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Supporting Information
© Wiley-VCH 2008
69451 Weinheim, Germany
S1
SUPPORTING INFORMATION FOR:
Ru-Hbpp Based Water Oxidation Catalysts Anchored into Conducting Solid Supports
Joaquim Mola, Elena Mas-Marza, Xavier Sala, Isabel Romero*, Montserrat Rodríguez, Clara Viñas, Teodor Parella and Antoni Llobet*
Experimental Details
[Ru2(µ-Cl)(µ-bpp)(t-trpy)2](PF6)2·3H2O, 1(PF6)2·3H2O. This compound was
prepared in the same manner as described for 1’, but using t-trpy instead of trpy
(see reference 5 of the main text). Yield: 0.160 g (36%). Anal. Calcd. for
C65H55ClF12N12O3P2Ru2·3H2O: C, 49.42; H, 3.51; N, 10.64; Found C, 49.11; H,
3.80, N, 10.43. IR: ν = 3090, 2920, 1625, 1390, 850 cm-1. 1H-NMR (500 MHz,
acetone-d6, 25 ºC): δ= 5.26 (s, H3), 6.10 (t, H1), 6.82 (t, H17), 6.84 (t, H2), 7.4 (d,
J5-6= 8.5 Hz, H5), 7.52 (d, J16-17= 5 Hz, H16), 7.64 (t, J14-13= J14-15= 4.5 Hz, H14),
7.83 (t, J18-19= J18-17= 7.5 Hz, H18), 7.96 (t, J13-12= J13-14= 7.5 Hz, H13), 8.06 (d, J6-
5= 8.5 Hz, H6), 8.28 (d, J19-18= 8 Hz, H19), 8.41 (d, J15-14= 4.5 Hz, H15), 8.52 (s,
H22), 8.71 (d, J12-13= 7.5 Hz, H12), 8.96 (s, H9). 13C-NMR (500 MHz, acetone-d6,
25ºC): δ = 52.1 (C3), 103.5 (C22), 108.1 (C1), 120.1 (C19), 120.3 (C9), 121.8
(C17), 122 (C2), 124 (C12), 127.3 (C14), 127.6 (C6), 128.2 (C5), 136 (C7), 137.3
(C18), 137.5 (C13), 141.4 (C4), 145.7 (C8), 148.4 (C21), 153.4 (C15), 153.9 (C16),
158.2 (C10), 158.6 (C20), 160 (C11). UV-vis [CH2Cl2; λmax/nm (ε/M-1cm-1)]: 285
(48318), 314 (40672), 383 (15902), 490 (12844), 516 (11500). E1/2
Ru(II,II)/Ru(II,III) (V): (CH2Cl2 + 0.1M TBAH) 0.71 and E1/2 Ru(II,III)/Ru(III,III) (V):
(CH2Cl2 + 0.1 M TBAH) 1.15 vs. SSCE.
[Ru2(µ-OAc)(µ-bpp)(t-trpy)2](PF6)2·4H2O, 2(PF6)2·4H2O. A sample of 0.083 g
(0.054 mmol) of 1·3H2O and 0.015 g (0.108 mmol) of sodium acetate were
dissolved in 20 mL of acetone:water (3:1) and heated at reflux for 2h. The resulting
solution was filtered and a few drops of saturated aqueous solution of NH4PF6
S2
added. Upon reducing the volume, a solid come out of the solution that was
washed with cold water and ether. Yield: 0.067g (80%). Anal. Calcd. for
C67H52F12N12O2P2Ru2·4H2O: C, 49.63; H, 3.73; N, 10.37; Found: C, 49.34; H, 3.59;
N, 10.08. IR: ν = 3090, 2920, 1625, 1390, 1230, 850 cm-1. 1H-NMR (500 MHz,
acetone-d6, 25 ºC): δ= 0.49 (s, H24), 5.31 (s, H3), 6.12 (t, H1), 6.85 (t, H2), 6.85 (t,
H2), 6.85 (t, H17), 7.47 (d, H5), 7.48 (d, H16), 7.55 (t, J14-13= J14-15= 7 Hz, H14),
7.76 (t, J18-19= J18-17= 7.5 Hz, H18), 8.06 (t, J13-12= J13-14= 8 Hz, H13), 8.16 (d, J6-5=
8 Hz, H6), 8.23 (d, J19-18= 7.5 Hz, H19), 8.48 (d, J15-14= = 5.5 Hz, H15), 8.57 (s,
H22), 8.84 (d, J12-13= 8 Hz, H12), 9.08 (s, H9). 13C-NMR (500 MHz, acetone-d6,
25ºC): δ = 25.6 (C24), 53 (C3), 102.5 (C22), 109.1 (C1), 120.4 (C19), 121.1 (C9),
121.8 (C2), 121.8 (C17), 124.6 (C12), 128.2 (C14), 128.6 (C6), 128.9 (C5), 136.8
(C18), 138.1 (C13), 138.8 (C7), 142.1 (C4), 146.5 (C8), 152.3 (C21), 153.7 (C16),
154.7 (C15), 157.3 (C20), 160.4 (C10), 160.4 (C11), 192.2 (C23). UV-vis [CH2Cl2;
λmax/nm; (ε/M-1cm-1)]: 285 (67297), 316 (57875), 370 (26918), 499 (15814), 547
(15141). E1/2 Ru(II,II)/Ru(II,III) (V): (CH2Cl2 + 0.1M TBAH) 0.67 and E1/2
Ru(II,III)/Ru(III,III) (V): (CH2Cl2 + 0.1M TBAH) 1.01 vs. SSCE.
For the NMR assignments of 1 and 2, we use the labeling scheme indicated in
Figure S1.
The anionic dicarbollide Cobalt complex containing a covalently bonded N-
substituted pyrrole monomer 4 was prepared according to literature procedures
(Masalles, C.; Llop, J.; Viñas, C.; Teixidor, F. Adv. Mat. 2002, 14, 826 and Llop, J.;
Masalles, C.; Viñas, C.; Teixidor, F.; Sillanpää, R.; Kivekäs, R. Dalton Trans.,
2003, 556).
Electrochemistry. Electrochemical experiments were performed in an IJ-
Cambria IH-660 potentiostat using a three electrode cell. Vitreous carbon sponge
(VCS) or fluorine-doped tin oxide (FTO) electrodes were used as working
electrodes, platinum plate (1x1 cm) as auxiliary and SSCE as the reference
electrode. All cyclic voltammograms presented in this work were recorded under
S3
nitrogen atmosphere unless explicitly mentioned. For electropolymerization
experiments, the complexes were dissolved in previously degassed CH2Cl2
containing 0.1 M n-Bu4N+PF6- (TBAH) as supporting electrolyte, and several
(between 5 and 30) consecutive cycles in a potential range from 0.0 to 1.2 V were
performed. The concentration of the complexes was approximately 0.2 mM. The
generated films were first transferred to a clean electrolyte CH2Cl2 solution and
further cycled 4-5 times, and finally were dipped in a 0.1 M triflic acid aqueous
solution for three days to achieve hydrolysis of the acetate bridging ligand. The
amount of catalyst supported was estimated from the intensity of the corresponding
two-electron III-III/II-II electrochemical wave in 0.1 M triflic acid solution.
Coulombimetric experiments for electrocatalytic generation of oxygen were
carried out in a Methrom cell containing 140 mL of 0.1 M triflic acid equip with
reference electrode (SSCE) and a platinum auxiliary electrode (surface area 2X1
cm2) with an applied potential of 1.17 V. The working electrode consisted on
VCS/poly-3 containing 13.0 nmols. The formation of molecular oxygen was
confirmed by the CV experiments showing a reduction wave at – 0.5-0.6 V due to
the superoxide formation which was not observed in the blank experiment.
Measurement of O2. In homogeneous phase oxygen evolution was
measured analyzing the concentration of the gas phase using a GC with TCD
detector. In this case the reactions are finished in less than 30 minutes. In
heterogeneous phase oxygen evolution was measured in solution with a
Hansatech Oxygraph System and the measurements were done during periods of
12-14 hours. See figure S7.
S4
Scheme S1. Synthetic pathway
2 [RuIIICl3(t-trpy)]
i)LiCl, NEt3ii)bpp-
4h reflux in MeOH
[Ru2II(µ-Cl)(bpp)(t-trpy)2]2+
2h reflux inwater:acetone (1:3)
H+
[Ru2II(µ-OAc)(bpp)(t-trpy)2]2+
1 2
[Ru2II(bpp)(t-trpy)2(H2O)2]3+
3
NaOAc
S5
Table S1. UV-vis spectroscopic features for the complex 3’ and its higher oxidation states species
generated with Ce(IV) measured at pH = 1.0 in a 0.1 M solution of triflic acid.
Complex λmax, nm (ε, M-1cm-1)
[Ru2II,II(bpp)(trpy)2(OH2)2]
3+
271.0(55372), 313.0(57484), 471.9
(11295),356.0(19192), 490.0(10468)
[Ru2II,III(bpp)(trpy)2(OH2)2]
4+ 272.1(50964), 312.0(46327), 465.1(8173)
sh at 377
wide band centered at a 574
[Ru2III,III(bpp)(OH)(trpy)2(OH2)]
4+ 272.1(1.058), 312.0(47337), 476.0(2617)
wide band centered at 549
[Ru2III,IV(bpp)(OH)2(trpy)2]
4+ 273.0(48531), 312.0(47337), 476.0(2250),
540(2204)
Table S2. E1/2 redox potentials for the complex 3’ extracted from cyclic voltammetry experimentes
at pH = 1.0 in a 0.1 M solution of triflic acid.
Redox couple E1/2 (V) vs. SSCE
RuIII-RuII/RuII-RuII 0.58
?E=110mV
RuIII-RuIII/RuIII-RuII 0.64
?E= 60 mV
RuIV-RuIII/RuIII-RuIII 0.88
?E= 100 mV
S6
Figure Captions.
- Figure S1. Drawings of: (a) complex 1, (b) complex 2.
- Figure S2. 1D and 2D NMR spectra (500 MHz, 298 K, acetona-d6) for complex 1:
(a) 1H-NMR, (b) COSY, (c) ROESY, (d) HSQC.
- Figure S3. 1D and 2D NMR spectra (500 MHz, 298 K, acetona-d6) for complex 2:
(a) 1H-NMR, (b) COSY, (c) ROESY, (d) HSQC.
- Figure S4. a) Growth of a VCS/poly-2 film (electrode volume, 2.0 x 0.7 x 0.7 cm;
pore size grade = 10 PPI) upon 5 repetitive scans from 0.0 to 1.2 V vs. SSCE in
0.2 mM 2, 0.1 M TBAH, CH2Cl2 (υ = 0.05 V·s-1). b) Five repetitive scans of the
transferred film generated in (a), after soaking it in a 0.1 M CF3SO3H solution for
three days (formation of a VCS/poly-3 film).
- Figure S5. a) Five repetitive scans for the FTO/poly-3 film (electrode area,1.0 x
1.0 cm; Γ Ru = 1.0 x 10-9 mol cm-2; see Figure 2 in the main text for the generation
of the FTO/poly-2 precursor) upon transferring it to a 0.1 M CF3SO3H solution after
three days soaking in the same media. b) CV for the analogous
[Ru2(bpp)(trpy)2(H2O)2]3+ 3’, complex in CF3SO3H 0.1 M solution. c) UV-vis spectra
of the different oxidation states generated chemically using Ce(IV) from the
FTO/poly-3 film in 0.1 M CF3SO3H solution. d) UV-vis spectra for the analogous
[Ru2(bpp)(trpy)2(H2O)2]3+ 3’, complex in CF3SO3H 0.1 M solution.
- Figure S6. a) Growth of a FTO/poly-(2-co-4) film upon 15 repetitive scans from
0.0 to 1.2 V vs. SSCE of a solution containing 0.2 mM 2, 0.2 mM 4, and 0.1 M
TBAH in CH2Cl2 (υ = 0.05 V·s-1). b) Five repetitive scans of the transferred film
generated in (a), after soaking it in a 0.1 M CF3SO3H solution for three days
(formation of a FTO/poly-(3-co-4) film (electrode area 1.0 x 1.0 cm2; ΓRu = 0.5 x 10-
S7
9 mol·cm-2)). c) UV-vis spectra for the FTO/poly-(3-co-4) film after 3 three soaking
in 0.1 M CF3SO3H solution.
- Figure S7. a) Oxygen evolution measured with a Hansatech Oxygraph System for
water oxidation caytalyzed by a FTO/poly-(3-co-4) film with Ce(IV) after 2
reutilizations (see main text for details in Table 1 entry 5). b) Background
experiment performed with 3.64 x 10-6 mols Ce(IV) in 2 mL total volume.
- Figure S8. Spectral changes for FTO/poly-3 film during catalytic reaction with a
Ce(IV):Ru-cat molar ratio of 3600:1 (1 nmol Ru catalyst anchored)
- Figure S9. Spectral changes for FTO/poly-(3-co-4) film after two reutilizations of
the catalytic system with a Ce(IV):Ru-cat molar ratio of 3600:1 in each experiment
(0.5 nmol Ru catalyst anchored).
- Figure S10. Cyclic voltammograms of VCS/poly-3 film: a) before and after the catalytic
reaction, b) CV obtained after the catalytic reaction in homogeneous phase using 3’.
- Figure S11. Intensity vs. time curves obtained applying a 1.17 V vs. SSCE potential to a
VCS/poly-3 film (blue) and to a similar VCS electrode without the poly-3 catalyst (pink).
S8
Figure S1. Drawings of: (a) complex 1, (b) complex 2.
(a)
1
2
3 4
5 6
7
8
9 10
11
12
13 14
15
16
17 18 19
20 21 22
Ru
N
NNN
Ru
N
N
N
Cl
N
N
N NN
(b)
Ru
N
NNN
Ru
N
N
N
N
N
N NN
OO
1
2
3 4
5 6
7
8
9 10
11
12
13 14
15
16 17
18 19
20 21
22
S9
Figure S2. 1D and 2D NMR spectra (500 MHz, 298 K, acetona-d6) for complex 1: (a) 1H-
NMR, (b) COSY, (c) ROESY, (d) HSQC.
(a)
5.56.06.57.07.58.08.59.0 ppm
(b)
ppm
5.05.56.06.57.07.58.08.59.0 ppm
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
S10
(c)
ppm
5.05.56.06.57.07.58.08.59.0 ppm
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
S11
(d)
ppm
5.56.06.57.07.58.08.59.09.5 ppm
50
60
70
80
90
100
110
120
130
140
150
S12
Figure S3. 1D and 2D NMR spectra (500 MHz, 298 K, acetona-d6) for complex 2:
(a) 1H-NMR, (b) COSY, (c) ROESY, (d) HSQC.
(a)
5.56.06.57.07.58.08.59.0 ppm
(b)
ppm
6.57.07.58.08.59.0 ppm
6.0
6.5
7.0
7.5
8.0
8.5
9.0
S13
(c)
ppm
6.57.07.58.08.59.0 ppm
6.0
6.5
7.0
7.5
8.0
8.5
9.0
S14
(d)
ppm
123456789 ppm
20
40
60
80
100
120
140
S15
Figure S4. a) Growth of a VCS/poly-2 film (electrode volume, 2.0 x 0.7 x 0.7 cm;
pore size grade = 10 PPI) upon 5 repetitive scans from 0.0 to 1.2 V vs. SSCE in
0.2 mM 2, 0.1 M TBAH, CH2Cl2 (υ = 0.05 V·s-1). b) Five repetitive scans of the
transferred film generated in (a), after soaking it in a 0.1 M CF3SO3H solution for
three days (formation of a VCS/poly-3 film).
(a)
-8,00E-04
-4,00E-04
0,00E+00
4,00E-04
8,00E-04
0 0,2 0,4 0,6 0,8 1 1,2 1,4
potential (V)
Cu
rren
t (A
)
(b)
-6,00E-04
-4,00E-04
-2,00E-04
0,00E+00
2,00E-04
4,00E-04
6,00E-04
0 0,2 0,4 0,6 0,8 1 1,2 1,4
potential (V)
Cu
rren
t (A
)
S16
- Figure S5. a) Five repetitive scans for the FTO/poly-3 film (electrode area,1.0 x
1.0 cm; Γ Ru = 1.0 x 10-9 mol cm-2; see Figure 2 in the main text for the generation
of the FTO/poly-2 precursor) upon transferring it to a 0.1 M CF3SO3H solution after
three days soaking in the same media. b) CV for the analogous
[Ru2(bpp)(trpy)2(H2O)2]3+ 3’, complex in CF3SO3H 0.1 M solution. c) UV-vis spectra
of the different oxidation states generated chemically using Ce(IV) from the
FTO/poly-3 film in 0.1 M CF3SO3H solution. d) UV-vis spectra for the analogous
[Ru2(bpp)(trpy)2(H2O)2]3+ 3’, complex in CF3SO3H 0.1 M solution.
S17
(a)
-1,50E-04
-1,00E-04
-5,00E-05
0,00E+00
5,00E-05
1,00E-04
1,50E-04
0 0,2 0,4 0,6 0,8 1 1,2 1,4
potential (V)
Cu
rren
t (A
)
(b)
- 4
- 2
0
2
4
6
0 0,2 0,4 0,6 0,8 1 1,2E (V)
I x 1
0-6 (A
)
S18
(c)
(d)
II- II II- III
III- III
III- IV 0
0,5
1
1,5
2
2,5
250 350 450 550 650 750
Wavelength (nm)
Abs
orba
nce
0
0,5
1
1,5
2
250 350 450 550 650
Wavelength (nm)
Abs
orba
nce
II-II II-III
III-IV
III-III
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1
320 420 520 620 720
λ (nm)
Ab
sorb
ance
S19
Figure S6. a) Growth of a FTO/poly-(2-co-4) film upon 15 repetitive scans from 0.0
to 1.2 V vs. SSCE of a solution containing 0.2 mM 2, 0.2 mM 4, and 0.1 M TBAH in
CH2Cl2 (υ = 0.05 V·s-1). b) Five repetitive scans of the transferred film generated in
(a), after soaking it in a 0.1 M CF3SO3H solution for three days (formation of a
FTO/poly-(3-co-4) film (electrode area 1.0 x 1.0 cm2; ΓRu = 0.5 x 10-9 mol·cm-2)). c)
UV-vis spectra for the FTO/poly-(3-co-4) film after 3 three soaking in 0.1 M
CF3SO3H solution.
(a)
-1,80E-04
-1,20E-04
-6,00E-05
0,00E+00
6,00E-05
1,20E-04
1,80E-04
0 0,2 0,4 0,6 0,8 1 1,2
potential (V)
Cu
rren
t (A
)
S20
(b)
-1,00E-04
-5,00E-05
0,00E+00
5,00E-05
1,00E-04
0 0,2 0,4 0,6 0,8 1 1,2 1,4
potential (V)
Cu
rren
t (A
)
(c)
0
0,2
0,4
0,6
320 370 420 470 520 570 620 670 720 770
λ (nm)
Ab
sorb
ance
S21
Figure S7. a) Oxygen evolution measured with a Hansatech Oxygraph System for
water oxidation caytalyzed by a FTO/poly-(3-co-4) film with Ce(IV) after 2
reutilizations (see main text for details in Table 1 entry 5). b) Background
experiment performed with 3.64 x 10-6 mols Ce(IV) in 2 mL total volume.
Figure S7. (a)
0
5
10
15
20
25
30
35
40
0 2 4 6 8 10 12 14 16 18
time (hours)
nm
ols
O2/
ml
1st reaction
2nd reaction
3rd reaction
(b)
0
5
10
15
20
25
30
35
40
0 2 4 6 8 10 12 14 16 18
time (hours)
nm
ols
O2/
ml
background
S22
Figure S8. Spectral changes for FTO/poly-3 film during catalytic reaction with a
Ce(IV):Ru-cat molar ratio of 3600:1 (1 nmol Ru catalyst anchored)
0
0,2
0,4
0,6
0,8
1
320 370 420 470 520 570 620 670 720 770
λ (nm)
Abs
orba
nce
before reaction
1st reaction
S23
Figure S9. Spectral changes for FTO/poly-(3-co-4) film after two reutilizations of
the catalytic system with a Ce(IV):Ru-cat molar ratio of 3600:1 in each experiment
(0.5 nmol Ru catalyst anchored).
0
0,2
0,4
0,6
320 370 420 470 520 570 620 670 720 770
λ (nm)
Ab
sorb
ance
before rx1st reaction2nd reaction3rd reaction
S24
Figure S10. Cyclic voltammograms of VCS/poly-3 film: a) before and after the catalytic
reaction, b) CV obtained after the catalytic reaction in homogeneous phase using 3’.
-6,00E-04
-4,00E-04
-2,00E-04
0,00E+00
2,00E-04
4,00E-04
6,00E-040,000 0,200 0,400 0,600 0,800 1,000
potential (V)
Cur
rent
(A
)
after reactionbefore reaction
Figure S10. (b)
-0,00012
-0,00007
-0,00002
0,00003
0,00008
0,00013
0,00018
0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1
potential (V)
Cu
rren
t (A
)
S25
Figure S11. Intensity vs. time curves obtained applying a 1.17 V vs. SSCE potential to a
VCS/poly-3 film (pink) and to a similar VCS electrode without the poly-3 catalyst (blue).
0,00E+00
2,00E-04
4,00E-04
6,00E-04
8,00E-04
1,00E-03
1,20E-03
1,40E-03
1,60E-03
1,80E-03
2,00E-03
0 1000 2000 3000 4000 5000
Time (s)
Cu
rren
t (A
)