Bis-carbazole benzothiadiazole compound as well as preparation method and co-sensitization application thereof
By designing and synthesizing bi-carbazole benzothiadiazole compounds and co-sensitizing them with the metal dye sensitizer Z907, the absorption spectrum range was broadened and the photoelectric conversion efficiency of dye-sensitized solar cells was improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG UNIV OF TECH
- Filing Date
- 2026-01-06
- Publication Date
- 2026-05-12
AI Technical Summary
Existing non-metallic organic dye sensitizers have narrow spectral response ranges, resulting in low photoelectric conversion efficiency of dye-sensitized solar cells, and there is a lack of effective co-sensitizing materials.
By designing and synthesizing bi-carbazole benzothiadiazole compounds, combining the bi-carbazole donor unit with the benzothiadiazole acceptor unit, and through structural modification, a compound that can be co-sensitized with the metal dye sensitizer Z907 was synthesized, thus broadening the absorption spectrum range.
This improves the photoelectric conversion efficiency of dye-sensitized solar cells and provides a new applicable material for the co-sensitization of dye sensitizer Z907.
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Abstract
Description
Technical Field
[0001] This invention relates to bi-carbazole benzothiadiazole compounds, their preparation methods, and applications. Background Technology
[0002] Compared with organometallic dye sensitizers, non-metallic organometallic dye sensitizers have received widespread research and attention due to their advantages such as readily available raw materials, high molar absorptivity, and the ability to achieve significant performance improvements through fine structural tuning. Among numerous electron-rich units, carbazole has become an important electron donor material due to its large conjugated planar structure, good molecular design flexibility, and excellent hole transport capability. In recent years, research on carbazole-based dye sensitizers has emerged continuously, demonstrating excellent photoelectric conversion efficiency. On the other hand, electron-withdrawing benzothiadiazole units also frequently appear in the structure of dye sensitizers, often acting as auxiliary acceptors to increase the molecular conjugation system, promote intramolecular charge transfer, and further optimize energy levels while broadening the molecular absorption spectrum. Therefore, this invention combines a bis-carbazole donor unit and a benzothiadiazole acceptor unit into the same molecule and, through structural modification, designs and synthesizes a series of bi-biscarbazole benzothiadiazole compounds. Meanwhile, to address the drawback of the narrow spectral response range of non-metallic organic dye sensitizers, they are co-sensitized with metallic dye sensitizers, with the aim of broadening the absorption spectral range while improving the photoelectric conversion efficiency of DSSCs. Summary of the Invention
[0003] To address the aforementioned problems in existing technologies, the present invention aims to provide a bi-carbazole benzothiadiazole compound, its preparation method, and its applications. This bi-carbazole benzothiadiazole compound can be co-sensitized with the metal dye sensitizer Z907, and the assembled dye-sensitized solar cell exhibits good photoelectric conversion efficiency, adding a new applicable substance to the screening of co-sensitizers for dye sensitizer Z907.
[0004] This invention discloses bi-carbazole benzothiadiazole compounds, including compounds with the following six structures, the molecular structures of which are shown as (ZR-2), (ZR-5), (ZR-6), (ZR-7), (ZR-8) or (ZR-9); .
[0005] This invention also discloses a method for preparing bicarbazole benzothiadiazole compounds, specifically, dissolving the compounds shown in formulas (IIa), (IIb), (IIc), (IId), and (IIe) with cyanoacetic acid or rhodanine-3-acetic acid in a solvent, adding an alkaline catalyst, and heating under reflux with stirring. After the reaction is completed, the solvent is removed by concentration, and the resulting concentrate is dissolved in an eluent and then separated and purified by column chromatography with silica gel. The eluent is collected and the eluent is evaporated to obtain ZR-2, ZR-5, ZR-6, ZR-7, ZR-8, and ZR-9. The structural formulas of the compounds shown in formulas (IIa), (IIb), (IIc), (IId), and (IIe) are as follows: .
[0006] Furthermore, the present invention also discloses that the alkaline catalyst is piperidine.
[0007] Furthermore, the present invention also discloses compounds represented by formula (IIa), formula (IIb), formula (IIc), formula (IId) or formula (IIe): the mass ratio of the catalyst is 1:6~10.
[0008] Furthermore, the present invention also discloses that the reaction time is 10 h.
[0009] Furthermore, the present invention also discloses a mixed solvent of acetonitrile and chloroform, wherein the volume ratio of acetonitrile to chloroform is 2:1.
[0010] Furthermore, the present invention also discloses that the eluent is a mixed solvent composed of dichloromethane and methanol, wherein the volume ratio of dichloromethane to methanol is 20:1.
[0011] Furthermore, the present invention also discloses that the molar ratio of the compound shown in formula (IIa), formula (IIb), formula (IIc), formula (IId) or formula (IIe) to cyanoacetic acid or rhodanine-3-acetic acid is 1:5~12.
[0012] Furthermore, the present invention also discloses that the ratio of the amount of substance to the volume of solvent of the compounds shown in (IIa), (IIb), (IIc), (IId) or (IIe) is 1:40~75, the unit of amount of substance is mmol, and the unit of volume is mL.
[0013] Furthermore, the present invention also discloses methods for synthesizing the compounds shown in formulas (IIa), (IIb), and (IIc), as detailed below: The compounds shown in formulas (Ⅳa), (Ⅳb), and (Ⅳc) were dissolved in tetrahydrofuran, and then added to a hexane solution of n-butyllithium at low temperature. After stirring for 1 h, trimethyl borate was added and stirred for 15 min, followed by stirring overnight at room temperature. The mixture was then added to a mixed solution of the compound shown in formula (Ⅲ), potassium carbonate, and tetra(triphenylphosphine)palladium in tetrahydrofuran and water, and heated under reflux. After the reaction was completed, the mixture was cooled to room temperature, extracted with dichloromethane, washed with saturated brine, and dried. The solvent was removed by rotary evaporation, and the mixture was purified by column chromatography to obtain the compounds shown in formulas (Ⅱa), (Ⅱb), and (Ⅱc).
[0014] The structural formulas of the compound shown in formula (Ⅲ) and the compounds shown in formulas (Ⅳa), (Ⅳb) and (Ⅳc) are as follows:
[0015] Furthermore, the present invention also discloses that when synthesizing the compounds shown in formulas (IIa), (IIb) and (IIc), the eluent is a mixed solvent of petroleum ether and dichloromethane; wherein the column chromatography separation process is as follows: the concentrate is dissolved in the eluent and then separated and purified by column chromatography with silica gel, the eluent is collected and the eluent is evaporated, and the product is dried to obtain a solid powder product.
[0016] Furthermore, the present invention also discloses a method for synthesizing the compound shown in formula (Ⅱd), as follows: The compound shown in formula (Ⅲ), the compound shown in formula (V), bis(triphenylphosphine)palladium dichloride, triphenylphosphine, cuprous iodide and triethylamine were dissolved in tetrahydrofuran and heated under reflux. After the reaction was completed, the mixture was cooled to room temperature, extracted with dichloromethane, washed with saturated brine and dried. The solvent was removed by rotary evaporation and purified by column chromatography to obtain the product compound shown in formula (Ⅱd).
[0017] The structural formula of the compound shown in formula (V) is as follows:
[0018] Furthermore, the present invention also discloses that when synthesizing the compound shown in formula (Ⅱd), the eluent is petroleum ether and dichloromethane in a volume ratio of 1:1; wherein the column chromatography separation process is as follows: the concentrate is dissolved in the eluent and then separated and purified by column chromatography silica gel, the eluent is collected and the eluent is evaporated, and the product is dried to obtain a solid powder product.
[0019] Furthermore, the present invention also discloses a method for synthesizing the compound represented by formula (Ⅱe), as follows: The compound shown in formula (Ⅳa) was dissolved in tetrahydrofuran, and then added to a hexane solution of n-butyllithium at low temperature. After stirring for 1 h, trimethyl borate was added, and the mixture was stirred for 15 min. The mixture was then stirred overnight at room temperature. The solution was then added to a solution of the compound shown in formula (VI), potassium carbonate, and tetra(triphenylphosphine)palladium in tetrahydrofuran and water, and heated to reflux. After the reaction was completed, the mixture was cooled to room temperature, extracted with dichloromethane, washed with saturated brine, and dried. The solvent was removed by rotary evaporation, and the product was purified by column chromatography to obtain the compound shown in formula (Ⅱe).
[0020] The structural formula of the compound shown in formula (VI) is as follows:
[0021] Furthermore, the present invention also discloses that when synthesizing the compound shown in formula (Ⅱe), the eluent is petroleum ether and dichloromethane in a volume ratio of 3:1; wherein the column chromatography separation process is as follows: the concentrate is dissolved in the eluent and then separated and purified by column chromatography silica gel, the eluent is collected and the eluent is evaporated, and the product is dried to obtain a solid powder product.
[0022] Furthermore, the present invention also discloses the application of bi-carbazole benzothiadiazole compounds as dye sensitizers.
[0023] By employing the above-mentioned technology, compared with the prior art, the beneficial effects of the present invention are as follows: The present invention synthesizes a bi-carbazole benzothiadiazole compound by connecting two N-butylcarbazole electron donors with benzothiadiazole, and then introducing electron acceptors cyanoacetic acid or rhodanine-3-acetic acid onto the benzothiadiazole, or by connecting cyanoacetic acid to the benzothiadiazole with a styrene bridge. This bi-carbazole benzothiadiazole compound can be used as a co-sensitizer for Z907. Dye-sensitized solar cells co-sensitized with this type of compound exhibit good photoelectric conversion efficiency, adding new applicable materials to the screening of dye sensitizers. Detailed Implementation
[0024] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.
[0025] Example 1: Synthesis of the compound shown in formula (ZR-1):
[0026] 1) Synthesis of the compound shown in formula (Ⅱa) Compound IVA (1.09 g, 3.6 mmol) was dissolved in redistilled tetrahydrofuran (8 mL) in a Shrek flask. Under nitrogen protection, the mixture was cooled to -78 °C and stirred for 15 min. A hexane solution of n-butyllithium (2.16 mL, 5.4 mmol) was added dropwise. After the addition was complete, the mixture was stirred at -78 °C for 1 h. Then, trimethyl borate (0.8 mL, 7.2 mmol) was added dropwise, and the mixture was stirred for 15 min. The mixture was then transferred to room temperature and stirred overnight. After the reaction was completed, the reaction solution was used directly for the next reaction.
[0027] Compound III (0.38 g, 1.2 mmol), potassium carbonate (0.50 g, 3.6 mmol), and tetrakis(triphenylphosphine)palladium (0.14 g, 0.12 mmol) were added to a Shrek flask. Under nitrogen protection, water (4 mL) and tetrahydrofuran (12 mL) were added, followed by slow dropwise addition of the reaction mixture. After the addition was complete, the mixture was heated under reflux for 10 h to complete the reaction. The mixture was extracted with dichloromethane, washed with saturated NaCl solution, dried over anhydrous Na₂SO₄, and the solvent was evaporated. The residue was purified by silica gel column chromatography (V... PE V DCM =3 : 1), yielding an orange-red solid IIa (0.50 g, 68.7%).
[0028] Compound shown in formula (Ⅱa): Melting point: 136-139 °C. 1 H NMR (500 MHz, CDCl3) δ 10.28 (s,1H), 8.80 (d, J = 1.6 Hz, 1H), 8.51 (s, 1H), 8.39 (t, J = 3.5 Hz, 1H), 8.25(d, J = 7.7 Hz, 1H), 8.21 (dd, J = 8.7, 1.9 Hz, 1H), 8.16 (d, J = 7.7 Hz, 1H), 7.82 (dd, J = 8.3, 1.7 Hz, 1H), 7.65 (d, J = 8.4 Hz, 1H), 7.62 (d, J=8.5 Hz, 1H), 7.57-7.46 (m, 4H), 7.33-7.28 (m, 2H), 4.48-4.34 (m, 4H), 2.02-1.89 (m, 4H), 1.53-1.42 (m, 4H), 1.04-0.99 (m, 6H). HRMS (ESI) m / z calcd forC 39 H 34 N4OSNa + (M+H) + 629.2351, found 629.2352. 2) Synthesis of the compound shown in formula (ZR-2) Compound IIa (0.18 g, 0.3 mmol) and cyanoacetic acid (0.13 g, 1.5 mmol) were added to a Shrek flask, dissolved in acetonitrile (8 mL) and chloroform (4 mL). Then, 0.2 mL of piperidine was slowly added dropwise under nitrogen protection and the mixture was heated to reflux for 10 h to complete the reaction. The solvent was removed by rotary evaporation, and the residue was purified by silica gel column chromatography (V... DCM V MeOH = 20 : 1), yielding an orange-red solid ZR-2 (0.15 g, 73.2%).
[0029] The compound shown in formula (ZR-2) has a melting point of 178-180 °C. 1 H NMR (500 MHz, DMSO- d 6 ) δ 8.86(d, J = 1.4 Hz, 1H), 8.61 (s, 1H), 8.36-8.32 (m, 1H), 8.29 (s, 1H), 8.20 (d, J = 7.6 Hz, 1H), 8.18-8.14 (m, 2H), 7.78 (d, J = 8.6 Hz, 1H), 7.75 (d, J =8.5 Hz, 1H), 7.67 (dd, J = 8.3, 3.3 Hz, 2H), 7.63 (dd, J = 8.5, 1.5 Hz, 1H), 7.52 (t, J= 7.6 Hz, 2H), 7.28-7.22 (m, 2H), 4.53-4.39 (m, 4H), 1.87-1.74 (m,4H), 1.43-1.29 (m, 4H), 0.90 (t, J = 5.3 Hz, 6H). HRMS (ESI) m / z calcd forC 42 H 35 N5O2SNa + (M+Na) + 696.2409, found 696.2401. Example 2: Synthesis of the compound shown in formula (ZR-5):
[0030] Compound IIa (0.18 g, 0.3 mmol) and rhodanine-3-acetic acid (0.29 g, 1.5 mmol) were added to a Shrek flask, followed by acetonitrile (8 mL) and chloroform (4 mL). After stirring to dissolve, 0.2 mL of piperidine was slowly added dropwise. Under nitrogen protection, the mixture was heated to reflux for 10 h until the reaction was complete. The solvent was removed by rotary evaporation, and the residue was purified by silica gel column chromatography (V... DCM :V MeOH =20:1), yielding an orange-yellow solid ZR-5 (0.19 g, 79.0%).
[0031] The compound shown in formula (ZR-5) has a melting point of 134-135 °C. 1 H NMR (500 MHz, DMSO- d 6 ) δ 8.93(s, 1H), 8.43 (s, 1H), 8.29 (d, J = 7.9 Hz, 1H), 8.22 (d, J = 7.5 Hz, 1H), 8.18 (d, J = 8.4 Hz, 1H), 8.14 (d, J = 2.8 Hz, 1H), 7.90 (d, J = 8.7 Hz, 1H), 7.84 (d, J= 8.7 Hz, 1H), 7.78 (s, 1H), 7.73-7.63 (m, 3H), 7.56-7.45 (m, 2H), 7.31-7.18 (m, 2H), 4.54-4.45(m, 4H), 4.28-4.17 (m, 2H), 1.91-1.79 (m, 4H),1.44-1.33 (m, 4H), 0.98-0.91 (m, 6H). HRMS (ESI) m / z calcd for C 44 H 37 N5O3S3Na + (M+Na) + 802.1951 was found to be 802.1948. Example 3 Synthesis of the compound shown in formula (ZR-6):
[0032] 1) Synthesis of the compound shown in formula (Ⅱb) Compound IVa (1.21 g, 4.0 mmol) was dissolved in redistilled tetrahydrofuran (6 mL) in a Shrek flask. Under nitrogen protection, the mixture was cooled to -78 °C and stirred for 15 min. A solution of n-butyllithium in n-hexane (2.4 mL, 6.0 mmol) was added dropwise. After the addition was complete, the mixture was stirred at -78 °C for 1 h. Then, trimethyl borate (1.0 mL, 8 mmol) was added, and the mixture was stirred for 15 min. The mixture was then moved to room temperature and allowed to react overnight. The reaction was then complete, and the reaction solution was used directly for the next reaction.
[0033] 1,4-Dibromobenzene (1.03 g, 4.4 mmol), potassium carbonate (1.66 g, 12.0 mmol), and tetra(triphenylphosphine)palladium (0.23 g, 0.2 mmol) were added to a Shrek flask. Water (6 mL) and tetrahydrofuran (18 mL) were added under nitrogen protection, followed by slow dropwise addition of the reaction mixture. After the addition was complete, the mixture was heated under reflux for 10 h to complete the reaction. The mixture was extracted with DCM, washed with saturated NaCl solution, dried over anhydrous Na₂SO₄, and the solvent was evaporated. The residue was separated by silica gel column chromatography (V... PE :V DCM The ratio of the two solutions was 10:1 to obtain compound IVb, a white solid (1.01 g, 66.7%). Melting point: 95-96 °C.
[0034] Compound IVb (0.91 g, 2.4 mmol) was added to a Shrek flask and dissolved in redistilled tetrahydrofuran (5 mL). Under nitrogen protection, the mixture was cooled to -78 °C and stirred for 15 min. A hexane solution of n-butyllithium (1.44 mL, 3.6 mmol) was added dropwise. After the addition was complete, the mixture was stirred at -78 °C for 1 h. Then, trimethyl borate (0.54 mL, 4.8 mmol) was added and stirred for 15 min. The mixture was then moved to room temperature and stirred overnight. The reaction was complete, and the reaction solution was used directly for the next reaction.
[0035] Compound III (0.25 g, 0.8 mmol), potassium carbonate (0.33 g, 1.4 mmol), and tetra(triphenylphosphine)palladium (0.05 g, 0.04 mmol) were placed in a Shrek flask. Water (4 mL) and tetrahydrofuran (12 mL) were added under nitrogen, followed by slow dropwise addition of the above reaction solution. After the addition was complete, the mixture was heated under reflux for 10 h to complete the reaction. The reaction solution was extracted with DCM, washed with saturated NaCl solution, dried over anhydrous Na₂SO₄, and the solvent was evaporated to dryness. The residue was purified by silica gel column chromatography (V... PE :V DCM =2:1), yielding an orange-yellow solid IIb (0.32 g, 53.4%).
[0036] The compound shown in formula (Ⅱb) has a melting point of 112-114 °C. 1 H NMR (400 MHz, CDCl3) δ 10.35 (s,1H), 8.50 (s, 1H), 8.46 (dd, J = 6.1, 1.6 Hz, 2H), 8.23-8.18 (m, 4H), 7.98(dd, J = 11.6, 8.3 Hz, 4H), 7.89-7.84 (m, 2H), 7.80 (d, J = 8.2 Hz, 2H),7.57-7.51 (m, 4H), 7.48 (dd, J = 8.1, 2.6 Hz, 2H), 7.33-7.31 (m, 2H), 4.39(t, J = 10.0 Hz, 4H), 1.98-1.91 (m, 4H), 1.54-1.42 (m, 4H), 1.00 (qd, J = 7.7,3.3 Hz, 6H). HRMS (ESI) m / z calcd for C 51 H43 N4OS + (M+H) + 759.3158, found 759.3153. 2) Synthesis of the compound shown in formula (ZR-6) Compound IIb (0.16 g, 0.2 mmol) and cyanoacetic acid (0.17 g, 2.0 mmol) were placed in a Shrek flask, dissolved in acetonitrile (8 mL) and chloroform (4 mL), and then 0.2 mL of piperidine was slowly added dropwise. The reaction was carried out under nitrogen protection and heated to reflux for 10 h until completion. The solvent was removed by rotary evaporation, and the residue was separated by silica gel column chromatography (V... DCM V MeOH = 20 : 1), yielding an orange-yellow solid ZR-6 (0.14 g, 85.0%).
[0037] The compound shown in formula (ZR-6) has a melting point of 285-289 °C. 1 H NMR (400 MHz, DMSO- d 6 ) δ 8.73-8.60 (m, 3H), 8.34-8.30 (m, 3H), 8.22-8.15 (m, 2H), 8.11-8.01 (m, 4H), 7.92-7.90 (m, 2H), 7.77-7.61 (m, 6H), HRMS(ESI) m / z calcd for C 54 H 43 N5O2SNa + (M+Na) + 848.3035, found 848.3040. Example 4: Synthesis of the compound shown in formula (ZR-7):
[0038] 1) Synthesis of the compound shown in formula (Ⅱc): Compound IVc (0.92 g, 2.4 mmol) (synthetic method of compound IVc is described in CN101205227 A) was added to a Shrek flask and dissolved in redistilled tetrahydrofuran (5 mL). Under nitrogen protection, the mixture was cooled to -78 °C and stirred for 15 min. A solution of n-butyllithium in n-hexane (1.44 mL, 3.6 mmol) was added dropwise. After the addition was complete, the mixture was stirred at -78 °C for 1 h. Then, trimethyl borate (0.54 mL, 4.8 mmol) was added and stirred for 15 min. The mixture was then moved to room temperature and stirred overnight. After the reaction was completed, the reaction solution was used directly for the next reaction. Compound III (0.25 g, 0.8 mmol), potassium carbonate (0.33 g, 1.4 mmol), and tetrakis(triphenylphosphine)palladium (0.05 g, 0.04 mmol) were added to a Shrek flask. Water (4 mL) and tetrahydrofuran (12 mL) were added under nitrogen protection, followed by slow dropwise addition of the reaction solution. After the addition was complete, the mixture was heated under reflux for 10 h to complete the reaction. The reaction solution was extracted with dichloromethane, washed with saturated NaCl solution, and dried over anhydrous Na₂SO₄. The solvent was removed by rotary evaporation, and the residue was purified by silica gel column chromatography (V... PE :V DCM = 2:1), yielding purple solid IIc (0.24 g, 56.9%).
[0039] Compound shown in formula (Ⅱc): Melting point: 218-220 °C. 1 H NMR (400 MHz, CDCl3) δ 10.45 (s,1H), 8.48-8.46 (m, 3H), 8.25 (d, J = 3.6 Hz, 1H), 8.20 (d, J = 4.5 Hz, 2H), 7.86 (d, J = 7.5 Hz, 2H), 7.59-7.37 (m, 9H), 7.32-7.31 (m, 2H), 4.36 (t, J =6.2 Hz, 4H), 1.98-1.84 (m, 4H), 1.52-1.40 (m, 4H), 1.00 (t, J = 7.2 Hz, 6H).HRMS (ESI) m / z calcd for C 47 H 38 N4OS3K + (M+K) + 809.1845, found 809.1846. 2) Synthesis of the compound shown in formula (ZR-7) Compound IIc (0.20 g, 0.25 mmol) and cyanoacetic acid (0.26 g, 3.0 mmol) were placed in a Shrek flask, dissolved in acetonitrile (8 mL) and chloroform (4 mL), and then 0.2 mL of piperidine was slowly added dropwise. The reaction was carried out under nitrogen protection and refluxed for 10 h until the solvent was removed by rotary evaporation. The residue was then separated by silica gel column chromatography (V... DCM :V MeOH = 20:1), yielding a purplish-black solid ZR-7 (0.11 g, 53.5%).
[0040] The compound shown in formula (ZR-7) has a melting point of 194-197 °C. 1 H NMR (400 MHz, DMSO- d 6 ) δ 8.66-8.65 (m, 2H), 8.62 (s, 1H), 8.55 (s, 1H), 8.31 (d, J = 7.8 Hz, 2H), 8.25 (d, J = 3.9 Hz, 1H), 7.93-789 (m, 2H), 7.78 (dd, J = 7.5, 3.6 Hz, 2H), 7.73 (d, J = 8.6 Hz, 2H), 7.66 (d, J = 8.1 Hz, 2H), 7.53-7.49 (m, 3H), 7.26 (t, J = 7.4Hz, 2H), 4.44 (t, J = 6.8 Hz, 4H), 1.86-1.73 (m, 4H), 1.39-1.30 (m, 4H), 0.91(t, J = 7.3 Hz, 6H). HRMS (ESI) m / z calcd for C 50 H 39 N5O2S3Na + (M+Na) + 860.2164, found 860.2164. Example 5: Synthesis of the compound shown in formula (ZR-8):
[0041] 1) Synthesis of the compound shown in formula (Ⅱd) Compound V (0.59 g, 2.4 mmol), compound III (0.19 g, 0.6 mmol), palladium dichloride (0.04 g, 0.1 mmol), triphenylphosphine (0.03 g, 0.1 mmol), and cuprous iodide (0.02 g, 0.1 mmol) were added to a Shrek flask under nitrogen protection. Triethylamine (6 mL) and tetrahydrofuran (6 mL) were added, and the reaction was heated under reflux for 10 h until complete. The mixture was extracted with DCM, washed with saturated NaCl solution, dried over anhydrous Na₂SO₄, and the solvent was removed by rotary evaporation. The residue was purified by silica gel column chromatography (V...). PE V DCM = 1:1), yielding red solid IId (0.35 g, 88.5%).
[0042] Compound shown in formula (Ⅱd): Melting point: 245-248 °C. 1 H NMR (400 MHz, CDCl3) δ 10.94 (s,1H), 8.49 (d, J = 13.9 Hz, 2H), 8.34 (s, 1H), 8.16 (t, J = 6.9 Hz, 2H), 7.85-7.79 (m, 2H), 7.63-7.41 (m, 6H), 7.39-7.29 (m, 2H), 4.38-4.34 (m, 4H), 1.99-1.84 (m, 4H), 1.48-1.42 (m, 4H), 1.00 (t, J = 7.2 Hz, 6H). HRMS (ESI) m / zcalcd for C 43 H 35 N4OS + (M+H) + 655.2532, found 655.2531. 2) Synthesis of the compound shown in formula (ZR-8) Compound IId (0.20 g, 0.3 mmol) and cyanoacetic acid (0.26 g, 3.0 mmol) were added to a Shrek flask, dissolved in acetonitrile (10 mL) and chloroform (5 mL). Then, 0.2 mL of piperidine was slowly added dropwise under nitrogen protection. The reaction was heated to reflux for 10 h until complete. The solvent was evaporated, and the residue was purified by silica gel column chromatography (V). DCM :V MeOH= 20:1), yielding a purplish-red solid ZR-8 (0.11 g, 55.4%).
[0043] The compound shown in formula (ZR-8) has a melting point of 305-308 °C. 1 H NMR (400 MHz, DMSO- d 6 ) δ 8.80(s, 1H), 8.63 (s, 1H), 8.58 (d, J = 8.7 Hz, 2H), 8.37-8.29 (m, 2H), 7.82-7.74(m, 4H), 7.68 (dd, J = 8.3, 4.2 Hz, 2H), 7.56-7.51 (m, 2H), 7.28 (q, J = 7.2Hz, 2H), 4.49-4.44 (m, 4H), 1.84-1.72 (m, 4H), 1.39-1.27 (m, 4H), 0.89 (t, J = 7.5 Hz, 6H). HRMS (ESI) m / z calcd for C 46 H 35 N5O2SNa + (M+Na) + 744.2409, found 744.2407. Example 6 Synthesis of the compound shown in formula (ZR-9): The synthesis process of compound VI, represented by formula (VI), is shown below:
[0044] a. Synthesis of the compound shown in formula (VII) Compound VIII (1.01 g, 2.8 mmol) and triethyl phosphite (5 mL) were placed in a Shrek flask and heated under reflux for 8 h under nitrogen protection until the reaction was complete. Triethyl phosphite was evaporated to dryness, and the residue was separated by silica gel column chromatography using pure EA as eluent to give a white viscous liquid VII (1.12 g, 94.7%).
[0045] The compound shown in formula (VII): 1 H NMR (400 MHz, CDCl3) δ 7.93 (s, 1H), 4.14 (q, J =7.2 Hz, 4H), 3.59 (d, J= 7.0 Hz, 1H), 3.54 (d, J = 7.0 Hz, 1H), 1.39-1.23(m, 6H). b. Synthesis of the compound shown in formula (VI): Compound VII (0.88 g, 2.0 mmol) was added to a Shrek flask, followed by the addition of DMF (6 mL) and stirring to dissolve. A methanol solution containing sodium methoxide (0.4 mL, 2.2 mmol) was slowly added dropwise under an ice-water bath. After the addition was complete, the mixture was stirred for 5 min. Then, terephthalaldehyde (0.27 g, 2.0 mmol) dissolved in DMF (4 mL) was slowly added dropwise. After the addition was complete, the reaction mixture was stirred for 4 h to complete the reaction. The mixture was extracted with DCM, washed with saturated NaCl solution, dried over anhydrous Na₂SO₄, and the solvent was evaporated. The residue was then subjected to silica gel column chromatography (V... PE :V DCM Preliminary purification (1:1) yielded crude product VI (0.38 g, 45.4%), which was used directly in the next reaction without further purification.
[0046] The synthesis process of the compound shown in formula (ZR-9) is as follows:
[0047] 1) Synthesis of the compound shown in formula (Ⅱe) Compound IVA (0.45 g, 1.5 mmol) was dissolved in redistilled tetrahydrofuran (2 mL) in a Shrek flask. Under nitrogen protection, the mixture was cooled to -78 °C and stirred for 15 min. A hexane solution of n-butyllithium (0.9 mL, 2.3 mmol) was added dropwise. After the addition was complete, the mixture was stirred at -78 °C for 1 h. Trimethyl borate (0.3 mL, 3.0 mmol) was added, and the mixture was stirred for 15 min. The mixture was then moved to room temperature and stirred overnight. After the reaction was completed, the reaction solution was used directly for the next reaction. Compound VI (0.22 g, 0.5 mmol), potassium carbonate (0.21 g, 1.5 mmol), and tetra(triphenylphosphine)palladium (0.11 g, 0.1 mmol) were added to a Shrek flask. Under nitrogen protection, water (3 mL) and tetrahydrofuran (9 mL) were added, followed by slow dropwise addition of the reaction mixture. After the addition was complete, the mixture was heated under reflux for 10 h to complete the reaction. The reaction mixture was extracted with DCM, washed with saturated NaCl solution, dried over anhydrous Na₂SO₄, and the solvent was evaporated. The residue was purified by silica gel column chromatography (V... PE :V DCM=3:1), yielding a crude product, a yellow solid IIe (0.16 g, 42.5%), which was used directly in the next step without further purification; 2) Synthesis of the compound shown in formula (ZR-9) Compound IIe (0.14 g, 0.2 mmol) and cyanoacetic acid (0.17 g, 2.0 mmol) were added to a Shrek flask, dissolved in acetonitrile (10 mL) and chloroform (5 mL). Then, 0.2 mL of piperidine was slowly added dropwise. The reaction was carried out under nitrogen protection and refluxed for 10 h. The solvent was removed by rotary evaporation, and the residue was purified by silica gel column chromatography (V...). DCM :V MeOH = 20:1), yielding an orange-yellow solid ZR-9 (0.10 g, 64.5%).
[0048] The compound shown in formula (ZR-9) has a melting point of 224-226 °C. 1 H NMR (400 MHz, DMSO- d 6 ) δ 8.85(s, 1H), 8.43 (d, J = 12.1 Hz, 1H), 8.30 (s, 1H), 8.24-8.07 (m, 3H), 7.95 (s,1H), 7.82-7.63 (m, 7H), 7.57-7.33 (m, 6H), 7.31-7.15 (m, 2H), 4.53-4.36 (m,4H), 1.87-1.70 (m, 4H), 1.42-1.26 (m, 4H), 0.89 (d, J = 6.8 Hz, 6H). HRMS(ESI) m / z calcd for C 50 H 41 N5O2SNa + (M+Na) + 798.2879, found 798.2875. Example 7: Application of bi-carbazole benzothiadiazole compounds as co-sensitizers for Z907: When used as a dye sensitizer, the application includes the following steps: The bi-carbazole benzothiadiazole compounds prepared in Examples 1-6 and dye Z907 were dissolved in a mixed solvent of CH3Cl-CH3OH to obtain a mixed solution of bi-carbazole benzothiadiazole compounds and Z907 (concentration 3×10⁻⁶). -4 mol•L -1The volume ratio of CH3Cl to CH3OH in the CH3Cl-CH3OH mixed solvent is 10:1. A bilayer TiO2 nanoparticle film prepared by screen printing was used as a photoelectrode: First, a 12 μm thick layer of 20 nm TiO2 particles was printed on conductive glass FTO, and then calcined in a muffle furnace at 450 ℃ for 30 min. After cooling the calcined film to room temperature, it was immersed in 0.04 mol•L... -1 The membrane was pretreated in a TiCl4 aqueous solution at 70 °C for 30 min, then removed from the TiCl4 aqueous solution and rinsed with water and ethanol respectively, and dried with a hair dryer. After being calcined again in a muffle furnace at 450 °C for 30 min, a bilayer TiO2 nanoparticle film photoelectrode was obtained.
[0049] After cooling the bilayer TiO2 nanoparticle film photoelectrode obtained by calcination to 80 °C, it was immersed in a mixed solution of the bi-carbazole benzothiadiazole compound and Z907 prepared in Examples 1-6, and sensitized at room temperature for 24 h to obtain a TiO2 electrode loaded with bi-carbazole benzothiadiazole compound and Z907 compound.
[0050] Preparation of platinum counter electrode: H2PtCl6 aqueous solution was printed onto FTO conductive glass using screen printing. The surface of FTO conductive glass was then wetted with H2PtCl6 aqueous solution, dried, and sintered in a muffle furnace at 400 °C for 20 min to obtain the platinum counter electrode.
[0051] The bilayer TiO2 nanoparticle film photoelectrode and platinum counter electrode prepared above were assembled into a sandwich structure. Electrolyte was dropped into the edge of the sandwich structure and introduced into the battery using capillary permeation, thus assembling a dye-sensitized solar cell (DSSC). A 100 mW / cm² solar cell was then used. 2 Under light intensity irradiation, the current-voltage curves of the DSSC assembled from bi-carbazole benzothiadiazole compounds and Z907 were measured, and the performance parameters are shown in Table 1: Table 1 Performance parameters of DSSCs assembled from bicarbazole-benzothiadiazole compounds
[0052] As can be seen from Table 1, the dye-sensitized solar cells assembled with the bi-carbazole benzothiadiazole compounds obtained in this invention and Z907 as dye sensitizers have good photoelectric conversion efficiencies, ranging from 3.51% to 6.18%, which are mostly higher than the efficiency of 5.29% of solar cells sensitized by Z907 alone. This adds a new applicable material to the screening of co-sensitizers of Z907.
[0053] The contents described in this specification are merely an enumeration of the implementation forms of the inventive concept. The scope of protection of this invention should not be regarded as limited to the specific forms described in the embodiments. The scope of protection of this invention is also limited to the equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.
Claims
1. A bis-carbazole benzothiadiazole compound, characterized in that... Its molecular structure is shown in formula (ZR-2), formula (ZR-5), formula (ZR-6), formula (ZR-7), formula (ZR-8) or formula (ZR-9); 。 2. A method for preparing the bi-carbazole benzothiadiazole compound according to claim 1, characterized in that... The compounds shown in formulas (IIa), (IIb), (IIc), (IId), and (IIe) are dissolved in a solvent with cyanoacetic acid or rhodanine-3-acetic acid. An alkaline catalyst is added, and the mixture is stirred and heated under reflux. After the reaction is completed, the solvent is removed by concentration. The resulting concentrate is dissolved in an eluent and then separated and purified by column chromatography with silica gel. The eluent is collected and the eluent is evaporated to obtain the target product. The structural formulas of the compounds represented by formulas (IIa), (IIb), (IIc), (IId), and (IIe) are as follows: 。 3. The method for preparing the bi-carbazole benzothiadiazole compound according to claim 2, characterized in that... The mass ratio of the base catalyst to the compounds represented by formulas (IIa), (IIb), (IIc), (IId), or (IIe) is 1:6~10.
4. The method for preparing the bi-carbazole benzothiadiazole compound according to claim 2, characterized in that... The alkaline catalyst used is piperidine.
5. The method for preparing the bi-carbazole benzothiadiazole compound according to claim 2, characterized in that... The heating and reflux reaction time was 10 h.
6. The method for preparing the bi-carbazole benzothiadiazole compound according to claim 2, characterized in that... The molar ratio of the compound represented by formula (IIa), formula (IIb), formula (IIc), formula (IId) or formula (IIe) to cyanoacetic acid or rhodanine-3-acetic acid is 1:5~12.
7. The method for preparing the bi-carbazole benzothiadiazole compound according to claim 2, characterized in that... The solvent is a mixture of acetonitrile and chloroform, wherein the volume ratio of acetonitrile to chloroform is 2:
1.
8. The method for preparing the bi-carbazole benzothiadiazole compound according to claim 2, characterized in that... The ratio of the amount of substance to the volume of solvent of the compound represented by formula (IIa), (IIb), (IIc), (IId) or (IIe) is 1:40~75, the unit of amount of substance is mmol, and the unit of volume is mL.
9. The method for preparing the bi-carbazole benzothiadiazole compound according to claim 2, characterized in that... The eluent is a mixed solvent composed of dichloromethane and methanol, wherein the volume ratio of dichloromethane to methanol is 20:
1.
10. The application of the bi-carbazole benzothiadiazole compound according to claim 1 as a dye sensitizer.