Tree-based organic dyestuff based on carbazole or triphenylamine derivatives and application thereof in preparation of dye-sensitized solar cell

[0052] Example 1:

[0053] 1. Synthesis of dye D1

[0054] 1. Compound 1a [3,6-di(thiophen-2-yl)-9H-carbazole]

[0055]

[0056] Take a 100 mL schlenk bottle and repeatedly evacuate and vent nitrogen three times to form an anhydrous and oxygen-free system. In the case of maintaining nitrogen gas, I 2 BocCz (3 mmol), 2-thiophene borate (6.6 mmol), tetrakis(triphenylphosphine) palladium (0.12 mmol), K 3 PO 4 (12 mmol) is added to the reactor. After DMF is dewatered and deoxygenated, 20 mL is added with a syringe as the reaction solvent. The oil bath was heated to 100 ℃ and stirred overnight (16 h), the reaction solution was cooled to room temperature, extracted with dichloromethane and water, and the organic phase was retained. After the solid was obtained by rotary evaporation, it was dissolved in 10 mL of dichloromethane, and 5 mL of trifluoroacetic acid (TFA) and 1.5 mL of anisole were added. After reacting for 2 h at room temperature, it was extracted with water and the organic phase was retained. After rotary evaporation, the crude product is obtained, which is purified by a silica gel column. The eluent is petroleum ether: dichloromethane (volume ratio) = 2:1. The product was obtained as a white solid, 520 mg, and the yield was 53%.

[0057] 1 (300 MHz, CDCl 3 ) δ (ppm): 8.32 (s, 1H), 8.14-8.11 (m, 0H), 7.70 (d, J =8.4 Hz, 1H), 7.43 (d, J =8.5 Hz, 1H), 7.36 (d, J =3.5 Hz, 1H), 7.28 (s, 0H), 7.11 (t, J =4.3 Hz, 1H). ESI-MS : m/z 330.2([M-H] - )

[0058] 2. Compound 1b [5'-(3,6-di(thiophen-2-yl)-9H-carbazol-9-yl)-[2,2'-bithiophene]-5-carbaldehyde]

[0059]

[0060] Take a 50 mL two-neck round-bottom flask, install a reflux condenser, repeatedly evacuate and vent nitrogen three times to form an anhydrous and oxygen-free system. In the case of maintaining nitrogen gas, the 1a (0.7 mmol), 5-bromo-2,2’-bithiophene-5’-formaldehyde ( 1c ) (0.77 mmol), copper powder (0.42 mmol), K 2 CO 3 (3.5 mmol), 18-crown-6 (0.35 mmol), and o-dichlorobenzene (4 mL) were added to the flask. The oil bath was heated to 180 ℃ and stirred for reflux overnight (20 h), and nitrogen was continuously flowed during the process. After the reaction solution is cooled to normal temperature, the reaction solution is filtered, the filtrate is collected, and the solution is evaporated in an oil bath to obtain a crude product. Purify with silica gel column, eluent is petroleum ether: dichloromethane (volume ratio) = 1:1. The product was obtained as a yellow solid, 130 mg, and the yield was 33%.

[0061] 1 (300 MHz, CDCl 3 ) δ (ppm): 9.87 (s, 1H), 8.32 (s, 2H), 7.73 (d, J =1.7 Hz, 1H), 7.71-7.68 (d, 2H), 7.52 (d, J =8.5 Hz, 2H), 7.42 (dd, J =3.9 Hz, 1.0, 1H), 7.37 (d, J =3.6 Hz, 1.1, 2H), 7.29 -7.27 (m, 3H), 7.20(d,1H), 7.19(d, 2H), 7.13-7.09 (m, 2H).

[0062] Dye D1

[0063]

[0064] Take a 50 mL two-neck round-bottom flask, install a reflux condenser, repeatedly evacuate and vent nitrogen three times to form an anhydrous and oxygen-free system. In the case of maintaining nitrogen gas, the 1b (0.2 mmol), cyanoacetic acid (1 mmol), piperidine (4 mmol), acetonitrile (4 mL) and chloroform (4 mL) were added to the flask. Heat to 65 ℃ and reflux for 6 h. After the reaction, cool to room temperature and acidify with hydrochloric acid with a mass concentration of 30%. Use CH 2 Cl 2 The reaction solution is extracted and the organic phase is retained. Suspend evaporation to obtain the crude product, which was separated and purified by silica gel column. The eluent was dichloromethane: acetic acid (volume ratio) = 1:1. The obtained dye is 100 mg of red powder, and the yield is 83%.

[0065] 1 (300 MHz, DMSO) δ (ppm): 8.68 (s, 2H), 8.15 (s, 1H), 7.80 (dd, J =8.6, 1.7 Hz, 2H), 7.75 (d, J =3.9 Hz, 1H), 7.65 (d, J =3.9 Hz, 1H), 7.62 (s, 1H), 7.60-7.55 (m, 4H), 7.53 (d, J =5.1 Hz, 2H), 7.50 (d, J =4.0 Hz, 1H), 7.19-7.15 (m, 2H). 13 C NMR (400 MHz, DMSO) δ (ppm): 144.44, 141.03, 138.28, 135.79, 128.93, 128.13, 126.97, 126.10, 125.82, 125.53, 125.42, 124.20, 123.59, 118.39, 111.40, 55.37, 29.49, 22.69. ESI-MS : m/z 741.102([M-H] - ).

[0066] 2. Synthesis of dye D2

[0067] 1. Compound 2a [3,6-bis(5-hexylthiophen-2-yl)-9H-carbazole]

[0068]

[0069] Reference 1a Synthesis method, first step I 2 BocCz (3 mmol), 5-hexyl-2-thiophene boronic acid (6.6 mmol), tetrakis(triphenylphosphine) palladium (0.12 mmol), K 3 PO 4 (12 mmol), DMF 20 mL. Go to Boc with CH 2 Cl 2 (10 mL), trifluoroacetic acid (5 mL), anisole (1.5 mL). 770 mg of white solid product was obtained with a yield of 51.5%.

[0070] 1 (400 MHz, DMSO) δ (ppm): 8.61 (s, 2H), 8.51 (s, 1H), 8.02 (s, 1H), 7.75 (d, J =9.1 Hz, 4H), 7.69 (d, J =3.8 Hz, 2H), 7.61 (d, J =8.5 Hz, 2H), 7.54 (d, J =3.8 Hz, 1H), 7.39 (d, J =3.4 Hz, 2H), 6.89 (s, 2H), 2.86-2.80 (m, 4H), 1.71-1.63 (m, 4H), 1.38 (s, 4H), 1.32 (s, 8H), 0.88 (s, 6H). 13 C NMR (400 MHz, DMSO) δ (ppm): 139.99, 138.11, 134.52, 122.31, 120.26, 119.75, 119.10, 117.03, 112.76, 106.29, 27.05, 26.98, 25.66, 24.19, 17.96, 9.46. ESI-MS : m/z 499.270 ([M-H] + ).

[0071] 2. Synthesis of compound 2b

[0072]

[0073] Reference 1b Synthesis method, 2a (0.7 mmol), 2c (0.64 mmol), copper powder (0.42 mmol), K 2 CO 3 (3.5 mmol), 18-crown-6 (0.35 mmol) and o-dichlorobenzene (4 mL). A red-brown solid 130 mg was obtained with a yield of 25%.

[0074] 1 (400 MHz, CDCl 3 ) δ (ppm): 9.95 (s, 1H), 8.27 (s, J =1.4 Hz, 2H), 7.67 (dd, J =8.5Hz, 1.7, 2H), 7.49-7.48 (m, 2H), 7.44 (dd, J =3.7Hz, 1.0 Hz, 1H), 7.38 (dd, J =5.1 Hz, 1.0 Hz, 1H), 7.19 (d, J =4.0 Hz, 1H), 7.18 (d, J =3.5Hz, 2H), 6.78 (d, J =3.5Hz, 2H), 4.42 (d, J =2.8 Hz, 4H), 2.85 (t, J =7.6 Hz, 4H), 1.73 (dd, J =14.6 Hz, 7.1 Hz, 4H), 1.48-1.40 (m, 4H), 1.34 (dd, J =7.2 Hz, 3.4 Hz, 8H), 0.90 (d, J =7.0 Hz, 6H). ESI-MS : m/z 748.543([M-H] + ).

[0075] 3. Dye D2

[0076]

[0077] Reference D1 Synthesis method, 2b (0.1mmol), cyanoacetic acid (0.5mmol), pyridine (2mmol), acetonitrile (4 mL) and chloroform (4 mL). 70 mg of a red-black solid was obtained with a yield of 85%.

[0078] 1 (400 MHz, CDCl 3 ) δ (ppm): 8.25 (s, 2H), 8.03 (s, 1H), 7.64 (d, J =8.4 Hz, 2H), 7.37 (d, J =8.4 Hz, 2H), 7.15 (d, J =3.3 Hz, 2H), 6.77 (d, J =2.9 Hz, 2H), 2.84 (t, J =7.5 Hz, 4H), 1.79-1.68 (m, 4H), 1.42 (s, 4H), 1.34 (d, J =3.3 Hz, 8H), 0.91 (s, 6H). 13 C NMR (101 MHz, DMSO) δ (ppm): 163.98, 162.77, 146.62, 145.30, 144.70, 141.75, 140.62, 139.02, 134.89, 133.22, 128.43, 126.64, 126.05, 124.97, 124.22, 123.06, 117.36.25, 31.59, 116.99 , 31.46, 31.24, 29.97, 28.62, 22.51, 14.41. ESI-MS : m/z 816.084([M-H] - ).

[0079] Third, the synthesis of dye D3

[0080] 1. Compound 3a

[0081]

[0082] Reference 1b Synthesis method, 2a (0.7 mmol), 2d’ (0.64 mmol), copper powder (0.42 mmol), K 2 CO 3 (3.5 mmol), 18-crown-6 (0.35 mmol) and o-dichlorobenzene (4 mL). A red-brown solid 100 mg was obtained with a yield of 20.6%.

[0083] 1 (400 MHz, DMSO) δ (ppm): 9.95(s, 1H), 8.27 (s, 2H), 7,68 (s, 1H), 7.55 (d, J =5.6 Hz, 2H), 7.44 (d, J =8.6 Hz, 2H), 7.36 (d, J =3.5 Hz, 2H), 6.97 (d, J =5.2 Hz, 1H), 6.79 (d, J =3.4 Hz, 2H), 4.48 (d, J =17.7 Hz, 4H), 2.83-2.74 (m, 8H), 1.63 (tt, J =15.8 Hz, 7.7 Hz, 8H), 1.38 (s, 8H), 1.32-1.23 (m, 16H), 0.90-0.82 (m, 12H). 13 C NMR (400 MHz, DMSO) δ (ppm): 164.36, 148.62, 144.60, 144.32, 143.10, 142.39, 141.80, 140.52, 138.32, 134.50, 133.53, 132.45, 132.17, 132.00, 131.47, 131.98, 130.24, 128.59 , 122.98, 120.53, 117.38, 109.98, 94.54, 66.15, 65.42, 31.59, 31.49, 30.63, 30.51, 30.10, 29.98, 29.06, 28.63, 22.47, 14.37. ESI-MS : m/z 833.170 ([M-H] - ).

[0084] 2. Dye D3

[0085]

[0086] Reference D1 Synthesis method, 3b (0.1 mmol), cyanoacetic acid (0.5 mmol), pyridine (2 mmol), acetonitrile (2 mL) and chloroform (2 mL). 55 mg of a red-black solid was obtained with a yield of 65%.

[0087] 1 (400 MHz, DMSO) δ (ppm): 8.55 (s, 2H), 8.19 (s, 1H), 7.68 (d, J =5.6 Hz, 2H), 7.54 (d, J =8.6 Hz, 2H), 7.35 (d, J =3.5 Hz, 2H), 7.07 (d, J =5.2 Hz, 1H), 6.85 (d, J =3.4 Hz, 2H), 4.48 (d, J =17.7 Hz, 4H), 2.83-2.74 (m, 8H), 1.63 (tt, J =15.8 Hz, 7.7 Hz, 8H), 1.38 (s, 8H), 1.32-1.23 (m, 16H), 0.90-0.82 (m, 12H). 13 C NMR (101 MHz, DMSO) δ (ppm): 164.31, 162.77, 149.29, 144.61, 141.78, 140.68, 140.20, 128.27, 126.05, 124.94, 124.22, 123.04, 117.80, 117.44, 66.32, 65.71, 36.25, 31.59, 31.46, 31.24 , 29.94, 28.62, 22.52, 14.41. ESI-MS : m/z 901.122([M-H] - ).

[0088] Fourth, the synthesis of dye D4

[0089] 1. Compound 4a

[0090] [4,4'-(9H-carbazole-3,6-diyl)bis(N,N-diphenylaniline)]

[0091]

[0092] Reference 1a Synthesis method, but here uses dibromocarbazole instead of I 2 As raw material, BocCz can be directly obtained 4a , Eliminating the need for Boc protection steps. Dibromocarbazole (1.5 mmol), 5-hexyl-2-thiopheneboronic acid (3.3 mmol), Tetrakis(triphenylphosphine)palladium (0.06 mmol), K 3 PO 4 (4.5 mmol), DMF 9 mL.

[0093] 1 (400 MHz, CDCl 3 ) δ (ppm): 8.35 (s, 2H), 8.12 (s, 1H), 7.71 (dd, J =8.4 Hz, 1.8, 2H), 7.65-7.63 (m, 4H), 7.53 (d, J =8.4 Hz, 2H), 7.32 (dt, J =7.3 Hz, 1.7 Hz, 8H), 7.24-7.22 (m, 4H), 7.20 (dd, J =8.6 Hz, 1.1 Hz, 8H), 7.07 (dd, J =10.4 Hz, 4.2 Hz, 4H). 13 C NMR (101 MHz, DMSO) δ (ppm): 147.87, 146.51, 136.38, 129.27, 127.94, 124.49, 124.23, 122.73, 118.41, 110.87, 58.49, 29.73, 26.95, 18.46. ESI-MS : m/z 652.961 ([M-H] - ).

[0094] 2. Synthesis of compound 4b

[0095] 7-(5'-(3,6-bis(4-(diphenylamino)phenyl)-9H-carbazol-9-yl)-3',4-dihexyl-[2,2'-bithiophen]-5-yl) -2,3-dihydrothieno[3,4-b][1,4]dioxine-5-carbaldehyde

[0096] Reference 1b Synthesis method, 4a (0.6 mmol), intermediate 2f’ (0.66 mmol), copper powder (0.36 mmol), K 2 CO 3 (3 mmol) and o-dichlorobenzene (2.5 mL). A reddish-brown solid 160 mg was obtained with a yield of 43%.

[0097]

[0098] Dye D4

[0099] (Z)-3-(7-(5'-(3,6-bis(4-(diphenylamino)phenyl)-9H-carbazol-9-yl)-3',4-dihexyl-[2,2'- bithiophen]-5-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2-cyanoacrylic acid

[0100]

[0101] Reference D1 Synthesis method, 4b (0.1 mmol), cyanoacetic acid (0.5 mmol), pyridine (2 mmol), acetonitrile (2 mL) and chloroform (2 mL). Obtained 119 mg of a red-black solid with a yield of 91%.

[0102] 1 (400 MHz, DMSO) δ (ppm): 8.66 (s, 1H), 8.48 (s, 1H), 7.78 (d, J =8.5 Hz, 1H), 7.73 (d, J =8.3 Hz, 2H), 7.65 (d, J =8.0 Hz, 2H), 7.33 (t, J =7.7 Hz, 4H), 7.09 (t, J =9.6 Hz, 8H), 4.48 (d, J =17.7 Hz, 4H), 2.83-2.74 (m, 8H), 1.63 (tt, J =15.8 Hz, 7.7 Hz, 8H), 1.38 (s, 8H), 1.32-1.23 (m, 16H), 0.90-0.82 (m, 12H). 13 C NMR (400 MHz, CDCl 3 ) δ (ppm): 147.78, 146.74, 141.15, 135.87, 134.00, 129.26, 127.95, 125.59, 124.28, 122.80, 31.71, 31.66, 30.42, 29.24, 29.21, 22.66, 22.60, 14.11, 1.02. ESI-MS: 1220.399([M-H] - ).

[0103] 5. Synthesis of dye D5

[0104] 1. Compound 1b’

[0105]

[0106] Carbazole (19.2 mmol), copper powder (6.5 mmol), potassium carbonate (47.8 mmol), and 18 crown 6 (1.2 mmol) were added to the reaction flask one by one, and then 50 ml o-dichlorobenzene which had been deoxygenated by nitrogen gas was added. Stir and heat to reflux. A solution of 4',4'',4'''-triiodotriphenylamine (9.6 mmol) in 24 ml o-dichlorobenzene was slowly dripped, and then the mixture was stirred and refluxed for 24 hours. After the reaction solution was cooled to room temperature, the reaction solution was filtered, the solvent in the filtrate was removed by rotary evaporation, and the obtained crude product was separated by column chromatography. The developing solvent was petroleum ether/dichloromethane (10:1, v/v) , To obtain 2.3 g of white powder, with a yield of 34%.

[0107] 1 H-NMR (400 MHz, DMSO- d 6) δ (ppm): 8.25 (d, J = 7.7 Hz, 4H), 7.76 (d, J = 8.8 Hz, 2H), 7.69 (d, J = 8.8 Hz, 2H), 7.62 (d, J = 8.8 Hz, 4H), 7.46-7.41 (m, 8H), 7.30 (ddd, J = 8.0, 5.6, 2.4 Hz, 4H), 7.12 (d, J = 8.8 Hz, 2H), 6.97 (d, J = 8.8 Hz, 2H). 13 C-NMR (100 MHz, DMSO- d 6) δ (ppm): 146.7, 145.7, 140.2, 138.5, 138.4, 131.9, 128.1, 126.4, 126.2, 125.1, 122.6, 120.5, 120.0, 109.7. EI-MS : m/z 576.4 ([M-I] + ). Elemental Analysis: Calcd for C 42 H 28 IN 3 : C, 71.90; H, 4.02; N, 5.99%. Found: C, 71.66; H, 4.32; N, 6.01%.

[0108] 2. Compound 1c’

[0109]

[0110] Under nitrogen atmosphere, add to Schlenk bottle one by one 1b’ (1.7 mmol), pinacol diboron (2.1 mmol), potassium acetate (5.1 mmol) and Pd(dppf)Cl 2 (0.1 mmol), and then add DMSO (50 mL) to remove water and oxygen, and react at 100°C for 5 h. After the reaction solution is cooled to room temperature, ethyl acetate is added, and then water is added to wash the organic phase, and the DMSO in the organic phase is taken away, and the organic phase is collected. The organic phase was dried with anhydrous magnesium sulfate. Rotate to evaporate the solvent and separate by column chromatography. The developing solvent is petroleum ether/ethyl acetate (5:1, v/v) to obtain a white solid 1c’ 900 mg, the yield is 75%.

[0111] 1 (400 MHz, CDCl 3 ) δ (ppm): 8.13 (d, J = 7.7 Hz, 4H), 7.83 (d, J = 8.5 Hz, 2H), 7.55 -7.37 (m, 16H), 7.33-7.24 (m, 6H), 1.35 (s, 12H). 13 C-NMR (100 MHz, CDCl 3 ) δ (ppm): 150.0, 146.3, 140.9, 136.3, 132.7, 128.0, 125.9, 125.4, 123.3, 123.2, 120.3, 119.9, 109.8, 83.7, 24.9.; MALDI-TOF: m/z 701.262 ([M + ]); Elemental Analysis: Calcd for C 48 H 40 BN 3 O 2 : C, 82.16; H, 5.75; N, 5.99. Found: C, 82.34; H, 5.79; N, 6.05.

[0112] 3. Compound 2c’

[0113]

[0114] Under the protection of nitrogen, add to the Schlenk reaction flask 2b’ (2.0 mmol), 3-hexylthiophene-2-boronic acid pinacol ester (2.6 mmol) and tetrakis(triphenylphosphine) palladium (0.12 mmol), then add deoxygenated glycol dimethyl ether (DME, 24 mL), add deoxygenated 2mol/L Na with stirring 2 CO 3 Aqueous solution (1.7 mL), stirred at room temperature for 15 min, and reacted at 90°C. Thin layer chromatography (TLC) tracks the progress of the reaction. After the reaction solution was cooled to room temperature, the solvent was removed by rotary evaporation, and extraction was performed with ethyl acetate/saturated NaCl aqueous solution. Collect the organic phase, anhydrous MgSO 4 The organic phase was dried, the solvent was removed by rotary evaporation again, and the column chromatography was separated. The developing solvent was petroleum ether/ethyl acetate (3:1, v/v) to obtain a yellow solid 2c’ 615 mg, the yield was 91%.

[0115] 1 H-NMR (400 MHz, CDCl 3 ) δ (ppm): 9.93 (s, 1H), 7.34 (d, J = 5.2 Hz, 1H), 6.95 (d, J = 5.2 Hz, 1H), 4.37 (tdd, J = 6.7, 4.1, 2.6 Hz, 5H), 2.81-2.74 (m, 2H), 1.69-1.56 (m, 2H), 1.39-1.26 (m, 6H), 0.88 (t, J = 6.9 Hz, 3H); 13 C-NMR (100 MHz, CDCl 3 ) δ (ppm): 179.6, 148.3, 142.9, 137.4, 129.7, 126.7, 126.1, 122.6, 116.3, 65.2, 64.6, 31.7, 30.4, 29.8, 29.3, 22.6, 14.1; MALDI-TOF: m/z 336.090 ([M + ]); Elemental Analysis: Calcd for C 17 H 20 O 3 S 2 : C, 60.68; H, 5.99. Found: C, 60.79; H, 6.23.

[0116] 3. Compound 2d’

[0117]

[0118] Add to the single neck round bottom flask 2c’ (0.47 mmol), add CHCl 3 (10 mL) to completely dissolve, add NBS (0.47 mmol) and stir overnight at room temperature. The solvent was removed by rotary evaporation, and the column chromatography was separated. The developing solvent was petroleum ether/ethyl acetate (3:1, v/v) to obtain a nearly colorless solid 2d’ 177 mg. The yield is 90%.

[0119] 1 H-NMR (400 MHz, CDCl 3 ) δ (ppm): 9.92 (s, 1H), 6.91 (s, 1H), 4.44-4.33 (m, 4H), 2.75-2.69 (m, 2H), 1.65-1.52 (m, 2H), 1.41-1.27 (m , 6H), 0.88 (t, J = 6.8 Hz, 3H); 13 C-NMR (100 MHz, CDCl 3 ) δ (ppm): 179.6, 148.2, 143.1, 137.6, 132.3, 127.9, 121.2, 116.3, 114.0, 65.2, 64.8, 31.6, 30.2, 30.0, 29.2, 22.6, 14.1.; MALDI-TOF: m/z 413.980 ([M + ]); Elemental Analysis: Calcd for C 17 H 19 O 3 S 2 Br: C, 49.16; H, 4.61. Found: C, 49.35; H, 4.56.

[0120] 4. Compound 2e’

[0121]

[0122] Under the protection of nitrogen, add to the Schlenk reaction flask 2d’ (1.5 mmol), 3-hexylthiophene-2-boronic acid pinacol ester (1.9 mmol) and tetrakis(triphenylphosphine) palladium (0.088 mmol), then add deoxygenated glycol dimethyl ether (DME, 18 mL), add deoxygenated 2mol/L Na with stirring 2 CO 3 Aqueous solution (1.3 mL), stirred at room temperature for 15 min, and reacted at 90°C. Thin layer chromatography (TLC) tracks the progress of the reaction. After the reaction solution was cooled to room temperature, the solvent was removed by rotary evaporation, and extraction was performed with ethyl acetate/saturated NaCl aqueous solution. Collect the organic phase, anhydrous MgSO 4 The organic phase is dried, and the solvent is removed by rotary evaporation again. The column chromatography is separated. The developing solvent is petroleum ether/ethyl acetate (5:1, v/v) to obtain a yellow solid 2e’ 592 mg, the yield is 80%.

[0123] 1 (400 MHz, CDCl 3 ) δ (ppm): 9.94 (s, 1H), 7.18 (d, J = 5.2 Hz, 1H), 6.96 (s, 1H), 6.93 (d, J = 5.2 Hz, 1H), 4.39 (dd, J = 11.1, 5.2 Hz, 4H), 2.78 (dd, J = 16.2, 9.4 Hz, 4H), 1.75-1.58 (m, 4H), 1.44-1.21 (m, 12H), 0.94-0.82 (m, 6H); 13 C-NMR (100 MHz, CDCl 3 ) δ (ppm): 179.5, 148.3, 143.1, 140.1, 137.4, 137.3, 130.2, 130.1, 128.3, 126.0, 124.1, 122.5, 116.1, 65.2, 64.7, 31.7, 31.6, 30.7, 30.3, 30.1, 29.3, 29.37, 29.2, 22.6, 14.1; MALDI-TOF: m/z 502.147 ([M + ]); Elemental Analysis: Calcd for C 27 H 34 O 3 S 3 : C, 64.50; H, 6.82. Found: C, 64.79; H, 6.73.

[0124] 5. Compound 2e’

[0125]

[0126] Add to the single neck round bottom flask 2e’ (0.56 mmol), add CHCl 3 (10 mL) to completely dissolve, add NBS (0.56 mmol) and stir overnight at room temperature. The solvent was removed by rotary evaporation, and the column chromatography was separated. The developing solvent was petroleum ether/ethyl acetate (5:1, v/v) to obtain a yellow solid 2f’ 294 mg. The yield is 90%.

[0127] 1 (400 MHz, CDCl 3 ) δ (ppm): 9.94 (s, 1H), 6.90 (s, 1H), 6.89 (s, 1H), 4.40 (dd, J = 11.8, 4.6 Hz, 5H), 2.83-2.74 (m, 2H), 2.74-2.65 (m, 2H), 1.75-1.60 (m, 4H), 1.45-1.18 (m, 12H), 0.88 (M, 6H) ).; 13 C-NMR (100 MHz, CDCl 3 ) δ (ppm): 179.6, 148.2, 143.1, 140.7, 137.4, 135.9, 132.8, 131.7, 128.6, 126.6, 122.1, 116.3, 110.9, 65.2, 64.7, 31.7, 31.6, 30.5, 30.3, 30.0, 29.3, 29.1, 22.6, 14.1; MALDI-TOF: m/z 578.895 ([M + ]); Elemental Analysis: Calcd for C 27 H 33 O 3 S 3 Br: C, 55.75; H, 5.72. Found: C, 55.86; H, 5.62.

[0128] 6. Compound D5’

[0129]

[0130] Under the protection of nitrogen, add to the Schlenk reaction flask 1c’ (1.1 mmol), 2f’ (0.96 mmol) and tetrakis(triphenylphosphine)palladium (0.047 mmol), then add deoxygenated ethylene glycol dimethyl ether (DME, 60 mL), add deoxygenated 2mol/L K under stirring 2 CO 3 Aqueous solution (1.3 mL), stirred at room temperature for 15 min, and reacted at 90°C. Thin layer chromatography (TLC) tracks the progress of the reaction. After the reaction solution was cooled to room temperature, the solvent was removed by rotary evaporation, and extraction was performed with ethyl acetate/saturated NaCl aqueous solution. Collect the organic phase, anhydrous MgSO 4 The organic phase was dried, the solvent was removed by rotary evaporation again, and the column chromatography was separated. The developing solvent was petroleum ether/ethyl acetate (3:1, v/v) to obtain a yellow solid D5’ 772 mg, the yield was 75%.

[0131] 1 H-NMR (400 MHz, CDCl 3 ) δ (ppm): 9.94 (s, 1H), 8.15 (dd, J = 7.0, 5.5 Hz, 8H), 7.60 (d, J = 8.4 Hz, 2H), 7.55-7.40 (m, 8H), 7.37-7.27 (m, 8H), 7.14 (s, 1H), 7.02 (s, 1H), 6.91 (d, J = 8.5 Hz, 2H), 4.40 (d, J = 4.7 Hz, 4H), 2.80 (m, 4H), 1.80-1.64 (m, 12H), 1.33 (s, 4H), 0.93-0.82 (m, 6H).; 13 C-NMR (100 MHz, CDCl 3 ) δ (ppm): 179.6, 147.0, 146.3, 141.2, 141.1, 141.0, 132.6, 131.5, 129.4, 128.3, 128.2, 128.0, 128.0, 126.8, 125.9, 125.9, 125.1, 124.9, 123.5, 123.3, 123.2, 120.4, 120.3, 119.9, 119.8, 116.8, 109.8, 65.2, 64.7, 31.7, 31.7, 30.5, 30.3, 30.1, 29.7, 29.3, 29.3, 22.7, 22.6, 14.1; MALDI-TOF: m/z 1075.331 ([M + ]); Elemental Analysis: Calcd for C 69 H 61 N 3 O 3 S 3 : C, 76.99; H, 5.71; N, 3.90. Found: C, 77.10; H, 5.64; N, 3.75.

[0132] 7. Compound D5

[0133]

[0134] In a nitrogen atmosphere, add to the Schlenk reaction flask D5’ (0.57 mmol), cyanoacetic acid (2.8 mmol), then add piperidine (5.7 mmol), toluene (20 mL) and acetonitrile (40 mL), stir at room temperature for 15 min, and reflux at 100 ℃ for 5 h. After the reaction solution was cooled to room temperature, 1 mol/L HCl aqueous solution was added to adjust the pH of the reaction solution to 2-3. Extract with ethyl acetate/saturated NaCl aqueous solution, collect the organic phase, anhydrous MgSO 4 Dry the organic phase. The solvent was removed by rotary evaporation again, and the column chromatography was separated. The developing solvent was dichloromethane/acetic acid (80:1, v/v) to obtain a deep red solid D5 522 mg, the yield is 80%.

[0135] 1 (400 MHz, DMF- d 7 ) δ (ppm): 8.34 (s, 1H), 8.30 (d, J = 7.8 Hz, 3H), 7.83 (d, J = 8.5 Hz, 2H), 7.72 (d, J = 8.6 Hz, 4H), 7.62-7.46 (m, 15H), 7.42(d, J = 8.5 Hz, 2H), 7.37-7.26 (m, 4H), 4.61 (dd, J = 17.5, 4.3 Hz, 4H), 2.99- 2.84 (m, 4H), 1.86-1.64 (m, 4H), 1.54-1.19 (m, 12H), 0.89 (t, J = 6.7 Hz, 6H); 13 C-NMR (100 MHz, DMF- d 7 ) δ (ppm): 166.0, 164.4, 149.0, 147.2, 146.6, 144.0, 142.1, 142.0, 141.1, 140.3, 138.2, 137.6, 132.7, 129.1, 128.9, 128.6, 127.1, 126.9, 126.4, 126.2, 125.7, 124.9, 123.4, 120.9, 120.7, 120.2, 117.4, 110.1, 108.0, 94.5, 66.3, 65.5, 31.73, 31.65, 30.7, 30.4, 24.4, 22.64, 22.63, 13.8.; MALDI-TOF: m/z 1142.328([M + ]); Elemental Analysis: Calcd for C 72 H 62 N 4 O 4 S 3 : C, 75.63; H, 5.47; N, 4.90. Found: C, 75.36; H, 5.39; N, 4.86.

[0136] Six, the synthesis of dye D6

[0137] 1. Compound 2g’

[0138]

[0139] Under the protection of nitrogen, add to the Schlenk reaction flask 2f’ (3.0 mmol), 3-hexylthiophene-2-boronic acid pinacol ester (3.3 mmol) and tetrakis(triphenylphosphine) palladium (0.18 mmol), then add deoxygenated glycol dimethyl ether (DME, 50 mL), add deoxygenated 2mol/L Na with stirring 2 CO 3 Aqueous solution (5.0 mL), stirred at room temperature for 15 min, and reacted at 90°C. Thin layer chromatography (TLC) tracks the progress of the reaction. After the reaction solution was cooled to room temperature, the solvent was removed by rotary evaporation, and extraction was performed with ethyl acetate/saturated NaCl aqueous solution. Collect the organic phase, anhydrous MgSO 4 The organic phase is dried, and the solvent is removed by rotary evaporation again. The column chromatography is separated. The developing solvent is petroleum ether/ethyl acetate (5:1, v/v) to obtain a yellow solid 2g’ 1.6 g, 80% yield.

[0140]

[0141] 1 H-NMR (400 MHz, CDCl 3 ) δ (ppm): 9.94 (s, 1H), 7.16 (d, J = 5.2 Hz, 1H), 6.99 (s, 1H), 6.94 (s, 1H), 6.93 (d, J = 5.2 Hz, 1H), 4.41 (dd, J = 10.5, 5.3 Hz, 4H), 2.86-2.72 (m, 6H), 1.78-1.60 (m, 6H), 1.48-1.28 (m, 18H), 0.97-0.81 (m, 9H); 13 C-NMR (100 MHz, CDCl 3 ) δ (ppm): 179.5, 148.3, 143.2, 140.3, 139.8, 137.3, 137.1, 134.7, 130.4, 130.1, 129.9, 128.8, 128.1, 126.1, 123.7, 122.6, 116.1, 65.2, 64.7, 31.7, 31.7, 31.7, 30.6, 30.5, 30.3, 30.1, 29.5, 29.3, 29.3, 29.24, 29.21, 22.64, 22.63, 14.1.; MALDI-TOF: m/z 668.200 ([M + ]); Elemental Analysis: Calcd for C 37 H 48 O 3 S 4 : C, 66.42; H, 7.23. Found: C, 66.26; H, 7.35.

[0142] 2. Compound 2h’

[0143]

[0144] Add to the single neck round bottom flask 2g’ (1.9 mmol), add CHCl 3 (40 mL) to completely dissolve, add NBS (1.9 mmol) and stir overnight at room temperature. The solvent was removed by rotary evaporation, and the column chromatography was separated. The developing solvent was petroleum ether/ethyl acetate (5:1, v/v) to obtain a yellow solid 2h’ 1.3 g. The yield is 90%.

[0145] 1 H-NMR (400 MHz, CDCl 3 ) δ (ppm): 9.94 (s, 1H), 6.98 (s, 1H), 6.90-6.86 (m, 2H), 4.40 (dd, J = 10.4, 5.2 Hz, 4H), 2.85-2.65 (m, 6H), 1.73 -1.53 ​​(m, 6H), 1.46-1.23 (m, 21H), 0.94-0.84 (m, 9H); 13 C-NMR (100 MHz, CDCl 3 ) δ (ppm) 179.5, 148.3, 143.2, 140.4, 140.3, 137.3, 136.7, 133.3, 132.8, 131.9, 130.5, 129.2, 128.2, 126.3, 122.4, 116.2, 110.5, 65.2, 64.7, 31.7, 31.6, 31.6, 30.5, 30.3 , 30.1, 29.4, 29.3, 29.2, 29.2, 29.1, 22.63, 22.62, 22.60, 14.1; MALDI-TOF: m/z 746.120 ([M + ]); Elemental Analysis: Calcd for C 37 H 47 O 3 S 4 Br: C, 59.42; H, 6.33. Found: C, 59.26; H, 6.50.

[0146] 3. Compound D6’

[0147]

[0148] Under the protection of nitrogen, add to the Schlenk reaction flask 1c’ (1.9 mmol), 2h’ (1.60 mmol) and tetrakis(triphenylphosphine)palladium (0.096mmol), then add deoxygenated ethylene glycol dimethyl ether (DME, 40 mL), add deoxygenated 2mol/L K under stirring 2 CO 3 Aqueous solution (4.4 mL), stirred at room temperature for 15 min, and reacted at 90°C. Thin layer chromatography (TLC) tracks the progress of the reaction. After the reaction solution was cooled to room temperature, the solvent was removed by rotary evaporation, and extraction was performed with ethyl acetate/saturated NaCl aqueous solution. Collect the organic phase, anhydrous MgSO 4 The organic phase was dried, the solvent was removed by rotary evaporation again, and the column chromatography was separated. The developing solvent was petroleum ether/ethyl acetate (3:1, v/v) to obtain a yellow solid D6’ 1.4 g, yield 70%.

[0149] 1 H-NMR (400 MHz, CDCl 3 ) δ (ppm): 9.87 (s, 1H), 8.09 (d, J = 7.7 Hz, 4H), 7.54 (d, J = 8.1 Hz, 2H), 7.49-7.31 (m, 16H), 7.24-7.16 (m, 6H), 7.07 (s, 1H), 6.93 (m, 2H), 4.33 (dd, J = 9.6, 4.8 Hz, 4H), 2.78-2.68 (m, 6H), 1.69-1.56 (m, 6H), 1.42-1.20 (m, 18H), 0.83 (s, 9H); 13 C-NMR (100 MHz, CDCl 3 ) δ (ppm): 179.6, 148.4, 146.8, 146.5, 143.4, 141.5, 141.1, 140.9, 140.6, 137.4, 137.2, 134.8, 132.7, 130.0, 129.8, 129.6, 128.7, 128.3, 128.3, 126.9, 126.2, 126.1, 126.0, 125.2, 125.0, 123.5, 122.7, 120.5, 120.1, 116.3, 110.0, 65.3, 64.9, 53.6, 31.8, 31.8, 30.7, 30.5, 30.2, 29.8, 29.7, 29.4, 29.4, 22.8, 22.8, 14.3, 14.2; MALDI-TOF: m/z 1241.449 ([M] + ); Elemental Analysis: Calcd for C 79 H 75 N 3 O 3 S 4 : C, 76.35; H, 6.08; N, 3.38. Found: C, 76.24; H, 6.00; N, 3.56.

[0150] 4. Compound D6

[0151]

[0152] In a nitrogen atmosphere, add D6’ (0.25 mmol) and 2i’ (0.25 mmol), triethylamine (0.2 mL) and anhydrous CaCl 2 (0.019 mmol), heated to reflux in a mixed solvent of toluene (3 mL) and dehydrated ethanol (15 mL) for 48 h. The reaction solution was cooled to room temperature, and the solvent was removed by rotary evaporation. The crude product was separated by column chromatography. The developing solvent was dichloromethane/methanol (10:1, v/v) to obtain a purple-black solid powder. D6 225 mg, the yield is 65%.

[0153] 1 (400 MHz, DMF- d 7 ) δ (ppm): 8.30 (d, J = 7.5 Hz, 4H), 7.82 (d, J = 6.1 Hz, 2H), 7.71 (s, 5H), 7.60 – 7.45 (m, 14H), 7.41 (d, J = 7.4 Hz, 2H), 7.36 – 7.28 (m, 4H), 7.25 (s, 2H), 4.51 (m, 4H), 3.69 – 3.31 (m, 6H), 2.90-2.82 (m, 6H), 1.84- 1.61 (m, 6H), 1.52-1.23 (m, 18H), 0.96-0.78 (m, 9H); 13 C-NMR (100 MHz, DMF- d 7 ) δ (ppm): 181.1, 178.910, 147.5, 147.0, 143.5, 142.5, 141.8, 141.7, 141.4, 141.1, 141.1, 135.5, 134.6, 133.0, 130.4, 129.6, 129.2, 128.9, 128.9, 127.6, 127.6, 127.3, 127.2, 126.7, 126.0, 125.3, 123.7, 121.0, 120.6, 118.7, 118.7, 117.3, 117.3, 116.2, 114.5, 114.3, 110.3, 65.9, 65.8, 32.1, 32.0, 31.0, 30.8, 30.8, 23.0, 22.9, 14.2, 14.2; MALDI-TOF: m/z 1388.428 ([M + ]); Elemental Analysis: Calcd for C 85 H 76 N 6 O 3 S 5 : C, 73.45; H, 5.51; N, 6.05. Found: C, 73.55; H, 5.64; N, 6.35.

[0154] The organic dye of the present invention can be used to prepare dye-sensitized solar cells, and the method for preparing dye-sensitized solar cells is as described in patent 200810151310.8.