running with the solvent front and a second spot remains on the

baseline. This reaction or the synthesis of a pentamer seems to lead to full

conversion, while reaction to 128 leads to a lot of by-products.

The purification of pentamer 129 proceeds smoothly by flash chromatography

(toluene/MeOH; 200:1100:1), as the excessive starting material can be seperated

easily due to its different polarity. First the excessive monomer can be reobtained in

the first fraction with the solvent mixture toluene/MeOH (200:1). The pentamer

remains on the column and can be removed by adding more MeOH to the eluent.

Thus, no by-products occur and the molecule with a molecular weight of 4725 g/mol

can be obtained in an excellent yield of 93%.

In contrast to that, the seperation of 128 from the diverse by-products offers problems

and does not suceed even after repeated flash chromatography. Although the

Figure 81: Pentamers 128 and 129.

128 129


112

formation of 128 can be proofed by mass spectrometry of the crude product, no pure

pentamer 128 is isolated.

The successful formation of pentamer 129 may be due to the position of the azide

units in porphyrin 60. Because of the ortho-position of the four azide units, the

autocatalytical process observed for the highly-substituted porphyrins (71/72 and

83/84) occurs also in this reaction. Since the alkyne units of porphyrin 124 are in

para-position the interspaces between the single reaction centers is too large for this

self-activation.

As pentamer 129 shows a higher symmetry as the trimeric systems 126 and 127, the

1H NMR spectrum is better resolved compared to the trimers‟ ones. In that case, the

signals can be assigned to the different protons. The eight β-pyrrolic protons of the

inner porphyrin appear as two doublets (red) at 9.06 and 8.61 ppm. The β-pyrrolic

protons of the four outer porphyrins (dark red) turn up as a multiplet and one doublet

at 8.72 ppm. The resonances of the arylic protons appear in doublets and can be

assigned to the protons via the different integrals. The four triazole protons can be

monitored at 6.58 ppm. Not depicted in Figure 82 are the resonances of the

methylene groups and the t-butyl groups as the interesting region of this spectrum is

9 8 7 6ppm

b-H

ortho

meta

b-H

ortho meta

meta

ortho triazole-H

Figure 82: Aromatic region of the 1H NMR spectrum (400 MHz, THF-d8) of pentamer 129.


113

the aromatic one. This approach to synthesize [4:1]pentamers in very high yields is

very interesting because in this way it should be possible to synthesize conjugates

with different metals in the core porphyrin and the outer porphyrins. These porphyrin

pentamers can feature exciting redox properties. In contrast to azidoporphyrins, the

insertion of other metals than zinc should be possible for alkyne porphyrin 125. Thus,

conjugates with zinc in the center porphyrin‟s core and iron or manganese in the

outer porphyrins‟ core can be generated.

The UV/Vis spectra of the different oligomers are depicted in Figure 83, showing the

different extinction coefficients of the conjugates 126, 127, and 129, respectively. The

extinction coefficient of the pentamer‟s SORET absorption with a value of 1701200

lmol-1cm-1 is the highest due to five porphyrin moieties. The SORET band of the

dimeric and trimeric system features an extinction coefficient of 624400 and 1042700

lmol-1cm-1. Furthermore, a slight bathochromic shift can be observed for 129, where

the SORET band is detected at 426 nm. 126 and 127 exhibit the maximum of this

absorption at 423 nm.

Figure 83: UV/Vis spectra in THF of the oligomers 129, 126 and 127.

0

1

2

0.5

1.5

400 600500300l [nm]

e [

10

6·l

·cm

-1·m

ol-1

] 129

127

126


114

3.11 Side-Selective Modification of Porphyrins

Once a triazole unit is formed on one side of the porphyrin plane, it stabilizes the

catalytically important Cu(I) oxidation state. Due to this observation, the formation of

the next triazole ring should be preferred selectively on one porphyrin side. Thus, it

could be possible to attach different functional groups on the different porphyrin

sides. Hydrophilic and hydrophobic sides can be created in a regioselective manner.

The regioselective cycloaddition can be achieved by using a stoichiometrical

deficiency of the acetylene compound.

Therefore, the first attempts are performed with zinc tetrakisazidoporphyrin 60 and

the asymmetric dendritic ferrocene derivative 75. In the case of a side-specific

reaction of ferrocene compound 75, the other side can be modified in a subsequent

reaction with another substrate.

As first approach, two equivalents of 75 were added to the zinc

tetrakisazidoporphyrin 60 and the reaction is performed according to the optimized

“click” conditions. Controlling the reaction by TLC after stirring for twelve hours at

40°C, it turns out that there is still unconverted educt in the reaction mixture and

further three different ferrocene porphyrin products are formed (see Figure 86).

Figure 84: Concept of modifying one side of the porphyrin with either the eight fold or the four fold substituted system.

upper side

lower side


115

Besides the tetrakis(ferrocenyltriazolyl) and the tris(ferrocenyltriazolyl) porphyrin,

three different bis(ferrocenyltriazolyl) porphyrins can be built up (see Figure 85). One

of those is the desired syn-product and the other two are the bis- and the anti-

isomers. Some of these by-products could have been generated in this process. Due

to the similar properties of these isomers the separation is quite exhausting. In

addition, amounts of not desired porphyrins are generated which reduces the

formation of the syn-isomer.

To improve the reaction, only one equivalent per porphyrin of 75 is added and the

“click” reaction is performed as usual. After stirring for one day at 40°C, the TLC of

the crude product shows only the formation of one product as well as unconverted

azidoporphyrin. The product can be separated from the starting material by flash

chromatography delivering the 1H NMR spectrum presented in Figure 87.

Scheme 38: Side-selective modification of zinc tetrakisazidoporphyrin 60.

Figure 85: Bis-isomers that can occur in the reaction in Scheme 38

syn anti bis


116

The splitting pattern of the aryl protons clearly shows the difference between the

upper and the lower side as an ABCD-system results for the protons of the

unsubstituted aryl rings. Furthermore, two different signals for the CH2-groups next to

the phenyl rings can be monitored. One resonance appears at 5.09 ppm, which can

be assigned to the methylene group next to the triazole moieties and one turns up

shifted to higher field at 3.79 ppm which is next to the azide units. The integrals of the

signals of the triazole linked ferrocene units show that only two units are linked.

2 eq 75 1 eq 75

product

azido educt

Figure 86: TLC plates of the reaction of zinc tetrakisazidoporphyrin 60 with different stoichiometrical amounts of the alkyne component 75

Figure 87: 1H NMR spectrum (400 MHz, CDCl3) of 130.

CH2Cl2:EtOAc 5:1

9 8 7 6 5 4 3 2 1 0

*

ppm

-CH2-

-NH-

-tBu

triazole-H

-FcH

-CH2--CH2-

β-H

phenyl-H

-tBu


117

The same approach is carried out with zinc octakisazidoporphyrin 55 as it is shown in

Scheme 39. The right amount of ethynyl ferrocene to obtain 131 has to be

determined again.

As first attempt, four equivalents of ethynyl ferrocene are used leading to the

formation of several products as observed by TLC. Improvements can be achieved

by reducing the amount of ethynyl ferrocene to two equivalents. But best results are

obtained with only 1.5 equivalents. The TLC plates after each reaction are depicted

in Figure 88.

Thus, the spot supposed to be the product spot is the biggest. Furthermore, only

traces of by-products occur. After the separation by flash chromatography the

1H NMR spectrum presented in Figure 89 is obtained. The resonance of the β-

Figure 88: TLC plates of the reaction in Scheme 39 with different stoichiometrical amounts of ethynyl ferrocene

Scheme 39: Side-selective modification of zinc octakisazidoporphyrin 55

1.5 eq ethynyl ferrocene4 eq ethynyl ferrocene 2 eq ethynyl ferrocene

CH2Cl2:EtOAc 4:1

product

azido educt


118

pyrrolic protons appear as a singlet which remains unchanged compared to the

octakis(triazolylferrocenyl) conjugate 83. But a change can be observed for the

resonance of the arylic protons emerging in this case as two singlets, which should

provide an indication for the selective triazole formation on one side of the porphyrin

plane. These protons appear as one singlet in the spectrum of

octakis(triazolylferrocenyl) porphyrin 83. The formation of four triazole rings is proven

further by the integrals of the triazole signal and the signals of the ferrocene ligands.

Concerning the β-pyrrolic protons, only four triazole protons exist in this compound

as well as only 36 protons for the ferrocene rings can be counted.

The two different methylene groups next to the triazole unit and next to the azide unit

turn up as two separate signals at 4.91 and 3.89 ppm.

Although, it can be assumed that the triazole formation only occurs on one porphyrin

side due to the self activation of the triazole units, this structure cannot be ensured

completely. Another isomer with D2h-symmetry shown in Figure 89 would result in the

same 1H NMR spectrum, a crystal structure is necessary to determine the absolute

structure. Many attempts with different solvents were carried out in order to get

suitable crystals, but until now, these approaches have unfortunately not succeeded.

Figure 89: 1H NMR spectrum obtained after the reaction of 55 with 1.5 equivalents of ethinyl ferrocene

9 8 7 6 5 4 3 2 1 0ppm

*

b-H

meta triazole-H-CH2-

- tBu

-FcH

-CH2-


119

Problems occurred for consecutive “click” reactions on porphyrin 130. No conversion

is observed here. The IR spectrum of this compound does not show a clear azide

band. Furthermore, the mass spectrum obtained for porphyrin 130 shows a peak at

m/z = 2478 although the molecular ion peak should appear at m/z = 2510. The

typical peak pattern concerning azidoporphyrins, which has been observed for the

basic azidoporphyrin systems, consists of the molecular ion peak and a fragment

peak that appears after splitting off N2. In the present cases, only the peak after the

complete cleavage of N3 can be detected. These facts underline the theory that the

azide moieties have split off or are unreactive due to inter- or intramolecular

interactions.

In contrast to that, porphyrin 131 shows the molecular peak in the MALDI-TOF mass

spectrum at m/z = 2184. Furthermore, in this case, the azide band in the IR spectrum

is more pronounced.

Figure 90: Possible Isomers which would lead to the spectrum shown in Figure 89

D4v C2h

Conclusion and Highlights

120

4 Conclusion and Highlights

The concept of the 1,3-dipolar “click” alkyne-azide cycloaddition was successfully

applied to the ortho-benzylic fuctionalized tetraphenylporphyrins developed by JUX in

2000.[84] As the further modification of these porphyrins is indispensable the

SHARPLESS[10] 1,3-dipolar “click” cycloaddition was optimized for these basic

porphyrins in order to obtain good yields and easy working procedures. Thus, over 40

sophisticated and complex molecular structures were prepared. All of these new

compounds feature the triazole ring as binding motif. The optimized reaction

conditions were determined successfully to be CuSO4∙H2O as Cu(I) source and

sodium ascorbate as reducing agent. As solvent, a mixture of CH2Cl2, ethanol and

water delivered the best results. Very important is the addition of the sterical

demanding base N,N‟-diisopropylethylamine, which increases the yield enormously.

Thus, diverse acetylene compounds were attached to various azidoporphyrins with

different symmetries.

The porphyrins synthesized by JUX et al.[84, 85] turned out to be favorable precursors

for this reaction class as the azido functionalized derivatives can be generated in a

few easy steps which all proceed under full conversion. The fundamental methoxy

porphyrins were converted with HBr (33% in HOAC) to the corresponding bromo

compounds which offer a better leaving group. In a second step the azido groups,

necessary for the SHARPLESS alkyne-azide coupling, were introduced. In this manner,

tetraphenylporphyrins with up to eight azido units in the ortho-benzylic positions can

be obtained easily. As acetylene compounds ethynyl ferrocene, phenyl acetylene and

a dendritic ferrocene alkyne conjugate were chosen and were reacted with the

different azidoporphyrins. The last mentioned conjugate is generated by the

asymmetric coupling of 1,1‟-ferrocene dicarboxylic acid with propargyl alcohol and

with the NEWKOME dendron 1st generation.[113] Thus, a plenitude of triazole connected

porphyrin conjugates was prepared. This modified “click” method allowed the easy

attachment of new functional groups to the basic porphyrins. The yields of the less

often functionalized systems (mono- and bis-substituted porphyrins) were satisfactory

with around 60%, but excellent results were achieved for the highly-substituted

systems (tetra- and octa-substituted porphyrins). These reactions proceeded with

complete conversion, which means that the yield for each single reaction center on


121

the porphyrin is higher than 99%. An autocatalytical mechanism and the stabilization

of the catalytically active Cu(I)-species by the triazole moieties were supposed to be

the reason for this excellent success. The structures of these systems were

determined by NMR spectroscopy as well as by mass spectrometry. The ferrocene

conjugates were also examined via cyclic voltammetry as the ferrocene unit offers

interesting electrochemical behavior.

The highly-substituted ferrocenyltriazolyl porphyrins bearing a dendritic NEWKOME

dendron moiety could be dissolved in water after the cleavage of the t-butyl esters.

The porphyrin systems with less dendritic ferrocenyltriazolyl groups did not have

enough carboxylic acids to dissolve these huge compounds in water. Thus, a larger

dendritic moiety with nine t-butyl esters was synthesized and used for the bis-

substituted systems. After cleavage of the esters, 18 carboxylic acid groups were

produced in the porphyrin environment, which was sufficient to give the desired water

solubility.

In addition, different metals, such as iron, manganese, nickel or copper were inserted

into the core of the highly-substituted ferrocene porphyrins. Therefore, the zinc

ferrocene porphyrins were first synthesized. Then the zinc ion was removed by acid

treatment and afterwards the desired metal can be inserted according to well-known

synthetic procedures. Above all, the metallo ferrocene porphyrins with a redox-active

center, such as the manganese(III) or iron(III), are very interesting systems. For

instance, a huge molecular structure with eight ferrocene moieties in the porphyrin

environment and one iron center in the porphyrin core can be formed. This porphyrin

features an extremely high density of iron ions. The metallo-conjugates built of

ferrocene porphyrins with dendritic NEWKOME dendron groups were converted into the

water-soluble porphyrin by splitting the t-butyl esters. This is important seeing the

generation of water-soluble metallo porphyrins is vital to mimic natural processes.

Since this “click” approach turned out to work very well with the JUX porphyrins

bridged porphyrins modeled on BALDWIN‟S capped porphyrins were created. As

bridging unit ferrocene or a dendritic compound were used and anchored to the azido

groups of two different azidoporphyrins. In this way, simple- and double-capped

ferrocene porphyrins as well as simple- and double-capped dendritic porphyrins were

formed. The electrochemical properties of these systems were investigated via cyclic


122

voltammetry and showed an astonishing additional oxidation step, whose origin can

be found in the strained configuration of the porphyrin.

The capability of the 1,3-dipolar “click” reaction with our porphyrin systems was

underlined by creating oligomers consisting of different porphyrins. An array of

conjugates built up of different porphyrins, ferrocene units and dendritic NEWKOME

branches was generated. One approach, for instance, was the synthesis of a

pentamer consisting of one porphyrin in the core and four porphyrins attached to it. A

tetrakisazidoporphyrin was used as core porphyrin and four alkyne porphyrins were

connected via the 1,3 dipolar SHARPLESS cycloaddition. Due to the autocatalytical

process caused by the ortho-position of the azido groups this reaction gave full

conversion. Other examples for synthesized oligomers are porphyrins which are

linked via a ferrocenyltriazolyl bridge or dendritic ferrocenyl-bridged porphyrins.

At last, a long desired approach was realized with this Cu(I)-catalyzed alkyne-azide

coupling on the azidoporphyrins: the side-selective functionalization of the tetrakis

and octakisazidoporphyrin. This synthesis is challenging due to a lot of isomers that

can be formed when the porphyrins are not converted on every of its four or eight

reaction centers. By taking the right stoichiometrically deficient proportion of the

alkyne compound, the triazole units were built only on one side of the porphyrin

plane. Thus, the side-selective modification was carried out successfully via the

“click” approach. The side-selective functionalization can clearly be determined via

the NMR spectra which prove the difference between the upper and the lower side of

the porphyrin plane. Thus, hydrophilic and hydrophobic groups can be attached to

the highly-substituted porphyrin in a regioselective manner.

Zusammenfassung

123

5 Zusammenfassung

Im Rahmen der vorliegenden Arbeit wurde die 1,3-dipolare SHARPLESS[10] Alkin-Azid

Cycloaddition sehr erfolgreich auf die von JUX im Jahr 2000[84] vorgestellten ortho-

benzylisch substituierten Tetraphenylporphyrinen übertragen. Durch diese Reaktion

gelang es, über 40 komplexe und anspruchsvolle Moleküle in sehr guter Ausbeute zu

synthetisieren. Als gemeinsames Verknüpfungsmotiv besitzen diese Strukturen den

durch die Cycloaddition gebildeten Triazolring. Dabei wurden die

Reaktionsbedingungen auf die Umsetzung mit den vorliegenden ortho-

funktionalisierten Porphyrinen erfolgreich optmimiert und bestimmt. Als Cu(I)-Quelle

wurde CuSO4∙5 H2O verwendet, welches in situ durch Natriumascorbat reduziert

wurde. Eine Mischung aus CH2Cl2, EtOH und Wasser diente als Lösungsmittel und

als zusätzliche Base lieferte N,N„-Diisopropylethylamin die besten Resultate. Auf

diese Weise konnten verschiedene Alkinkomponenten an die entsprechenden

Porphyrine gekoppelt werden und so eine Fülle an komplizierten Porphyrinstrukturen

mit verschiedenen Symmetrien erhalten werden.

Die Azidopophyrine, welche die Ausgangsverbindungen für die entsprechenden

„Click“ Reaktionen sind, wurden sehr einfach aus den von JUX et al.[84, 85]

vorgestellten ortho-benzylisch funktionalisierten Porphyrinen erhalten. Die

Umsetzung gelang in drei quantitativ verlaufenden Reaktionsschritten: Zuerst wurden

die benzylischen Methoxygruppen durch Bromide ersetzt, welche für die

nachfolgende Substitution eine bessere Abgangsgruppe boten. Anschließend

wurden die Azidoeinheiten ebenfalls durch eine nukleophile Substitution an das

Porphyrin gebunden. Diese, durch einfache Synthesen hergestellten,

Azidoporphyrine dienten als Vorstufe für die Anwendung der 1,3-dipolaren

SHARPLESS Cycloaddition. Als Alkinkomponente wurden Phenylacetylen,

Ethinylferrocen und ein dendritisches Ferrocenderivat eingesetzt. Letzteres konnte

durch die asymmetrische Kopplung von 1,1„-Ferrocendicarbonsäure mit

Propargylalkohol und dem NEWKOME Dendron[113] der ersten Generation dargestellt

werden. Bei den durchgeführten „Click“ Cycloadditionen fiel auf, dass die Ausbeuten

je Reaktionszentrum zunahm, desto mehr Substituenten das Porphyrin trägt. So

verlief die Umsetzung von einfach und doppelt funktionalisierten Azidoporphyrinen

mit etwa 50 - 60% zwar mit einer zufriedenstellenden Ausbeute, doch eine

Zusammenfassung

124

quantitative Umsetzung wurde für die Reaktion der hochsubstituierten Systeme (vier

und achtfach funktionalisierte Porphyrine) beobachtet. Als Erklärung hierfür wurde

ein autokatalytischer Prozess postuliert, der durch die steigende Anzahl an

Triazoleinheiten hervorgerufen wird. Die Triazolringe können das katalytisch-aktive

Cu(I) stabilisieren, was zu einer signifikanten Verbesserung der Ausbeute führt.

Weiterhin wurden wasserlösliche Konjugate der Ferrocenporphyrine erzeugt. Hierfür

wurden die t-Butylester der NEWKOME Dendrimere sauer gespalten. Durch die freien

Carbonsäuren besaßen die Porphyrine Wasserlöslichkeit in leicht basischem

Medium. Für die niedrig funktionalisierten Systeme musste ein größerer dendritischer

Rest eingeführt werden. Anstatt der ersten Generation des NEWKOME Dendrons

wurde hier die zweite Generation verwendet, aus der pro Einheit neun freie

Säuregruppen gebildet werden können. Dies führt auch bei den niedrig-substituierten

Systemen zu einer verbesserten Wasserlöslichkeit. Als Zentralatom wurden in die

entsprechenden Porphyrine statt Zink auch andere Metalle wie Eisen, Mangan,

Nickel oder Kupfer eingesetzt. Ein Beispiel hierfür ist das achtfach substituierte

Ferroceneporphyrin mit Eisen als Zentralatom, welches in einem geringen Volumen

eine sehr hohe Dichte an Eisenzentren besitzt. Auch diese Konjugate konnten durch

Abspaltung der t-Butylgruppen in Wasser gelöst werden, was wichtig ist, um

natürliche Prozesse zu imitieren.

Aufgrund der guten Ergebnisse, wurden überbrückte Porphyrinsysteme nach dem

Beispiel von „BALDWINS capped porphyrin“[82] synthetisiert. Als Brückeneinheit wurde

ein Ferrocendialkin und ein dendritisches Dialkin verwendet, welche jeweils an den

Azidogruppen des Porphyrins verankert wurden. Dieser Ansatz gelang mit dem

zweifach substituierten syn-Porphyrin und dem vierfach substituierten Porphyrin. Auf

diese Art und Weise konnten einfach und doppelt verbrückte Porphyrine in guten

Ausbeuten erhalten werden. Die elektrochemischen Eigenschaften dieser Konjugate

wurden mit Hilfe von zyklischer Voltammetrie untersucht. Zu den typischen zwei Ein-

Elektronen-Oxidationen des Porphyrins wurde bei diesen Systemen eine zusätzliche

Oxidation detektiert, deren Ursache die verzerrrte Konfiguration der Porphyrine ist.

Weiterhin wurde durch die „Click“ Chemie eine Reihe von oligomeren Konjugaten

aus verschiedenen Porphyrinen synthetisiert. Einerseits gelang es Oligomere, die

durch Ferroceneinheiten verknüpft sind darzustellen andererseits wurden auch

verschiedene Porphyrine durch Triazolringe zu höheren Konjugaten verknüpft.

Zusammenfassung

125

Die Idee der einseitigen Funktionalisierung an den beiden verschiedenen Seiten des

Porphyrins konnte durch die optimierte „Click“ Reaktion verwirklicht werden. Durch

den richtig-berechneten stöchiometrischen Unterschuss wurde der Triazolring nur an

einer Seite der Porphyrinebene gebildet. Dadurch können verschiedene

Substituenten auf beiden Seiten eingeführt werden und die beiden Ebenen selektiv

modifiziert werden. So kann durch die SHARPLESS Cycloaddition z. B. eine hydrophile

und eine hydrophobe Halbsphäre um das Porphyrin erzeugt werden.

Experimental Section

126

6 Experimental Section

6.1 Chemicals, Methods and Equipment

The chemicals used in this work are purchased from SIGMA-ALDRICH, FLUKA, ACROS

ORGANICS and ALFA AESAR and are used without further purification.

Dichloromethane, chloroform, ethyl acetate, acetone, ethanol and toluene are freshly

distilled from K2CO3 via evaporation rotary, methanol and THF are distilled from

CaCl2. THF and DMF for the reactions are purchased from ACROS ORGANICS (HPLC

grade).

Thin Layer Chromatography (TLC) is carried out on aluminum sheets coated with

silica 60 F254 purchased from MERCK. Visualization is performed by using an UV

lamp (254 or 366 nm) or by developing with a Ce(SO4)2-solution (25 g

phosphomolybdenum acid, 10 g Ce(SO4)2, 60 mL H2SO4, 940 mL H2O).

Flash Column Chromatography (FC) is performed on silica 60 (230-400 mesh,

0.04-0.063 nm) purchased from MACHEREY-NAGEL. Eluents are purified in

advance as mentioned above.

NMR Spectroscopy is conducted on machines from JEOL (EX 400, GX 400) or

BRUKER (AVANCE 300, AVANCE 400). The chemical shifts are given in ppm with

the used solvents as references; CDCl3 is set on 7.26 ppm (77 ppm in the

13C NMR spectra) and THF-d8 on 3.58 ppm (67.6 ppm in the 13C NMR spectra) and

1.73 ppm. Multiplicities are denoted “s” (singlet), “d” (doublet), “t” (triplet), “m”

(multiplet) or as combinations thereof. Signals annexed “br.” are not clearly resolved

or significantly broadened. Peripheral aryl moieties are referred to as “Ar” or “Ar*”,

whereby “Ar*” labels the higher substituted aryl ring. The raw data was processed by

using MESTREC[131] for the 13C NMR spectra or ACD Labs[132] for 1H NMR spectra or

HETCOR and COSY spectra.

IR Spectroscopy is performed on an ASI React IR 1000 (Analytical Services Inc.).

UV/Vis Spectroscopy is conducted on a Shimadzu UV-3102 PC UV/Vis/NIR

Scanning Spectrophotometer or a SPECORD® S 600 spectrophotometer (Analytik

Jena AG); processing was done with Origin 8G.


127

Mass spectrometry (MS) is done on either a MIRCOMASS ZABSPEC spectrometer

(FAB+ mode, 3-nitro benzylic alcohol (NBA) as matrix) or on a Shimadzu AXIMA

Confidence spectrometer (MALDI-TOF, linear mode, as matrices 2,5-

dihydroxybenzoic acid (DHB), trans-2-(3-(4-t-butylphenyl)-2-methyl-2-propenylidene)-

malononitrile (DCTB) or sinapic acid (sin) are used).

Elemental Analysis (EA) is done on a CE INSTRUMENTS EA 1110 CHNS.

X-Ray Measurements are performed on BRUKER NONIUS KAPPA CCD (MoKα-

radiation); λ = 0.71073 Å; the visualization is done with Ortep and Mercury[133].

Calculations are performed by utilization of SPARTAN®130[134] on the semiempirical

PM3 level. The Visualization by Raytracing is performed with PovChem[135] and POV-

Ray™[136].

Cyclic Voltammetry Measurements are performed on an Autolab Instrument with

PGSTAT 30 in a three electrodes arrangement (Deutsche Metrohm GmbH & Co.

KG): measuring electrode: gold disc electrode (0.07 cm2); counter electrode: Pt wire;

reference electrode: Ag/AgCl (3M NaCl) at constantly 25°C in CH2Cl2 solution

(electrochemistry grade). Scan rates: ν = 0.1 V/s. Supporting electrolyte: n-Bu4NPF6

at c = 0.1 M. Half-wave potentials are determined vs. ferrocene with

E(Fc/Fc+) = +0.53 V (or vs. Fc*; E(Fc*/Fc*+) = -0.03 V) as internal standard.

Precursors and Basic Building Blocks

The precursors, methoxy- and bromoporphyrins are synthesized according to

literature procedures:

4-t-butyl-2,6-dimethyl-bromobenzene 41[86, 87]

2-(bromomethyl)-4-t-butyl-6-methyl-bromobenzene 42a and 2,6-bis-(bromo-

methyl)-4-t-butyl-bromobenzene 42b[89]

4-t-butyl-2-(methoxymethyl)-6-methyl-bromobenzene 43a and 4-t-butyl-2,6-bis-

(methoxymethyl)-bromobenzene 43b[90]

4-t-butyl-2-(methoxymethyl)-6-methyl-benzaldehyde 44a[85, 93] and 4-t-butyl-2,6-

bis-(methoxymethyl)-benzaldehyde 44b[84]

54-t-butyl-52-(methoxymethyl)-56-methyl-5-phenyldipyrromethane 45a[85, 93] and

54-t-butyl-52,56-bis-(methoxymethyl)-5-phenyldipyrromethane 45b[94]

t-butyl 2-(4-formy-phenoxy)acetate 101[137, 138]


128

4-acetylenehydroxybenzaldehyde 126[130]

NEWKOME dendron 1st generation[113, 139]

NEWKOME dendron 2nd generation[113, 139]

Methoxyporphyrins

54,104,154,204-tetra-t-butyl-52-(methoxymethyl)-56-methyl-5,10,15,20-tetraphenyl-

porphyrin (monomethoxy porphyrin) 46[85, 93]

54,104,154,204-tetra-t-butyl-52,56-bis(methoxymethyl)-5,10,15,20-tetraphenyl-

porphyrin 47[95]

syn-54,104,154,204-tetra-t-butyl-52,152-bis(methoxymethyl)-56,156-dimethyl-

5,10,15,20-tetraphenylporphyrin 48[85, 93]

anti-54,104,154,204-tetra-t-butyl-52,152-bis(methoxymethyl)-56,156-dimethyl-

5,10,15,20-tetraphenylporphyrin 49[85, 93]

54,104,154,204-tetra-t-butyl-52,56,152,156-tetrakis(methoxymethyl)-5,10,15,20-

tetraphenyl-porphyrin 50[95]

54,104,154,204-tetra-t-butyl-52,56,102,106,152,156,202,206-octakis(methoxymethyl)-

5,10,15,20-tetraphenyl-porphyrin 51[95]

Bromoporphyrins

52-(bromomethyl)-54,104,154,204-tetra-t-butyl-56-methyl-5,10,15,20-tetraphenyl-

porphyrin[85, 93]

52,56-bis(bromomethyl)-54,104,154,204-tetra-t-butyl-5,10,15,20-

tetraphenylporphyrin[95]

syn-52,152-bis(bromomethyl)-54,104,154,204-tetra-t-butyl-56,156-dimethyl-

5,10,15,20-tetraphenylporphyrin[85, 93]

anti-52,152-bis-bromomethyl)-54,104,154,204-tetra-t-butyl-56,156-dimethyl-

5,10,15,20-tetraphenylporphyrin[85, 93]

52,56,152,156-tetrakis(bromomethyl)-54,104,154,204-tetra-t-butyl-5,10,15,20-

tetraphenyl-porphyrin[95]

52,56,102,106,152,156,202,206-octakis(bromomethyl)-54,104,154,204-tetra-t-butyl-

5,10,15,20-tetraphenyl-porphyrin 52[95, 125]


129

6.2 Synthetic Procedures

General procedures:

GP I: Metalation of the free base porphyrins with zinc:

The free base porphyrin is dissolved in THF (30 mL for 0.1 mmol porphyrin) and an

excess of Zn(OAc)2∙2 H2O (20 eq) is added to the solution. The mixture is stirred at

reflux for 5 h, the solvent is removed by evaporation and the residue is redissolved in

EtOAc. After washing the solution twice with water, the organic layer is dried over

MgSO4. Mostly, the pure product can be obtained after removing the solvent under

reduced pressure. Only in a few cases flash chromatography is necessary as further

purification step; however this is mentioned in the corresponding substance

procedure.

GP II: Substitution reaction of the bromo substituents with azide units:

The bromoporphyrin is dissolved in DMF (30 mL for 0.1 mmol bromoporphyrin) and

an excess of NaN3 (the exact amount is stated in the substance procedure) is added.

After the mixture is stirred at 50°C for 24 h, the solution is poured into a mixture of ice

and saturated NH4Cl-solution and is stirred until the ice has melted. The violet

precipitate is filtered off and is redissolved in CH2Cl2. After washing the organic layer

twice with water, the organic layer is dried over MgSO4. Final purification can be

achieved by flash chromatography on silica.

GP III: Cu(I)-catalyzed 1,3 dipolar “click” cycloaddition:

The porphyrin azide and the acetylene compound are dissolved in CH2Cl2 (30 mL per

0.1 mmol porphyrin azide). Sodium ascorbate and CuSO4·5 H2O are separately

dissolved in H2O. While stirring the organic layer, first the CuSO4·5 H2O-solution and

then the sodium ascorbate solution are added. A small amount of ethanol and the

base DIPEA are subsequently given to the reaction mixture. The ratio of the solvents

should be CH2Cl2/H2O/EtOH 10:2:1. After stirring the two-layer-mixture vigorously at

40°C for 12 h, the reaction is finished and the Cu(I) catalyst is removed by washing

the organic layer three times with H2O. The solution is dried over MgSO4. Further

purification by flash chromatography (silica) gives the pure product.


130

52-(Azidomethyl)-54,104,154,204-tetra-t-butyl-56-methyl-5,10,15,20-

tetraphenylporphyrinato-zinc(II) (zinc monoazidoporphyrin) 56

An amount of 300 mg (0.32 mmol) 52-(bromomethyl)-

54,104,154,204-tetra-t-butyl-56-methyl-5,10,15,20-tetraphenyl-

porphyrin is first brought to reaction according to GP I with

347.9 mg (1.59 mmol) Zn(OAc)2∙2 H2O to give the zinc

monobromoporphyrin. Second, GP II is applied in order to

deliver the azidoporphyrin. Therefore, the zinc porphyrin is

reacted with 103.4 mg (1.59 mmol) NaN3. The pure product can be isolated after

flash chromatography (silica; CH2Cl2/hexane, 1:2). The product is a pink powder.

Yield: 281.8 mg (0.29 mmol), 90%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 8.97 (s, 4H, b-pyrr.), 8.92 (d, 3J=4.5 Hz,

2H, β-pyrr.), 8.63 (d, 3J=4.7 Hz, 2H, β-pyrr.), 8.14 (d, 3J=8.5 Hz, 6H, ArH), 7.75 (dd,

3J=7.5 Hz, 4J=3.0 Hz, 6H, ArH), 7.56 (s, 1H, Ar*H), 7.43 (s, 1H, Ar*H), 3.59 (br. s.,

2H, CH2), 1.87 (s, 3H, CH3), 1.62 (s, 9H, tBu), 1.61 (s, 18H, tBu), 1.59 (s, 9H, tBu).

13C NMR (100.5 MHz, CDCl3, 20°C): (ppm) = 150.5, 150.4, 150.3, 149.7, 139.9,

139.8, 134.4, 134.3, 132.8, 132.1, 130.4, 126.1, 123.5, 121.7, 121.6, 53.4, 34.8,

34.8, 31.6, 31.5, 29.6.

MS (MALDI-TOF, DCTB): [m/z] = 971 [M]+, 941 [M-N2]+.

UV/Vis (CH2Cl2): l [nm] (e [lmol-1cm-1]) = 422 (504600), 550 (19500), 599 (1400).

IR (ATR): [cm-1] = 2980, 2920, 2852, 2092, 1493, 1261, 1187, 1181, 997, 966, 797,

751, 697.

EA for C62H63N7Zn∙H2O: cal.: C 75.25, H 6.62, N 9.91;

found: C 75.30; H 6.53, N 10.25.


131

52,56-Bis(azidomethyl)-54,104,154,204-tetra-t-butyl-5,10,15,20-

tetraphenylporphyrinato-zinc(II) 57 (zinc bisazidoporphyrin)

An amount of 400 mg (0.39 mmol) 52,56-bis(bromomethyl)-

54,104,154,204-tetra-t-butyl-5,10,15,20-tetraphenylporphyrin is

reacted with 428 mg (2 mmol) Zn(OAc)2∙2 H2O as it is described

in GP I. As next step, the zinc porphyrin is converted following

GP II with 130 mg (2 mmol) NaN3. Final purification is achieved

by flash chromatography (silica, CH2Cl2/hexane, 1:1) to give the product as pink

powder.

Yield: 355.4 (0.35 mmol), 90%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 9.00 (d, 3J=4.6 Hz, 2H, β-pyrr.), 8.95 (d,

3J=4.6 Hz, 2H, β-pyrr.), 8.77 (d, 3J=4.6 Hz, 2H, β-pyrr.), 8.18 (d, 3J=8.1 Hz, 2H, ArH),

8.14 (t, 3J=4.5 Hz, 2H, β-pyrr.), 8.06 (d, 3J=8.3 Hz, 4H, ArH), 7.79 (d, 3J=8.3 Hz, 2H,

ArH), 7.73 (d, 3J=8.3 Hz, 4H, ArH), 6.82 (s, 2H, Ar*H), 2.67 (br. s, 4H, CH2), 1.65 (s,

9H, tBu), 1.61 (s, 18H, tBu), 1.43 (s, 9H, tBu).


150.1, 148.8, 139.9, 139.6, 136.4, 134.4, 134.2, 132.9, 132.3, 132.1, 129.5, 123.4,

123.1, 122.0, 121.2, 51.8, 34.8, 34.8, 31.6, 31.6, 31.3.

MS (FAB, NBA): [m/z] = 1012 [M]+.


IR (ATR): [cm-1] = 2980, 2922, 2098, 1489, 1461, 1261, 1203, 1066, 997, 796, 750,

719.

EA for C62H62N10Zn∙EtOAc: cal.: C 72.02, H 6.41, N 12.72;

found: C 72.57, H 5.93, N 13.35.


132

Syn-52,152-bis(azidomethyl)-54,104,154,204-tetra-t-butyl-56,156-dimethyl-

5,10,15,20-tetraphenylporphyrinato-zinc(II) (zinc synazidoporphyrin) 58

An amount of 400 mg (0.38 mmol) syn-52,152-bis-

(bromomethyl)-54,104,154,204-tetra-t-butyl-56,156-dimethyl-

5,10,15,20-tetraphenylporphyrin is converted with 416.9 mg

(1.9 mmol) Zn(OAc)2∙2 H2O according GP I. In a second step,

the product 58 is synthesized following GP II with 123.5 mg

(1.9 mmol) NaN3. The purification of the crude product succeeds by flash

chromatography (silica, CH2Cl2/hexane, 1:1) to give the pure product as pink powder.

Yield: 359.9 mg (0.34 mmol), 91%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 8.94 (d, 3J=4.6 Hz, 4H, b-pyrr.), 8.47 (d,

3J=4.4 Hz, 4H, b-pyrr.), 8.20 (d, 3J=8.1 Hz, 2H, ArH), 8.03 (d, 3J=8.1 Hz, 2H, ArH)

7.79 (m, 4H, ArH), 7.50 (s, 2H, Ar*H), 6.62 (s, 2H, Ar*H), 2.57 (s, 4H, CH2) 1.73 (s,

6H, CH3) 1.69 (s, 18H, tBu) 1.55 (s, 18H, tBu).


139.6, 138.0, 135.6, 134.5, 133.9, 132.9, 130.1, 125.8, 123.4, 123.3, 120.8, 120.4,

116.1, 51.8, 34.8, 34.6, 31.6, 31.5, 21.4.

MS (FAB, NBA): [m/z] = 1039 [M]+, 1011 [M-N2]+, 983 [M-2 N2]

+.


IR (ATR): [cm-1] = 2960, 2904, 2867, 2096, 1490, 1461, 1337, 1260, 1203, 995.


found: C 72.24, H 6.57, N 12.25.


133

Anti-52,152-bis(azidomethyl)-54,104, 154,204-tetra-t-butyl-56,156-dimethyl-

5,10,15,20-tetraphenylporphyrinato-zinc(II) (zinc antiazidoporphyrin) 59

An amount of 400 mg (0.38 mmol) anti-52,152-bis-

(bromomethyl)-54,104,154,204-tetra-t-butyl-56,156-dimethyl-5,10,

15,20-tetraphenylporphyrin is brought to reaction with 416.9 mg

(1.9 mmol) Zn(OAc)2∙2 H2O according GP I. Then following

GP II, the zinc porphyrin is converted with 123.5 mg (1.9 mmol)

NaN3. At last, the purification of the crude product succeeds with flash

chromatography (silica, CH2Cl2/hexane, 1:1) to give the pure product 59 as pink

solid.

Yield: 352.0 mg (0.34 mmol), 89%.


3J=4.6 Hz, 4H, β-pyrr.), 8.09 (d, 3J=8.1 Hz, 4H, ArH), 7.73 (d, 3J=8.1 Hz, 4H, ArH),

7.53 (s, 2H, Ar*H), 7.11 (s, 2H, Ar*H), 3.11 (s, 4H, CH2), 1.86 (s, 6H, CH3), 1.60 (s,

18H, tBu), 1.54 (s, 18H, tBu).


139.5, 138.2, 135.9, 134.2, 132.7, 130.3, 125.9, 123.3, 121.4, 120.8, 116.3, 41.3,

36.0, 34.8, 34.7, 31.9, 31.6, 31.6, 27.6.

MS (FAB, NBA): [m/z] = 1038 [M]+ , 1011 [M-N2]+ , 983 [M-2 N2]

+ .


IR (ATR): [cm-1] = 2958, 2865, 2100, 2091, 1478, 1393, 1289, 1109, 809, 796.

EA for C64H66N10Zn∙½ EtOAc: cal.: C 73.08; H 6.50, N 12.91;

found: C 73.02, H 6.46, N 12.33.


134

52,56,152,156-Tetrakis(azidomethyl)-54,104,154,204-tetra-t-butyl-5,10,15,20-

tetraphenylporphyrinato-zinc(II) (zinc tetrakisazidoporphyrin) 60

An amount of 400 mg (0.33 mmol) 52,56,152,156-tetrakis-

(bromomethyl)-54,104,154,204-tetra-t-butyl-5,10,15,20-tetra-

phenylporphyrin and 362.6 mg (1.7 mmol) Zn(OAc)2∙2 H2O is

reacted as it is described in GP I. The subsequent conversion is

carried out according to GP II with 214.6 mg (3.3 mmol) NaN3.

Final purification is achieved by flash chromatography (silica;

CH2Cl2/hexane, 2:1).

Yield: 332.7 mg (0.29 mmol), 93%.


3J=4.6 Hz, 4H, b-pyrryl), 8.00 (d, 3J=8.1 Hz, 4H, ArH), 7.71 (d, 3J=8.1 Hz, 4H, ArH),

7.15 (s, 4H, Ar*H), 3.13 (s, 8H, CH2), 1.60 (s, 18H, tBu), 1.50 (s, 18H, tBu).


137.4, 136.8, 134.2, 133.4, 130.1, 123.5, 123.4, 121.5, 113.7, 52.3, 34.9, 34.8, 31.6,

31.4.

MS (MALDI-TOF, DCTB): [m/z] = 1122 [M]+ , 1094 [M-N2]+.


IR (ATR): [cm-1] = 2961, 2867, 2281, 2100, 1456, 1362, 1338, 1228, 997, 810, 797,

720.


found: C 67.50, H 6.08, N 18.02.


135

52,56,102,106,152,156,202,206-Octakis(azidomethyl)-54,104,154,204-tetra-t-

butyl-5,10,15,20-tetraphenylporphyrinato-zinc(II)

(zinc octakisazidoporphyrin) 55

An amount of 400 mg (0.25 mmol) 52,56,102,106,152,156,202,206-

octakis- (bromomethyl)- 54,104,154,204-tetra-t-butyl-5,10,15,20-

tetraphenylporphyrin 52 and 277.4 mg (1.26 mmol)

Zn(OAc)2∙2 H2O is brought to reaction according to GP I. Next,

GP II is used with 243.8 mg (3.75 mmol) NaN3. Final purification

is achieved by flash chromatography (silica; CH2Cl2/hexane, 4:1).

Yield: 302.1 mg (0.23 mmol), 91%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 8.33 (s, 8H, b-pyrr.), 7.37 (s, 8H, ArH),

3.28 (br. s, 16H, CH2), 1.55 (s, 36H, tBu).

13C NMR (100.5 MHz, CDCl3, 20°C): (ppm) = 152.3 (4C), 149.9 (8C, b-pyrr.), 137.3

(4C), 136.9 (8C), 131.2 (8C, -pyrr.), 124.3 (8C), 114.4 (4C, meso-C), 52.7 (8C,

CH2), 35.0 (4C, tBu), 32.4 (12C, tBu).

MS (FAB,NBA): [m/z] = 1342 [M]+, 1315 [M-N2]+, 1267 [M-2 N2]

+.


IR (ATR): [cm-1] = 2085, 2024, 1962, 1478, 1337, 1272, 1233, 1200, 1064, 995,

797.

EA for C68H68N28Zn∙2 THF∙H2O: cal.: C 60.65, H 5.76, N 26.06;

found: C 60.21, H 5.78, N 26.17.


136

104,154,204-Tris-t-butyl-54-propargyloxy-5,10,15,20-tetraphenylporphyrin

2H-125

An amount of 5 g (31.22 mmol) 4-propargyloxybenzaldehyde

126, 16.7 g (102.9 mmol) t-butylbenzaldehyde and 9.2 g

(137.1 mmol) pyrrole is dissolved in 3 L CH2Cl2 and 1.56 mL

BF3·OEt2 are added. After stirring for 1 h, 25 g DDQ are added

and the solution is again stirred for 2 h. In order to remove

excessive DDQ, the crude product is filtrated over silica. The

solvent is removed by rotary evaporation. Purification by flash chromatography

(silica, CH2Cl2/hexane, 2:1) gives the product as a purple solid.

Yield: 1.6 g (1.78 mmol), 5.6% based on 4-popargyloxybenzaldehyde 126.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 8.85 (m, 8H, b-pyrr.), 8.19 (d, 3J=8.3 Hz,

8H, ArH, Ar*H), 7.78 (d, 3J=8.3 Hz, 6H, ArH), 7.34 (d, 3J=8.3 Hz, 2H, Ar*H), 4.93 (d,

4J=2.2 Hz, 2H, CH2), 2.70 (t, 4J=2.3 Hz, 1H, CH), 1.64 (s, 27H), -2.51 (br. s, 2H, NH).


134.6, 123.6, 120.3, 119.4, 113.1, 78.6, 75.8, 56.0, 34.8, 33.8, 31.9, 31.6, 31.5, 29.6,

29.6, 29.5, 29.1, 28.9, 22.6, 14.1.

MS (FAB, NBA): [m/z] = 837 [M]+.

UV/Vis (CH2Cl2): l [nm] (e [lmol-1cm-1]) = 417 (449000), 516 (21000), 548 (13500),

592 (8100), 644 (4300).

IR (ATR): [cm-1] = 3301, 2970, 2890, 2140, 1504, 1473, 1370, 1266, 1215, 1108,

1023, 966.

EA for C59H56N4O: cal.: C 82.96, H 7.08, N 6.34;

found: C 83.13, H 6.90, N 6.42.


137

104,154,204-Tris-t-butyl-54-propargyloxy-5,10,15,20-tetraphenyl-

porphyrinato-zinc(II) 125

An amount of 1 g (1.19 mmol) free base porphyrin 2H-125 is

brought to reaction according to GP I with 6.0 g (23.89 mmol)

Zn(OAc)2. The reaction mixture is stirred at reflux for 8 h. After

cooling down, the solvent is distilled under reduced pressure, the

residue redissolved in CH2Cl2 and washed three times with H2O.

The organic layer is dried over MgSO4, the solvent is removed

and the product is yielded as a pink powder.

Yield: 1 g (1.12 mmol), 94%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 9.00 (m, 8H, b-pyrr.), 8.15 (m, 8H, ArH,

Ar*H), 7.76 (m, 6H, ArH), 7.33 (d, 3J=8.5 Hz, 2H, ArH), 4.94 (d, 4J=2.4 Hz, 2H, CH2),

2.67 (d, 4J=2.4 Hz, 1H, CH), 1.62 (s, 27H, tBu).


136.3, 135.5, 134.4, 132.1, 132.1, 131.8, 123.5, 121.3, 120.4, 114.1, 113, 78.7, 77.6,

75.8, 56.1, 41.3, 34.8, 33.8, 31.9, 31.7, 31.5, 30.1, 29.6, 29.6, 29.4, 29.3, 29.1, 28.9,

22.6, 14.0.

MS (FAB, NBA): [m/z] = 898 [M]+.


IR (ATR): [cm-1] = 3303, 2968, 2890, 2150, 1503, 1473, 1370, 1264, 1215, 1010,

1023, 967.

EA for C59H54N4OZn·THF: cal.: C 77.80, H 6.43, N 5.76;

found: C 77.64, H7.04, N 5.46.


138

54,104,154,204-Tetrakis(propargyloxy)-5,10,15,20-tetraphenylporphyrin

2H-124

An amount of 5.8 g (36.21 mmol) 4-popargyloxy-

benzaldehyde 126 and 2.43 g (36.21 mmol) pyrrole is

dissolved in 1 L CH2Cl2 and 0.3 ml BF3∙OEt2 are added to

this solution. After stirring for one hour, 6 g DQQ are added

and the solution is stirred two more hours. The solvent is

removed by rotary evaporation. The crude product is

recrystallized from MeOH at -18°C and further purified by

flash chromatography (silica, CH2Cl2). The product can be obtained as purple colored

powder.

Yield: 1.25 g (1.51 mmol), 16.6% based on 4-popargyloxybenzaldehyde 126.


8H, ArH), 7.36 (d, 3J=8.5 Hz, 8H, ArH), 4.98 (d, 4J=2.2 Hz, 8H, CH2), 2.69 (t,

4J=2.4 Hz, 4H, CH), -2.76 (br. s, 2H, NH).

13C NMR (100.5 MHz, CDCl3, 20°C): (ppm) = 157.6 (4C, ArCq), 135.6 (8C, o-

ArCH), 119.6 (4C, Cq), 113.2 (8C, m-ArCH), 78.7, (4C, meso-Cq), 75.8 (4C, Cq-

alkyne), 56.2 (4C, CH2), 29.6 (4C, CH-alkyne).

MS (FAB, NBA): [m/z] = 832 [M]+.


596 (3500), 647 (5200).

IR (ATR): [cm-1] = 3298, 2150,1604, 1501, 1471, 1448, 1289, 1216, 1021, 990,

796.

EA for C56H38N4O4: cal.: C 80.95, H 4.61, N 6.67;

found: C 80.39, H 4.82, N 6.67.


139

54,104,154,204-Tetrakis(propargyloxy)-5,10,15,20-tetraphenyl-

porphyrinato-zinc(II) 124

An amount of 500 mg (0.61 mmol) 54,104,154,204-

tetrakis(propargyloxy)- 5,10,15,20-tetraphenylporphyrin

2H-124 is converted according to GP I with 2.77 g

(12.03 mmol) Zn(OAc)2. The pure product can be obtained

as a pink powder after short flash chromatography (silica,

CH2Cl2).

Yield: 491.3 mg (0.55 mmol), 90%.


8H, ArH), 7.35 (d, 3J=8.5 Hz, 8H, ArH), 4.98 (d, 4J=2.4 Hz, 8H, CH2), 2.69 (t,

4J=2.4 Hz, 4H, CH).

13C NMR (100.5 MHz, CDCl3, 20°C): (ppm) = 157.4 (4C, ArCq), 150.5 (8 C, α-pyrr.),

135.4 (8C, o-ArCH), 132.0 (8C, β-pyrryl.), 120.6 (4C, ArCq), 113.0 (8C, m-ArCH),

78.7 (4C, meso-Cq), 75.8 (4C, C≡ CH), 56.2 (4C, CH2), 29.6 (4C, C≡ CH).

MS (FAB, NBA): [m/z] = 892 [M]+.


IR (ATR): [cm-1] = 3278, 2919, 2849, 2156, 1738, 1601, 1487, 1338, 1280, 1212,

994.

EA for C56H36N4O4Zn∙2 THF: cal.: C 74.02, H 5.05, N 5.39;

found: C 73.73, H 4.71, N 5.49.


140

54,104,154,204-Tetra-t-butyl-56-methyl-52-(1-methyl-4-phenyl-1,2,3-

triazole)-5,10,15,20-tetraphenylporphyrinato-zinc(II)

(zinc mono(phenyltriazolyl)porphyrin) 61

The synthesis is carried out according to GP III with the

following amounts: 100 mg (0.10 mmol) zinc

monoazidoporphyrin 56, 17.3 mg (0.15 mmol) phenyl

acetylene, 3.8 mg (0.015 mmol) CuSO4·5 H2O, 5.9 mg

(0.03 mmol) sodium ascorbate, 38.8 mg (0.30 mmol) DIPEA.

Purification is achieved by flash chromatography (silica, CHCl3). The product is

obtained in the third fraction. The first two fractions contain excessive phenyl

acetylene and zinc monoazidoporphyrin 56.

Yield: 75.1 mg (0.07 mmol), 67%.


3J=4.6 Hz, 2H, b-pyrr.), 8.81 (d, 3J=4.6 Hz, 2H, b-pyrr.), 8.47 (d, 3J=4.4 Hz, 2H, b-

pyrr.), 8.16 (m, 2H, ArH), 8.10 (dd, 3J=7.9, 4J=1.8 Hz, 2H, ArH), 7.98 (dd, 3J=7.9 Hz,

4J=1.8 Hz, 2H, ArH), 7.77 (m, 2H, ArH), 7.72 (dd, 3J=7.8 Hz, 4J=2.0 Hz, 2H, ArH),

7.68 (dd, 3J=8.1 Hz, 4J = 2.0 Hz, 2H, ArH), 7.66 (d, 4J=1.7 Hz, 1H, Ar*H), 7.40 (s, 1H,

Ar*H), 7.13 (t, 3J=7.1 Hz, 1H, PhH), 7.01 (t, 3J=7.6 Hz, 2H, PhH), 6.71 (d, 3J=7.6 Hz,

2H, ArH), 5.94 (s, 1H, triazole-H), 4.63 (s, 2H, CH2), 2.03 (s, 3H, CH3), 1.63 (s, 9H,

tBu), 1.62 (s, 18H, tBu), 1.58 (s, 9H, tBu).

13C NMR (100.5 MHz, CDCl3, 20°C): (ppm) = 151.8 (2C), 150.6 (1C), 150.5 (1C),

150.2 (4C), 150.1 (2C), 149.3 (2C), 146.2 (1C), 140.1 (2C), 139.9 (2C), 139.7 (1C),

135.8 (1C), 134.5 (2C), 134.4 (2C), 134.3 (2C), 132.8 (2C), 132.1 (4C), 129.9 (2C),

128.3 (2C), 127.6 (1C), 127.1 (1C), 125.0 (2C), 123.8 (1C), 123.4 (6C), 121.7 (1C),

121.1 (1C), 119.1 (1C, triazole-C), 114.9 (1C), 52.9 (1C) 34.8 (4C), 31.7 (27C), 31.5

(9C), 21.9 (1C).

MS (FAB, NBA): [m/z] = 1071 [M]+, 927 [M-phenyltriazole]+.


IR (ATR): [cm-1] = 2961, 1526, 1463, 1395, 1362, 1338, 1268, 1204, 996, 797.

EA for C70H69N7Zn·H2O: cal.: C 77.01; H 6.55; N 8.98;

found: C 76.68; H 6.23; N 8.27.


141

54,104,154,204-Tetra-t-butyl-52,56-bis-(1-methyl-4-phenyl-1,2,3-triazole)-

5,10,15,20-tetraphenylporphyrinato-zinc(II)

(zinc bisphenyl(triazolyl) porphyrin) 62

The synthesis is carried out according to GP III with 100 mg

(0.1 mmol) zinc bisazidoporphyrin 57 and 33.2 mg (0.3 mmol)

phenyl acetylene. Furthermore, 7.5 mg (0.03 mmol)

CuSO4·5 H2O, 11.9 mg (0.06 mmol) sodium ascorbate and

77.6 mg (0.6 mmol) DIPEA are added. Purification is achieved

by flash chromatography (silica, CH2Cl2/EtOAc, 30:1). The

product can be obtained in the third violet fraction.

Yield: 54.9 mg (0.045 mmol), 46%.


3J=4.6 Hz, 2H, b-pyrr.), 8.47 (d, 3J = 4.4 Hz, 2H, β-pyrr.), 8.17 (d, 3J=4.6 Hz, 2H, b-

pyrr.), 8.16 (m, 2H, ArH), 7.86 (d, 3J=8.3 Hz, 4H, ArH), 7.78 (d, 3J=8.3 Hz, 2H, ArH),

7.64 (d, 3J=8.3 Hz, 4H¸ ArH), 7.51 (br. s, 2H, Ar*H), 7.05 (t, 3J=7.4 Hz, 2H, PhH),

6.86 (t, 3J=7.8 Hz, 4H, PhH), 6.40 (d, 3J=7.6 Hz, 4H, PhH), 5.48 (s, 2H, triazole-H),

4.66 (s, 4H, CH2), 1.64 (s, 9H, tBu), 1.60 (s, 18H, tBu), 1.51 (s, 9H, tBu).


150.1, 148.7, 146.2, 140.1, 139.8, 139.7, 136.5, 134.6, 134.4, 133.2, 132.4, 132.4,

129.3, 129.1, 128.8, 128.7, 128.2, 127.6, 126.7, 124.9, 123.4, 123.3, 122.4, 121.6,

119.2, 77.3, 52.4, 35.0, 34.8, 34.8, 31.6, 31.4.

MS (FAB, NBA): [m/z] = 1216 [M]+, 925 [M-2·phenyltriazole]+.


IR (ATR): [cm-1] = 2176, 2025, 1990, 995, 973, 809, 760, 721, 690, 643.

EA for C78H74N10Zn∙EtOH: cal.: C 76.08; H 6.38; N 11.09;

found C 76.44; H 6.40; N 10.37.


142

Syn-54,104,154,204-tetra-t-butyl-56,156-dimethyl-52,152-bis-(1-methyl-4-

phenyl-1,2,3-triazole)-5,10,15,20-tetraphenylporphyrinato-zinc(II)

(zinc syn(phenyltriazolyl)porphyrin) 63

According to GP III, 100 mg (0.096 mmol) zinc

synazidoporphyrin 58 is subjected to the following setup:

32.3 mg (0.29 mmol) phenyl acetylene, 7.2 mg (0.029 mmol)


75.0 mg (0.58 mmol) DIPEA. Purification of the crude product is

achieved by flash chromatography (silica, CH2Cl2/EtOAc, 25:1).

The product can be isolated as violet powder.

Yield: 60 mg (0.5 mmol), 53%.


4J=4.6 Hz, 4H, b-pyrr.), 8.07 (dd, 3J=7.9 Hz, 4J=2.1 Hz, 2H, ArH), 7.88 (dd,

3J=7.9 Hz, 4J = 2.1 Hz, 2H, ArH), 7.69 (dd, 3J=8.1 Hz, 4J=2.2 Hz, 2H, ArH), 7.66 (s,

2H, Ar*H), 7.64 (s, 2H, Ar*H), 7.61 (dd, 3J=8.1 Hz, 4J=2.2 Hz, 2H, ArH), 7.05 (m, 10H,

PhH), 6.43 (br. s, 2H, triazole-H), 4.34 (br. s, 4H, CH2), 2.03 (s, 6H, CH3), 1.61 (s,

18H, tBu), 1.55 (s, 18H, tBu).


139.9, 139.8, 139.7, 135.9, 134.8, 134.1, 132.8, 130.0, 128.4, 127.6, 127.0, 125.4,

123.2, 123.3, 121.1, 119.1, 34.8, 34.8, 31.9, 31.7, 31.52, 29.6, 29.6, 29.3, 21.9, 14.0.

MS (FAB, NBA): [m/z] = 1245 [M]+, 954 [M-2 phenyltriazole]+.


IR (ATR): [cm-1] = 2361, 2340, 2323, 1479, 1461, 1338, 1267, 1063, 995, 809.

EA for C80H78N10Zn·EtOH: cal.: C 76.29, H 6.56, N 10.85;

found: C 76.32, H 6.55, N 10.45.


143

Anti-54,104,154,204-tetra-t-butyl-56,156-dimethyl-52,152-bis-(1-methyl-4-

phenyl-1,2,3-triazole)-5,10,15,20-tetraphenylporphyrinato-zinc(II)

(zinc anti(phenyltriazolyl)porphyrin) 64

According to GP III 100 mg (0.096 mmol) zinc

antiazidoporphyrin 59 are brought to reaction with 29.5 mg

(0.29 mmol) phenyl acetylene. Furthermore, 7.2 mg

(0.029 mmol) CuSO4·5 H2O, 11.5 mg (0.058 mmol) sodium

ascorbate and 75 mg (0.58 mmol) DIPEA are added.

Purification of the crude product is achieved by flash

chromatography on silica (CH2Cl2/EtOAc, 30:1). After evaporation of the solvent the

product can be obtained as a violet powder.

Yield: 60.3 mg (0.048 mmol), 50%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 8.85 (d, 3J=4.5 Hz, 4H, β-pyrr.) 8.44 (d,

3J=4.5 Hz, 4H, β-pyrr.) 7.87 (d, 3J=8.4 Hz, 4H, ArH) 7.65 (d, 3J=8.4 Hz, 4H, ArH) 7.55

(s, 4H, Ar*H), 6.98 (t, J=7.5 Hz, 2H, PhH), 6.82 (t, 3J=7.8 Hz, 4H, PhH), 6.29 (d,

J=7.7 Hz, 4H, PhH), 5.23 (s, 2H, triazole-H), 3.71 (br. s, 4H, CH2), 1.89 (s, 6H, CH3)

1.62 (s, 18H, tBu), 1.44 (s, 18H, tBu).


139.8, 139.5, 139.3, 135.4, 134.3, 133.1, 130.1, 129.2, 128.3, 128.0, 127.4, 126.8,

124.7, 123.2, 123.0, 121.3, 118.8, 115.5, 51.8, 34.8, 34.7, 31.6, 31.4, 21.8.



IR (ATR): [cm-1] = 2962, 1481, 1463, 1395, 1362, 1270, 1204, 1111, 1072, 998.

EA for C80H78N10Zn: cal.: C 77.18, H 6.32, N 11.25;

found: C 76.78, H 6.16, N 10.82.


144

54,104,154,204-Tetra-t-butyl-52,56,152,156-tetrakis-(1-methyl-4-phenyl-

1,2,3-triazole)-5,10,15,20-tetraphenylporphyrinato-zinc(II)

(zinc tetrakis(phenyltriazolyl)porphyrin) 65

According to GP III, 100 mg (0.09 mmol) zinc

tetrakisazidoporphyrin 60 is subjected to the following setup:

59.9 mg (0.53 mmol) phenyl acetylene, 12.5 mg (0.05 mmol)


137.0 mg (1.06 mmol) DIPEA. The crude product is purified by

flash chromatography (silica, CH2Cl2/EtOAc, 15:1) to give the product as a violet

powder.

Yield: 125.4 mg (0.081 mmol), 92%.


3J=4.6 Hz, 4H, b-pyrr.), 7.75 (br. s, 4H, Ar*H), 7.72 (d, 3J=8.3 Hz, 4H, ArH), 7.57 (d,

3J=8.3 Hz, 4H, ArH), 7.18 (t, 3J=7.3 Hz, 4H, PhH), 7.10 (t, 8H, 3J=7.3 Hz, PhH), 6.99

(d, 3J=7.6 Hz, 8H, ArH), 6.34 (s, 4H, triazole-H), 5.02 (s, 8H, CH2), 1.61 (s, 18H, tBu),

1.58 (s, 18H, tBu).


139.5, 136.8, 134.4, 133.4, 133.3, 129.9, 129.5, 128.5, 127.8, 126.7, 125.3, 123.2,

122.0, 119.0, 112.1, 77.6, 77.3, 52.8, 35.1, 34.7, 31.6, 31.4.



IR (ATR): [cm-1] = 2963, 1610, 1464, 1363, 1363, 1223, 1075, 1047, 996, 764.

EA for C96H88N16Zn·CH2Cl2: cal.: C 73.65, H 5.70, N 14.24;

found: C 74.07, H 6.06, N 13.91.


145

54,104,154,204-Tetra-t-butyl-52,56,102,106,152,156,202,206-octakis-(1-

methyl-4-phenyl-1,2,3-triazole)-5,10,15,20-tetraphenylporphyrinato-

zinc(II) (zinc octakis(phenyltriazolyl)porphyrin) 66

Following GP III, the following substances and amounts are

used for the reactions with 100 mg (0.075 mmol) zinc

octakisazidoporphyrin 55: 100.0 mg (0.9 mmol) phenyl

acetylene, 22.5 mg (0.09 mmol) CuSO4·5 H2O, 35.7 mg

(0.18 mmol) sodium ascorbate, 232.6 mg (1.80 mmol)

DIPEA. Purification of the crude product is achieved by

flash chromatography on silica (CHCl3/EtOAc, 10:1) to give

the product as a violet powder.

Yield: 144.9 mg (0.067 mmol), 89%.


7.03 (m, 21H, ArH), 6.96 (d, 3J=7.3 Hz, 16H, ArH), 6.58 (s, 8H, triazole-H), 4.72 (s,

16H, CH2), 1.61 (s, 36H, tBu).


130.6, 130.2, 128.4, 127.8, 127.0, 125.5, 120.0, 113.4, 77.3, 52.8, 35.0, 31.5.



IR (ATR): [cm-1] = 2360, 2342, 2323, 1479, 1461, 1338, 1267, 1063, 995, 809.

EA for C135H128N28Zn·CHCl3: cal.: C 70.08, H 5.17, N 17.21;

found: C 70.53, H 5.71, N 17.20.


146

54,104,154,204-Tetra-t-butyl-56-methyl-52-(1-methyl-4-ferrocene-1,2,3-

triazole)-5,10,15,20-tetraphenylporphyrinato-zinc(II)

(zinc mono(ferrocenyltriazolyl)porphyrin) 67

According to GP III, these substances and amounts are

converted with 100 mg (0.1 mmol) zinc monoazidoporphyrin 56:

31.5 mg (0.15 mmol) ethinyl ferrocene, 3.7 mg (0.015 mmol)

CuSO4·5 H2O, 5.9 mg (0.03 mmol) sodium ascorbate, 38.8 mg

(0.3 mmol) DIPEA. Purification of the crude product is achieved

by flash chromatography on silica (CHCl3/EtOAc, 100:1).

Yield: 76.8 mg (0.066 mmol), 66%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 9.01 (s, 4H, β-pyrr.), 8.95 (d, 3J=4.6 Hz,

2H, β-pyrr.), 8.61 (d, 3J=4.6 Hz, 2H, β-pyrr.), 8.18 (m, 6H, ArH), 7.77 (d, 3J=8.3 Hz,

6H, ArH), 7.63 (d, 4J=1.5 Hz, 1H, Ar*H), 7.30 (s, 1H, Ar*H), 5.89 (s, 1H, triazole-H),

4.63 (s, 2H, CH2), 4.06 (t, 3J=2.0 Hz, 2H, FcH), 3.98 (t, 3J=1.8 Hz, 2H, FcH), 3.70 (s,

5H, FcH), 2.02 (s, 3H, CH3), 1.64 (s, 27H, tBu), 1.55 (s, 9H, tBu).


149.5, 145.6, 140.0, 139.8, 139.6, 136.4, 134.6, 134.5, 134.3, 132.9, 132.3, 132.2,

130.2, 126.6, 123.5, 122.8, 121.8, 121.2, 118.5, 115.4, 76.7, 74.9, 69.5, 69.2, 68.1,

66.6, 66.2, 60.2, 52.4, 34.8, 34.8, 31.7, 31.5, 31.1, 29.6, 21.9, 15.1.

MS (FAB, NBA): [m/z] = 1181 [M]+, 927 [M-ferrocenyltriazole]+.


551 (20000), 594 (8600).

IR (ATR): [cm-1] = 2956, 1593, 1524, 1480, 1338, 1296, 1270, 1065, 997, 812.

EA for C74H73FeN7Zn·EtOAc: cal.: C 73.78, H 6.43, N 7.72;

found: C 73.69, H 6.27, N 8.02.


147

54,104,154,204-Tetra-t-butyl-52,56-bis(1-methyl-4-ferrocene-1,2,3-triazole)-

5,10,15,20-tetraphenylporphyrinato-zinc(II)

(zinc bis(ferrocenyltriazolyl)porphyrin) 68

An amount of 100 mg (0.10 mmol) zinc bisazidoporphyrin 57 is

converted with 63.0 mg (0.3 mmol) ethinyl ferrocene according

to GP III. The amounts of the other necessary substances are:

7.5 mg (0.03 mmol) CuSO4·5 H2O, 11.9 mg (0.06 mmol) sodium

ascorbate, 77.6 mg (0.6 mmol) DIPEA. The crude product is

purified by flash chromatography (silica, CH2Cl2/EtOAc, 30:1) to

give the pure purple product.

Yield: 69.2 mg (0.048 mmol), 48%.


2H, b-pyrr.), 8.40 (d, 3J=4.6 Hz, 2H, b-pyrr.), 8.17 (d, 3J=8.3 Hz, 2H, ArH), 8.09 (d,

3J=8.3 Hz, 4H, ArH), 7.78 (d, 3J=8.3 Hz, 2H, ArH), 7.73 (d, 3J=8.3 Hz, 4H, ArH), 7.54

(s, 2H, Ar*H), 5.89 (s, 2H, triazole-H), 4.85 (s, 4H, CH2), 4.04 (t, 3J=1.8 Hz, 4H, FcH),

3.96 (s, 4H, FcH), 3.69 (s, 10H, FcH), 1.63 (s, 27H, tBu), 1.49 (s, 9H, tBu).


148.9, 145.8, 139.9, 139.7, 136.9, 134.5, 133.3, 132.5, 132.4, 129.5, 125.7, 123.5,

122.3, 121.6, 118.6, 74.6, 69.2, 68.2, 66.2, 52.2, 35.0, 34.8, 31.7, 31.4.

MS (FAB, NBA): [m/z] = 1432 [M]+, 925 [M-2 ferrocenyltriazole]+.


552 (20500), 595 (9000).

IR (ATR): [cm-1] = 2956, 1593, 1524, 1480, 1338, 1296, 1270, 1065, 997, 812.

EA for C86H82Fe2N10Zn: cal.: C 72.10, H 5.77, N 9.78;

found: C 72.32, H 5.84, N 9.79.


148

Syn-54,104,154,204-tetra-t-butyl-56,156-dimethyl-52,152-bis(1-methyl-4-

ferrocene-1,2,3-triazole)-5,10,15,20-tetraphenylporphyrinato-zinc(II)

(zinc syn(ferrocenyltriazolyl)porphyrin) 69



synazidoporphyrin 58, 60.9 mg (0.29 mmol) ethinyl ferrocene,

7.5 mg (0.029 mmol) CuSO4∙5 H2O, 11.5 mg (0.058 mmol)

sodium ascorbate, 75.0 mg (0.58 mmol) DIPEA. The crude

product is purified by flash chromatography (silica,

CH2Cl2/EtOAc, 25:1).

Yield: 83 mg (0.059 mmol), 59%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 8.93 (d, 3J=4.4 Hz, 4H, ), 8.57 (d,

3J=4.4 Hz, 4H, ), 8.16 (m, 4H, ArH), 7.78 (m, 4H, ArH), 7.68 (s, 2H, Ar*H), 7.25 (s,

2H, Ar*H), 6.32 (s, 2H, triazole-H), 4.59 (s, 4H, CH2), 4.13 (s, 4H, FcH), 4.09 (br. s,

4H, FcH), 3.75 (s, 10H, FcH), 2.08 (s, 6H, CH3), 1.66 (s, 18H, tBu), 1.57 (s, 18H,

tBu).

13C NMR (75 MHz, CDCl3, 20°C): (ppm) = 151.7, 150.5, 150.1, 149.4, 145.7, 139.9,

139.6, 139.4, 136.3, 135.0, 134.1, 132.9, 130.0, 126.7, 123.3, 121.0, 118.5, 115.5,

69.2, 68.2, 66.4, 34.8, 31.7, 31.5, 21.8.

MS (MALDI-TOF, DCTB): [m/z] = 1462 [M]+.


559 (18400), 596 (7100).

IR (ATR): [cm-1] = 2955, 1655, 1561, 1543, 1509, 1459, 1202, 794, 718, 486.

EA for C88H86Fe2N8Zn·CH2Cl2: cal.: C 69.16, H 5.74, N 9.06;

found: C 69.69, H 5.86, N 9.17.


149

Anti-54,104,154,204-tetra-t-butyl-56,156-dimethyl-52,152-bis(1-methyl-4-

ferrocene-1,2,3-triazole)-5,10,15,20-tetraphenylporphyrinato-zinc(II)

(zinc anti(ferrocenyltriazolyl)porphyrin) 70

Applying GP III 100 mg (0.1 mmol) zinc antiazidoporphyrin 59

are brought to reaction with the following substances and

amounts: 60.9 mg (0.29 mmol) ethinyl ferrocene, 7.2 mg


ascorbate, 75 mg (0.58 mmol) DIPEA. The crude product is

purified by flash chromatography (silica, CH2Cl2/EtOAc, 25:1).

The product can be obtained as a violet powder.

Yield: 74.8 mg (0.053 mmol), 53%.


3J=4.5 Hz, 4H, b-pyrr.), 8.07 (d, 3J=8.1 Hz, 4H, ArH), 7.72 (d, 3J=8.3 Hz, 6H, ArH,

Ar*H), 7.56 (s, 2H, Ar*H), 6.80 (br. s, 2H, triazole-H), 5.60 (s, 4H, CH2), 3.99 (d,

3J=1.8 Hz, 4H, FcH), 3.80 (s, 4H, FcH), 3.60 (s, 10H, FcH), 1.98 (s, 6H, CH3), 1.64

(s, 18H, tBu), 1.45 (s, 18H, tBu).


139.7, 139.3, 138.9, 135.9, 134.3, 133.1, 130.2, 126.4, 123.2, 121.2, 118.3, 115.7,

74.4, 69.1, 68.0, 66.1, 34.9, 34.7, 31.7, 31.5, 22.0.

MS (FAB, NBA): [m/z] = 1460 [M]+, 953 [M-2·ferrocenyltriazole]+.


560 (8560), 602 (3200).

IR (ATR): [cm-1] = 2956, 2856 1590, 1525, 1465, 1338, 1296, 1089, 1065, 997,

812.

EA for C88H86Fe2N10Zn·⅓ CH2Cl2: cal.: C 71.25, H 5.87, N 9.41;

found: C 71.07, H 5.77, N 9.35.


150

54,104,154,204-Tetra-t-butyl-52,56,152,156-tetrakis(1-methyl-4-ferrocene-

1,2,3-triazole)-5,10,15,20-tetraphenylporphyrinato-zinc(II)

(zinc tetrakis(ferrocenyltriazolyl)porphyrin) 71

The synthesis is carried out according to GP III and the

following amounts of substances are used: 100 mg

(0.089 mmol) zinc tetrakisazidoporphyrin 60, 111.4 mg

(0.53 mmol) ethinyl ferrocene, 12.5 mg (0.05 mmol)

CuSO4·5 H2O, 21.8 mg (0.11 mmol) sodium ascorbate,

137.0 mg (1.06 mmol) DIPEA. The crude product is purified by

flash chromatography (silica, CH2Cl2/EtOAc, 15:1) to give the violet product.

Yield: 166.3 mg (0.084 mmol), 94%.


3J=4.7 Hz, 4H, b-pyrr.), 8.09 (d, 3J=8.1 Hz, 4H, ArH), 7.79 (s, 4H, Ar*H), 7.70 (d,

3J=8.3 Hz, 4H, ArH), 6.38 (s, 4H, triazole-H), 5.14 (s, 8H, CH2), 4.21 (d, 3J=1.9 Hz,

8H, FcH), 4.17 (s, 8H, FcH), 3.76 (s, 20H, FcH), 1.62 (s, 18H, tBu), 1.60 (s, 18H,

tBu).

13C NMR (75 MHz, CDCl3, 20°C): (ppm) = 153.0, 150.7, 150.0, 149.0, 146.0, 139.7,

139.5, 137.0, 134.8, 133.3, 129.5, 126.3, 123.2, 121.8, 118.6, 112.2, 77.4, 75.0,

69.5, 69.3, 68.4, 66.5, 52.9, 35.2, 34.8, 31.8, 31.6, 29.7.

MS (FAB, NBA): [m/z] = 1962 [M]+, 929 [M-4 ferrocenyltriazole]+.


564 (12900), 605 (10800).

IR (ATR): [cm-1] = 3092, 2958, 2357, 1581, 1463, 1394, 1363, 1272, 1204, 1207,

997.

EA for C112H104Fe4N16Zn·CH2Cl2: cal.: C 66.28, H 5.22, N 10.94;

found: C 66.12, H 5.55, N 10.18.


151

54,104,154,204-Tetra-t-butyl-52,56,102,106,152,156,202,206-octakis(1-methyl-

4-ferrocene-1,2,3-triazole)-5,10,15,20-tetraphenylporphyrinato-zinc(II)

(zinc octakis(ferrocenyltriazolyl)porphyrin) 72


following amounts of substances: 100 mg (0.075 mmol)

zinc octakisazidoporphyrin 55, 189.1 mg (0.9 mmol) ethinyl

ferrocene, 22.5 mg (0.09 mmol) CuSO4·5 H2O, 35.7 mg

(0.18 mmol) sodium ascorbate and 232.6 mg (1.80 mmol)

DIPEA. The crude product is purified by flash

chromatography (silica, CH2Cl2/EtOAc, 10:1). Thus, the

pure product can be isolated as dark orange solid.

Yield: 196.9 mg (0.069 mmol), 89%.


6.54 (s, 8H, triazole-H), 4.92 (s, 16H, CH2), 4.05 (t, 3J=1.8 Hz, 16H, FcH), 3.93 (t,

3J=1.8 Hz, 16H, FcH), 3.72 (s, 40H, FcH), 1.61 (s, 36H, tBu).


130.7, 126.3, 119.4, 113.4, 75.1, 69.5, 69.2, 68.1, 66.7, 66.3, 60.3, 53.2, 35.1, 31.5,

30.9, 21.0, 14.1.

MS (FAB, NBA): [m/z] = 3022 [M]+, 1511 [M]2+.


412 (54900), 434 (453500), 564 (32100), 601 (19400).

IR (ATR): = 2970, 2954, 2919, 2359, 2341, 1767, 1457, 1437, 1366, 1228.

EA for C164H148Fe8N28Zn: cal.: C 65.15, H 4.93, N 12.97;

found: C 64.87, H 5.07, N 12.77.


152

1-[4-(2-t-Butoxycarbonyl-ethyl)-heptandicarboxylix acid-di- t-butylester]-1’-(methoxyprop-2-yne)-ferrocene 75

An amount of 860 mg (3.14 mmol) 1,1‟-ferrocene dicarboxylic acid

is suspended in 20 mL EtOAc and 40 mL oxalyl chloride are added

to the mixture. The suspension is stirred at reflux until the mixture

turns clear, which lasts approx. 2 h. After cooling down to rt, the oxalyl chloride and

the solvent are removed using the oil pump. The residue is dissolved in CH2Cl2 and a

solution of 1.65 g (3.98 mmol) NH2 [G1], 0.22 mg (3.98 mmol) propargyl alcohol and

496.59 mg (6.3 mmol) pyridine dissolved in CH2Cl2 are added drop wise to the

solution. This mixture is stirred overnight, the solvent is distilled off and the crude

product is purified by flash chromatography (silica, hexane/THF, 7:1).

Yield: 403 mg (0.57 mmol), 18%.

1H NMR (300 MHz, CDCl3, 20°C): (ppm) = 6.32 (s, 1H, NH), 4.81 (t, 3J=1.9 Hz, 2H,

FcH), 4.79 (d, 4J=2.4 Hz, 2H, CH2), 4.66 (t, 3J=2.1 Hz, 2H, FcH), 4.44 (t, 3J=1.9 Hz,

2H, FcH), 4.35 (t, 3J=1.9 Hz, 2H, FcH), 2.53 (t, 4J=2.4 Hz, 1H, CH), 2.27 (t,

3J=7.7 Hz, 6H, CH2), 2.02 (t, 3J=7.8 Hz, 6H, CH2), 1.38 (s, 27H, tBu).

13C NMR (100.5 MHz, CDCl3, 20°C): (ppm) = 172.9 (3C, C=O), 170.4 (1C, C=O),

168.3 (1C, C=O), 80.5 (1C, C≡ CH), 78.9 (1C, FcCq), 78.5 (1C, FcCq), 74.8 (1C,

C≡ CH), 73.2 (2C, FcCH), 71.7 (2C, FcCH), 71.4 (2C, FcCH), 70.3 (1C, Cq), 69.5

(2C, FcCH), 57.6 (3C, tBu), 51.5 (1C, CH2), 29.9 (3C, CH2), 29.7 (3C, CH2), 27.8(9C,

tBu).


UV/Vis (CH2Cl2): l [nm] (e [lmol-1cm-1]) = 235 (12300), 256 (11400), 310 (3100), 445

(700).

IR (ATR): [cm-1] = 3291, 2970, 2359, 2341, 2160, 1719, 1653, 1521, 1366, 1217,

1149.

EA for C37H51FeNO9∙THF: cal: C 63.07, H 7.49, N 1.79;

found: C 62.77, H 7.97, N 1.69.


153

1-[9-Cascade:aminomethan[3]:(2-aza-3-oxopentylidin):propionacid-t-

butylester]-1’-(methoxyprop-2-yne)-ferrocene 85

An amount of 500 mg (1.83 mmol) 1,1‟-ferrocene dicarboxylic

acid is dissolved in 50 mL DMF and (1.83 mmol) NH2 [G2],

102.5 mg (1.83 mmol) propargyl alcohol, 540.5 mg (4 mmol)

HOBt, 488.7 mg (4 mmol) DMAP are added. After stirring for 5

min., 825.3 mg (4 mmol) DCC are added. The reaction mixture

is stirred at rt for 4 d under the exclusion of light. The solvent

is removed under reduced pressure and the brown crude product is purified by flash

chromatography (silica, CH2Cl2/EtOAc, 5:1).

Yield: 311.9 mg (0.18 mmol), 10%.

1H NMR (300 MHz, CDCl3, 20°C): (ppm) = 6.28 (s, 2H, NH), 4.86 (d, 4J=2.3 Hz,

2H, CH2), 4.80 (t, 3J=2.0 Hz, 2H, FcH), 4.77 (t, 3J=2.0 Hz, 2H, FcH), 4.53 (t,

3J=1.9 Hz, 2H, FcH), 4.38 (t, 3J=1.9 Hz, 2H, FcH), 2.65 (t, 4J=2.3 Hz, 1H, CH), 2.31

(t, 3J=7.3 Hz, 6H, CH2), 2.18 (t, 3J=6.4 Hz, 18H, CH2), 2.08 (t, 3J=7.3 Hz, 6H, CH2),

1.95 (t, 3J=6.4 Hz, 18H, CH2), 1.41 (s, 81H, tBu).


171.0 (1C, C=O), 168.9 (1C, C=O), 80.5 (3C), 80.4 (1C), 79.7 (1C), 78.4(1C), 75.3

(1C, C≡ CH), 72.8 (2C, FcCH), 71.8 (2C, FcCH), 71.3 (2C, FcCH), 70.7 (1C), 70.1

(2C, FcCH), 69.5 (1C), 57.9 (1C, tBu), 57.3 (3C, tBu), 57.2, 52.2 (1C, CH2), 31.8 (3C,

CH2), 31.6 (3C, CH2), 29.7 (9C, CH2), 29.6 (9C, CH2), 27.9 (21C, tBu).

MS (MALDI-TOF, DCTB): [m/z] = 1734 [MH]+, 1757 [M+Na]+.

UV/Vis (CH2Cl2): l [nm] (e [lmol-1cm-1]) = 235 (11000), 256 (9200), 310 (1900), 445

(500).

IR (ATR): [cm-1] = 2970, 2367, 2355, 2341, 2101, 1737, 1520, 1454, 1366, 1216,

1148.

EA for C91H144FeN4O24∙CH2Cl2: cal.: C 60.75, H 8.09, N 3.08;

found: C 60.82, H 8.47, N 3.02.


154

Mono(dendritic-ferrocene) conjugate 79

This reaction is carried out according to GP III with

100 mg (0.10 mmol) zinc monoazidoporphyrin 56,

109.6 (0.15 mmol) 75, 3.7 mg (0.02 mmol)

CuSO4·5 H2O, 5.9 mg (0.03 mmol) sodium

ascorbate and 38.8 mg (0.3 mmol) DIPEA. The

crude product is purified by flash chromatography

(silica, CH2Cl2/EtOAc, 50:1) to give the pure violet product.

Yield: 105.9 mg (0.063 mmol), 63%.

1H NMR (400 MHz, THF-d8, 20°C): (ppm) = 8.86 (m, 6H, b-pyrr.), 8.56 (d,

3J=4.5 Hz, 2H, b-pyrr.), 8.21 (d, 3J=7.8 Hz, 2H, ArH), 8.14 (m, 4H, ArH), 7.81 (m, 6H,

ArH), 7.70 (d, 4J=2.0 Hz, 1H, Ar*H), 7.56 (d, 4J=2.0 Hz, 1H, Ar*H), 6.30 (s, 1H,

triazole-H), 6.19 (s, 1H, NH), 5.07 (s, 2H, CH2), 4.88 (s, 2H, CH2), 4.47 (t, 3J=2.0 Hz,

2H, FcH), 4.43 (t, 3J=1.8 Hz, 2H, FcH), 4.23 (t, 3J=1.9 Hz, 2H, FcH), 3.77 (t,

3J=1.9 Hz, 2H, FcH), 2.14 (t, 3J=8.3 Hz, 6H, CH2), 1.98 (s, 3H, CH3), 1.91 (t, 3J=8.3

Hz ,6H, CH2), 1.62 (s, 27H, tBu), 1.55 (s, 9H, tBu), 1.33 (s, 27H, tBu).

13C NMR (100.5 MHz, THF-d8, 20°C): (ppm) = 173.1, 172.9, 171.7, 159.6, 152.8,

151.7, 150.7, 144.5, 140.0, 138.5, 136.4, 136.4, 130.8, 125.7, 124.5, 121.8, 114.7,

113.5, 80.3, 63.1, 60.8, 58.0, 54.1, 50.2, 35.9, 35.8, 33.4, 31.9, 30.9, 30.9, 30.7,

30.6, 30.2, 28.4, 28.3, 28.0, 27.2.


UV/Vis (CH2Cl2): l [nm] (e [lmol-1cm-1]) = 227 (5500), 230 (2400), 426 (287000). 554

(32000), 598 (13200).

IR (ATR): [cm-1] = 2971, 2931, 2367, 2338, 1737, 1456, 1366, 1229, 1217, 1206.

EA for C99H114FeN8O9Zn∙3 EtOAc∙2 EtOH: cal.: C 67.44, H 7.55, N 5.38;

found: C 67.42, H 7.30, N 5.11.


155

Bis(dendritic-ferrocene) conjugate 80

The synthesis is performed according to GP III

with the following amounts: 100 mg (0.1 mmol)

zinc bisazidoporphyrin 57, 213 mg (0.3 mmol) 75,

7.5 mg (0.03 mmol) CuSO4·5 H2O, 11.9 mg

(0.06 mmol) sodium ascorbate and 77.6 mg

(0.6 mmol) DIPEA. The purification of the crude

product is carried out by flash chromatography

(silica, CH2Cl2/EtOAc, 50:1 20:1) to give the pure product as violet powder.

Yield: 126.4 mg (0.052 mmol), 52%.

1H NMR (400 MHz, THF-d8, 20°C): (ppm) = 8.91 (m, 6H, b-pyrr.) 8.49 (d,

3J=4.8 Hz, 2H, b-pyrr.), 8.23 (d, 3J=8.1 Hz, 4H, ArH), 8.17 (d, 3J=8.1 Hz, 2H, ArH),

7.86 (m, 6H, ArH) 7.76 (s, 2H, Ar*H), 6.40 (s, 2H, triazole-H), 6.24 (s, 2H, NH), 5.19

(s, 4H, CH2), 4.91 (s, 4H, CH2), 4.50 (t, 3J=1.9 Hz, 2H, FcH) 4.47 (t, 3J=1.9 Hz, 2H,

FcH), 4.27 (t, 3J=1.9 Hz, 2H, FcH), 3.83 (t, 3J=1.9 Hz, 2H, FcH), 2.17 (t, 3J=8.6 Hz,

12H, CH2), 1.95 (t, 3J=8.6 Hz, 12H, CH2), 1.65 (s, 18H, tBu), 1.64 (s, 9H, tBu), 1.54

(s, 9H, tBu), 1.35 (s, 54H, tBu).


151.3, 151.2, 151.0, 150.4, 143.1, 141.4, 141.3, 140.1, 138.5, 135.5, 135.4, 133.7,

132.6, 132.6, 130.5, 126.4, 124.6, 124.3, 124.2, 122.5, 122.1, 113.1, 80.4, 80.2,

73.8, 72.6, 72.1, 71.9, 70.4, 58.4, 57.7, 53.1, 35.8, 35.6, 32.1, 32.1, 31.9, 30.3, 28.3.



601 (3200).

IR (ATR): [cm-1] = 2967, 1720, 1666, 1366, 1272, 1229, 1216, 1148, 995, 795.

EA for C136H164Fe2N12O18Zn∙CH2Cl2: cal.: C 65.38, H 6.65, N 6.60;

found: C 65.03, H 6.92, N 6.43.


156

Syn(dendritic-ferrocene) conjugate 81

According to GP III, the following amounts are

used: 100 mg (0.096 mmol) zinc

synazidoporphyrin 58, 205.8 mg (0.29 mmol)

75, 7.3 mg (0.029 mmol) CuSO4·5 H2O,

11.5 mg (0.058 mol) sodium ascorbate and

75.0 mg (0.58 mmol) DIPEA. Final Purification

can be achieved by flash chromatography

(silica, CH2Cl2/EtOAc, 50:14:1) whereas the

product can be isolated in the third fraction.

Yield: 132.4 mg (0.054 mmol), 56%.

1H NMR (400 MHz, THF-d8, 20°C): (ppm) = 8.88 (d, 3J=4.8 Hz, 4H, b-pyrr.), 8.59

(d, 3J=4.8 Hz, 4H, b-pyrr.), 8.26 (dd, 3J=8.0 Hz, 4J= 1.9 Hz, 2H, ArH), 8.16 (dd,

3J=8.1 Hz, 4J=1.8 Hz, 2H, ArH), 7.85 (dd, 3J=8.0 Hz, 4J=1.9 Hz, 2H, ArH), 7.81 (dd,

3J=8.1 Hz, 4J=1.8 Hz, 2H, ArH), 7.70 (d, 4J=1.5 Hz, 2H, Ar*H), 7.54 (d, 4J=1.8 Hz, 2H,

Ar*H), 6.79 (s, 2H, triazole-H), 6.31 (s, 2H, NH), 5.12 (s, 4H, CH2), 5.01 (s, 4H, CH2),

4.62 (t, 3J=1.9 Hz, 4H, FcH), 4.55 (t, 3J=1.9 Hz, 4H, FcH), 4.33 (t, 3J=1.9 Hz, 4H,

FcH), 3.96 (d, 3J=1.9 Hz, 4H, FcH), 2.21 (t, 3J=8.8 Hz, 12H, CH2), 1.99 (t, 3J=8.8 Hz,

12H, CH2), 1.96 (s, 6H, CH3), 1.63 (s, 18H, tBu), 1.55 (s, 18H, tBu), 1.37 (s, 54H,

tBu).


151.1, 150.7, 143.4, 141.4, 140.6, 140.4, 137.9, 135.8, 135.5, 133.6, 130.8, 127.2,

124.8, 124.5, 124.2, 123.8, 121.9, 116.8, 80.6, 80.3, 74.0, 72.8, 72.3, 72.0, 70.6,

58.5, 57.9, 53.4, 35.6, 32.1, 32.0, 30.3, 28.3, 22.1.

MS (MALDI-TOF, DHB): [m/z] = 2459 [M]+, 2482 [M+Na]+.


601 (3900).

IR (ATR): [cm-1] = 2975, 2860, 1711, 1522, 1460, 1392, 1273, 1148, 1050, 1027.

EA for C138H168Fe2N12O18Zn∙½ CH2Cl2: cal.: C 66.42, H 6.88, N, 6.71;

found: C 66.49, H 7.01, N, 6.69.


157

Anti(dendritic-ferrocene) conjugate 82

This reaction is carried out according

to GP III with 100 mg (0.01 mmol)

zinc antiazidoporphyrin 59, 205.8 mg

(0.29 mmol) 75, 7.2 mg (0.03mmol)

CuSO4·5 H2O, 11.5 mg (0.04 µmol)

sodium ascorbate and 75.0 mg

(0.6 mmol) DIPEA. The crude

product can be purified by flash

chromatography (silica, CH2Cl2/EtOAc, 50:1 5:1) to give the pure violet product.

Yield: 125.3 mg (0.051 mmol), 53%.

1H NMR (400 MHz, THF-d8, 20°C): (ppm) =8.87 (d, 3J=4.8 Hz, 4H, b-pyrr.), 8.57 (d,


7.70 (d, 4J=1.5 Hz, 2H, Ar*H), 7.57 (d, 4J=1.5 Hz, 2H, Ar*H), 6.59 (s, 2H, triazole-H),

6.24 (s, 2H, NH), 5.09 (s, 4H, CH2), 4.98 (s, 4H, CH2), 4.57 (t, 3J=1.9 Hz, 4H, FcH),


FcH), 2.17 (m, 12H, CH2), 1.99 (s, 6H, CH3), 1.94 (m, 12H, CH2), 1.62 (s, 18H, tBu),

1.55 (s, 18H, tBu), 1.34 (s, 54H, tBu).


150.7, 143.3, 141.3, 140.5, 140.5, 138.0, 135.7, 133.6, 130.9, 127.3, 124.7, 124.3,

122.0, 116.9, 80.5, 80.2, 73.9, 72.7, 72.2, 72.0, 70.5, 35.6, 32.1, 32.0, 30.3, 28.3,

25.8, 25.7, 25.6, 25.5, 25.4, 25.3, 25.2, 25.1, 24.9.

MS (MALDI-TOF, DHB): [m/z] = 2459 [M]+, 2482 [M+Na]+.


557 (18000), 602 (4200).

IR (ATR): [cm-1] = 2970, 1720, 1666, 1523, 1457, 1366, 1272, 1228, 1148, 1064.

EA for C138H168Fe2N12O18Zn∙½ CH2Cl2: cal.: C 66.42, H 6.88, N 6.71;

found: C 66.36, H 7.05, N 6.51.


158

Tetrakis(dendritic-ferrocene) conjugate 83

This reaction is carried out according to GP III

with 250 mg (0.23 mmol) zinc

tetrakisazidoporphyrin 60, 979.3 mg

(1.38 mmol) 75, 32.5 mg (0.14 mmol)


ascorbate and 336.1 mg (2.60 mmol) DIPEA.

The crude product is purified by flash

chromatography (silica, CH2Cl2/EtOAc, 50:1

2:1): Only two fractions can be separated: the first one contains excessive 75. The

second one contains the product, which can be obtained as a violet powder after

evaporating of the solvent.

Yield: 838.3 mg (0.21 mmol), 92%.



7.66 (s, 4H, ArH), 6.33 (s, 4H, triazole-H), 6.27 (s, 4H, NH), 5.17 (s, 8H, CH2), 4.80

(s, 8H, CH2), 4.48 (t, 3J=2.0 Hz, 8H, FcH), 4.33 (d, 3J=1.8 Hz, 8H, FcH), 4.25 (d,

3J=1.8 Hz, 8H, FcH), 3.90 (d, 3J=1.8 Hz, 8H, FcH), 2.17 (t, 24H, CH2), 1.91 (t, 24H,

CH2), 1.61 (s, 18H, tBu), 1.50 (s, 18H, tBu), 1.35 (s, 108H, tBu).


149.8, 148.6, 141.6, 138.9, 138.5, 136.3, 133.8, 133.0, 128.0, 125.2, 123.3, 122.9,

122.3, 111.4, 79.9, 78.2, 68.8, 57.0, 56.3, 52.3, 35,8, 34.0, 32.1, 30.0, 29.2, 29.1,

27.3.

MS (MALDI-TOF, sin): [m/z] = 3961 [M]+, 3984 [M+Na]+.


558 (16700), 599 (8300).

IR (ATR): [cm-1] = 2980, 2861, 1720, 1520, 1460, 1392, 1273, 1148, 1050, 1027.

EA for C212H268Fe4N20O36Zn∙CH2Cl2: cal.: C 63.23, H 6.73, N 6.92;

found: C 62.70, H 6.84, N 6.83.


159

Octakis(dendritic-ferrocene) conjugate 84

This reaction is carried out according to

GP III with 200 mg (0.15 mmol) zinc

octakisazidoporphyrin 55, 1.31 g (1.8 mmol)

ferrocene derivative 75, 45 mg (0.18 mmol)



The crude product can be purified by flash

chromatography (silica, CH2Cl2/EtOAc,

50:1 1:1) to give the pure orange brown

product.

Yield: 979.3 mg (0.14 mmol), 93%.


7.29 (s, 8H, triazole-H), 6.40 (s, 8H, NH), 5.26 (s, 16H, CH2), 5.00 (s, 16H, CH2), 4.62

(s, 16H, FcH), 4.52 (s, 16H, FcH), 4.32 (s, 16H, FcH), 4.07 (s, 16H, FcH), 2.27 (t,

3J=7.3 Hz, 48H, CH2), 2.03 (t, 3J=7.3 Hz, 48H, CH2), 1.45 (s, 36H, tBu), 1.38 (s,

216H, tBu).


142.7, 138.3, 137.2, 131.1, 125.3, 124.4, 113.6, 80.6, 78.7, 73.2, 71.9, 71.2, 69.5,

57.6, 56.9, 52.9, 35.0, 31.3, 30.0, 29.8, 27.9.

MS (MALDI-TOF, DCTB): [m/z] = 7022 [M]+, 7090 [M+3 Na]+.


562 (18500), 597 (33400).

IR (ATR): [cm-1] = 2975, 1706, 1523, 1460, 1392, 1273, 1148, 1050, 1027, 845.

EA for C364H476Fe8N36O72Zn∙3 CHCl3: cal.: C 60.56, H 6.64, N 6.65;

found: C 60.71, H 6.69, N 6.98.


160

Syn(dendritic-NEKOME 2nd generation-ferrocene) conjugate 86

An amount of 250.3 mg (0.15 mmol) 75 is

converted with 50 mg (0.048 mmol) zinc

synazidoporphyrin 58 according to GP III.

3.8 mg (0.015 mmol) CuSO4∙5 H2O,

5.9 mg (0.03 mmol) sodium ascorbate

and 38.7 mg (0.3 mmol) DIPEA are used

in this “click” reaction. Purification

succeeds by flash chromatography

(silica, CH2Cl2/EtOAc, 5:11:2 ).

Yield: 110.1 mg (0.031 mmol), 65%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 8.81 (d, 3J=4.6 Hz, 4H; β-pyrr.), 8.47 (d,

3J=4.6 Hz, 4H; β-pyrr.), 8.28 (dd, 3J=7.9 Hz, 4J=1.8 Hz, 2H; ArH), 8.07 (dd,

3J=8.1 Hz, 4J=1.7 Hz, 2H, ArH), 7.86 (s, 2H, Ar*H), 7.78 (dd, 3J=8.1 Hz, 4J=2.0 Hz,

2H, ArH), 7.70 (dd, 3J=8.1, 4J=2.0 Hz, 2H, ArH), 7.62 (d, 4J=1.5 Hz, 2H, Ar*H), 7.47

(s, 2H), 7.07 (br. s, 2H, NH), 6.27 (br. s, 2H, triazole-H), 5.13 (br. s, 4H, CH2), 4.96

(br. s, 4H, CH2), 4.61 (br. s, 4H, FcH), 4.59 (s, 4H, FcH), 4.36 (s, 4H, FcH), 4.08 (s,

4H, FcH), 2.16 (m, 48H, CH2), 1.92 (m, 48H, CH2), 1.59 (s, 18H, tBu), 1.55 (s, 18H,

tBu), 1.38 (s, 162H, tBu).


199.0, 197.7, 197.3, 196.6, 189.6, 183.4, 181.7, 180.0, 177.1, 171.2, 170.7, 168.0,

162.6, 127.8, 120.3, 118.9, 118.8, 117.3, 115.1, 105.1, 104.6, 82.1, 79.1, 79.0, 78.8,

75.3, 75.1, 69.0, 64.6, 63.6, 62.9, 61.8, 20.5, 20.2.



559 (18400), 599 (7800).

IR (ATR): [cm-1] = 2970, 2890, 2341, 1736, 1522, 1367, 1229, 1217, 1152, 668.

EA for C246H354Fe2N18O48Zn∙2 CH2Cl2: cal.: C 63.67, H 7.71, N 5.39;

found: C 63.54, H 7.90, N 5.05.


161

Dipropargyl ferrocene dicarboxylate 74

An amount of 500 mg (1.82 mmol) 1,1‟-ferrocene dicarboxylic acid,

204.0 mg (3.65 mmol) propargyl alcohol, 445.7 mg (3.65 mmol) DMAP

and 492.9 mg (3.65 mmol) HOBt is dissolved in 100 mL CH2Cl2. The mixture is

cooled to 0°C. 753.1 mg (3.65 mmol) DCC dissolved in 10 mL CH2Cl2 are added and

the solution is stirred at rt for 3 d. The solvent is evaporated off under reduced

pressure and the orange residue is purified by flash chromatography (silica,

CH2Cl2/EtOAc, 5:1).

Yield: 590 mg (1.68 mmol), 92%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 4.86 (t, 3J=2.1 Hz, 4H, FcH), 4.81 (d,

4J=2.4 Hz, 4H, CH2), 4.46 (d, 4J=2.1 Hz, 4H, FcH), 2.49 (t, 4J=2.4 Hz, 2H, CH).

13C NMR (100.5 MHz, CDCl3, 20°C): (ppm) = 169.9, 78.3, 74.7, 73.2, 71.8, 71.6,

69.8, 51.0.

MS (FAB, NBA): [m/z] = 350 [M]+.


IR (ATR): [cm-1] = 3266, 2953, 2920, 2200, 1722, 1674, 1460, 1398, 1372, 1268,

1124.

EA for C18H14FeO4: cal.: C 61.74, H 4.03;

found: C 61.83, H 4.06.

3,5-Bis(propargyloxy)benzoic acid 92

10 g (64.90 mmol) 3,5-dihydroxy benzoic acid, 171.8 mg (0.65 mmol)

18-crown 6-ether, 20 g K2CO3 and 19.1 g (129.76 mmol) propargyl

bromide (80% in toluene) are suspended in 200 mL acetone and stirred at reflux for

24 h. After cooling down, the solvent is removed, the residue is redissoved in CH2Cl2

and the salt is filtrated off. After washing the organic layer twice with H2O, the solvent

is removed under reduced pressure and the brown crude product is recrystallized

from EtOH. The obtained white solid is dissolved in THF and 100 mL 1N NaOH are

added. This reaction mixture is refluxed for 24 h. After cooling down, the solution is

neutralized with citric acid. 100 mL CH2Cl2 are added to the mixture and the organic


162

layer is washed three times with H2O, dried over MgSO4 and purified by flash

chromatography (silica, EtOAc). The product can be obtained as a white solid.

Yield: 4.38 g (19.03 mmol), 29%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 13.13 (br. s, 1H, COOH), 7.17 (d, 4J=2.4

Hz, 2H, PhH), 6.85 (t, 4J=2.3 Hz, 1H, PhH), 4.85 (d, 4J=2.4 Hz, 4H, CH2), 3.60 (t,

4J=2.4 Hz, 2H, CH).


79.0, 78.7, 55.8.

MS (FAB, NBA): [m/z] = 230 [M]+, 191 [M-CH2-C≡ CH]+.


IR (ATR): = 2994, 2905, 2863, 1683, 1604, 1481, 1306, 1267, 1204, 995.

EA for C13H10O4∙⅓ EtOH: cal.: C 66.86, H 4.93;

found: C 66.77, H 4.46.

Di-t-butyl-4-(3,5-bis(propargyloxy)-benzamido)-4-(3-tert-butoxy-3-oxo-

propyl) heptanedioate 93

350 mg (1.52 mmol) 92, 631.9 mg (1.52 mmol) NH2 [G1], 185.7 mg

(1.52 mmol) DMAP and 205.2 mg (1.52 mmol) HOBt are dissolved

in DMF. The solution is cooled to 0°C, 313.6 mg (1.52 mmol) DCC

is added and the mixture is stirred at rt for 3 d. After removing the

solvent under reduced pressure, the crude product is purified by flash

chromatography (silica; EtOAc). The yellow oily product elutes in the first fraction.

Yield: 400.2 mg (0.64 mmol), 42%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 7.04 (d, 4J=2.4 Hz, 2H, PhH), 6.87 (br.

s, 1H, NH), 6.72 (t, 4J=2.3 Hz, 1H, PhH), 4.71 (d, 4J=2.4 Hz, 4H, CH2), 2.54 (t,

4J=2.4 Hz, 2H, CH), 2.28 (t, 3J=7.8 Hz, 6H, CH2), 2.09 (t, 3J=7.8 Hz, 6H, CH2), 1.43

(s, 27H, tBu).


105.4, 80.8, 78.0, 75.9, 57.7, 56.1, 30.1, 29.8, 28.0.


163

MS (FAB, NBA): [m/z] = 628 [M]+, 460, 213.

UV/Vis (CH2Cl2): l [nm] (e [lmol-1cm-1]) =243 (7100), 248 (6800), 294 (2800).

IR (ATR): [cm-1] = 3317, 3295, 2980, 2933, 2157, 1976, 1722, 1638, 1598, 1216.

EA for C35H49NO9∙EtOAc: cal.: C 65.43, H 8.03, N 1.96;

found: C 65.50, H 7.75, N 2.08.

Di-t-butyl-4-(4-bromobutyrylamido)-4-(3-t-butoxy-3-oxopropyl)-heptanedioate

114

1.2 g (6.47 mmol) 4-bromo butyryl chloride, 2.69 g (6.47 mmol)

NH2 [G1] and 511.78 mg (6.47 mmol) pyridine are dissolved in

100 mL CH2Cl2. After stirring for 2 d, the solvent is distilled under

reduced pressure and the crude product is purified by flash

chromatography (silica, cyclohexane/EtOAc, 2:1). The product is yielded as a white

solid.

Yield: 2.44 g (4.33 mmol); 67%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 6.00 (br. s, 1H, NH), 3.58 (t, 3J=6.2 Hz,

2H, CH2), 2.29 (t, 3J=7.1 Hz, 2H, CH2), 2.21 (d, 3J=7.9 Hz, 6H, CH2), 2.06 (t,

3J=6.8 Hz, 2H, CH2), 1.96 (t, 3J=7.9 Hz, 6H, CH2), 1.43 (s, 27H, tBu).


80.7 (3C, Cq), 57.5 (1C, Cq), 44.4 (1C, CH2), 33.8 (1C, CH2), 29.9 (3C, CH2), 29.8

(3C, CH2), 28.0 (9C, tBu).

MS [EI+]: [m/z] = 565 [M]+, 519, 410.

IR (ATR): [cm-1] = 3360, 2970, 2860, 2943, 1720, 1675, 1417, 1366, 1320, 1248.

EA for: C26H46BrNO7∙C6H12: cal.: C 59.25, H 9.01, N 2.16;

found: C 59.33, H 8.85, N 2.58.


164

Di-t-butyl-4-(4-azidobutyrylamido)-4-(3-t-butoxy-3-oxopropyl)-heptanedioate

116

An amount of 820 mg (1.46 mmol) di-t-butyl-4-(4-

bromobutyrylamido)-4-(3-t-butoxy-3-oxopropyl)-heptanedioate 114

and 1.90 g (29.20 mmol) NaN3 is dissolved in 80 ml DMF and the

reaction mixture is stirred for 24 h at 50°C. The solvent is distilled

under reduced pressure and the crude product is redissolved in EtOAc. Excessive

NaN3 is removed by filtration and the organic filtrate is washed twice with H2O. The

combined organic layers are dried over MgSO4 and after removing the solvent, the

product is yielded as a white solid.

Yield: 732.9 mg, (1.39 mmol), 95%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 6.05 (s, 1H, NH), 3.57 (t, 3J=6.2 Hz, 2H,

CH2), 3.33 (t, 3J=6.6 Hz, 2H, CH2), 2.21 (d, 3J=7.9 Hz, 6H, CH2), 1.96 (d, 3J=7.9 Hz,

6H, CH2), 1.88 (t, 3J=7.0 Hz, 2H, CH2), 1.42 (s, 27H, tBu).


33.8, 29.9, 28.0.

MS (FAB, NBA): [m/z] = 528 [M]+.

IR (ATR): [cm-1] = 3359, 2971, 2943, 2102, 1718, 1675, 1417, 1366, 1320, 1248.

EA for C26H46N4O7∙EtOAc: cal.: C 58.61, H 8.85, N 9.11;

found: C 59.38, H 8.59, N 8.69.


165

Capped ferrocene porphyrin 88

The synthesis is carried out according to GP III with following

amounts: 100 mg (0.096 mg) zinc synazidoporphyrin 58,

33.6 mg (0.01 mmol) dipropargyl ferrocene dicarboxylate 74,

7.2 mg (0.03 mmol) CuSO4·5 H2O, 11.5 mg (0.06 mmol)

sodium ascorbate and 75.0 mg (0.58 mmol) DIPEA. The

volume of CH2Cl2 is increased to 150 mL in this approach. Purification by flash

chromatography (silica, CHCl3 CHCl3/EtOAc, 50:1) gives the product as a purple

solid.

Yield: 70 mg (0.05 mmol), 52%.



7.85 (d, 4J=1.7 Hz, 2H, Ar*H), 7.76 (d, 3J=9.3 Hz, 4H, ArH), 7.69 (d, 4J=1.5 Hz, 2H,

Ar*H), 5.05 (s, 4H, CH2), 4.16 (s, 4H, CH2), 4.00 (s, 2H, triazole-H), 3.69 (t,

3J=2.0 Hz, 4H, FcH), 3.30 (s, 4H, FcH), 2.08 (s, 6H, CH3,), 1.64 (s, 18H, tBu), 1.62 (s,

18H, tBu).

13C NMR (100.5 MHz, CDCl3, 20°C): (ppm) = 169.9 (2C), 151.7 (2C), 150.5 (4C),

150.2 (2C), 149.8 (2C), 149.8 (4C), 140.5 (2C), 140.1 (2C), 140.0 (2C), 139.5 (2C),

136.1 (2C), 134.4 (4C), 134.0 (4C), 132.9 (4C), 130.2 (4C), 127.2 (4C), 125.0 (4C),

124.6 (2C), 122.4 (4C), 120.8 (2C), 115.6 (2C), 72.1 (4C), 71.1 (2C), 70.4 (4C), 56.4

(2C), 53.2(2C), 34.8 (4C), 31.6 (12C), 30.0 (2C).

MS (FAB, NBA): [m/z] = 1390 [M]+, 953 [M-ferrocenylbistriazole]+.


IR (ATR): [cm-1] = 2970, 2929, 2865, 2853, 2358, 2341, 1718, 1560, 1270, 1137.

EA for C82H80FeN10O4Zn·½ CHCl3: cal.: C 68.31, H 5.59, N 9.66;

found: C 68.66, H 5.51, N 9.61.


166

Double-capped ferrocene porphyrin 89

According to GP III 200 mg (0.18 mmol) zinc

tetrakisazidoporphyrin 60 are converted with 126.2 mg

(0.36 mmol) dipropargyl ferrocene dicarboxylate 74. In this

case, 150 mL CH2Cl2 are used to dissolve the starting

materials. The amounts of the other substances are:

10.0 mg (0.04 mmol) CuSO4·5 H2O, 15.8 mg (0.08 mmol)

sodium ascorbate and 93.1 mg (0.72 mmol) DIPEA. The crude

product is purified by flash chromatography (silica, CH2Cl2/EtOAc, 40:120:1).

Yield: 120.4 mg (0.07 mmol), 37%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 8.79 (d, 4H, 3J=4.6 Hz, β-pyrr.), 8.22 (d,

4H, 3J=8.1 Hz, ArH), 8.17 (d, 4H, 3J=4.6 Hz, β-pyrr.), 8.13 (s, 4H, Ar*H), 7.78 (d, 4H,

3J=8.1 Hz, ArH), 5.26 (s, 8H, CH2), 4.15 (s, 8H, CH2), 4.08 (s, 4H, triazole-H), 3.78 (t,

8H, 3J=1.8 Hz, FcH), 3.58 (s, 8H, FcH), 1.69 (s, 18H, tBu), 1.61 (s, 18H, tBu).

13C NMR (100.5 MHz, CDCl3, 20°C): (ppm) = 169.4(4C), 153.0 (2C), 150.9 (4C),

150.53 (2C), 149.8 (4C), 140.7 (4C), 140.6 (2C), 140.5 (2C), 136.6 (4C), 134.0 (4C),

133.5 (4C), 130.0 (4C),128.4 (4C), 124,6 (4C), 123.5 (4C), 121.7 (2C), 112.5 (2C),

71.8 (4C), 71.4 (4C), 70.5 (4C), 56.1 (4C), 53.0 (4C), 35.1 (2C), 34.8 (2C), 31.6 (6C),

31.5 (6C).

MS (FAB, NBA): [m/z] = 1822 [M]+, 950 [M-2∙ferrocenylbistriazole]+.


IR (ATR): [cm-1] = 3387, 2962, 2901, 2358, 2341, 1718, 1560, 1461, 1132, 994.

EA for C100H92Fe2N16O8Zn·CH2Cl2: cal.: C 63.58; H 4.97; N 11.75;

found: C 63.86; H 5.34; N 11.94.


167

Capped dendritic porphyrin 94

According to GP III, 100 mg (0.096 mg) zinc

synazidoporphyrin 58 are converted with 60.3 mg

(0.096 mmol) 93. Furthermore, 7.5 mg (0.029 mmol)


75.0 mg (0.58 mmol) DIPEA are added to the solution. After

purification by flash chromatography (silica, CH2Cl2/EtOAc

30:1) the product can be obtained as a purple solid.

Yield: 96.8 mg (0.054 mmol), 56%.



7.85 (s, 2H, Ar*H), 7.75 (d, 3J=7.8 Hz, 2H, ArH), 7.71 (d, 3J=8.1 Hz, 2H, ArH), 7.66

(s, 2H, Ar*H), 6.45 (s, 2H, PhH), 6.14 (br. s, 1H, NH), 5.85 (br. s, 1H, PhH), 5.21 (br.

s, 6H, triazole-H, CH2), 4.19 (s, 4H, CH2), 2.07 (t, 3J=7.9 Hz, 6H, CH2), 1.88 (d,

3J=7.9 Hz, 6H, CH2), 1.84 (s, 6H, CH3), 1.65 (s, 18H, tBu), 1.61 (s, 18H, tBu), 1.32 (s,

27H, tBu).


150.3, 149.5, 141.8, 140.2, 139.8, 139.7, 137.1, 135.5, 134.5, 133.9, 132.7, 130.2,

127.4, 124.9, 123.5, 122.9, 120.8, 115.7, 107.1, 80.6, 77.3, 60.8, 57.4, 54.0, 34.9,

34.8, 31.6, 31.6, 29.7, 29.5, 27.9, 21.7.

MS (FAB, NBA): [m/z] = 1668 [M]+, 953 [M-phenylbistriazole]+.


IR (ATR): [cm-1] = 2970, 2870, 2355, 1723, 1591, 1520, 1455, 1366, 1229, 1217.

EA for C99H115N11O9Zn∙EtOAc: cal.: C 70.43, H 7.06, N 8.77;

found: C 70.05, H 7.02, N 9.01.


168

Double-capped dendritic porphyrin 95

200 mg (0.18 mmol) zinc tetrakisazidoporphyrin 60 are

brought to reaction according to GP III with following

substances and amounts: 226.0 mg (0.36 mmol) 93, 10.0 mg


ascorbate and 93.1 mg (0.72 mmol) DIPEA. After purification

by flash chromatography (silica, CH2Cl2/EtOAc, 20:1) the

product can be obtained as a purple powder.

Yield: 74.2 mg (0.074 mmol), 41%.


3J=4.6 Hz, 4H, β-pyrr.), 8.15 (d, 3J=8.3Hz, 4H, ArH), 8.10 (s, 4, Ar*H), 7.72 (d,

3J=8.5 Hz, 4H, ArH), 6.41 (d, 4J=2.2 Hz, 4H, PhH), 6.18 (br. s, 2H, NH), 5.63 (br. s,

2H, PhH), 5.19 (s, 8H, CH2), 5.00 (s, 4H, triazole-H), 4.25 (s, 8H, CH2), 2.03 (t,

3J=7.8 Hz, 12H, CH2), 1.85 (t, 3J=7.6 Hz, 12H, CH2), 1.69 (s, 18H, tBu), 1.60 (s, 18H,

tBu) 1.29 (s, 54H, tBu).


150.7, 149.4, 142.2, 140.2,139.3, 137.2, 136.8, 134.2, 133.2, 130.1, 128.5, 123.8,

122.7, 121.6, 112.7, 107, 80.6, 77.3, 61.1, 57.5, 53.3, 35.2, 34.9, 31.6, 31.5, 31.0,

29.8, 29.6, 29.5, 28.0, 27.9, 27.9.

MS (FAB, NBA): [m/z] = 2376 [M]+, 950 [M-2∙phenylditriazole]+.


IR (ATR): [cm-1] = 2970, 2933, 3870, 2223, 1722, 1668, 1590, 1522, 1456, 1303.

EA for C134H162N18O18Zn∙CH2Cl2: cal.: C 65.83, H 6.71, N 10.24;

found: C 66.27, H 7.09, N 9.89.


169

Ferrocene-linked porphyrin dimer 96

The synthesis is carried out according to

GP III with 200 mg (0.21 mmol) zinc

monoazidoporphyrin 56 and 36 mg

(0.10 mmol) dipropargyl ferrocene

dicarboxylate 74. As catalyst, 5.0 mg

(0.02 mmol) CuSO4·5 H2O, 7.9 mg

(0.04 mmol) sodium ascorbate and 54.3 mg (0.42 mmol) DIPEA are added.

Purification by flash chromatography (silica, CH2Cl2/EtOAc 20:1) delivers the product

as a purple solid.

Yield: 150.3 mg (0.07mmol), 31% based on 74.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 8.89 (s, 8H, β-pyrr.), 8.58 (d, 3J=4.6 Hz,

4H, β-pyrr.), 8.12 (s, 8H, ArH), 8.03 (d, 3J=6.8 Hz, 8H, ArH, β-pyrr.), 7.77 (d,

3J=6.8 Hz, 6H, ArH), 7.71 (d, 3J=8.5 Hz, 8H, ArH, Ar*H), 7.50 (d, 4J=1.7 Hz, 2H,

Ar*H), 6.50 (s, 2H, triazole-H), 4.24 (s, 4H, CH2), 3.76 (s, 4H, FcH), 3.53 (s, 4H,

CH2), 3.35 (s, 4H, FcH), 2.01 (s, 6H, CH3), 1.66 (s, 18H, tBu), 1.63 (s, 36H, tBu), 1.35

(s, 18H, tBu).


189.9, 140.4, 140.4, 140.1, 139.2, 138.9, 135.1, 134.8, 134.6, 132.6, 131.9, 131.8,

129.1, 126.5, 123.4, 123.3, 121.1, 120.8, 114.2, 71.8, 71.0, 70.9, 34.8, 34.7, 34.5,

31.3, 21.8.

MS (FAB, NBA): [m/z] = 2292 [M]+, 1052 [M-porphyrin]+, 927 [M-(porphyrinyl-

ferrocenyl)bistriazole]+.


IR (ATR): [cm-1] = 2969, 2922, 2853, 1718, 1524, 1461, 1270, 1130, 995, 795.

EA for C142H14FeN14O4Zn·EtOH·CH2Cl2: cal.: C 71.90, H 6.08, N 8.10;

found: C 72.60, H 6.29, N 8.04.


170

Alkyne ferrocene-porphyrin conjugate 99

The synthesis is carried out according to GP III with


monoazidoporphyrin 56, 70 mg (0.2 mmol) dipropargyl

ferrocene dicarboxylate 74, 2.5 mg (0.01 mmol)

CuSO4·5 H2O, 4.0 mg (0.02 mmol) sodium ascorbate, and

27.2 mg (0.2 mmol) DIPEA. After purification by flash chromatography (silica, CHCl3)

the product can be obtained as a purple solid.

Yield: 89.4 mg (0.068 mmol), 68% based on 56.


3J=4.6 Hz, 4H, β-pyrr.), 8.38 (d, 3J=4.6 Hz, 2H, β-pyrr.), 8.18 (d, 3J=8.4 Hz, 2H, ArH),

8.13 (d, 3J=7.8 Hz, 2H, ArH), 8.00 (d, 3J=7.3 Hz, 2H, ArH), 7.92 (br. s, 1H, Ar*H),

7.77 (d, 3J=7.9 Hz, 2H, ArH), 7.73 (d, 3J=8.1 Hz, 2H, ArH), 7.68 (d, 3J=7.3 Hz, 2H,

ArH), 7.61 (s, 1H, Ar*H), 4.51 (br. s, 2H, CH2), 3.99 (d, 4H, FcH), 3.93 (s, 4H, FcH),

3.65 (s, 2H, CH2), 3.14 (br. s, 2H, CH2), 2.00 (s, 3H, CH3), 1.77 (m, 1H, CH), 1.63 (s,

18H, tBu), 1.61 (s, 9H, tBu), 1.50 (s, 9H, tBu).


149.9, 149.5, 140.1, 139.8, 139.6, 135.6, 134.6, 134.5, 134.5, 134.4, 132.7, 131.9,

129.8, 126.8, 123.5, 123.4, 123.3, 123.0, 121.3, 120.6, 114.9, 74.0, 72.1, 72.0, 71.2,

71,0, 50.1, 34.8, 34.7, 31.7, 31.5, 29.6, 21.8.

MS (FAB, NBA): [m/z] = 1321 [M]+, 980, 927 [M+-ferrocenyltriazole] +.


IR (ATR): [cm-1] = 3298, 3006, 2970, 2948, 1719, 2514, 1610, 1437, 1366, 1229,

1217.

EA for C80H76FeN7O4Zn·2 EtOH: cal.: C 71.41, H 6.28, N 6.94;

found: C 71.35, H 6.28, N, 6.90.


171

Ferrocene-linked porphyrin trimer 97

The synthesis is carried out according to

GP III using following substances and

amounts: 200 mg (0.15 mmol) 99 and

25.54 mg (0.05 mmol) zinc

bisazidoporphyrin 57. Furthermore, 1.2 mg

(0.005 mmol) CuSO4·5 H2O, 2 mg

(0.01 mmol) sodium ascorbate, and

12.9 mg (0.1 mmol) DIPEA are used in

this reaction. Purification can be achieved

after flash chromatography (silica;

CHCl3 CHCl3:EtOAc, 100:1) delivering

pure 97 after evaporating off the solvent.


1H NMR (400 MHz, THF-d8, 20°C): (ppm) = 8.83 (s, 12H, β-pyrr.), 8.78 (d,

3J=4.7 Hz, 4H, β-pyrr.), 8.73 (d, 3J=4.5 Hz, 2H, β-pyrr.), 8.47 (d, 3J=4.7 Hz, 4H, β-

pyrr.), 8.32 (d, 3J=4.7 Hz, 2H, β-pyrr.), 8.08 (m, 18H, Ar-H), 7.76 (d, 3J=8.5 Hz, 18H,

ArH), 7.64 (s, 2H, Ar*H), 7.56 (s, 2H, Ar*H), 7.40 (s, 2H, Ar*H), 6.11 (s, 2H, triazole-

H), 6.09 (s, 2H, triazole-H), 4.98 (s, 4H, CH2), 4.91 (s, 4H, CH2), 4.50 (s, 4H, CH2)

4.45 (s, 4H, CH2), 3.99 (t, 3J=1.9 Hz, 4H, FcH), 3.96 (t, 3J=1.9 Hz, 4H, FcH), 3.68 (t,

3J=1.9 Hz, 4H, FcH) 3.66 (t, 3J=1.9 Hz, 4H, FcH), 1.93 (s, 6H, CH3), 1.61 (s, 18H,

tBu) 1.60 (s, 9H, tBu), 1.58 (s, 36H, tBu), 1.55 (s, 18H, tBu) ,1.47 (s, 18H, tBu), 1.37

(s, 9H, tBu).


151.3, 151.2, 151.0, 150.5, 150.5, 142.9, 142.8, 141.7, 141.5, 141.4, 140.5, 140.4,

138.5, 137.9, 135.6, 135.6, 135.5, 133.7, 133.4, 132.7, 132.6, 132.5, 130.6, 127.2,

124.6, 123.9, 122.1, 121.7, 116.1, 113.1, 73.1, 71.8, 57.7, 57.7, 53.3, 53.0, 35.6,

35.5, 32.1, 32.0, 31.9, 31.7.

MS (FAB, NBA): [m/z] = 3653 [M]+.



172

IR (ATR): [cm-1] = 3103, 3074, 3008, 2959, 2867, 1718, 1461, 1362, 1275, 1262,

1203, 1130, 749.

EA for C222H212Fe2N24O8Zn3·CH2Cl2: cal.: C 71.67, H 5.77, N 9.00;

found: C 71.38, H 6.18, N 8.60.


173

Ferrocene-porphyrin cycle 100

An amount of 100 mg (0.01 mmol) zinc

bisazidoporphyrin 57 and 31.1 mg

(0.01 mmol) dipropargyl ferrocene

dicarboxylate 74 is converted according

to GP III with 2.5 mg (0.002 mmol)

CuSO4·5 H2O, 4.0 mg (0.004 mmol)

sodium ascorbate and 25.9 mg (0.02 mmol) DIPEA. The reaction is carried out under

dilution using 100 mL CH2Cl2. Flash chromatography (silica, CHCl3 CHCl3/EtOAc,

50:1) delivers the pure product after removing the solvent under reduced pressure as

a violet powder.

Yield: 35.4 mg (0.0013 mmol), 25%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 8.98 (d, 3J=4.6 Hz, 4H, β-pyrr.), 8.91 (m,

12H, β-pyrr.) 8.42 (br. s, 2H, ArH), 8.30 (d, 4J=4.2 Hz, 2H, ArH), 8.23 (s, 2H, ArH),

8.10 (d, 3J=7.8 Hz, 4H, ArH), 7.91 (br. s, 2H, ArH), 7.75 (d, 3J=8.3 Hz, 10H, ArH),

7.48 (d, 3J=8.1 Hz, 4H, ArH), 7.40 (s, 2H, ArH), 6.51 (br. s, 4H, triazole-H), 4.73 (s,

8H, CH2), 4.48 (br. s, 8H, FcH), 4.31 (br. s, 8H, CH2), 4.16 (br. s, 8H, FcH), 1.63 (s,

36H, tBu), 1.39 (s, 18H, tBu), 1.38 (s, 18H, tBu).


189.9, 140.4, 140.1, 139.2, 138.9, 133.1, 134.8, 135.6, 132.6, 131.9, 131.8, 129.1,

126.5, 125.4, 123.3, 121.1, 120.8, 114.2, 71.8, 71.8, 71.0, 70.9, 34.8, 34.7, 34.5,

31.3, 21.8.

MS (FAB, NBA): [m/z] = 2725 [M]+, 1365.

UV/Vis (CH2Cl2): l [nm] (e [lmol-1cm-1]) = 222 (20400), 228, (7100), 427 (58700), 553

(11000), 598 (6200).

IR (ATR): [cm-1] = 3139, 3004, 2970, 2951, 1722, 1455, 1366, 1366, 1229, 1217.

EA for C160H150Fe2N20O8Zn2∙2 CHCl3∙7 EtOAC: cal: C 63.76, H 5.86, N 7.83;

found: C 63.65, H 6.26, N 7.83.


174

104,154,204-Tris-t-butyl-54-(t-butyl-2-hydroxyacetate)-102,106,202,204-

tetrakis(methoxymethyl)-5,10,15,20-tetraphenylporphyrin 102

An amount of 6 g (16.38 mmol) 54-t-butyl-52,56-bis-

(methoxymethyl)-5-phenyl-dipyrromethan 45b, 1.32 g (8.19

mmol) 4-t-butylbenzaldehyd and 1.94 g (8.19 mmol) t-butyl 2-(4-

formylphenoxy)acetate 101 is dissolved in 1.8 L CH2CL2 and

2.43 mL TFA are added. After stirring the mixture for one hour

4.89 mL NEt3 and 1 min. later 4.08 g DDQ are given to the

solution. Then stirring is continued for 1 h. After removing 1 L of the solvent under

reduced pressure, the residue is filtered through a silica plug (CH2Cl2/EtOAc, 20:1)

and afterwards purified by flash chromatography (silica, CH2Cl2/EtOAc, 20:1). The

product is obtained as second fraction and is a violet powder after evaporation.

Yield: 660 mg (0.61 mmol), 7.5%.


3J=4.9 Hz, 2H, b-pyrr.), 8.66 (d, 3J=4.9 Hz, 4H, b-pyrr.), 8.12 - 8.17 (m, 4H, ArH),

7.88 (s, 4H, ArH), 7.77 (d, 3J=8.1 Hz, 2H, ArH), 7.29 (d, 3J=8.6 Hz, 2H, ArH), 4.81 (s,

2H, CH2), 3.93 (s, 8H, CH2), 2.77 (s, 12H, CH3), 1.64 (s, 18H, tBu), 1.60 (s, 9H, tBu),

1.55 (s, 9H, tBu), -2.64 (br. s, 2H, NH).

13C NMR (100.5 MHz, CDCl3, 20°C): (ppm) = 168.3 (C=O), 162.6, 158.0, 152.0,

150.7, 139.7, 138.7, 135.7, 135.3, 134.6, 123.8, 122.3, 120.2, 115.0, 113.1, 73.0,

66.1, 58.1, 35.1, 34.8, 31.7, 31.6, 28.1.

MS (FAB, NBA): [m/z] = 1089 [M]+.


596 (12500), 637 (8200).

IR (ATR): [cm-1] = 2970, 2869, 2365, 1455, 1365, 1216, 1148, 1108, 965, 802.

EA for C70H80N4O7∙EtOAc: cal.: C 75.48, H 7.53, N 4.76;

found: C 75.12, H 7.37, N 4.73.


175

102,106,202,204-Tetrakis(bromomethyl)-104,154,204-tris-t-butyl-54-(-2-

hydroxyacetic acid)-5,10,15,20-tetraphenylporphyrin 2H-105

An amount of 600 mg (0.55 mmol) porphyrin 102 is dissolved in

300 mL CH2Cl2 and 40 mL HBr (33% in glacial acid) are added

whereupon the solution turns dark green. The reaction mixture

is stirred for 3 h and saturated NaHCO3 solution is given to the

mixture until the organic layer turns violet again. After washing

the organic layer twice with water and drying over MgSO4, the solvent is removed

under reduced pressure to give the pure product as violet powder.

Yield: 630 mg (0.51mmol), 93%.


3J=3.7 Hz, 2H, b-pyrr.), 8.59 (br. s, 4H, b-pyrr.), 8.11 (m, 4H, ArH), 7.79 (s, 4H, C),

7.70 (d, 3J=7.3 Hz, 2H, ArH), 7.37 (m, 2H, ArH), 4.97 (br. s, 2H, CH2), 4.01 (s, 8H,

CH2, tBu), 1.56 (s, 9H, tBu), 1.51 (s, 18H, tBu), -2.63 (br. s, 2H, NH).


138.6, 137.8, 135.8, 134.6, 127.2, 123.7, 120.8, 113.0, 108.0, 107.7, 76.8, 76.7,

67.7, 67.6, 67.4, 35.0, 34.8, 32.1, 31.6, 31.4, 31.4, 31.4.

MS (FAB, NBA): [m/z] = 1129 [M]+.


596 (10200), 637 (5600).

IR (ATR): [cm-1] = 2969, 2870, 2365, 1450, 1360, 1216, 1254, 1108, 966, 802.

EA for C62H60Br4N4O3∙CH2Cl2: cal.: C 57.60, H 4.76, N 4.26;

found: C 57.21, H 5.02, N 3.90.


176

102,106,202,204-Tetrakis(bromomethyl)-104,154,204-tris-t-butyl-54-(-2-

hydroxy-acetic acid)-5,10,15,20-tetraphenylporphyrinato-zinc(II) 105

This reaction is carried out according to GP I with 600 mg

(0.49 mmol) 2H-105. After final purification by flash

chromatography (silica, CH2Cl2/MeOH, 10:1) the product can be

obtained as a pink powder.

Yield: 580 mg (0.45 mmol), 92%.


3J=4.6 Hz, 2H, b-pyrr.), 8.70 (d, 3J=4.6 Hz, 4H, b-pyrr.), 8.17 (m, 4H, ArH), 7.87 (s,

4H, ArH), 7.76 (m, 2H, ArH), 7.28 (m, 2H, ArH), 4.84 (br. s, 2H, CH2), 4.07 (s, 8H,

CH2), 1.63 (s, 18 H, tBu), 1.60 (s, 9H, tBu).


150.0, 139.5, 139.3, 138.8, 135.7, 134.5, 132.6, 132.3, 131.8, 127.2, 123.6, 121.6,

113.8, 112.9, 65.2, 65.1, 63.2, 37.2, 35.1, 34.8, 32.4, 31.7, 31.6, 31.5, 31.3.

MS (FAB, NBA): [m/z] = 1292 [M]+, 967 [M-4 Br]+.


IR (ATR): [cm-1] = 2968, 2867, 2358, 2341, 1739, 1605, 1434, 1364, 1216, 997.

EA for C62H58Br4N4O3Zn∙CH2Cl2: cal.: C 54.95, H 4.39, N 4.07;

found: C 55.13, H 4.60, N 3.99.


177

102,106,202,204-Tetrakis(azidomethyl)-104,154,204-tris-t-butyl-54-(-2-

hydroxy-acetic acid)-5,10,15,20-tetraphenylporphyrinato-zinc(II) 106

The reaction is converted according to GP II with 500 mg

(0.39 mmol) 105 and final purification is achieved by flash

chromatography (silica, CH2Cl2/MeOH 10:1). After evaporation

of the solvent, the pure product can be obtained as a pink

powder.

Yield: 401.6 mg (0.35 mmol), 91%.

1H NMR (400 MHz, THF-d8, 20°C): (ppm) = 8.86 (m, 4H), 8.59 (d, 3J=4.5 Hz, 4H),

8.13 (m, 4H), 7.92 (s, 4H), 7.80 (d, 3J=8.1 Hz, 2H), 7.35 (m, 2H), 4.87 (s, 2H), 3.99

(s, 8H), 1.67 (s, 18H), 1.61 (s, 9H).


151.1, 150.9, 140.1, 138.7, 136.4, 135.5, 133.4, 130.9, 125.8, 124.3, 122.1, 121.9,

114.8, 113.6, 54.1, 35.8, 35.5, 32.0, 31.9.

MS (FAB, NBA): [m/z] = 1142 [M]+.


IR (ATR): [cm-1] = 2965, 2870, 2358, 2101, 1729, 1602, 1434, 1414, 1216, 998.


178

Tetrakis(ferrocenyltriazole)porphyrin with carboxylic acid group 107

The reaction is carried out according to GP III with 100 mg

(0.088 mmol) 106 and 110.9 mg (0.53 mmol) ethinyl ferrocene.

Furthermore, 13.2 mg (0.053 mmol) CuSO4∙5 H2O, 21.0 mg

(0.11 mmol) sodium ascorbate and 140.9 mg (1.09 mmol)

DIPEA are added. Purification is achieved by flash

chromatography (silica, CHCl3/THF, 1:1 THF) to give the pure

product as violet powder.

Yield: 165.6 mg, (0.084 mmol), 95%.


3J=4.5 Hz, 2H, b-pyrr.), 8.33 (t, 3J=4.7 Hz, 4H, b-pyrr.), 8.10 (d, 3J=8.3 Hz, 2H, ArH),

8.02 (d, 3J=8.5 Hz, 2H, ArH), 7.85 (s, 4H, Ar*H), 7.70 (d, 3J=8.3 Hz, 2H, ArH), 7.20

(d, 3J=8.7 Hz, 2H, ArH), 6.44 (s, 4H, triazole-H), 5.19 (s, 8H, CH2), 4.90 (s, 2H, CH2),

4.25 (s, 8H, FcH), 4.18 (s, 8H, FcH), 3.77 (s, 20H, FcH), 1.63 (s, 18H, tBu), 1.62 (s,

9H, tBu).


151.7, 150.7, 144.5, 140.0, 138.5, 136.4, 136.4, 130.8, 125.7, 124.5, 121.8, 114.7,

113.5, 80.3, 63.1, 60.8, 58.0, 54.1, 50.2, 35.9, 35.8, 33.4, 31.9, 30.9, 30.9, 30.7,

30.6, 30.2, 28.4, 28.3, 28.0, 27.2.

MS (MALDI-TOF, DCTB): [m/z] = [1980]+.


560 (13100), 603 (4100).

IR (ATR): [cm-1] = 2925, 2854, 2341, 1737, 1616, 1364, 1218, 995, 796, 669.

EA for C110H98Fe4N16O3Zn∙CHCl3∙4 EtOH: cal.: C 62.56, H 5.43, N 9.81;

found: C 61.96, H 6.27, N 9.86.


179

Tetrakis(ferrocenyltriazole) porphyrin with propargyl ester 108

An amount of 150 mg (0.076 mmol) 107, 12.9 mg (0.23 mmol)

propargyl alcohol, 28.1 mg (0.23 mmol) DMAP and 31.1 mg

(0.23 mmol) HOBt is dissolved in DMF and the mixture is

cooled to 0°C. 47.5 mg (0.23 mmol) DCC dissolved in CH2Cl2

are added; then, the reaction mixture is no longer cooled and is

stirred for 2 d days at rt. The solvent is removed under reduced

pressure. The crude product is purified by flash chromatography (silica,

CH2Cl2/EtOAc, 7:1) to yield the product as purple solid.



3J=4.5 Hz, 2H, b-pyrr.), 8.33 (t, 3J=4.7 Hz, 4H, b-pyrr.), 8.10 (d, 3J=8.3 Hz, 2H, ArH),

8.02 (d, 3J=8.5 Hz, 2H, ArH), 7.85 (s, 4H, Ar*H), 7.70 (d, 3J=8.3 Hz, 2H, ArH), 7.20

(d, 3J=8.7 Hz, 2H, ArH), 6.44 (s, 4H, triazole-H), 5.19 (s, 8H, CH2), 4.96 (d,

4J=2.6 Hz, 2H, CH2), 4.90 (s, 2H, CH2), 4.25 (s, 8H, FcH), 4.18 (s, 8H, FcH), 3.77 (s,

20H, FcH), 2.61 (t, 4J=2.4 Hz, 1H, CH), 1.63 (s, 18H, tBu), 1.62 (s, 9H, tBu).


150.7, 150.1, 149.0, 146.1, 139.7, 139.6, 137.0, 136.3, 136.0, 134.8, 133.3, 132.9,

129.6, 129.5, 126.3, 123.2, 121.8, 120.8, 118.5, 112.6, 112.2, 69.2, 68.3, 66.3, 65.5,

60.3, 52.9, 52.7, 35.0, 34.7, 31.6, 31.4, 20.9.



560 (14200), 603 (5400).

IR (ATR): [cm-1] = 3320, 3080, 2960, 2866, 2516, 2210, 1767, 1720, 1462, 1275,

1261, 994, 755, 750.

EA for C113H100Fe4N16O3Zn∙4 DMF: cal.: C 64.96, H 5.58, N 12.12;

found: C 65.25, H 5.90, N 12.71.


180

Ferrocene porphyrin syn-triade 109

According to GP III,

26 mg (0.025 mmol) zinc

synazidoporphyrin 56 and

150 mg (0.07 mmol)

porphyrin 108 are

dissolved in CH2Cl2. 2 mg

CuSO4∙5 H2O, 3 mg

sodium ascrobate and

18 mg DIPEA are

separately solved in water and are added to the mixture. After stirring vigourosly for

2 d, the crude product is purified by flash chromatography (silica, hexane/THF, 2:1)

to give the pure product in the third fraction.

Yield: 50 mg (0.01 mmol), 40%.

1H NMR (300 MHz, CDCl3, 20°C): (ppm) = 8.90 (m, 12H, b-pyrr.), 8.58 (m, 12H, b-

pyrr.), 8.27 (m, 2H, ArH), 8.16 (m, 4H, ArH), 7.97 (d, 3J=8.5 Hz, 4H, ArH), 7.83 (m,

4H, ArH), 7.77 (s, 6H, ArH), 7.73 (d, 4J=1.5 Hz, 2H, ArH), 7.62 (s, 2H, ArH), 7.12 (d,

3J=8.5 Hz, 4H, ArH), 6.92 (s, 8H, ArH), 6.56 (s, 2H, triazole-H), 6.54 (s, 2H,

triazole-H), 5.13 (s, 4H, CH2), 5.11 (m, 16H, CH2), 4.99 (s, 4H, CH2), 4.68 (s, 4H,

CH2), 4.29 (m, 16H, FcH), 4.08 (s, 16H, FcH), 3.74 (s, 40H, FcH), 1.99 (s, 6H, CH3),

1.62 (s, 36H, tBu), 1.58 (s, 18H, tBu), 1.56 (s, 18H, tBu), 1.54 (s, 36H, tBu).


126.5, 126.1, 124.5, 119.8, 113.7, 77.4, 70.1, 68.9, 53.0, 35.9, 35.7, 35.2, 32.1, 32.0,

31.9, 30.8, 30.7, 29.9, 21.4.



561 (21200), 602 (6700).

IR (ATR): [cm-1] = 2980, 2861, 1720, 1520, 1460, 1392, 1273, 1148, 1050, 1027.


181

54,154-Bis-t-butyl-104,204-dihydroxy-52,56,152,166-

tetrakis(methoxymethyl)-5,10,15,20-tetraphenylporphyrin 110

An amount of 1.5 g (4.1 mmol) 54-t-butyl-52,56-bis-

(methoxymethyl)-5-phenyl-dipyrromethan 45b and 1 g

(8.2 mmol) 4-hydroxybenzaldehyd is dissolved in 1 L CH2Cl2.

The mixture is stirred for about half an hour until the

4-hydroxybenzaldehyd is almost dissolved. After the addition of

0.7 mL TFA, the reaction mixture is stirred at rt for one hour.

1.5 mL NEt3 are added followed by the addition of 1.5 g DDQ. Stirring is continued for

one hour. The first purification is achieved by filtration over a silica plug

(CH2Cl2/EtOAc; 5:1) and final purification suceeds by flash chromatography (silica,

CHCl3/EtOAc, 20:1). After removing the solvent under reduced pressure, the residue

is washed with MeOH. The product can be obtained as a violet powder.

Yield: 456 mg (0.49 mmol), 11.9%.

1H NMR (400 MHz, THF-d8, 20°C): (ppm) = 8.96 (s, 2H, OH), 8.85 (d, 3J=4.6 Hz,

4H, b-pyrr.), 8.61 (d, 3J=4.6 Hz, 4H, b-pyrr.), 8.01 (d, 3J=8.3 Hz, 4H, ArH), 7.93 (s,

4H, ArH), 7.17 (d, 3J=8.3 Hz, 4H, ArH), 3.91 (s, 8H, CH2), 2.74 (s, 12H, CH3), 1.63 (s,

18H, tBu), -2.52 (br. s, 2H, NH).

13C NMR (100.5 MHz, THF-d8, 20°C): (ppm) = 159.1 (2C), 152.3 (2C), 141.0 (4C),

136.7 (4C), 136.5 (2C), 133.6 (2C), 123.2 (4C), 121.3 (2C), 115.7(2C), 114.8 (4C),

73.8 (4C), 58.2 (4C), 35.9 (2C), 32.1 (6C).



599 (1100), 653 (5100).

IR (ATR): [cm-1] = 2961, 2927, 1608, 1590, 1517, 1463, 1361, 1245, 1098, 802.

EA for C60H62N4O6∙CH2Cl2: cal.: C 71.82, H 6.32, N 5.49;

found: C 71.91 H 6.83, N 4.83.


182

52,56,152,166-Tetrakis(bromomethyl)-54,154-bis-t-butyl-104,204-dihydroxy-

5,10,15,20-tetraphenylporphyrin 111

An amount of 400 mg (0.43 mmol) 110 is dissolved in 300 mL

CHCl3 and 30 mL HBr (33% in HOAc) are added whereupon

the solution turns dark green. The reaction mixture is stirred for

3 h and saturated NaHCO3-solution is given to the mixture until

the organic layer turns violet again. After washing the organic

layer twice with water and drying over MgSO4, the solvent is

removed under reduced pressure.

Yield: 447.9 mg (0.40 mmol), 93%.

1H NMR (400 MHz, THF-d8, 20°C): (ppm) = 8.86 (d, 3J=4.6 Hz, 4H, b-pyrr.), 8.79

(s, 2H, OH), 8.61 (d, 3J=4.6 Hz, 4H, b-pyrr.), 8.03 (m, 8H, ArH), 7.16 (d, 3J=8.3 Hz,

4H, ArH), 4.17 (s, 8H, CH2), 1.65 (s, 18H, tBu), -2.49 (br. s, 2H, NH).

13C NMR (100.5 MHz, THF-d8, 20°C): (ppm) = 159.2 (2C), 153.9 (2C), 140.9 (4C),

139.6 (2C), 136.8 (4C), 133.7 (2C), 128.4 (4C), 121.9 (2C), 114.7 (4C), 113.8 (2C),

35.9 (2C), 32.6 (4C), 31.8 (6C).

MS (FAB, NBA): [m/z] = 1131 [M]+.

UV/Vis (CHCl3): l [nm] (e [lmol-1cm-1]) = 421 (451400), 520 (12100), 556 (29900),

599 (1200), 653 (4200).

IR (ATR): [cm-1] = 3853, 2866, 2242, 2003, 1503, 1478, 1259, 1165, 980.

EA for C56H50Br4N4O2∙½ CHCl3: cal.: C 57.01, H 4.28, N 4.71;

found: C 57.17, H 4.13, N 4.60.


183

52,56,152,156-Tetrakis(bromomethyl)-54,154-bis-t-butyl-104,204-bis

(proparyloxy)-5,10,15,20-tetraphenylporphyrin 2H-112

An amount of 400 mg (0.36 mmol) 111 and 1.1 g

(7.2 mmol) propargyl bromide (80% in toluene) is

dissolved in 400 mL acetone. 248.8 mg (1.8 mmol) K2CO3

are added and the mixture is stirred at reflux for 12 h.

After cooling down the suspension, K2CO3 is filtered off

and the solvent is distilled under reduced pressure. Pure

product is obtained by flash chromatography (silica, CH2Cl2/hexane; 1:1). The

product elutes in the first fraction and can be obtained as violet powder.

Yield: 300 mg (0.24 mmol), 69% based on 111.


3J=4.4 Hz, 4H, b-pyrr.), 8.17 (d, 3J=8.8 Hz, 4H, ArH), 7.88 (s, 4H, ArH), 7.37 (d,

3J=8.5 Hz, 4H, ArH), 4.98 (d, 4J=2.5 Hz, 4H, CH2), 4.07 (s, 8H, CH2), 2.68 (t,

4J=2.3 Hz, 2H, CH), 1.56 (s, 18H, tBu), -2.63 (br. s, 2H, NH).


135.0, 127.3, 120.1, 113.3, 113.1, 56.1, 53.4, 35.1, 32.6, 31.4, 29.6.


UV/Vis (CHCl3): l [nm] (e [lmol-1cm-1]) = 423 (447600), 518 (11900), 556 (30900),

597 (600), 654 (2800).

IR (ATR): [cm-1] = 3321, 2969, 2929, 2850, 2360, 2120, 1720, 1601, 1366, 1217,

1174, 965.

EA for C62H54Br4N4O2∙2 CH2Cl2: cal.: C 55.84, H 4.25, N 2.07;

found: C 55.16, H 4.87, N 2.71.


184

52,56,152,156-Tetrakis(bromomethyl)-54,154-bis-t-butyl-104,204-

bis(propargyloxy)-5,10,15,20-tetraphenylporphyrinato-zinc(II) 112

The metalation of 300 mg (0.24 mmol) 111 is carried out

according to GP I. Purification is achieved by flash

chromatography (silica, CHCl3/Hexan; 1:1). Pure 112 can

be obtained after removing the solvent under reduced

pressure as a violet powder.

Yield: 274.3 mg (0.21 mmol), 90%.


3J=4.6 Hz, 4H, b-pyrr.), 8.14 (d, 3J=8.5 Hz, 4H, ArH), 8.01 (s, 4H, ArH), 7.37 (d,

3J=8.5 Hz, 4H, ArH), 5.01 (d, 4J=2.4 Hz, 4H, CH2), 4.21 (s, 8H, CH2), 3.15 (t,

4J=2.4 Hz, 2H, CH), 1.66 (s, 18H, tBu).


140.8, 137.3, 136.5, 132.7, 132.1, 128.1, 121.6, 114.2, 113.7, 80.0, 77.0, 56.8, 54.0,

35.9, 32.9, 31.9.



IR (ATR): [cm-1] = 3403, 3320, 3281, 2961, 2866, 2214, 2120, 1982, 1936, 1785,

1604.

EA for C62H58Br4N4O3Zn∙CH2Cl2: cal.: C 55.84, H 4.02, N 4.13;

found: C 55,87, H 4.20, N 3.83.


185

Triazole-linked dendritic tetrakisbromoporphyrin 117

According to GP III the following amounts are

used: 150 mg (0.12 mmol) porphyrin 112,

155.4 mg (0.30 mmol) azido compound 116,

7.5 mg (0.03 mmol) CuSO4·5 H2O, 11.9 mg


(0.6 mmol) DIPEA. Final purification can be

achieved by flash chromatography (silica,

CH2Cl2/EtOAc, 10:1) whereas the product can be isolated in the third fraction. After

evaporating off the solvent, pure product can be obtained as purple solid.


1H NMR (400 MHz, THF-d8, 20°C): (ppm) = 8.83 (d, 3J=4.4 Hz, 4H, β-pyrr.), 8.60

(d, 3J=4.6 Hz, 4H, β-pyrr.), 8.12 (m, 6H, triazole-H, ArH), 7.99 (s, 4H, ArH), 7.42 (d,

3J=8.5 Hz, 4H, ArH), 6.71 (s, 2H, NH), 4.50 (s, 4H, CH2), 4.20 (s, 8H, CH2), 2.20 (m,

16H, CH2), 1.95 (m, 16H, CH2), 1.65 (s, 18H, tBu), 1.41 (s, 54H, tBu).


154.5, 153.4, 151.8, 150.9, 144.7, 140.7, 136.8, 136.6, 132.7, 132.0, 128.1, 124.5

(2C, triazole-C), 113.5, 80.3, 63.2, 58.0, 50.2, 35.8, 33.3, 32.9, 31.8, 30.3, 30.2, 28.3,

27.1.

MS (FAB, NBA): [m/z] = 2322 [M]+.


IR (ATR): [cm-1] = 2960, 2929, 1638, 1590, 1520, 1480,1460, 1361, 1245, 1098,

802.


186

Triazole-linked dendritic tetrakisazido zinc porphyrin 118

The reaction is carried out according to GP II with

150 mg (0.065 mmol) 117 and 52.1 mg (0.8 mmol)

NaN3. No flash chromatography is necessary in this

procedure.

Yield: 133.6 mg (0.062 mmol), 95%.

1H NMR (400 MHz, THF-d8, 20°C): (ppm) = 8.87 (d, 3J=4.5 Hz, 4H, β-pyrr.), 8.58

(d, 3J=4.7 Hz, 4H, β-pyrr.), 8.12 (s, 2H, triazole-H), 8.11 (d, 3J=8.5 Hz, 4H, ArH), 7.92

(s, 4H, Ar*H), 7.03 (d, 3J=8.5 Hz, 4H, ArH), 6.78 (br. s, 2H, NH), 4.50 (s, 4H, CH2),

3.99 (s, 8H, CH2), 2.21 (m, 18H, CH2), 1.96 (m, 12H, CH2), 1.67 (s, 18H, tBu), 1.42

(s, 54H, tBu).


151.7, 150.7, 144.5, 140.0, 138.5, 136.4, 136.4, 133.2, 130.8, 125.7, 124.5, 121.8,

114.7, 113.5, 80.3, 63.1, 60.8, 58.0, 54.1, 50.2, 35.9, 35.8, 33.4, 31.9, 30.7, 30.6,

30.2, 28.4, 28.3, 27.2.



IR (ATR): [cm-1] = 2956, 2930, 2101, 1638, 1591, 1479, 1460, 1230, 1245, 1098,

802.

EA for C114H144N24O16Zn∙NaN3: cal.: C 57.85; H, 6.13; N, 19.53;

found: C 58.35, H 5.76, N 20.22.


187

Triazole-linked dendritic ferrocene porphyrin119

An amount of 50 mg (0.023 mmol) 118 is

converted with 29 mg (0.14 mmol) ethinyl

ferrocene according to GP III. 3.5 mg

(0.014 mmol) CuSO4∙5 H2O, 5.6 mg

(0.028 mmol) sodium ascorbate and

36.2 mg (0.28 mmol) DIPEA are used in

this case. Purification is achieved by flash




3J=4.2 Hz, 4H, β-pyrr.), 8.05 (s, d, 3J=8.3 Hz, 6H, triazole-H, ArH), 7.84 (s, 4H, ArH),

7.11 (d, 4H, ArH), 6.28 (br. s, 4H, triazole-H), 6.17 (s, 2H, NH), 5.17 (s, 8H, CH2),

4.24 (s, 8H, FcH), 4.16 (s, 8H, FcH), 3.79 (s, 20H, FcH), 3.14 (t, 3J=8.3 Hz, 4H, CH2),

2.22 (m, 12H, CH2), 1.94 (m, 20H, CH2), 1.60 (s, 18H, tBu), 1.44 (s, 54H, tBu).


153.1, 151.0, 149.4, 146.1, 137.0, 136.2, 135.5, 133.2, 130.0, 126.2, 122.7, 121.3,

118.7, 112.8, 112.7, 80.8, 80.7, 75.0, 69.3, 68.4, 66.4, 60.4, 57.5, 52.7, 49.2, 34.6,

31.4, 30.1, 30.0, 29.8, 29.7, 29.6, 28.0.

MS (MALDI-TOF, without matrix): [m/z] = 3010 [M]+.


606 (15700).

IR (ATR): [cm-1] = 2970, 2890, 2360, 2310, 1682, 1366, 1217, 1103, 800.

EA for C162H184Fe4N24O16Zn∙3 EtOH∙2 CH2Cl2: cal.: C 61.50, H 6.25, N 10.25;

found: C 61.43, H 6.74, N 10.31.


188

Triazole linked dentritic ferrocene double-capped porphyrin120

The synthesis follows GP III with these amounts: 100 mg

(0.046 mmol) 119, 2.5 mg (0.092 mmol) 74, 7.5 mg

(0.01 mmol) CuSO4·5 H2O, 4 mg (0.02 mmol) sodium

ascorbate and 25.9 mg (0.2 mmol) DIPEA. The purification of

the crude product is performed out by flash chromatography

(silica, CHCl3/EtOAc, 10:1 2:1) to give the pure product as

violet powder.

Yield: 26.4 mg (9.2 µmol), 20% based on 119.


3J=4.2 Hz, 4H, β-pyrr.), 7.75 (m, 8H, Ar*H, ArH), 7.44 (br. s, 4H, triazole-H), 7.09 (d,

3J=8.3 Hz, 4H, ArH), 6.02 (s, 2H, NH), 5.24 (s, 8H, CH2) 5.01 (s, 8H, CH2), 4.45 (m,

4H, CH2), 4.21 (s, 8H, CH2), 4.09 (s, 8H, FcH), 3.75 (s, 4H, triazole-H), 3.59 (m, 8H,

FcH), 2.21 (m, 12H, CH2), 1.91 (m, 20H, CH2), 1.69 (s, 18H, tBu), 1.29 (s, 54H, tBu).


153.1, 151.0, 149.4, 146.1, 137.0, 136.2, 135.5, 133.2, 130.0, 126.2, 122.7, 121.3,

118.7, 112.8, 112.7, 80.8, 80.7, 75.0, 69.3, 68.4, 66.4, 60.4, 57.5, 52.7, 49.2, 34.6,

31.4, 30.1, 30.0, 29.8, 29.7, 29.6, 28.0.

MS (MALDI-TOF, without matrix): [m/z] = 2872 [M]+.


IR (ATR): [cm-1] = 2993, 2988, 2890, 2360, 2310, 1722, 1366, 1217, 1103, 800.


189

Porphyrin dimer 128

The synthesis is carried out according to GP III

applying the following amounts of substances:

100 mg (0.1 mmol) zinc monoazidoporphyrin 56,

91.9 mg (0.1 mmol) 125, 2.5 mg (0.01 mmol)



Purification is achieved by flash chromatography

(silica, CH2Cl2).


1H NMR (400 MHz, CDCl3+pyridin-d5, 20°C): (ppm) = 9.40 (d, 3J=4.6 Hz, 2H, β-

pyrr.), 9.30 (d, 3J=4.6 Hz, 2H, β-pyrr.), 9.01 (s, 4H, β-pyrr.), 8.89 (d, 3J=4.6 Hz, 2H, β-

pyrr.), 8.96 (d, 3J=4.6 Hz, 2H, β-pyrr.), 8.48 (s, 1H, ArH), 8.21 (m, 12H, ArH), 7.96 (d,

3J=8.5 Hz, 2H, ArH), 7.81 (d, 3J=8.3 Hz, 12H, ArH), 7.66 (s, 1H, ArH), 7.41 (s, 1H,

triazole-H), 6.82 (d, 3J =8.5 Hz, 2H, ArH), 5.09 (s, 2H, CH2), 4.75 (s, 2H, CH2), 2.06

(s, 3H, CH3), 1.68 (s, 18H, tBu), 1.64 (s, 18H, tBu), 1.61 (s, 18H, tBu), 1.50 (s, 9H,

tBu).

13C NMR (100.5 MHz, CDCl3+pyridin-d5, 20°C): (ppm) = 157.1, 151.4, 150.3,

150.2, 150.0, 149.9, 149.8, 149.5, 142.7, 140.4, 140.1, 139.4, 139.3, 136.0, 135.9,

134.2, 132.5, 131.8, 131.7, 131.4, 131.4, 131.2, 129.8, 126.4, 121.2, 120.5, 120.3,

119.7, 114.7, 111.9, 61.2, 52.7, 34.5, 34.5, 34.4, 31.4, 31.3, 31.3, 31.2, 21.6.

MS (FAB, NBA): [m/z] = 1872 [M]+, 927 [M-porphyrinyltriazole]+.

UV/Vis (THF): l [nm] (e [lmol-1cm-1]) = 423 (624400), 550 (40700), 588 (9100).

IR (ATR): [cm-1] = 3619, 2960, 2860, 2037, 1080, 1010, 996, 2170, 795.

EA for C121H117N11OZn2∙CH2Cl2: cal.: C 74.87, H 6.13, N 7.87 ;

found: C 75.37, H 6.60, N 7.62.


190

Bisporphyrin trimer 127

According to GP III 100 mg (0.11 mmol) 125

and 56.23 mg (0.056 mmol) zinc

bisazidoporphyrin 57 are converted with

2.5 mg (0.01 mmol) CuSO4·5 H2O, 4.0 mg


(0.2 mmol) DIPEA. The crude product is

purified by flash chromatography (silica;

CH2Cl2/EtOAc, 50:1). The product can be

isolated as violet powder.



pyrr.), 8.91 (d, 3J=4.6 Hz, 2H, β-pyrr.), 8.84 (s, 8H, β-pyrr.), 8.79 (m, 6H, β-pyrr.),

8.66 (d, 3J=4.6 Hz, 4H, β-pyrr.), 8.45 (d, 3J=4.6 Hz, 2H, β-pyrr.), 8.17 (d, 3J=8.1 Hz,

4H, ArH), 8.06 (m, 12H, ArH), 7.86 (d, 3J=8.1 Hz, 2H, ArH), 7.82 (d, 3J=8.5 Hz, 4H,

ArH), 7.78 (s, 2H, ArH), 7.69 (d, 3J=8.3 Hz, 4H, ArH), 7.65 (dd, 3J=8.2 Hz, 4J=1.8 Hz,

12H, ArH), 7.27 (d, 2H, ArH), 7.13 (s, 2H, triazole-H), 6.68 (d, 3J=8.5 Hz, 4H, ArH),

5.10 (s, 4H, CH2), 4.64 (s, 4H, CH2), 1.53 (s, 36H, tBu), 1.52 (s, 36H, tBu), 1.51 (s,

9H, tBu), 1.41 (s, 9H, tBu).


150.1, 150.0, 149.9, 143.0, 140.3, 139.8, 136.7, 136.1, 134.4, 134.3, 132.2, 132.0,

131.4, 131.1, 129.3, 121.2, 120.3, 111.9, 61.3, 34.8, 34.5, 34.2, 31.4, 31.3, 31.2,

31.1.

MS (FAB, NBA): [m/z] = 2813 [M]+, 293 [M-2 porphyrinyltriazole]+.


IR (ATR): [cm-1] = 2956, 2890, 2163, 1490, 995, 794.


191

Antiporphyrin trimer 126

The synthesis is carried out according

to GP III with following substances:

100 mg (0.11 mmol) 125, 57.2 mg

(0.055 mmol) zinc anti-azidoporphyrin

59, 2.5 mg (0.01 mmol) CuSO4·5 H2O,

4.0 mg (0.02 mmol) sodium ascorbate

and 25.9 mg (0.2 mmol) DIPEA. The

crude product is purified by flash

chromatography (silica; CHCl3/:EtOAc,

50:1). After removing the solvent, the

pure product is obtained as a violet

powder.



pyrr.), 8.82 (s, 8H, β-pyrr.), 8.79 (d, 3J=4.6 Hz, 4H, β-pyrr.), 8.68 (d, 3J=4.6 Hz, 4H, β-

pyrr.), 8.52 (d, 3J=4.5 Hz, 4H, β-pyrr.), 8.34 (s, 2H, ArH), 8.13 (d, 3J=8.2 Hz, 4H,

ArH), 8.03 (m, 12H, ArH), 7.85 (d, 3J=8.5 Hz, 4H, ArH), 7.62 (m, 12H, ArH), 7.50 (s,

2H, ArH), 7.48 (m, 4H, ArH), 7.09 (s, 2H, triazole-H), 6.78 (d, 3J=8.5 Hz, 4H), 4.99 (s,

4H, CH2), 4.79 (s, 4H, CH2), 1.81 (s, 6H, CH3), 1.49 (s, 18H, tBu), 1.48 (s, 36H, tBu),

1.40 (s, 18H, tBu), 1.36 (s, 18H tBu).


149.9, 149.5, 149.5, 142.9, 140.3, 139.7, 139.4, 139.2, 136.1, 135.7, 134.3, 134.3,

134.2, 132.8, 131.4, 131.1, 130.0, 120.7, 120.2, 119.5, 115.5, 112.0, 61.5, 52.6,

34.4, 34.4, 34.3, 31.3, 31.2, 31.1,

MS (FAB, NBA): [m/z] = 2841 [M]+, 953 [M-2 porphyrinyltriazole]+.


IR (ATR): [cm-1] = 2958, 2903, 2868, 2823, 1524, 1506, 1338, 1243, 1108, 996.

EA for C182H174N18O2Zn3∙4 CHCl3: cal.: C 67.31, H 5.41, N 7.60;

found: C 67.39, H 5.86, N 7.48.


192

Porphyrin pentamer 129

The reaction is carried out according to

GP III with following substances and

amounts: 44.9 mg (0.04 mmol) zinc

tetrakisazidoporphyrin 60, 150 mg

(0.17 mmol) 125 and 4.2 mg (0.017 mmol)

CuSO4∙5 H2O, 6.7 mg (0.034 mmol)

sodium ascorbate and 44.0 mg (3.4 mmol)

DIPEA. Purification of 129 is achieved by

flash chromatography (silica,

toluene/MeOH, 100:1).


1H NMR (400 MHz, THF-d8, 20°C): (ppm) = 9.06 (d, 3J=4.4 Hz, 4H, β-pyrr.) 8.84

(m, 24H, β-pyrr.), 8.72 (d, 3J=4.6 Hz, 8H, β-pyrr.), 8.61 (d, 3J=4.4 Hz, 4H, β-pyrr.),

8.37 (d, 3J=8.1 Hz, 4H, ArH), 8.09 (d, 3J=8.1 Hz, 16H, ArH), 8.02 (d, 3J=8.3 Hz, 8H,

ArH), 7.94 (d, 3J=8.3 Hz, 4H, ArH), 7.84 (d, 3J=8.3 Hz, 8H, ArH), 7.79 (s, 2H, ArH),

7.77 (s, 2H, ArH), 7.73 (d, 3J=8.3 Hz, 16H, ArH), 7.64 (d, 3J=8.1 Hz, 8H, ArH), 6.79

(d, 3J=8.3 Hz, 8H, ArH), 6.59 (s, 4H, triazole-H), 5.28 (s, 8H, CH2), 4.71 (s, 8H, CH2),

1.61 (s, 18H, tBu), 1.57 (s, 72H, tBu), 1.55 (s, 36H, tBu).


150.9, 150.9, 141.9, 141.8, 137.0, 136.3, 135.6, 132.5, 132.4, 132.3, 124.3, 124.2,

121.6, 121.3, 113.3, 78.6, 78.6, 77.7, 76.9, 76.3, 76.1, 76.1, 75.7, 67.5, 62.7, 59.2,

56.9, 53.4, 35.9, 35.7, 35.6, 35.6, 33.0, 32.1, 32.1, 31.9, 30.7, 30.7, 30.4, 23.7, 14.5.

MS (MALDI-TOF, DCTB): [m/z] = 4725 [MH]+, 3781 [M-porphyrinyltriazole]+, 2814

[M-2 porphyrinyltriazole]+.


IR (ATR): [cm-1] = 2957, 2927, 2865, 1524, 1460, 1338, 1204, 999, 809, 795.

EA for C300H280N32O4Zn5: cal.: C 76.26, H 5.97, N 9.49;

found: C 75.04, H 6.84, N 7.81.


193

Side-selective modified porphyrin 130


tetrakisazidoporphyrin 60 is converted with

63.2 mmol (0.09 mmol; 1 eq) 75 as it is

described in GP III. 4.9 mg (0.018 mmol)

CuSO4∙5 H2O, 6.3 mg (0.032 mmol) sodium

ascorbate and 41.3 mg (0.32 mmol) DIPEA

are used in this case. The crude product can be purified by flash chromatography

(silica, CH2Cl2/EtOAc, 5:1).

Yield: 68 mg (0.029 mmol), 32% based on 60.



7.79 (dd, 3J=7.9 Hz, 4J=1.8 Hz, 2H, ArH), 7.73 (m, 4H, ArH, Ar*H), 7.62 (s, 2H, Ar*H),

6.29 (br. s, 2H, NH), 6.24 (s, 2H, triazole-H), 5.09 (br. s, 4H, CH2), 4.70 (br. s, 4H,

CH2), 4.43 (s, 4H, FcH), 4.24 (t, 3J=3.4 Hz, 8H, FcH), 3.91 (s, 4H, FcH), 3.79 (br. s,

4H, CH2), 2.14 (t, 3J=7.7 Hz, 12H, CH2), 1.86 (t, 3J=7.7 Hz, 12H, CH2), 1.61 (s, 18H,

tBu), 1.54 (s, 18H, tBu), 1.36 (s, 54H, tBu).


150.2, 149.3, 141.9, 139.6, 138.7, 137.4, 136.6, 134.5, 134.2, 133.2, 129.7, 124.9,

123.9, 123.4, 123.4, 121.4, 112.9, 80.6, 78.5, 73.1, 71.5, 71.1, 70.8, 69.3, 57.5, 52.9,

34.9, 34.7, 31.6, 31.4, 29.7, 29.6, 28.2, 27.9, 27.8, 27.7.

MS (MALDI-TOF, DCTB): [m/z] = 2525, 2501, 2478 [M-2 N3]+, 1761, 983.


IR (ATR): [cm-1] = 3727, 3627, 2959, 2341, 2103, 1729, 1523, 1458, 1152, 669.


194

Side-selective modified porphyrin 131


octakisazidoporphyrin is converted with 23.6 mg (0.11 mmol)

ethinyl ferrocene following GP III. Furthermore, the following

substances are added: 11 mg (0.044 mmol) CuSO4∙5 H2O,

17.4 mg (0.088 mmol) sodium ascorbate and 113.5 mg

(0.88 mmol) DIPEA are used in this case. The crude product can be purified by flash


Yield: 47.0 mg (0.019 mmol), 25%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 8.21 (s, 8H, β-pyrr.), 7.83 (s, 4H, ArH),

7.77 (s, 4H, ArH), 6.62 (s, 4H, triazole-H), 4.91 (s, 8H, CH2), 4.19 (br. s, 8H, FcH),

3.99 (s, 8H, FcH), 3.81 (s, 20H, FcH), 1.65 (s, 36H, tBu).


136.6, 130.7, 126.2, 125.3, 119.3, 113.5, 75.3, 69.3, 69.2, 69.1, 68.1, 66.4, 66.3,

53.8, 53.1, 35.1, 31.5, 29.6.

MS (MALDI-TOF, DCTB): [m/z] = 2184 [MH]+.


560 (29100), 601 (11300).

IR (ATR): [cm-1] = 2968, 2925, 2358, 2092, 1439, 1365, 1261, 1216, 1105, 1045.


195

Free base tetrakis(ferrocenyltriazolyl)porphyrin 2H-71

400 mg (0.2 mmol) 71 are dissolved in 100 mL CH2Cl2 and

50 mL half-concentrated (6N) HCl are added. After stirring for

one hour, the acid is neutralized with saturated NaHCO3-

solution. Afterwards the organic layer is washed twice with

water and is dried over MgSO4. After removing the solvent

under reduced pressure, the product is obtained as a purple

solid.

Yield: 360.9 mg (0.19 mmol), 95%.



7.75 (s, 4H, Ar*H), 6.10 (s, 4H, triazole-H), 5.12 (s, 8H, CH2), 4.23 (t, 3J=1.8 Hz, 8H,

FcH), 4.14 (t, 3J=1.8 Hz, 8H, FcH), 3.76 (s, 20H, FcH), 1.63 (s, 18H, tBu) 1.54 (s,

18H, tBu), -2.48 (br. s, 2H, NH).


125.9, 123.9, 121.8, 118.7, 75.0, 69.2, 68.3, 67.0, 66.3, 52.3, 34.8, 31.6, 31.3.

MS (MALDI-TOF, sin): [m/z] = 1900 [M]+.


558 (4200), 600 (4000), 624 (3500).

IR (ATR): [cm-1] = 2969, 1723, 1680, 1589, 1438, 1366, 1216, 1043, 996, 798, 505.

EA for C112H106Fe4N16∙2 CH2Cl2∙EtOAc: cal.: C 65.37, H 5.49, N 10.51;

found: C 65.58, H 6.06, N 10.35.


196

Free base dendritic tetrakis(ferrocenyltriazolyl)porphyrin 2H-83


dissolved in 150 mL CH2Cl2, 50 mL 4N HCl

are added and the mixture is stirred for

½ h. After neutralization with saturated

NaHCO3-solution, the organic layer is

washed twice with water and dried over

MgSO4. The solvent is evaporated completely to give the product as an orange-

brown powder.

Yield: 477.8 mg (0.12 mmol), 97%.



7.54 (s, 4H, Ar*H), 6.53 (s, 4H, triazole-H), 6.40 (s, 4H, NH), 5.14 (s, 8H, CH2), 4.90

(s, 8H, CH2), 4.60 (s, 8H, FcH), 4.47 (s, 8H, FcH), 4.32 (s, 8H, FcH), 3.98 (s, 8H,

FcH), 2.24 (t, 3J=7.2 Hz, 24H, CH2), 2.01 (t, 3J=7.2 Hz, 24H, CH2), 1.60 (s, 18H, tBu),

1.43 (s, 18H, tBu), 1.36 (s, 108H, tBu), -2.55 (br. s, 2H, NH).


142.3, 137.7, 136.8, 136.6, 134.4, 125.0, 123.9, 123.8, 123.7, 121.6, 112.4, 80.4,

78.6, 73.0, 71.6, 71.1, 71.0, 69.4, 57.6, 56.7, 52.3, 35.0, 34.8, 31.5, 31.2, 29.8, 29.7,

29.5, 29.2, 27.9, 27.6.


558 (3900), 600 (3900), 624 (3100).

MS (MALDI-TOF, sin): [m/z] = 3898 [MH]+, 3921 [M+Na]+.

IR (ATR): [cm-1] = 2961, 2925, 2853, 1723, 1661, 1459, 1367, 1273, 1140, 1025.

EA for C212H270Fe4N20O36∙CH2Cl2: cal.: C 64.23, H 6.88, N 7.03;

found: C 64.50, H 7.06, N 6.96.


197

Free base octakis(ferrocenyltriazolyl)porphyrin 2H-72

An amount of 400 mg (0.13 mmoL) 72 is dissolved in

100 mL CH2Cl2 and 50 mL half-concentrated HCl are

added. After stirring for one hour the acid is neutralized with

saturated NaHCO3-solution. Then the organic layer is

washed twice with water and dried over MgSO4. After

removing the solvent under reduced pressure, the product

can be obtained as a brown-purple solid.

Yield: 369.4 mg (0.12 mmol), 96%.


6.64 (s, 8H, triazole-H), 5.01 (s, 16H, CH2), 3.83 (s, 16H, FcH), 3.82 (s, 16H, FcH),

3.62 (s, 40H, FcH), 1.57 (s, 36H, tBu), -2.47 (s, 2H, NH).

13C NMR (100.5 MHz, CDCl3, 20°C): (ppm) = 153.6 (4C), 145.7 (8C), 137.3 (8 C),

136.7 (4C), 125.7 (8C), 119.7 (8C), 113.7 (4C), 74.9 (8C), 69.1 (40C), 68.0 (16C),

66.2 (16C), 53.0 (8C), 35.1 (4C), 31.4 (12C).



519 (39609), 599 (25992).

IR (ATR): [cm-1] = 2969, 1723, 1589, 1438, 1366, 1216, 1043, 996, 798, 505.

EA for C164H160Fe8N28∙CH2Cl2: cal.: C 65.09, H 5.03, N 12.88;

found: C 65.02, H 5.79, N 12.56.


198

Free base dendritic octakis(ferrocenyltriazolyl)porphyrin H-84


dissolved in 150 mL CH2Cl2, 50 mL 4N HCl

are added and the mixture is stirred for half

an hour. After neutralization with saturated

NaHCO3-solution, the organic layer is

washed twice with water and dried over

MgSO4. The solvent is evaporated

completely to give the product as an

orange-brown powder.

Yield: 475.6 mg (0.07mmol), 96 %.


7.37 (s, 8H, triazole-H), 6.42 (s, 8H, NH), 5.23 (s, 16H, CH2), 5.01 (s, 16H, CH2), 4.64

(t, J=2.0 Hz, 16H, FcH), 4.53 (t, 3J=1.8 Hz, 16H. FcH), 4.34 (t, 3J=2.0 Hz, 16H, FcH),

4.07 (t, 3J=2.0 Hz, 16H, FcH), 2.27 (t, 3J=7.8 Hz, 24H, CH2), 2.04 (t, 3J=7.6 Hz, 24H,

CH2), 1.40 (s, 36H, tBu), 1.38 (s, 216H, tBu), -2.44 (br. s, 2H, NH).


168.3 (8C, C=O), 153.9, 142.8, 137.4, 136.0, 124.9, 124.4, 114.0, 80.6, 78.7, 73.3,

71.9, 71.2, 69.5, 57.6, 57.0, 52.5, 35.0, 31.2, 30.0, 29.8, 28.3, 27.9.

MS (MALDI-TOF, sin): [m/z] = 6957 [MH]+, 6975 [M+Na]+.


518 (13600), 477(4600), 558 (4600), 620 (4100).

IR (ATR): [cm-1] = 2963, 2933, 2917, 1895, 1715, 1659, 1525, 1458, 1367, 1098.

EA for C364H478Fe8N36O72∙2 CH2Cl2: cal: C 61.68, H 6.82, N 7.08;

found: C 61.48, H 7.22, N 6.67.


199

Nickel(II) tetrakis(ferrocenyltriazolyl)porphyrin Ni(II)-71

An amount of 100 mg (0.05 mmol) 2H-71 is dissolved in 40 mL

toluene, 135 mg (0.53 mmol) Ni(acac)2 are added and the

solution is refluxed for 5 h. After distilling the solvent under

reduced pressure, the residue is redissolved in CH2Cl2 and

washed twice with water. After drying over MgSO4 and

evaporation of the solvent the product can be obtained as an

orange powder without any further purification.

Yield: 91.6 mg (0.046 mmol), 89%.



7.63 (s, 4H, ArH), 6.10 (s, 4H, triazole-H), 5.08 (s, 8H, CH2) 4.20 (s, 8H, FcH), 4.12

(s, 8H, FcH), 3.71 (s, 20H, FcH), 1.58 (s, 18H, tBu), 1.48 (s, 18H, tBu).


136.8, 136.6, 135.7, 134.2, 133.5, 130.7, 125.6, 123.9, 120.7, 118.7, 112.2, 69.2,

68.3, 66.2, 52.2, 35.1, 34.8, 31.6, 31.3, 29.6.



418 (252300), 529 (21900), 570 (7600).

IR (ATR): [cm-1] = 2963, 2867, 1630, 1351, 1090, 1002, 800, 717, 609, 505.

Copper(II) tetrakis(ferrocenyltriazolyl)porphyrin Cu(II)-71


CH2Cl2, 92.9 mg (0.53 mmol) Cu(OAc)2∙H2O dissolved in

10 mL MeOH are added and the mixture is stirred at rt for 24 h.

The solution is washed twice with water and afterwards is dried

over MgSO4. The pure product can be obtained after flash

chromatography (silica, CH2Cl2/EtOAc, 20:1). The product is

obtained as red solid.

Yield: 96 mg (0.49 mmol), 93%.


200

1H NMR (300 MHz, CDCl3, 20°C): (ppm) = 7.0 (br.s, 20, β-pyrr., ArH), 4.5 (br.s,

CH2), 4.14 (br.s, FcH), 3.87 (br.s, FcH), 1-2 (br. m, tBu).



546 (29200), 590 (8100).

IR (ATR): [cm-1] = 2958, 1462, 1344, 1204, 1107, 1043, 998, 876, 798, 717.

Manganese(III) tetrakis(ferrocenyltriazolyl)porphyrin Mn(III)Cl-71


CHCl3. 133.4 mg (1.06 mmol) MnCl2 dissolved in 10 mL MeOH

and one drop of 2,6-lutidine are added. The mixture is stirred at

reflux for 12 h, afterwards washed with water and dried over

MgSO4. Purification of the crude product is achieved by flash

chromatography (silica, CH2Cl2/MeOH, 10:1) to give the product

as a greenish brown solid.

Yield: 82.8 mg (0.042 mmol), 79%.

1H NMR (300 MHz, CDCl3, 20°C): (ppm) = 6.37, 6.31, 6.18, 4.21, 4.16, 4.09, 3.65,

3.53, 3.42, 3.22, 2.92, 1.26.

MS (MALDI-TOF, DCTB): [m/z] = no detection.


408 (25100), 426 (32300), 485 (81900).

IR (ATR): [cm-1] = 2962, 2924, 2852, 1779, 1707, 1461, 1365, 1261, 1202, 1009.


201

Iron(III) tetrakis(ferrocenyltriazolyl)porphyrin Fe(III)Cl-71


CHCl3. 134.4 mg (1.06 mmol) FeCl2 dissolved in EtOH and one

drop of 2,6-lutidine are added. The brown solution is stirred at

reflux for 12 h, then washed with water and dried over MgSO4.

Final Purification can be achieved by flash chromatography

(silica, CH2Cl2/MeOH, 10:1) to give the product as a brown

powder.

Yield: 83.5 mg (0.42 mmol), 82%.

1H NMR (300 MHz, CDCl3, 20°C): (ppm) = 82-79 ppm (br. s, β-pyrr.), 16.35 (br. s,

ArH), 15.16 (br. s, ArH), 14.31 (br. s, ArH), 4.86 (s, FcH), 5.50 (s, FcH), 4.28 (s, FcH),

3.32, 2.85.



422 (83200), 512 (2700), 585 (6200).

IR (ATR): [cm-1] = 2963, 2852, 1711, 1462, 1264, 1201, 1108, 999, 802, 721.

Nickel(II) dendritic tetrakis(ferrocenyltriazolyl)porphyrin Ni(II)-83

An amount of 100 mg (0.025 mmol) 2H-83

is dissolved in 40 mL toluene, 64.2 mg

(0.25 mmol) Ni(acac)2 are added and the

solution is stirred at reflux for 5 h. After

distilling off the solvent under reduced

pressure, the residue is redissolved in CH2Cl2 and washed twice with water. After

drying over MgSO4 and evaporation of the solvent the product can be obtained as an

orange powder without any further purification.

Yield: 85 mg (0.024 mmol), 96%.



7.44 (s, 4H, Ar*H), 6.58 (s, 4H), 6.39 (s, 4H), 5.09 (s, 8H, CH2), 4.83 (s, 8H, CH2),


202


FcH), 3.97 (t, 3J=2.0 Hz, 8H, FcH), 2.24 (t, 3J=7.8 Hz, 24H, CH2), 2.01 (t, 3J=7.8 Hz,

24H, CH2), 1.58 (s, 18H, tBu), 1.37 (s, 108H, tBu), 1.36 (s, 18H, tBu).


151.2, 143.7, 142.5, 142.2, 137.0, 136.6, 135.5, 134.3, 133.6, 130.5, 124.1, 124.0,

120.6, 111.9, 80.5, 78.7, 73.2, 71.7, 71.2, 71.1, 69.5, 57.7, 56.7, 52.3, 34.9, 34.8,

31.5, 31.1, 29.9, 29.8, 29.6, 29.4, 27.9, 22.5.

MS (MALDI-TOF; DCTB): [m/z] = 3954 [M]+.


418 (205900), 529 (19800), 570 (6700).

IR (ATR): [cm-1] = 2970, 1722, 1660, 1529, 1456, 1366, 1229, 1217, 1147, 1198.

Copper(II) dendritic tetrakis(ferrocenyltriazolyl)porphyrin Cu(II)-83


is dissolved in CH2Cl2, 46.4 mg

(0.25 mmol) Cu(OAc)2∙H2O dissolved in

10 mL MeOH are added and the mixture is

stirred at rt for 24 h. Then the solution is

washed twice with water and afterwards

dried over MgSO4. The pure product can be obtained after flash chromatography

(silica, CH2Cl2/EtOAc, 10:1). The product is obtained as red solid.

Yield: 93.3 mg (0.23 mmol), 94%.

1H NMR (300 MHz, CDCl3, 20°C): (ppm) = 7-8 (br.s), 4.21 (br.s), 4.02 (br.s,), 3.92

(br.s), 1-2 (br. m, tBu).

MS (MALDI-TOF, DCTB): [m/z] = 3959 [M]+(low intensity).


420 (219100), 546 (23100), 590 (7700).

IR (ATR): [cm-1] = 2967, 1722, 1660, 1525, 1456, 1366, 1229, 1217, 1148, 999.


203

Manganese(III) dendritic tetrakis(ferrocenyltriazolyl) porphyrin

Mn(III)Cl-83


is dissolved in 40 mL CHCl3, 62.92 mg

(0.5 mmol) MnCl2 solved in 10 mL MeOH

and one drop of 2,6-lutidine were added.

The mixture is refluxed for 12 h, afterwards

washed with water and dried over MgSO4.

Purification of the crude product is achieved by flash chromatography (silica,

CH2Cl2/MeOH, 10:1) to give the product as a dark green solid.

Yield: 68.76 mg (0.017 mmol), 69%.

1H NMR (300 MHz, CDCl3, 20°C): (ppm) = 8.5 (br. s), 3.9 (br. s), 1.7 (s), 1.5(br. s).

MS (MALDI-TOF, DCTB): [m/z] = 3930 [M-tBu]+.


406 (22000), 425, (30100), 481 (63200).

IR (ATR): [cm-1] = 2969, 1722, 1659, 1527, 1457, 1367, 1260, 1147, 1010, 844.

Iron(III) dendritic tetrakis(ferrocenyltriazolyl)porphyrin Fe(III)Cl-83


is dissolved in 40 mL CHCl3 and 63.38 mg

(0.5 mmol) FeCl2 dissolved in EtOH and

one drop of 2,6-lutidine are added. The

brown solution is refluxed for 12 h, then

washed with water and dried over MgSO4.

Final Purification can be archived by flash chromatography (silica, CH2Cl2/MeOH,

10:1) to give the product as a brown powder.

Yield: 79.7 mg (0.02 mmol), 78%.

1H NMR (300 MHz, CDCl3, 20°C): (ppm) = 85-75 (br. s, 8H, β-pyrr.), 15.62, 13.80,

12.41 (3 br. s, 12H, ArH), 2.03 (s, 36H, tBu), 1.39 (s, 108H, tBu).

MS (MALDI-TOF, DCTB): [m/z] = 3930 [M-tBu]+.


204


423 (79200), 508 (1100), 585 (3700).

IR (ATR): [cm-1] = 2968, 1721, 1659, 1530, 1290, 1367, 1261, 1147, 1010, 844.

Nickel(II) octakis(ferrocenyltriazolyl)porphyrin Ni(II)-72

An amount of 100 mg (0.03 mmol) 2H-72 is dissolved in

40 mL toluene, 86 mg (0.33 mmol) Ni(acac)2 are added and

the solution is refluxed for 5h. After distilling the solvent

under reduced pressure, the residue is redissolved in

CH2Cl2 and washed twice with water. After drying over

MgSO4 and evaporation of the solvent the product can be

obtained as an orange powder without any further

purification.

Yield: 87.81 mg (0.029 mmol), 87%.


6.65 (s, 8H, triazole-H), 4.98 (s, 16H, CH2), 4.15 (t, 3J=1.8 Hz, 16H, FcH), 3.99 (t,

3J=1.8 Hz, 16H, FcH), 3.82 (s, 40H, FcH), 1.67 (s, 36H, tBu).


133.7, 122.3, 119.9, 112.3, 75.7, 69.1, 69.2, 68.1, 66.8, 67.2, 61.1, 53.2, 32.5, 31.1,

30.9, 22.0, 14.1.



528 (31200), 570 (7900).

IR (ATR): [cm-1] = 3278, 2919, 2849, 1738, 1601, 1487, 1338, 1280, 1212, 994.


205

Copper(II) octakis(ferrocenyltriazolyl)porphyrin Cu(II)-72

100 mg (0.03 mmol) 2H-72 are dissolved in CH2Cl2,

62.17 mg (0.33 mmol) Cu(OAc)2∙H2O solved in 10 mL

MeOH are added an the mixture is stirred at rt for 24 h.

Then the solution is washed twice with water and afterwards

dried over MgSO4. The pure product can be obtained after

flash chromatography (silica, CH2Cl2/EtOAc, 10:1). The

product is obtained as red solid.

Yield: 89.7 mg (0.30 mmol), 90%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 7.6 (br.s, 16H, β-pyrr., ArH), 4.61 (br.s,

CH2), 4.21 (br.s, FcH), 3.92 (br.s, FcH), 1-2 (br. m, tBu).



543 (14600), 585 (4200).

IR (ATR): [cm-1] = 2963, 1723, 1589, 1439, 1366, 1260, 1217, 1221, 797, 504.

Manganese(III) octakis(ferrocenyltriazolyl)porphyrin Mn(III)Cl-84


40 mL CHCl3, 84.3 mg (0.67 mmol) MnCl2 solved in 10 mL

MeOH and one drop of 2,6-lutidine are added. The mixture

is stirred at reflux for 12 h, afterwards washed with water

and dried over MgSO4. Purification of the crude product is

achieved by flash chromatography (silica, CH2Cl2/MeOH,

10:1) to give the product as a green-brown solid.

Yield: 86.9 mg (0.028 mmol), 95%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 8.5 (br. s), 4.0 (br. s), 1.6 (s), 1.5(br. s).

MS (MALDI-TOF, DCTB): [m/z] = 3097 [M-Cl]+.


400 (35400), 424 (25600), 476 (76300), 576 (low intensity), 610 (low intensity).


206

IR (ATR): [cm-1] = 2969, 2870, 1722, 1638, 1437, 1366, 1217, 1105, 1044, 1009.

Iron(III) octakis(ferrocenyltriazolyl)porphyrin Fe(III)Cl-72


40 mL CHCl3 and 84.81 mg (0.67 mmol) FeCl2 dissolved in

EtOH and one drop of 2,6-lutidine are added. The brown

solution is refluxed for 4 h, then washed with water and

dried over MgSO4. Final Purification can be achieved by

flash chromatography (silica, CH2Cl2/MeOH, 10:1) to give

the product as a brown powder.

Yield: 76.52 mg (0.25 mmol), 75%.

1H NMR (400 MHz, CDCl3, 20°C): (ppm) = 82-78 (br. s, 8H, β-pyrr.), 15.62, 13.80,

12.41 (3 br. s, 12H, ArH), 2.03 (s, 36H, tBu).



423 (82400), 508 (6300), 585 (4200).

IR (ATR): [cm-1] = 3030, 2929, 2982, 2871, 1724, 1579, 1456, 1365, 1272, 1121,

1072.

Nickel(II) dendritic octakis(ferrocenyltriazolyl)porphyrin Ni(II)-84

An amount of 150 mg (0.02 mmol) 2H-84 is

dissolved in 40 mL toluene. 51.4 mg

(0.20 mmol) Ni(acac)2 are added and the

solution is refluxed for 5 h. After destilling

the solvent under reduced pressure, the

residue is redissolved in CH2Cl2 and

washed twice with water. After drying over

MgSO4 and evaporation of the solvent the

product can be obtained as an orange

powder without any further purification.

Yield: 126.2 mg (0.018 mmol), 90%.


207


7.41 (br. s, 8H, triazole-H), 6.42 (s, 8H, NH), 5.26 (m, 16H, CH2), 5.01 (br. s, 16H,

CH2), 4.64 (s, 16H, FcH), 4.53 (s, 16H, FcH), 4.34 (s, 16H, FcH), 4.07 (s, 16H, FcH),

2.28 (t, 3J=7.6 Hz, 48H, CH2), 2.04 (t, 3J=8.0 Hz, 48H, CH2), 1.40 (s, 18H, tBu), 1.39

(s, 216H, tBu).


71.2, 69.5, 57.7, 35.0, 31.2, 30.0, 29.8, 28.0, 24.7.

MS (MALDI-TOF, DCTB): [m/z] = 7013 [M]+, 6982 [M-tBu]+.


417 (182300), 529 (14800), 570 (5400).

IR (ATR): [cm-1] = 3030, 2970, 1722, 1660, 1529, 1456, 1366, 1229, 1217, 1147.

Copper(II) dendritic octakis(ferrocenyltriazolyl)porphyrin Cu(II)-84


dissolved in CH2Cl2, 37.2 mg (0.20 mmol)

Cu(OAc)2∙H2O dissolved in 10 mL MeOH

are added and the mixture is stirred at rt for

24 h. The solution is washed twice with

water and dried over MgSO4. The pure

product can be obtained after flash

chromatography (silica, CH2Cl2/EtOAc,

10:1) as red solid.

Yield: 127.7 mg (0.018 mmol), 91%.

1H NMR (300 MHz, CDCl3, 20°C): (ppm) = 7.3 (br.s, 16H, β-pyrr., ArH), 4.6 (br.s,

CH2), 4.44 (br.s, FcH), 3.82 (br.s, FcH), 1-2 (br. m, CH2, tBu).


UV/Vis (CH2Cl2): l [nm] (e [lmol-1cm-1]) = 228 (35200), 254 (21300), 312(8900), 419

(201200), 544 (13000), 610 (4600).

IR (ATR): [cm-1] = 2970, 2929, 1720, 1660, 1529, 1455, 1367, 1274, 1216, 1148.


208

Manganese(III) dendritic octakis(ferrocenyltriazolyl)porphyrin

Mn(III)Cl-84


dissolved in 40 mL CHCl3. 50.3 mg

(0.4 mmol) MnCl2 dissolved in 10 mL MeOH

and one drop of 2,6-lutidine are added. The

mixture is stirred for 12 h at reflux,

afterwards washed with water and dried over

MgSO4. Purification of the crude product is

achieved by flash chromatography (silica,

CH2Cl2/MeOH, 10:1) to give the product as a

dark green solid.

Yield: 105.7 mg (0.015 mmol), 75%.

1H NMR (300 MHz, CDCl3, 20°C): (ppm) = 6.5 (br. s), 4-5 (br. s), 2.8 (br. s), 2.3 (br.

s), 1.7 (s), 1.5 (br. s).

MS (MALDI-TOF, DCTB): [m/z] = 7045 [M]+ (broad signal).


407 (19200), 427, (24100), 480 (52400).

IR (ATR): [cm-1] = 2918, 2915, 2769, 1712, 1658, 1367, 1273, 1149, 843, 800.

EA for C364H476ClFe8MnN36O72∙3 CHCl3: cal.: C 59.54, H 6.52, N 6.81;

found: C 59.61, H 6.81, N 6.66.


209

Iron(III) dendritic octakis(ferrocenyltriazolyl)porphyrin Fe(III)-Cl-84


dissolved in 40 mL CHCl3 and 50.7 mg

(0.4 mmol) FeCl2 dissolved in EtOH and one

drop of 2,6-lutidine is added. The brown

solution is refluxed for 12 h, then washed

with water and dried over MgSO4. Final

Purification can be achieved by flash

chromatography (silica, CH2Cl2/MeOH, 10:1)

to give the product as a brown powder.

Yield: 102.9 mg (0.015 mmol), 73%.

1H NMR (300 MHz, CDCl3, 20°C): (ppm) = 82-78 (br s, 8H, β-pyrr.), 6.36, 4.66-

4.30, 2.42, 2.28, 2.03, 1.45, 1.27.



422 (69200), 508 (1400), 585 (4800).

IR (ATR): [cm-1] = 2970, 1722, 1659, 1256, 1457, 1367, 1274, 1217, 1148, 845.

EA for C364H476ClFe9N36O72: cal.: C 62.05; H 6.81, N 7.16;

found: C 62.08, H 7.15, N 6.40.

Appendix

210

Crystal data and structure refinement for 72.

Empirical formula C181 H192Cl4Fe8N28O2Zn

Formula weight 3445.60

Temperature 150(2) K

Wavelength 0.71073 Å

Crystal system, space group monoclinic, P2(1)/n

Unit cell dimensions

a 20.915(2) Å

α 90°

b 15.7885(12) Å

β 107.819(7)°

c 26.913(2) Å

γ 90°

Volume 8460.8(12) Å3

Z, Calculated density 2, 1.352 mg/m3

Absorption coefficient 0.929 mm-1

F(000) 3592

Crystal size 0.27 x 0.18 x 0.03 mm

Theta range for data collection 3.37 to 27.10 °.

Limiting indices -26<=h<=26, -20<=k<=20, -34<=l<=34

Reflections collected / unique 137279 / 18623 [R(int) = 0.0994]

Completeness to theta = 27.10 99.7%

Absorption correction semi-empirical from equivalents

Max. and min. transmission 0.970 and 0.734

Refinement method full-matrix least-squares on F2

Data / restraints / parameters 18623 / 321 / 1239

Goodness-of-fit on F2 1.019

Final R indices [I>2sigma(I)] R1 = 0.0553, wR2 = 0.1274

R indices (all data) R1 = 0.1011, wR2 = 0.1479

Largest diff. peak and hole 0.930 and -0.543 e.A-3

References

211

7 References

[1] H. C. Kolb, M. G. Finn, K. B. Sharpless, Angew. Chem., Int. Ed. 2001, 40, 2004.

[2] Chem. Eur. J. 2004, 10/21.

[3] Angew. Chem. 2004, 116/30.

[4] ChemComm 2008, 21.

[5] Angew. Chem. 2009, 121/28.

[6] SciFinder Scholar® 2007 © American Chemistry Society

[7] J. Lahan, (editor), Click Chemistry for Biotechnology and Materials Science Wiley-Blackwell 2009.

[8] J. Opsteen, Modular synthesis of well-defined macromoleculararchitectures: Employment of "click" reactions in polymer chemistry VDM Verlag 2009.

[9] M. V. Gil, M. J. Arevalo, O. Lopez, Synthesis 2007, 1589.

[10] V. V. Rostovtsev, L. G. Green, V. V. Fokin, K. B. Sharpless, Angew. Chem., Int. Ed. 2002, 41, 2596.

[11] B. Gacal, H. Durmaz, M. A. Tasdelen, G. Hizal, U. Tunca, Y. Yagci, A. L. Demirel, Macromolecules 2006, 39, 5330.

[12] T. Siu, A. K. Yudin, J. Am. Chem. Soc. 2002, 124, 530.

[13] F.-S. Liang, A. Brik, Y.-C. Lin, J. H. Elder, C.-H. Wong, Bioorg. Med. Chemistry 2006, 14, 1058.

[14] I. M. Pastor, M. Yus, Curr. Org. Chem. 2005, 9, 1.

[15] J. E. Moses, A. D. Moorhouse, Chem. Soc. Rev. 2007, 36, 1249.

[16] R. Huisgen, Angew. Chem. 1963, 75, 604.

[17] D. J. Hlasta, J. H. Ackerman, J. Org. Chem. 1994, 59, 6184.

[18] S. J. Howell, N. Spencer, D. Philp, Tetrahedron 2001, 57, 4945.

[19] C. A. Booth, D. Philip, Tetrahedron Lett. 1998, 39, 6987.

[20] C. W. Tornoe, C. Christensen, M. Meldal, J. Org. Chem. 2002, 67, 3057.

[21] L. Zhang, X. Chen, P. Xue, H. H. Y. Sun, I. D. Williams, K. B. Sharpless, V. V. Fokin, G. Jia, J. Am. Chem. Soc. 2005, 127, 15998.

References

212

[22] P. L. Golas, N. V. Tsarevsky, B. S. Sumerlin, K. Matyjaszewski, Macromolecules 2006, 39, 6451.

[23] V. O. Rodionov, V. V. Fokin, M. G. Finn, Angew. Chem., Int. Ed. 2005, 44, 2210.

[24] F. Himo, T. Lovell, R. Hilgraf, V. V. Rostovtsev, L. Noodleman, K. B. Sharpless, V. V. Fokin, J. Am. Chem. Soc. 2004, 127, 210.

[25] R. Chinchilla, C. Najera, Chem. Rev. 2007, 107, 874.

[26] V. D. Bock, H. Hiemstra, J. H. van Maarseveen, Eur. J. Org. Chem. 2005, 51.

[27] Donald J. Darensbourg, Way-Zen Lee, M. Jason Adams, Jason C. Yarbrough, Eur. J. Inorg. Chem. 2001, 2001, 2811.

[28] W.-h. Zhan, H. N. Barnhill, K. Sivakumar, H. Tian, Q. Wang, Tetrahedron Lett. 2005, 46, 1691.

[29] B. H. M. Kuijpers, S. Groothuys, A. R. Keereweer, P. J. L. M. Quaedflieg, R. H. Blaauw, F. L. van Delft, F. P. J. T. Rutjes, Org. Lett. 2004, 6, 3123.

[30] K. Sivakumar, F. Xie, B. M. Cash, S. Long, H. N. Barnhill, Q. Wang, Org. Lett. 2004, 6, 4603.

[31] E.-H. Ryu, Y. Zhao, Org. Lett. 2005, 7, 1035.

[32] L. Ciavatta, D. Ferri, R. Palombari, J. Inorg. Nucl. Chem. 1980, 42, 593.

[33] H. A. Orgueira, D. Fokas, Y. Isome, P. C. M. Chan, C. M. Baldino, Tetrahedron Lett. 2005, 46, 2911.

[34] Laura Durán Pachón, Jan H. van Maarseveen, Gadi Rothenberg, Adv. Synth. Catal. 2005, 347, 811.

[35] M. B. Thathagar, J. Beckers, G. Rothenberg, J. Am. Chem. Soc. 2002, 124, 11858.

[36] Y.-M. Wu, J. Deng, X. Fang, Q.-Y. Chen, J. Fluorine Chem. 2004, 125, 1415.

[37] F. Fazio, M. C. Bryan, O. Blixt, J. C. Paulson, C.-H. Wong, J. Am. Chem. Soc. 2002, 124, 14397.

[38] T. R. Chan, R. Hilgraf, K. B. Sharpless, V. V. Fokin, Org. Lett. 2004, 6, 2853.

[39] A. E. Speers, G. C. Adam, B. F. Cravatt, J. Am. Chem. Soc. 2003, 125, 4686.

[40] I. D. Campbell, G. Eglinton, Org. Synth. 1965, 45, 39.

[41] G. Hermanson, Accademic Press, 1996.

[42] Rolf Breinbauer, Maja Köhn, ChemBioChem 2003, 4, 1147.

References

213

[43] X.-L. Sun, C. L. Stabler, C. S. Cazalis, E. L. Chaikof, Bioconjugate Chem. 2005, 17, 52.

[44] R. Jagasia, J. M. Holub, M. Bollinger, K. Kirshenbaum, M. G. Finn, Eur. J. Org. Chem. 2009, 74, 2964.

[45] Q. Wang, T. R. Chan, R. Hilgraf, V. V. Fokin, K. B. Sharpless, M. G. Finn, J. Am. Chem. Soc. 2003, 125, 3192.

[46] S. S. Gupta, J. Kuzelka, P. Singh, W. G. Lewis, M. Manchester, M. G. Finn, Bioconjugate Chem. 2005, 16, 1572.

[47] H. Li, F. Cheng, A. M. Duft, A. Adronov, J. Am. Chem. Soc. 2005, 127, 14518.

[48] Wolfgang H. Binder, Robert Sachsenhofer, Macromol. Rapid Commun. 2007, 28, 15.

[49] Wolfgang H. Binder, Robert Sachsenhofer, Macromol. Rapid Commun. 2008, 29, 952.

[50] P. Wu, A. K. Feldman, A. K. Nugent, Hawker, A. Scheel, B. Voit, J. Pyun, Jean M. J. Fréchet, K. Barry Sharpless, Valery V. Fokin, Angew. Chem. Int. Ed. 2004, 43, 3928.

[51] B. Parrish, R. B. Breitenkamp, T. Emrick, J. Am. Chem. Soc. 2005, 127, 7404.

[52] Philippe Lecomte, Raphaël Riva, Stéphanie Schmeits, Jutta Rieger, Kathy Van Butsele, Christine Jérôme, Robert Jérôme, Macromol. Symp. 2006, 240, 157.

[53] R. Riva, S. Schmeits, F. Stoffelbach, C. Jerome, R. Jerome, P. Lecomte, Chem. Commun. 2005, 5334.

[54] W. H. Binder, C. Kluger, Macromolecules 2004, 37, 9321.

[55] H. Gao, G. Louche, B. S. Sumerlin, N. Jahed, P. Golas, K. Matyjaszewski, Macromolecules 2005, 38, 8979.

[56] N. V. Tsarevsky, B. S. Sumerlin, K. Matyjaszewski, Macromolecules 2005, 38, 3558.

[57] J. A. Opsteen, J. C. M. v. Hest, Chem. Commun. 2005, 57.

[58] H. Gao, K. Matyjaszewski, Macromolecules 2006, 39, 4960.

[59] M. R. Whittaker, C. N. Urbani, M. J. Monteiro, J. Am. Chem. Soc. 2006, 128, 11360.

[60] A. P. Vogt, B. S. Sumerlin, Macromolecules 2006, 39, 5286.

[61] D. A. Fleming, C. J. Thode, M. E. Williams, Chem. Mater.2006, 18, 2327.

[62] J. K. Lee, Y. S. Chi, I. S. Choi, Langmuir 2004, 20, 3844.

References

214

[63] G. Conte, F. Ely, H. Gallardo, Liq. Cryst.2005, 32, 1213

[64] H. Gallardo, F. Ely, A. J. Bortoluzzi, G. Conte, Liq. Cryst.2005, 32, 667

[65] R. Alvarez, S. Velazquez, A. San-Felix, S. Aquaro, E. De Clercq, C. F. Perno, A. Karlsson, J. Balzarini, M. J. Camarasa, J. Med. Chem.1994, 37, 4185.

[66] M. J. Genin, D. A. Allwine, D. J. Anderson, M. R. Barbachyn, D. E. Emmert, S. A. Garmon, D. R. Graber, K. C. Grega, J. B. Hester, D. K. Hutchinson, J. Morris, R. J. Reischer, C. W. Ford, G. E. Zurenko, J. C. Hamel, R. D. Schaadt, D. Stapert, B. H. Yagi, J. Med. Chem.2000, 43, 953.

[67] M. Whiting, J. Muldoon, Y.-C. Lin, S. M. Silverman, W. Lindstrom, A. J. Olson, H. C. Kolb, M. G. Finn, K. B. Sharpless, J. H. Elder, V. V. Fokin, Angew. Chem. Int. Ed. 2006, 45, 1435.

[68] M. Whiting, J. C. Tripp, Y.-C. Lin, W. Lindstrom, A. J. Olson, J. H. Elder, K. B. Sharpless, V. V. Fokin, J. Med. Chem.2006, 49, 7697.

[69] D. Klatzmann, E. Champagne, S. Chamaret, J. Gruest, D. Guetard, T. Hercend, J. C. Gluckman, L. Montagnier, Nature 1984, 312, 767.

[70] H. N. Gopi, K. C. Tirupula, S. Baxter, S. Ajith, I. M. Chaiken, ChemMedChem 2006, 1, 54.

[71] L. V. Lee, M. L. Mitchell, S. J. Huang, V. V. Fokin, K. B. Sharpless, C. H. Wong, J. Am. Chem. Soc. 2003, 125, 9588.

[72] X. Gu, L. Creasy, A. Kester, M. Zeece, J. Agric. Food Chem. 1999, 47, 3223.

[73] F. Pagliai, T. Pirali, E. Del Grosso, R. Di Brisco, G. C. Tron, G. Sorba, A. A. Genazzani, J. Med. Chem.2005, 49, 467.

[74] B.-C. Suh, H. Jeon, G. H. Posner, S. M. Silverman, Tetrahedron Lett. 2004, 45, 4623.

[75] W. G. Lewis, L. G. Green, F. Grynszpan, Z. Radic, P. R. Carlier, P. Taylor, M. G. Finn, K. B. Sharpless, Angew. Chem., Int. Ed. 2002, 41, 1053.

[76] S. L. Elmer, S. Man, S. C. Zimmerman, Eur. J. Org. Chem. 2008, 3845.

[77] M. Kimura, Y. Nakano, N. Adachi, Y. Tatewaki, H. Shirai, N. Kobayashi, Chem. Eur. J. 2009, 15, 2617.

[78] J. Iehl, R. P. d. Freitas, B. Delavaux-Nicot, J.-F. Nierengarten, Chem. Commun. 2008, 2450.

[79] J. Iehl, I. Osinska, R. Louis, M. Holler, J.-F. Nierengarten, Tetrahedron Lett. 2009, 50, 2245.

[80] A. Hirsch, I. Lamparth, T. Groesser, H. R. Karfunkel, J. Am. Chem. Soc. 1994, 116, 9385.

References

215

[81] J. E. A. Webb, F. Maharaj, I. M. Blake, M. J. Crossley, Synlett 2008, 2147.

[82] J. Almog, J. E. Baldwin, R. L. Dyer, M. Peters, J. Am. Chem. Soc. 1975, 97, 226.

[83] J. Almog, J. E. Baldwin, M. J. Crossley, J. F. Debernardis, R. L. Dyer, J. R. Huff, M. K. Peters, Tetrahedron 1981, 37, 3589.

[84] N. Jux, Org. Lett. 2000, 2, 2129.

[85] N. H. Huyen, U. Jannsen, H. Mansour, N. Jux, J. Porphyrins Phthalocyanines 2004, 8, 1356.

[86] R. C. Fuson, J. Mills, T. G. Klose, M. S. Carpenter, J. Org. Chem. 1947, 12, 587.

[87] M. Tashiro, T. Yamato, J. Chem. Soc., Perkin Trans. 1 1979, 176.

[88] J. E. Field, T. J. Hill, D. Venkataraman, J. Org. Chem. 2003, 68, 6071.

[89] S. Jasinski, PhD thesis, Friedrich-Alexander Universität (Erlangen), 2009.

[90] R. C. Fuson, B. Freedman, J. Org. Chem. 1958, 23, 1161.

[91] J. S. Lindsey in The Porphyrin Handbook, Vol. 1 (Eds.: K. M. Kadish, K. M. Smith, R. Guilard), Academic Press, 2000, p. 45 ff.

[92] C.-H. Lee, J. S. Lindsey, Tetrahedron 1994, 50, 11427.

[93] N. Lang, diploma thesis, Friedrich-Alexander Universität (Erlangen), 2006.

[94] S. Eigler, diploma thesis, Friedrich-Alexander-Universität (Erlangen), 2003.

[95] D. Balbinot, PhD thesis, Friedrich Alexander Universität (Erlangen), 2006.

[96] H. Mansour, pHD thesis, Friedrich-Alexander Universität (Erlangen), 2005.

[97] M. Hesse, H. Meier, B. Zeeh, Spektroskopische Methoden der Organischen Chemie, 5th ed., Georg Thieme Verlag, Stuttgart-New York, 1995.

[98] S. Chittaboina, F. Xie, Q. Wang, Tetrahedron Lett. 2005, 46, 2331.

[99] C. Bucher, C. H. Devillers, J.-C. Moutet, G. Royal, E. Saint-Aman, Coordination Chemistry Reviews 2009, 253, 21.

[100] Y. Chen, G.-Y. Jung, D. A. A. Ohlberg, X. Li, D. R. Stewart, J. O. Jeppesen, K. A. Nielsen, J. F. Stoddart, R. S. Williams, Nanotechnology 2003, 14, 462.

[101] J. R. Health, P. R. Kuekes, G. S. Snider, R. S. Williams, Sciene 1998, 280, 1716.

[102] A. J. Bard, Nature (London) 1995, 374, 13.

References

216

[103] K. Matsushige, H. Yamada, H. Tada, T. Horiuchi, X. Q. Chen, Ann. N. Y. Acad. Sci. 1998, 852, 290.

[104] Z. Liu, A. A. Yasseri, J. S. Lindsey, D. F. Bocian, Science (Washington, DC, U. S.) 2003, 302, 1543.

[105] K. M. Kadish, M. M. Morrison, Bioinorg. Chem.1977, 7, 107.

[106] I. Noviandri, K. N. Brown, D. S. Fleming, P. T. Gulyas, P. A. Lay, A. F. Masters, L. Phillips, J. Phys. Chem. B 1999, 103, 6713.

[107] J. Ruiz Aranzaes, M.-C. Daniel, D. Astruc, Can. J. Chem. 2006, 84, 288.

[108] C. Ornelas, J. Ruiz Aranzaes, E. Cloutet, S. Alves, D. Astruc, Angew. Chem. Int. Ed. 2007, 46, 872.

[109] J. Fajer, D. C. Borg, A. Forman, D. Dolphin, R. H. Felton, J. Am. Chem. Soc. 1970, 92, 3451.

[110] K. M. Kadish, L. R. Shiue, R. K. Rhodes, L. A. Bottomley, Inorg. Chem.1981, 20, 1274.

[111] P. Hambright, in The Porphyrin Handbook, Vol. 3 (Eds.: K. M. Kadish, K. M. Smith, R. Guilard), Academic Press, 2000.

[112] D. M. Guldi, G. M. A. Rahman, N. Jux, D. Balbinot, U. Hartnagel, N. Tagmatarchis, M. Prato, J. Am. Chem. Soc. 2005, 127, 9830.

[113] G. R. Newkome, R. K. Behera, C. N. Moorefield, G. R. Baker, J. Org. Chem. 1991, 56, 7162.

[114] B. Neises, W. Steglich, Angew. Chem. 1978, 90, 556.

[115] K. M. Kadish, E. Van Caemelbecke, G. Royal in The Porphyrin Handbook, Vol. 8 (Ch.55) (Eds.: K. M. Kadish, K. M. Smith, R. Guilard), Academic Press, New York, 2000.

[116] J. K. M. Sanders, N. Bampos, Z. Clyde-Watson, S. L. Darling, J. C. Hawley, H.-J. Kim, C. C. Mak, S. J. Webb in The Porphyrin Handbook, Vol. 3 (Eds.: K. M. Kadish, K. M. Smith, R. Guilard), Academic Press, New York, 2000, pp. 3.

[117] J. W. Buchler, in The Porphyrins, Vol. I (Ed.: D. Dolphin), Academic Press, San Diego, 1978, pp. 389.

[118] J. Dannhäuser, PhD thesis, Friedrich-Alexander-Universität (Erlangen), 2007.

[119] V. V. Borovkov, J. M. Lintuluoto, Y. Inoue, Synlett 1999, 61.

[120] A. D. Adler, F. R. Longo, F. Kampas, J. Kim, J. Inorg. Nucl. Chem. 1970, 32, 2443.

[121] S. Richeter, C. Jeandon, J.-P. Gisselbrecht, R. Ruppert, H. J. Callot, J. Am. Chem. Soc. 2002, 124, 6168.

References

217

[122] F. A. Walter, Vol. 5 (Ch. 3) (Eds.: K. M. Kadish, K. M. Smith, R. Guilard), Academic Press, New York, 2000.

[123] M. Gouterman, J. Mol. Spectrosc. 1961, 6, 138.

[124] M. Gouterman, G. H. Wagnière, L. C. Snyder, J. Mol. Spectrosc. 1963, 11, 108.

[125] H.-H. Perkampus, UV/Vis Atlas of Organic Compounds, 2nd ed., Wiley-VCH, Weinheim.

[126] D. K. Lavallee, Comments on Inorg. Chem.1986, 5, 155

[127] J. W. Buchler, in Porphyrins and Metalloporphyrins (Ed.: K. M. Smith), Elsevier, New York, 1976, p. 157.

[128] J. Seth, V. Palaniappan, D. F. Bocian, Inorg. Chem.1995, 34, 2201.

[129] J. Y. Becker, D. Dolphin, J. B. Paine, T. Wijesekera, J. Electroanal. Chem. 1984, 164, 335.

[130] L. Dulog, J. Breitenbuecher, Liebigs Ann. Chem. 1993, 201.

[131] MestRe-C Lite 4.7.4.0.

[132] ACD/Labs Release: 10.00 Product Version: 10.02 (built: 14033, 06.Oct 2006).

[133] Mercury 1.3 ©CCDC 2001-2004.

[134] SPARTAN®130 1991-2003 ©Wavefunction Inc.

[135] PovChem 2.1.1 built 13.Dec.2000 ©Paul A. Thiessen.

[136] POV-Ray™ for Windows 3.6 ©Persistance of Vision Raytracer Pty. Ltd.

[137] A. McKillop, J. C. Fiaud, R. P. Hug, Tetrahedron 1974, 30, 1379.

[138] S. Schlundt, G. Kuzmanich, F. Spänig, G. de Miguel Rojas, C. Kovacs, Miguel A. Garcia-Garibay, D. M. Guldi, A. Hirsch, Chem. Eur. J. 2009, 15, 12223.

[139] A. Ebel, diploma thesis, Friedrich-Alexander-Universität (Erlangen), 2006.

218

Publikations:

Studies on an iron(III)-peroxo porphyrin. Iron(III)-peroxo or iron(II)-superoxo?

Katharina Duerr, Julianna Olah, Roman Davydov, Michael Kleimann, Jing Li, Nina

Lang, Ralph Puchta, Eike Hübner, Thomas Drewello, Jeremy N. Harvey, Norbert Jux,

Ivana Ivanovic-Burmazovic, Dalton Trans., 2010, 2049.

Multiple triazole “click” reactions with porphyrin oligoazides; Nina Lang, Frank

Heinemann, Norbert Jux, manuscript in preparation.

Generating Cationic, Dendritic Structures and their Application in Surface

Modifications of ZnO-Nanostructures; Jan-Frederik Gnichwitz, Renata Marczak,

Fabian Werner, Nina Lang, Norbert Jux, Dirk M. Guldi, Wolfgang Peukert, Andreas

Hirsch, J. Am. Chem. Soc., accepted.

Conferences and Meetings:

Synthesis of novel porphyrin-crown ether-conjugates; Nina Lang, Katharina Dürr,

Norbert Jux, abstract book and poster, International Conference of Porphyrins and

Phthalocyanines 4, 2006.

Novel triazole-porphyrin conjugates by 1,3-dipolar “click” cycloaddition; Nina Lang,

Norbert Jux, abstract book and poster, International Conference of Porphyrins and

Phthalocyanines 5, 2008.

219

Thank You!

An dieser Stelle möchte ich mich zuerst bei meinem Doktorvater PD Dr. Norbert Jux

für das Interesse am Fortgang dieser Arbeit und die Möglichkeit die Themenstellung

weitgehend selbstständig zu bearbeiten bedanken. Weiterhin danke ich Professor Dr.

Andreas Hirsch für die angenehme Arbeitsatmosphäre in seinem Lehrstuhl, sowie für

die gemeinsamen Arbeitsgruppenseminare. Großer Dank gilt auch den

akademischen Räten Dr. Marcus Speck, Dr. Michael Brettreich und Dr. Frank Hauke.

Dank gilt natürlich auch den Angestellten und Mitarbeitern des Instituts für

Organische Chemie. Hervorzuheben sind hierbei: Erna Erhardt, Dr. Thomas Röder,

Prof. Dr. Walter Bauer, Wilfried Schätzke und Christian Placht, Wolfgang

Donaubauer, Margarete Dzialach, Eva Hergenröder, Detlef Schagen, Robert Panzer,

Hannelore Oschmann, dem Werkstatt-Team Erwin Schreier und Eberhard

Rupprecht, den Glasbläsern St ef an Fronius und Bahram Saberi und dem

Hausmeister Holger Wohlfahrt.

Weiterhin möchte ich allen Kollegen aus dem Arbeitskreis für die schöne Zeit in der

OC danken (in absolut willkürlicher Reihenfolge): Dr. Jürgen “Abe” Abraham, Dr.

Adrian Jung, Dr. Domenico “Nick” Balbinot, Dr. Torsten “Tosche” Brandmüller (danke

für´s Grillen), Dr. Harald Maid, Dr. Jörg Dannhäuser, Dr. Siegfried “Sci-Guy” Eigler,

Dr. Kristine “Bine” Hartnagel, Dr. Uwe Hartnagel, Dr. Matthias Helmreich, Dr. Hanaa

Mansour, Dr. Florian Beuerle, Dr. Jutta Rath, Dr. Miriam Becherer, Dr. Stefan

„Steffele“ Jasinski, Dr. Keulo, Dr. David Wunderlich, Dr. Florian “Wessi” Wessendorf,

Dr. Karin Rosenlehner, Freddy Gnichwitz, Katja Maurer-Chronaki, Helmut

Degenbeck, Nadine Ulm, Miriam Biedermann, Maria Alfaro Blasco, Tine Böhner,

Steffi Bade, Christian Kovacs, Katharina Dürr, Alex Ebel, Alex Gmehling, Felix

Grimm, Astrid Hopf, Frank Hörmann, Rainer Lippert, Michaela Ruppert, Cordula

Schmidt, Torsten Schunk, Sebastian Schlundt, Zois Syrgiannis, Ute Pinkert, Lennard

Wasserthal, Claudia Backes, Christoph Dotzer, Benjamin Gebhardt, Jenny Malig und

Jan Englert, Wolfgang Brenner, Steffi Petzi, Tina Andrä, Simone Berngruber, Hanne

Jasch, Nico Bernhard, Ferdinand Hof, Bhasem Gharib und Jörg Schönamsgruber.

Danke an die PostDocs und Post-Profs: Ryosuke “Yoshi” Miyake, Dr. Nikos

Chronakis, Prof. Dr. Yannis Elemes, Dr. Haruhito Kato, Dr. Feng Lai, Dr. Dina

Ibragimova, Dr. Bojan Johnev und Dr . Rad hakr ishnan Visw anat han .

220

Aus der AC möchte ich Katharina und Anita für die Hilfe bei der Messung der

Zyklischen Voltammogramme danken.

Vielen Dank auch an meine Mitarbeiter und Bachelorstudenten Sabine, Leoni, Lilli,

Regina, Elena und Nadja.

Besonderer Dank für das sorgfältige Korrekturlesen meiner Arbeit gilt nochmals

Freddy, Miri, Nadine, Astrid, Felix und Babsi sowie Marcus für die Verbesserung

meiner deutschen Zusammenfassung

Last but not least danke ich meiner Familie für die Unterstützung während meines

Studiums und meiner Promotion. Für den Beistand und die Unterstützung v.a. in den

Wochen vor der Promotionsprüfung geht ein ganz großes Dankeschön an Freddy.

221

Nina Lang

geb. am 10.02.1981

in Bamberg

Staatsangehörigkeit: deutsch

LEBENSLAUF

PROMOTION

05/2006 - 06/2010 Anfertigung der Doktorarbeit am Institut für Organische Chemie II der Friedrich-Alexander-Universität Erlangen-Nürnberg unter der Leitung von Herrn PD Dr. N. Jux

Anstellung als wissenschaftliche Mitarbeiterin

Thema: Multiple “click“ reactions on porphyrins

STUDIUM

06/2005 - 03/2006

10/2004 - 03/2006

Diplomarbeit: Synthese und Charakterisierung von Poly-(Kronenether-Porphyrin)-Konjugaten unter der Leitung von Herrn PD Dr. N. Jux

Abschluss des Chemiestudiums an der Friedrich-Alexander-Universität Erlangen-Nürnberg

10/2002 - 07/2004 Hauptstudium der Chemie an der Technischen Universität Berlin

Wahlfach: Technische Chemie

10/2000 - 07/2002 Grundstudium der Chemie an der Julius-Maximilians-Universität Würzburg

SCHULBILDUNG

06/2000 Abitur

09/1991 - 06/2000 Clavius-Gymnasium Bamberg

09/1987 - 07/1991 Grundschule Zapfendorf

Documents

Mehrfache „Click” Reaktionen an Porphyrinen · MELDAL as well as SHARPLESS proposed a stepwise mechanism for the Cu(I)- catalyzed cycloaddition [10, 20] in their first publication