Ruthenium-Cobalt Dinuclear complexes as Photocatalysts for CO2 reduction
X.Wang,a V. Goudy,b G. Genesiob, J. Maynadiéb, D. Meyerb and M. Fontecavea*
aLaboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université P. et M. curie, PSL research University, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05, FranceE-mail: [email protected]
bLaboratoire des Systèmes Hybrides pour la Séparation, Institut de Chimie Séparative de Marcoule, UMR 5257 CEA/CNRS/UM/ENSCM, BP17171, 30207 Bagnols-sur-Cèze CEDEX, France
Electronic Supplementary Material (ESI) for ChemComm.This journal is © The Royal Society of Chemistry 2017
Index
A. Synthesis and characterization of [Ru(bpy-Me2)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2 and complexes 1-5 3
Mass Spectra (Figures S1-S6) 5
UV-visible spectra (Figures S7-S9) 11
Emission Spectra (Figures S10-S15) 14
Lifetime decay profile (Figures S16-S21) 17
Cyclic Voltammograms (Figures S22-S27) 20
B. Photocatalytic studies 23
Catalytic essay (Figures S28-S30) 24
2
A. Synthesis and characterization of [Ru(bpy-Me2)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2 and complexes 1-5
A.1 Materials. Reagent grade chemicals and solvent obtained from commercial source were used as received. 1,10-phenanthroline-5,6-dione1 and cis-[Ru(bpy)2Cl2]2 were synthetized according to the literature procedures. cis-[Ru(bpy-Me2)2Cl2] was prepared from a modified reported method using 5,5’-dimethyl-2,2’-bipyridine instead of 2,2’-bipyridine.3 2-(3-formylphenyl)imidazo[4,5-f]-[1,10]phenanthroline, [Ru(bpy)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2, Ru(bpy)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)4-tert-butylphenol)](PF6)2 and complex 6 were synthetized as previously described.4
A.2 Materials characterisation. Elemental (C, H and N) analyses were performed on a flash EA 1112 (ThermoFinnigan 2003) instrument. Elemental (Ru and Co) analyses were determined by ICP-AES on a Perkin Elmer Optima 2000 DV after full digestion of complexes in a 2M HNO3 solution. 1H NMR were recorded on a Bruker AvanceIII 400 spectrometer with (CD3)2SO as solvent at room temperature. Electro-spray mass spectra were obtained in acetonitrile at room temperature with an Alliance 2790 Waters analyser with (CH3)2SO as mobile phase. UV-visible spectra were measured on a Shimadzu UV-3600 UV-VIS-NIR spectrophotometer in acetonitrile at room temperature. Cyclic voltammetry was performed on a biologic SP 300 potensiostat. The supporting electrolyte was tetrabutylammonium hexafluorophosphate in dry and deaerated acetonitrile by purging with nitrogen. A standard three electrodes system was used with a glassy carbon working electrode, platinum counter-electrode and a nonaqueous Ag/AgCl reference electrode. Emission spectra and luminescence lifetime were recorded with a Horiba FluoroMax-4 in deaerated acetonitrile at room temperature. The luminescence lifetime were calculated with the Time Correlated Single Photon Counting method.
A.3 Synthesis of [Ru(bpy-Me2)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2.
A mixture of 2-(3-formylphenyl)imidazo[4,5-f]-[1,10]phenanthroline (0.080 g, 0.28 mmol, 1.2 equiv), Ru(bpy-Me2)2(phendione)Cl2 (0.172 g, 0.22 mmol, 1 equiv) and ammonium acetate (0.351 g, 4.56 mmol, 20 equiv) in acetic acid (5 mL) was refluxed for 16 hours and then cooled to room temperature. Addition of NH4PF6 gave a brown precipitate which was collected and then washed with water, and ethanol/ether. (0.216 g, 74%)
Elemental analysis: calculated for C56H46N12P2F12Ru: C 52.63%, H 3.63%, N 13.15%; Found: C 52.32%, H 3.47%, N 13.38%1H NMR (400 MHz, ppm, DMSO-d6): δ 14.60 (s, 1H), 14.16 (s, 1H), 9.32 (s, 1H), 9.14-9.09(m, 8H), 8.76 (s, 2H), 8.72 (s, 2H), 8.47-8.40 (m, 2H), 8.11 (d, J = 5.2 Hz, 2H), 8.01-7.88 (m, 5H), 7.68 (d, J = 5.6 Hz, 2H), 7.44 (m, 4H), 7.19 (d, J = 5.4 Hz, 2H), 2.57 (s, 6H), 2.47 (s, 6H).
ESI-MS (DMSO, m/z): 492.14 (M2+/2, [C56H42N12Ru]2+/2 requires 492.14)
A.4 Synthesis of the ruthenium-cobalt dinuclear complexes
Complex 1. A mixture of [Ru(bpy)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2 (0.100 g, 0.08 mmol, 1 equiv) and Co(Phen)2Cl2 (0.053 g, 0.11 mmol, 1.3 equiv) in methanol (3 mL) was
3
refluxed for 12 hours and then cooled to room temperature. Methanol was eliminated under vacuum and the solid was washed with water, and ethanol/ether. (0.098 g, 72%)
Elemental analysis: calculated for C76H50N16P2F12Cl2RuCo: C 53.44%, H 2.95%, N 13.12%; Found: C 53.13%, H 2.82%, N 13.30%
ICP-AES (HNO3 2M / [1] = 84 mg L-1): calculated Ru 5.92%, Co 3.45%; Found Ru 5.87%, Co 3.43%
ESI-MS (DMSO, m/z): 448.76 (M3+/3, [C76H49N16RuCo]3+/3 requires 448.77)
Complex 2. The same procedure as for 1 was used with [Ru(bpy)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2 (0.097 g, 0.08 mmol, 1 equiv) and Co(terpy)Cl2 (0.064 g, 0.10 mmol, 1.3 equiv) as starting compounds. (0.086 g, 70%)
Elemental analysis: calculated for C67H45N15P2F12Cl2RuCo: C: 50.90%, H: 2.87%, N: 13.29%; Found: C 51.22%, H 2.78%, N 13.41%
ICP-AES (HNO3 2M / [2] = 82 mg L-1): calculated Ru 6.40%, Co 3.73%; Found Ru 6.32%, Co 3.67%
ESI-MS (DMSO, m/z): 406.41 (M3+/3, [C67H44N15RuCo]3+/3 requires 406.39)
Complex 3. The same procedure as for 1 was used with [Ru(bpy-Me2)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2 (0.120 g, 0.09 mmol, 1 equiv) and Co(Phen)2Cl2 (0.058 g, 0.12 mmol, 1.3 equiv) as starting compounds. (0.117 g, 75%)
Elemental analysis: calculated for C80H62N16P2F12Cl2RuCo: C 54.34%, H 3.53%, N 12.67%; Found: C 53.96%, H 3.38%, N 12.81%
ICP-AES (HNO3 2M / [3] = 79 mg L-1): calculated Ru 5.72%, Co 3.33%; Found Ru 5.78%, Co 3.37%
ESI-MS (DMSO, m/z): 468.80 (M3+/3, [C80H61N16RuCo]3+/3 requires 468.81)
Complex 4. The same procedure as for 1 was used with [Ru(bpy-Me2)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2 (0.120 g, 0.09 mmol, 1 equiv) and Co(terpy)Cl2 (0.077 g, 0.12 mmol, 1.3 equiv) as starting compounds. (0.117 g, 75%)
Elemental analysis: calculated for C71H57N15P2F12Cl2RuCo: C 51.96%, H 3.50%, N 12.80%; Found: C 51.72%, H 3.32%, N 12.98%
ICP-AES (HNO3 2M / [4] = 75 mg L-1): calculated Ru 6.16%, Co 3.59%; Found Ru 6.08%, Co 3.47%
ESI-MS (DMSO, m/z): 425.09 (M3+/3, [C71H56N15RuCo]3+/3 requires 425.09)
Complex 5. The same procedure as for 1 was used with Ru(bpy)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)4-tert-butylphenol)](PF6)2 (0.071 g, 0.05 mmol, 1 equiv) and Co(Phen)2Cl2 (0.034 g, 0.07 mmol, 1.3 equiv) as starting compounds. (0.063 g, 72%)
Elemental analysis: calculated for C80H58N16OP2F12Cl2RuCo: C 53.97%, H 3.28%, N 12.59%, Found: C 54.12%, H 3.18%, N 12.87%
ICP-AES (HNO3 2M / [5] = 80 mg L-1): calculated Ru 5.68%, Co 3.31%; Found Ru 5.55%, Co 3.23%
ESI-MS (DMSO, m/z): 472.77 (M3+/3, [C80H58N16ORuCo]3+/3 requires 472.81)
4
m/z
A.5 Mass Spectra
5
Figure S1. ESI spectrum of [Ru(bpy-Me2)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2 in DMSO (m/z: 492.14= Ru-complex2+/2; 328.43= Ru-complex3+/3)
6
Figure S2. ESI spectrum of complex 1 in DMSO (m/z: 464.10= Ru-complex2+/2;
7
m/z
448.75= 13+/3; 309.74= Ru-complex3+/3; 299.57= Co(Phen)32+/2; 209.54= Co(Phen)2
2+/2; 181.08= PhenH+)
8
Figure S3. ESI spectrum of complex 2 in DMSO (m/z: 464.10= Ru-complex2+/2; 406.41= 23+/3)
9
m/z
Figure S4. ESI spectrum of complex 3 in DMSO (m/z: 500.13= Ru-complex2+/2; 472.77= 33+/3; 333.76= Ru-complex3+/3; 209.54= Co(Phen)2
2+/2; 181.08= PhenH+)
10
m/z
Figure S5. ESI spectrum of complex 4 in DMSO (m/z: 492.14= Ru-complex2+/2; 425.09= 43+/3; 328.43= Ru-complex3+/3; 262.56= Co(terpy)2
2+/2; 146.01= Co(terpy)2+/2)
11
m/z
Figure S6. ESI spectrum of complex 5 in DMSO (m/z: 500.13= Ru-complex2+/2; 472.77= 53+/3; 333.76= Ru-complex3+/3; 209.54= Co(Phen)2
2+/2; 181.08= PhenH+)
12
m/z
0
0,5
1
1,5
2
2,5
3
220 320 420 520 620 720
Abso
rban
ce
Wavenumber (nm)
0
0,2
0,4
0,6
0,8
1
1,2
200 300 400 500 600 700 800
Abso
rban
ce
Wavelength (nm)
A.6 UV-visible spectra
Figure S7. UV-vis spectra of [Ru(bpy-Me2)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2 (red), complex 3 (green) and complex 4 (blue) in CH3CN.
Figure S8. UV-vis spectra of [Ru(bpy)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2 (green), complex 1 (red) and complex 2 (blue) in CH3CN.
13
0
0,5
1
1,5
2
2,5
200 300 400 500 600 700 800
Abso
rban
ce
Wavelength (nm)
Figure S9. UV-vis spectra of complex 5 (red) and complex 6 (blue) in CH3CN.
14
450 500 550 600 650 700 750 800 850 900-100000
0
100000
200000
300000
400000
500000
600000
700000
Inte
nsity
Wavelength (nm)
450 500 550 600 650 700 750 800 850 900
0
100000
200000
300000
400000
500000
600000
S1c
/ R1c
(CPS
/ M
icroA
mps
)
Wavelength (nm)
Inte
nsity
A.7 Emission Spectra
Figure S10. Emission spectrum of [Ru(bpy-Me2)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2 in CH3CN
Figure S11. Emission spectrum of complex 1 in CH3CN
15
450 500 550 600 650 700 750 800 850 900-50000
0
50000
100000
150000
200000
250000
300000
350000
400000In
tens
ity
Wavelength (nm)
450 500 550 600 650 700 750 800 850 900
0
200000
400000
600000
800000
1000000
1200000
Inte
nsity
Wavelength (nm)
Figure S12. Emission spectrum of complex 2 in CH3CN
Figure S13. Emission spectrum of complex 3 in CH3CN
16
450 500 550 600 650 700 750 800 850 900
0
200000
400000
600000
800000In
tens
ity
Wavelength (nm)
450 500 550 600 650 700 750 800 850 900
0
100000
200000
300000
400000
Inte
nsity
Wavelength (nm)
Figure S14. Emission spectrum of complex 4 in CH3CN
Figure S15. Emission spectrum of complex 5 in CH3CN
17
A.8 Lifetime decay profile
18
1000 2000 3000 4000
0
2000
4000
6000
8000
10000C
ount
s (L
in)
Channels
15 bis
= 1418 ns
820 1640 2460 3280
Time (ns)
19
Figure S16. Lifetime decay profile of [Ru(bpy-Me2)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2 in CH3CN (χ² = 1.022)
20
1000 2000 3000 4000
0
2000
4000
6000
8000
10000Co
unts
(Lin
)
Channels
13
= 767 ns
820 1640 2460 3280
Time (ns)
21
Figure S17. Lifetime decay profile of complex 1 in CH3CN (χ² = 1.053)
22
1000 2000 3000 4000
0
2000
4000
6000
8000
10000Co
unts
(Lin
)
Chanel
14
Channels
= 699 ns
820 1640 2460 3280
Time (ns)
23
Figure S18. Lifetime decay profile of complex 2 in CH3CN (χ² = 1.001)
24
0 1000 2000 3000 4000
0
2000
4000
6000
8000
10000Co
unts
(Lin
)
Chanel
9A
Channels
= 706 ns
820 1640 2460 3280
Time (ns)
25
Figure S19. Lifetime decay profile of complex 3 in CH3CN (χ² = 1.024)
26
1000 2000 3000 4000
0
2000
4000
6000
8000
10000
Coun
ts (L
in)
Channels
18
= 647 ns
820 1640 2460 3280
Time (ns)
27
1000 2000 3000 4000
0
2000
4000
6000
8000
10000
Coun
ts (L
in)
Channels
20
= 813 ns
820 1640 2460 3280
Time (ns)
Figure S20. Lifetime decay profile of complex 4 in CH3CN (χ² = 1.023)
28
Figure S21. Lifetime decay profile of complex 5 in CH3CN (χ² = 1.010)
29
-8,00E-03
-6,00E-03
-4,00E-03
-2,00E-03
0,00E+00
2,00E-03
4,00E-03
6,00E-03
8,00E-03
-3 -2,5 -2 -1,5 -1 -0,5 0 0,5 1 1,5 2 2,5
I (µA
)
Ewe/V vs Ag/AgCl nonaqueous
-1,00E-02
-5,00E-03
0,00E+00
5,00E-03
1,00E-02
-3 -2,5 -2 -1,5 -1 -0,5 0 0,5 1 1,5 2
I (µA
)
Ewe/V vs Ag/AgCl nonaqueous
A.9 Cyclic Voltammograms
Figure S22. Cyclic voltammogram of [Ru(bpy-Me2)2(2,6-di(1H-imidazo[4,5-f][1,10]phenantrolin-2-yl)benzene)](PF6)2 in acetonitrile at 50 mV/s
Figure S23. Cyclic voltammogram of complex 1 in acetonitrile at 50 mV/s
30
-0,008
-0,006
-0,004
-0,002
0
0,002
0,004
0,006
-3 -2,5 -2 -1,5 -1 -0,5 0 0,5 1 1,5 2 2,5
I (µA
)
Ewe/V vs Ag/AgCl nonaqueous
Figure S24. Cyclic voltammogram of complex 2 in acetonitrile at 50 mV/s
Figure S25. Cyclic voltammogram of complex 3 in acetonitrile at 50 mV/s
31
-0,007
-0,006
-0,005
-0,004
-0,003
-0,002
-0,001
0
0,001
0,002
0,003
-3 -2,5 -2 -1,5 -1 -0,5 0 0,5 1 1,5 2 2,5
I (µA
)
Ewe/V vs Ag/AgCl nonaqueous
-0,006
-0,004
-0,002
0
0,002
0,004
0,006
-3 -2,5 -2 -1,5 -1 -0,5 0 0,5 1 1,5 2 2,5
I (µA
)
Ewe/V vs Ag/AgCl nonaqueous
Figure S26. Cyclic voltammogram of complex 4 in acetonitrile at 50 mV/s
Figure S27. Cyclic voltammogram of complex 5 in acetonitrile at 50 mV/s
32
-8,00E-03
-6,00E-03
-4,00E-03
-2,00E-03
0,00E+00
2,00E-03
4,00E-03
6,00E-03
-3 -2,5 -2 -1,5 -1 -0,5 0 0,5 1 1,5 2 2,5
I (µA
)
Ewe/V vs Ag/AgCl nonaqueous
B. Photocatalytic studies
B.1 Photocatalytic experimental details
Photochemical reactions were performed using a 300 W, high pressure Xe arc lamp (Oriel Instruments). The beam was passed through an infrared filter, a collimating lens, a filter holder equipped with a 415 nm band pass filter. Samples were prepared in a 1 cm path length quartz cuvette (Starna) which was placed in a temperature controlled cuvette holder (Quantum Northwest) maintained at 20°C with a circulated water bath.
For the entirety of the study, a 5:1 (v:v) mixture of ACN/TEOA was used as a solvent mixture (ACN and TEOA purchased from Sigma Aldrich and used without further purification). The electron donor utilized was a 100 mM solution of BIH (BIH was synthesized according to previously reported procedure5). For assays of complexes 1-6, 0.1 mM of each complex was utilized. For assays consisting mononuclear catalyst and [Ru(bpy)3]Cl2 photosensitizer (purchased from Strem Chemicals, used without further purification), 0.1 mM of each compound was utilized. Samples were saturated with CO2 via directely bubbling CO2 through the solution mixture for 10 minutes.
B.2 Product Detection Chemical Analysis Detection Details
H2 measurements were performed by gas chromatography on a Shimadzu GC-2014 equipped with a Quadrex column, a Thermal Conductivity Detector and using N2 as a carrier gas. CO was measured using a Shimadzu GC-2010 Plus gas chromatography, fitted with a S9 Restek Shin Carbon column, Helium carrier gas, a methanizer and a Flame Ionization Detector. The typical volume of gas injected was 50 μL.
Formate concentration was determined using a Metrohm 883 Basic IC plus ionic exchange chromatography instrument, using a Metrosep A Supp 5 column and a conductivity detector. A typical measurement requires the sampling of 200 μL of solution, followed by a 100-fold dilution in deionised 18 MΩ water and injection of 20 μL of the final solution into the instrument.
33
B.3 Catalytic essay
Figure S28. CO (dot), H2 (square) and formate (triangle) evolution catalyzed by a 0.1 mM solution of complex 5 in the presence of 100 mM BIH as electron donor in a CO2-saturated ACN/TEOA (5:1, v:v) solvent mixture upon irradiation with a 300W Xe arc lamp equipped with a 415 nm filter at 20°C
Figure S29. CO (dot), H2 (square) and formate (triangle) evolution catalyzed by a solution of 0.1 mM [Co(phen)3]Cl2 and 0.1 mM [Ru(bpy)3]Cl2 in the presence of 100 mM BIH as electron donor in a CO2-saturated ACN/TEOA (5:1, v:v) solvent mixture upon irradiation with a 300W Xe arc lamp equipped with a 415 nm filter at 20°C
34
Figure S30. CO (dot), H2 (square) and formate (triangle) evolution catalyzed by a solution of 0.1 mM Ru(bpy)2Cl2 and 0.1 mM [Ru(bpy)3]Cl2 in the presence of 100 mM BIH as electron donor in a CO2-saturated ACN/TEOA (5:1, v:v) solvent mixture upon irradiation with a 300W Xe arc lamp equipped with a 415 nm filter at 20°C
35
References
1 W. Paw and R. Eisenberg, Inorg. Chem., 1997, 36, 2287–2293.
2 C. Viala and C. Coudret, Inorganica Chim. Acta, 2006, 359, 984–989.
3 C. E. McCusker and J. K. McCusker, Inorg. Chem., 2011, 50, 1656–1669.
4 V. Goudy, J. Maynadié, X. L. Goff, D. Meyer and M. Fontecave, New J Chem, 2016, 40, 1704–1714.
5 X.-Q. Zhu, M.-T. Zhang, A. Yu, C.-H. Wang and J.-P. Cheng, J. Am. Chem. Soc., 2008, 130, 2501–2516.
36