Thiolate/Disulfide Organic Redox Couples for Efficient Organic Dye-Sensitized Solar Cells

Thiolate/Disulfide Organic Redox Couples for Efficient Organic Dye-Sensitized Solar Cells

Wenyan Li, Haikuo Zhen, Jianwen Wang, Lele Zhang, Hui-Min Han, Mingxing Wu,*

College of Chemistry and Material Science, Hebei Normal University, No. 20 Rd. East of 2nd Ring South, Yuhua District, Shijiazhuang City, Hebei Province 050024, PR China

1.  Experimental Section

General

All the chemicals were of analytic grade and used without further purification. TLC was performed on Merck precoated (0.25 mm) silica gel 60 F254 plates. NMR and spectra were measured with a Bruker ARX-500 (500 MHz) spectrometer in hexadeuterodimethyl sulfoxide (DMSO-d6). Mass spectra (MS) were taken on a ABSciex3200 mass spectrometer operating at an ionization potential of 70 eV.

Characterization of organic thiolate/disulfide redox couples

1,2-Bis(5-(trifluoromethyl)benzo[d]thiazol-2-yl)disulfane (2a)

1H-NMR (DMSO-d6) δ: 8.31-8.33 (1H, m, 4-H), 8.07 (1H, d, J = 7.9 Hz, 6-H), 7.95 (1H, d, J = 7.9 Hz, 6’-H), 7.77-7.78 (1H, m, 4-H), 7.53 (1H, t, J = 7.5 Hz, 7-H), 7.44 (1H, t, J = 7.6 Hz, 7’-H). 13C-NMR (DMSO-d6) δ: 153.78, 139.68, 135.59, 126.88, 125.51, 123.85, 122.33, 122.20, 119.0. ESI-MS, m/z: 469.5 [M + H]+.

[5-(Trifluoromethyl)benzo[d]thiazole-2-thiolate]-tetramethylammonium (3a)

1H-NMR (DMSO-d6) δ: 7.60 (1H, d, J = 8.1 Hz, 6-H), 7.45 (1H, s, 4-H), 7.20 (1H, d, J = 8.1 Hz, 7-H), 3.12 (12H, s, 1’’-H). 13C-NMR (DMSO-d6) δ: 187.70, 155.94, 141.60, 119.39, 116.07, 116.04, 112.36, 112.33, 54.39, 54.36, 54.33. ESI-MS, m/z: 234.0 [M - NMe4]-, 74.1 [NMe4]+.

1,2-Bis(benzo[d]thiazol-2-yl)disulfane (2b)

1H-NMR (DMSO-d6) δ: 8.08 (2H, d, J = 8.1 Hz, 4-H, 4’-H), 7.96 (2H, d, J = 8.2 Hz, 7-H, 7’-H), 7.55 (2H, t, J = 7.4 Hz, 5-H, 5’-H), 7.46 (2H, t, J = 7.5 Hz, 6-H, 6’-H). 13C-NMR (DMSO-d6) δ: 167.26, 153.87, 135.64, 126.95, 125.57, 122.41, 122.26. ESI-MS, m/z: ESI-MS, m/z: 332.5 [M + H]+.

[Benzo[d]thiazole-2-thiolate]-tetramethylammonium (3b)

1H-NMR (DMSO-d6) δ: 7.45 (1H, d, J = 7.7 Hz, 4-H), 7.28 (1H, d, J = 8.0 Hz, 7-H), 7.13 (1H, t, J = 7.5 Hz, 5-H), 6.97 (1H, d, J = 7.5 Hz, 6-H), 3.10 (12H, s, 1’’-H). 13C-NMR (DMSO-d6) δ: 184.73, 153.52, 135.76, 124.59, 120.95, 119.42, 116.29, 54.38, 54.35, 54.32. ESI-MS, m/z: 166.2 [M - NMe4]-, 74.1 [NMe4]+.

1,2-bis(1H-benzo[d]imidazol-2-yl)disulfane (2c)

1H-NMR (DMSO-d6) δ: 13.05 (2H, br, 1-NH, 1’-NH), 7.54 (4H, s, 4-H,7-H, 4’-H, 7’H), 7.21-7.23 (4H, m, 5-H, 6-H, 5’-H, 6’H). 13C-NMR (DMSO-d6) δ: 141.14, 131.18, 126.45, 122.94, 114.98, 111.86. ESI-MS, m/z: 299.1 [M + H]+, 321.1 [M + Na]+. [1H-benzo[d]imidazol-2-thiolate]-tetramethylammonium (3c)

1H-NMR (DMSO-d6) δ: 7.03-7.01 (2H, m, 4-H, 7-H), 6.78-6.76 (2H, m, 5-H, 6-H), 3.10 (12H, s, 1’’-H). 13C-NMR (DMSO-d6) δ: 154.77, 143.60, 139.50, 121.12, 113.73, 109.74, 54.35, 54.32, 54.29. ESI-MS, m/z: 149.0 [M - NMe4]-, 74.1 [NMe4]+.

1,2-Bis(benzo[d]oxazol-2-yl)disulfane (2d)

1H-NMR (DMSO-d6) δ: 7.73 (4H, s, 4-H,7-H, 4’-H, 7’H), 7.39 (4H, s, 5-H, 6-H, 5’-H, 6’H) 13C-NMR (DMSO-d6) δ: 159.70, 154.32, 151.83, 143.28, 130.27, 125.98, 125.24, 123.70, 119.59, 110.92, 109.69, 109.43. ESI-MS, m/z: 301.0 [M + H]+, 323.0 [M + Na]+.

[Benzo[d]oxazol-2-thiolate]-tetramethylammonium (3d)

1H-NMR (DMSO-d6) δ: 7.04-7.02 (2H, m, 4-H, 7-H ), 6.91-6.88 (1H, m, 5-H), 6.82-6.79 (1H, m, 6-H), 3.09 (12H, s). 13C-NMR (DMSO-d6) δ: 181.88, 151.16, 145.66, 121.58, 119.09, 113.70, 106.64, 54.39, 54.36, 54.32. ESI-MS, m/z: 150.1 [M - NMe4]-, 74.1 [NMe4]+.

2a-1H-NMR

2a-13C-NMR

3a-1H-NMR

3a-13C-NMR

2b-1H-NMR

2b-13C-NMR

3b-1H-NMR

3b-13C-NMR

2c-1H-NMR

2c-13C-NMR

3c-1H-NMR

3c-13C-NMR

2d-1H-NMR

2d-13C-NMR

3d-1H-NMR

3d-13C-NMR

2.  Electrochemical Data of Different Redox Couples

Table S1 The electrochemical data of different redox couples

Redox couple / Ered vs Ag/Ag+
[V] / Eox vs Ag/Ag+
[V] / E1/2 vs Ag/Ag+
[V]
2a/3a-C / -0.19 / 0.45 / 0.13
2a/3a -Pt / -1.37 / 1.31 / -0.03
2b/3b-C / -0.35 / 0.33 / -0.01
2b/3b -Pt / -1.22 / 0.92 / -0.15
2c/3c-C / -0.34 / 0.42 / 0.04
2c/3c -Pt / -0.97 / 0.49 / -0.24
2d/3d-C / 0.026 / 0.372 / 0.199
2d/3d -Pt / -0.51 / 0.71 / 0.10

3.  Electrochemical Impedance Spectroscopy

Figure S1. EIS of dummy cells based on Pt and C CEs with different electrolytes

4.  The EIS data fitted by Z-view

Table S2 The EIS fitting data

electrolyte / Rct ( Ω) / ZN ( Ω)
A / 158 / 23
B / 162 / 497
C / 347 / 2468
D / 431 / 1730