Bis-carbazole bipyridine compound as well as preparation method and co-sensitization application thereof

Abstract

The invention discloses a dicarbazole bipyridine compound as well as a preparation method and co-sensitization application thereof, and the specific preparation process comprises the following steps: dissolving a compound as shown in a formula II and 4-pyridylboronic acid in a solvent, adding an alkaline substance and a catalyst, carrying out heating reflux reaction under stirring, and after the reaction is finished, carrying out post-treatment to obtain a compound as shown in a formula DSB-6; the preparation method comprises the following steps: dissolving 4-bromophenylpyridine, bis (pinacolato) diboron, PdCl2 (dppf) and potassium acetate in 1, 4-dioxane, heating and refluxing, then adding a compound as shown in a formula II, an alkaline substance aqueous solution and a catalyst, heating and refluxing to react while stirring, and after the reaction is finished, carrying out post-treatment to obtain a compound as shown in a formula DSB-7, and using the compound as a dye sensitizer to prepare the dye sensitizer. According to the preparation method disclosed by the invention, an alkyl chain is connected with dicarbazole and bipyridine, and benzothiadiazole or phenyl benzothiadiazole is introduced into carbazole, so that the dicarbazole and bipyridine compound is synthesized, and a new applicable substance is added for screening dye sensitizers.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic chemical synthesis, and relates to a bis-carbazole bis-pyridine compound, a preparation method thereof, and a co-sensitization application thereof. Background Art

[0002] The dye sensitizer is a key structural material in DSSCs that determines the visible light absorption and photoelectric conversion efficiency. Compared with metal-organic dyes with high toxicity and high cost, non-metal organic dyes have advantages such as high molar extinction coefficient and excellent electrochemical properties that can be modulated by structural modification, and are the research hotspots of dye sensitizers in recent years. However, non-metal organic dye sensitizers can only absorb sunlight of some wavelengths, and the spectral response range is narrow. Due to the limited broadening of the absorption spectrum of a single dye, people have turned to the co-sensitization strategy using the characteristic of complementary light absorption of dye molecules. By co-sensitizing with two dyes with complementary absorption spectra, the absorption spectrum range of DSSCs can be effectively expanded, and the series connection of the battery can be effectively avoided, thereby greatly improving the photocurrent and photoelectric conversion efficiency of the battery. Summary of the Invention

[0003] Aiming at the above problems existing in the prior art, the purpose of the present invention is to provide a bis-carbazole bis-pyridine compound, a preparation method thereof, and a co-sensitization application thereof. The bis-carbazole bis-pyridine compound can be co-sensitized with the metal dye sensitizer Z907, and the assembled dye-sensitized solar cell has good photoelectric conversion efficiency, adding a new applicable substance for the screening of the co-sensitizer of the dye sensitizer Z907.

[0004] The present invention provides a bis-carbazole bis-pyridine compound, including compounds with the following two structures, and the structural formula is shown as formula DSB-6 or formula DSB-7;

[0005]

[0006] The present invention also provides a preparation method of the bis-carbazole bis-pyridine compound DSB-6. Specifically, the compound shown in formula II and 4-pyridineboronic acid are dissolved in a solvent, an aqueous solution of a basic substance and a catalyst are added, and the reaction is heated under reflux with stirring. After the reaction is completed, the reaction solution is poured into water, extracted with dichloromethane, and then concentrated to remove the solvent. The obtained concentrate is dissolved in an eluent and separated and purified by column chromatography silica gel. The eluate is collected and the eluent is evaporated to obtain DSB-6;

[0007] The structural formula of the compound shown in formula (II) is as follows:

[0008]

[0009] Further, the catalyst is tetrakis(triphenylphosphine)palladium.

[0010] Further, the mass ratio of the compound shown in Formula II to the catalyst is 10 - 15:1.

[0011] Further, the reaction time is 8 h.

[0012] Further, the solvent is tetrahydrofuran.

[0013] Further, the eluent is a mixed solvent composed of petroleum ether and methanol, and the volume ratio of the petroleum ether to the methanol is 20:1.

[0014] Further, the molar ratio of the compound shown in Formula II, 4 - pyridineboronic acid, and the basic substance is 1:8:4.

[0015] Further, the aqueous solution of the basic substance is an aqueous potassium carbonate solution with a concentration of 2 mol / L.

[0016] Further, the ratio of the amount of substance of the compound shown in Formula II to the volume of the solvent is 1:30, where the unit of the amount of substance is mmol and the unit of the volume is mL.

[0017] The present invention also provides a preparation method of the biscarbazole bipyridine compound DSB - 7. Dissolve 4 - bromophenylpyridine, bis(pinacolato)diboron, PdCl2(dppf), and potassium acetate in 1,4 - dioxane, heat under reflux for 5 h, then add the compound shown in Formula (II), the aqueous solution of the basic substance, and the catalyst, and heat under reflux with stirring for the reaction. After the reaction is completed, pour the reaction solution into water, extract with dichloromethane, and then concentrate to remove the solvent. Dissolve the obtained concentrate in the eluent and separate and purify it through column chromatography silica gel. Collect the eluate and evaporate the eluent to obtain the target product DSB - 7;

[0018] Further, the catalyst is tetrakis(triphenylphosphine)palladium.

[0019] Further, the mass ratio of the compound shown in Formula II to the catalyst is 5.4:1.

[0020] Further, the reaction time is 5 h.

[0021] Further, the aqueous solution of the basic substance is an aqueous potassium carbonate solution.

[0022] Further, the concentration of the aqueous solution of the basic substance is 2 mol / L.

[0023] Further, the eluent is a mixed solvent composed of petroleum ether and methanol, and the volume ratio of the petroleum ether to the methanol is 20:1.

[0024] Further, the molar ratio of Formula II, 4 - bromophenylpyridine, and the basic substance is 1:2:8.

[0025] Further, the molar ratio of the compound shown in Formula II to the volume of the solvent 1,4-dioxane is 1:66, where the unit of the amount of substance is mmol and the unit of the volume is mL.

[0026] Further, the synthesis method of the compound shown in Formula II is specifically as follows:

[0027] Dissolve the compound shown in Formula III, the compound shown in Formula IV and cesium carbonate in N,N-dimethylformamide, heat under reflux for reaction. After the reaction is completed and cooled to room temperature, pour the reaction solution into a large amount of water, extract with dichloromethane, dry, then remove the solvent by rotary evaporation and purify by column chromatography to obtain the product, the compound shown in Formula II.

[0028] The structural formulas of the compound shown in Formula III and the compound shown in Formula IV are as follows:

[0029]

[0030] Further, when synthesizing the compound shown in Formula II, the eluent is petroleum ether and ethyl acetate with a volume ratio of 5:1; in the process of column chromatography separation: the concentrate is dissolved in the eluent and then separated and purified by column chromatography silica gel, collect the eluate and evaporate the eluent, and dry to obtain a solid powder product.

[0031] The present invention also provides an application of the bis-carbazole bis-pyridine compound in a dye sensitizer.

[0032] By adopting the above technologies, compared with the prior art, the beneficial effects of the present invention are as follows: the present invention synthesizes a bis-carbazole bis-pyridine compound by connecting bis-carbazole bis-pyridine with an alkyl chain and introducing benzothiadiazole or biphenyl-substituted benzothiadiazole into one carbazole, and the bis-carbazole bis-pyridine compound can be used as a co-sensitizer for Z907. The dye-sensitized solar cell co-sensitized by this compound and Z907 has a good photoelectric conversion efficiency, adding new applicable substances to the screening of dye sensitizers. Specific Embodiments

[0033] The following further illustrates the present invention with specific examples, but the protection scope of the present invention is not limited thereto.

[0034] Example 1 Synthesis of the compound shown in DSB-6:

[0035]

[0036] 1) Synthesis of the compound shown in Formula II

[0037] Compound III (0.51 g, 1.36 mmol), compound IV (0.57 g, 1.50 mmol) and cesium carbonate (0.88 g, 2.72 mmol) were added to a single-necked flask, and the solvent DMF (20 ml) was added. The mixture was refluxed for 6 h. After the reaction was completed, the reaction solution was poured into a large amount of water and extracted with dichloromethane three times. The organic layers were combined. After drying over anhydrous sodium sulfate, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (V PE :V EA = 5:1) to obtain orange solid compound II (0.68 g, 73.5%).

[0038] Compound of formula II: Melting point: 135 - 139 °C. 1 1H NMR (400 MHz, CDCl3) δ 8.67 (s, 1H), 8.20 (d, J = 8.4 Hz, 2H), 8.12 - 7.98 (m, 3H), 7.85 - 7.72 (m, 2H), 7.57 - 7.41 (m, 4H), 7.35 - 7.25 (m, 3H), 7.14 (d, J = 8.6 Hz, 1H), 4.31 (s, 2H), 4.22 (s, 2H), 2.00 (s, 4H).

[0039] 2) Synthesis of the compound of formula DSB-6

[0040] Compound II (132 mg, 0.2 mmol), pyridine-4-boronic acid (196 mg, 1.6 mmol) and Pd(PPh3)4 (10 mg) were added to a Schlenk flask. The flask was evacuated and refilled with nitrogen three times, and then an aqueous solution of saturated potassium carbonate (110 mg, 0.8 mmol, 2M) and THF (6 ml) as the solvent were added. The mixture was stirred and refluxed for 8 h under nitrogen protection. After the reaction was completed, the reaction solution was poured into a large amount of water and extracted with dichloromethane three times. The organic layers were combined, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (V PE :V MeOH = 20:1) to obtain orange solid compound DSB-6 (22 mg, 15.2%).

[0041] Compound of formula DSB-6: Melting point: 167 - 170 °C. 11H NMR (400 MHz, CDCl3) δ 8.81 (d, J = 6.0 Hz, 2H), 8.72 (d, J = 1.5 Hz, 1H), 8.66 (d, J = 6.0 Hz, 2H), 8.38 (d, J = 1.6 Hz, 1H), 8.20 (d, J = 7.7 Hz, 1H), 8.17 (d, J = 7.7 Hz, 1H), 8.07 (dd, J = 8.5, 1.7 Hz, 1H), 8.02 - 7.96 (m, 2H), 7.92 (d, J = 7.6 Hz, 1H), 7.89 (d, J = 7.4 Hz, 1H), 7.71 (dd, J = 8.5, 1.7 Hz, 1H), 7.64 (dd, J = 4.6, 1.6 Hz, 2H), 7.54 - 7.46 (m, 2H), 7.42 (d, J = 8.5 Hz, 1H), 7.38 - 7.27 (m, 5H), 4.30 - 4.28 (m, 4H), 2.07 - 2.04 (m, 4H). HRMS (ESI) m / z calcd for C 44 H 33 N6S + (M + H) + 677.2487, found 677.2488.

[0042] Synthesis of the compound shown in Formula DSB-7 of Example 2:

[0043]

[0044] Add 4-bromophenylpyridine (69 mg, 0.30 mmol), bis(pinacolato)diboron (135 mg, 0.6 mmol), PdCl2(dppf) (10 mg) and potassium acetate (117 mg, 1.2 mmol) into a Schlenk reaction flask, evacuate and replace with nitrogen three times, then add the solvent 1,4-dioxane (10 ml), and heat the reaction for 5 h; then add compound II (81 mg, 0.15 mmol), Pd(PPh3)4(15 mg) and an aqueous solution of saturated potassium carbonate (165 mg, 1.20 mmol, 2 M) to the system, and continue the reflux reaction for 5 h. After the reaction is completed, pour the reaction solution into a large amount of water, extract with dichloromethane, repeat three times, and combine the organic layers. Then wash with saturated NaCl solution, evaporate the solvent under reduced pressure, and purify by column chromatography (V DCM :V MeOH = 20:1) to obtain the orange-yellow solid compound DSB-7 (56 mg, 22.7%).

[0045] The compound shown in Formula DSB-7: Melting point: 190 - 194 °C. 11H NMR (400 MHz, DMSO) δ 8.84 (s, 1H), 8.79 - 8.66 (m, 3H), 8.59 (s, 1H), 8.28 (d, J = 7.9 Hz, 1H), 8.25 (d, J = 7.7 Hz, 1H), 8.21 (d, J = 8.2 Hz, 1H), 8.14 - 7.98 (m, 4H), 7.95 - 7.74 (m, 6H), 7.70 - 7.45 (m, 12H), 7.26 (d, J = 7.2 Hz, 1H), 7.22 (d, J = 7.2 Hz, 1H), 4.53 - 4.39 (m, 4H), 1.93 (s, 4H). HRMS (ESI) m / z calcd for C 56 H 41 N6S + (M + H) + 829.3113, found 829.3105.

[0046] Application of the dicarbazole dipyridine compound as a co - sensitizer for Z907:

[0047] When used as a dye sensitizer, the application includes the following steps:

[0048] Dissolve the dicarbazole dipyridine compound prepared in Examples 1 - 2 and the dye Z907 in a CH3Cl - CH3OH mixed solvent to obtain a mixed solution of the dicarbazole dipyridine compound and Z907 (concentration: 3×10 -4 mol·L -1 ); the volume ratio of CH3Cl to CH3OH in the CH3Cl - CH3OH mixed solvent is 10:1;

[0049] Use the double - layer TiO2 nanoparticle film prepared by screen printing as a photo - electrode: First, print a layer of 20 nm TiO2 particles with a thickness of 12 μm on the conductive glass FTO, calcine it in a muffle furnace at 450 °C for 30 min. After cooling the calcined film to room temperature, immerse it in a 0.04 mol·L -1 aqueous TiCl4 solution at 70 °C for 30 min. Then take the film out of the TiCl4 aqueous solution and rinse it with water and ethanol respectively, and dry it with a hair dryer. After calcining it again in a muffle furnace at 450 °C for 30 min, the double - layer TiO2 nanoparticle film photo - electrode is obtained.

[0050] Cool the double - layer TiO2 nanoparticle film photo - electrode obtained by the above calcination to room temperature and immerse it in the mixed solution of the dicarbazole dipyridine compound and Z907 prepared in Examples 1 - 2, and sensitize it at room temperature for 24 h to obtain a TiO2 electrode loaded with the dicarbazole dipyridine compound and Z907 compound.

[0051] Preparation of platinum counter electrode: By using the screen printing method, an aqueous solution of H2PtCl6 was printed on the FTO conductive glass. The surface of the FTO conductive glass was wetted by the aqueous solution of H2PtCl6, dried, and then sintered in a muffle furnace at 400 °C for 20 min to obtain the platinum counter electrode.

[0052] The above-prepared bilayer TiO2 nanoparticle film photoanode and platinum counter electrode were assembled into a sandwich structure. An electrolyte was dropped at the edge of the sandwich structure and introduced into the battery interior by the capillary penetration principle to assemble a dye-sensitized solar cell (DSSC). Under the illumination of 100 mW / cm 2 light intensity, the current-voltage curve of the DSSC assembled with the dicarbazole dipyridine compound and Z907 was measured. The performance parameter results are shown in Table 1:

[0053] Table 1 Performance parameters of DSSC assembled with dicarbazole dipyridine compound

[0054]

[0055]

[0056] As can be seen from Table 1: The dye-sensitized solar cells assembled with the dicarbazole dipyridine compounds and Z907 of the present invention as dye sensitizers have good photoelectric conversion efficiencies. The photoelectric conversion efficiencies are 5.00% and 6.63% respectively. Among them, the DSB-7 / Z907 co-sensitized solar cell is higher than the solar cell sensitized by Z907 alone, adding new applicable substances for the screening of co-sensitizers of Z907.

[0057] The content described in this specification is only a listing of the implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments. The protection scope of the present invention is also only equivalent technical means that can be conceived by those skilled in the art according to the inventive concept.

Claims

1. A dicarbazole dipyridine compound, characterized in that, Its structural formula is shown in Formula DSB-6 or Formula DSB-7:

2. A method for preparing the biscarbazole bipyridine compound according to claim 1, characterized in that, The preparation process of compound DSB-6 includes the following steps: Dissolve the compound shown in Formula II and 4-pyridineboronic acid in a solvent, add an aqueous solution of a basic substance and a catalyst, heat under reflux with stirring. After the reaction is completed, pour the reaction solution into water, extract with dichloromethane, and then concentrate to remove the solvent. The obtained concentrate is dissolved in an eluent and separated and purified by column chromatography silica gel. Collect the eluent and evaporate the eluent to obtain the target product DSB-6; The structural formula of the compound shown in Formula II is as follows:

3. A method for preparing the biscarbazole bipyridine compound according to claim 1, characterized in that, The preparation process of compound DSB-7 includes the following steps: Dissolve 4-bromophenylpyridine, bis(pinacolato)diboron, PdCl2(dppf) and potassium acetate in 1,4-dioxane, heat under reflux for 5 h, then add the compound shown in Formula II, an aqueous solution of a basic substance and a catalyst, heat under reflux with stirring. After the reaction is completed, pour the reaction solution into water, extract with dichloromethane, and then concentrate to remove the solvent. The obtained concentrate is dissolved in an eluent and separated and purified by column chromatography silica gel. Collect the eluent and evaporate the eluent to obtain the target product DSB-7; The structural formula of the compound shown in Formula II is as follows:

4. The preparation method according to claim 2, wherein The mass ratio of the compound shown in Formula II to the catalyst is 10 - 15:1; the catalyst is tetrakis(triphenylphosphine)palladium.

5. The preparation method according to claim 2, wherein The time for heating under reflux is 8 h; the solvent is tetrahydrofuran, and the molar ratio of the compound shown in Formula II to the volume of the solvent is 1:30, where the unit of the amount of substance is mmol and the unit of volume is mL.

6. The preparation method according to claim 2, characterized in that, The molar ratio of the compound shown in Formula II, 4-pyridineboronic acid and the basic substance is 1:8:4, and the aqueous solution of the basic substance is a 2 mol / L potassium carbonate aqueous solution.

7. The preparation method according to claim 3, characterized in that, The mass ratio of the compound shown in Formula II to the catalyst is 5.4:1; the catalyst is tetrakis(triphenylphosphine)palladium; the time for heating under reflux is 5 h, and the aqueous solution of the basic substance is a 2 mol / L potassium carbonate aqueous solution.

8. The preparation method according to claim 3, characterized in that, The molar ratio of the compound shown in Formula II, 4-bromophenylpyridine and the basic substance is 1:2:8, and the molar ratio of the compound shown in Formula II to the volume of the solvent 1,4-dioxane is 1:66, where the unit of the amount of substance is mmol and the unit of volume is mL.

9. The preparation method according to claim 2 or 3, characterized in that The eluent is a mixed solvent composed of petroleum ether and methanol, and the volume ratio of the petroleum ether to the methanol is 20:

1.

10. Use of the bis-carbazole bis-pyridine compound according to claim 1 in a dye sensitizer.

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