Method for catalytically synthesizing hole transport material Spiro-OMeTAD by nickel-based catalyst
The reaction of 2,2’,7,7’-tetrabromo-9,9’-spirobifluorene and 4,4’-dimethoxydipaniline is catalyzed by a nickel-based catalyst, combined with the auxiliary catalysis of sodium hydride and zinc powder, and the efficient, non-toxic and green synthesis of Spiro-OMeTAD is achieved, which solves the problems of harsh conditions and toxic ligand use in traditional synthesis, improves yield and purity, and is suitable for industrial production.
Patent Information
- Application Number
- CN202510276235.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-10
- Publication Date
- 2025-06-10
AI Technical Summary
The conditions in the synthesis process of Spiro-OMeTAD are harsh and the preparation process is complex. The toxic phosphine-containing ligands are commonly used, and the purification is difficult, which affects its large-scale, safe and green production in industrialization.
The reaction of 2,2’,7,7’-tetrabromo-9,9’-spirobifluorene and 4,4’-dimethoxydipaniline was catalyzed by a nickel-based catalyst, and the efficient synthesis of Spiro-OMeTAD was achieved through the auxiliary catalysis of sodium hydride and zinc powder. This method simplifies the process flow, avoids the use of toxic ligands, and improves yield and purity by recrystallization.
It realizes the efficient, non-toxic and green synthesis of Spiro-OMeTAD, simplifies the process flow, improves yield and purity, reduces the burden on the environment, and is suitable for industrial large-scale production.
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Figure CN120117993A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of the synthesis of the hole transporting material Spiro-OMeTAD, and particularly relates to a method for synthesizing Spiro-OMeTAD by catalyzing the reaction of 2,2',7,7'-tetrabromo-9,9'-spirobifluorene with 4,4'-dimethoxydiphenylamine using a nickel-based catalyst. Background Art
[0002] The development and utilization of solar energy are regarded as one of the effective means to cope with the energy crisis and ecological problems, and its role in reducing carbon emissions and promoting energy transformation is irreplaceable. Among them, the third-generation solar cells have been widely studied for their low cost and environmental friendliness compared with traditional solar cells. Among them, the research on perovskite solar cells is the most in-depth.
[0003] In recent years, perovskite solar cells have witnessed unprecedented development. The power conversion efficiency of this type of new solar cell has been improved to the point where it begins to compete with more mature technologies. Although various structures of perovskite solar cells have been developed, a hole transporting material must still be used. As a main component of perovskite solar cells, the hole transporting material has been proven to have a huge impact on the collection of solar energy, the extraction and transportation of carriers, stability and price, and also directly affects the transport of holes in the battery and the recombination of electrons and holes, thus determining the battery performance. Orthogonal molecules with a spiro ring structure can form relatively good contacts on the perovskite film, have uniform charge transport properties, a relatively high glass transition temperature, etc., and are often widely used as the backbone unit of high-efficiency hole transporting materials in perovskite solar cells. Among them, Spiro-OMeTAD has such a structure. As the most commonly used hole transporting material at present, it plays a key role in perovskite solar cells. It can effectively transport holes and improve the overall performance of the battery. However, the synthesis process of Spiro-OMeTAD is harsh, the preparation process is relatively complex, toxic phosphine ligands are often used in the preparation process, and purification is difficult in the post-treatment. Therefore, inventing a non-toxic and efficient method for synthesizing Spiro-OMeTAD is of great significance for the industrial large-scale, safe and green production of Spiro-OMeTAD. Summary of the Invention
[0004] The object of the present invention is to provide a method for synthesizing Spiro-OMeTAD by catalysis using a nickel-based catalyst. This method has a short synthesis process, high selectivity, high yield, and is non-toxic in the preparation process.
[0005] The method for catalytic synthesis of Spiro-OMeTAD using the nickel-based catalyst provided by the present invention is as follows: 2,2'-7,7'-tetrabromo-9,9'-spirobifluorene, 4,4'-dimethoxydiphenylamine, sodium hydride, and zinc powder are added to toluene, and then bis-(1,5-cyclooctadiene)nickel and 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene are added. The reflux reaction is carried out under a nitrogen atmosphere. After the reaction is completed, the reaction solution is cooled to room temperature, and then subjected to extraction, drying, and recrystallization to obtain a pale yellow solid powder of Spiro-OMeTAD. The synthesis route is as follows:
[0006]
[0007] In the above method, it is preferred that the molar ratio of 2,2'-7,7'-tetrabromo-9,9'-spirobifluorene to 4,4'-dimethoxydiphenylamine is 1:4 to 6.
[0008] In the above method, it is preferred that the molar ratio of 4,4'-dimethoxydiphenylamine to sodium hydride is 1:1 to 1.5.
[0009] In the above method, it is preferred that the addition amount of bis-(1,5-cyclooctadiene)nickel is 2% to 5% of the molar amount of 2,2'-7,7'-tetrabromo-9,9'-spirobifluorene.
[0010] In the above method, it is preferred that the molar ratio of bis-(1,5-cyclooctadiene)nickel to 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene is 1:2 to 4.
[0011] In the above method, it is preferred that the molar ratio of bis-(1,5-cyclooctadiene)nickel to zinc powder is 1:0.5 to 1.
[0012] In the above method, it is preferred that the system temperature is controlled at 60°C to 90°C when adding bis-(1,5-cyclooctadiene)nickel and 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene.
[0013] In the above method, it is preferred that the temperature of the reflux reaction is 80°C to 110°C and the time is 12 to 24 hours.
[0014] In the above method, it is preferred that the solvent for recrystallization is selected from any one or a mixed system of two of dichloromethane, chloroform, tetrahydrofuran, ethyl acetate, and petroleum ether solvents.
[0015] The beneficial effects of the present invention are as follows:
[0016] 1. The present invention uses a nickel-based catalyst with bis-(1,5-cyclooctadiene) nickel as the precursor and 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene as the ligand source for catalysis, and zinc powder is used for auxiliary catalysis to directly react 2,2',7,7'-tetrabromo-9,9'-spirobifluorene with 4,4'-dimethoxydiphenylamine to synthesize Spiro-OMeTAD. Compared with palladium-based catalysts, nickel-based catalysts are more environmentally friendly and economical. At the same time, the nickel-based catalyst produces relatively fewer by-products or wastes after the reaction, reducing the environmental burden to some extent.
[0017] 2. The ligand used in the reaction process of the present invention is an N-heterocyclic carbene ligand, and sodium hydride is used as the dehydrogenating agent. Both the ligand and the dehydrogenating agent used are safe and non-toxic, making the reaction more environmentally friendly and the operation simpler. It is not easy to occur dangerous situations, and it is easier to control the reaction rate and selectivity in actual operation, reducing the occurrence of side reactions.
[0018] 3. During the reaction process of the present invention, with the auxiliary catalysis of zinc powder, the occurrence of cyclic reactions can be further promoted, shortening the reaction time. At the same time, by controlling the amount of zinc powder added, the reaction rate and selectivity can be effectively controlled, reducing the occurrence of side reactions.
[0019] 4. The method of the present invention has mild conditions and a short reaction time. The post-treatment only uses recrystallization for purification, avoiding the redundancy of using silica gel column chromatography for purification. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 is the 1H NMR spectrum of the Spiro-OMeTAD synthesized in Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] The present invention will be further described in detail below with reference to the drawings and embodiments, but the protection scope of the present invention is not limited to these embodiments.
[0022] Example 1
[0023] Add 917.2 mg (4 mmol) of 4,4'-dimethoxydiphenylamine, 631.9 mg (1 mmol) of 2,2',7,7'-tetrabromo-9,9'-spirobifluorene, 96 mg (4 mmol) of sodium hydride, and 1.517 mg (0.0232 mmol) of zinc powder into a two-necked flask. Evacuate the air in the flask and fill it with nitrogen, repeating the operation three times. Then add 15 mL of toluene that has been dehydrated and deoxygenated. Heat it up under a nitrogen atmosphere. When the temperature reaches above 60 °C, add 7.977 mg (0.029 mmol) of bis-(1,5-cyclooctadiene)nickel and 33.80 mg (0.087 mmol) of 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene dissolved in 5 mL of toluene. Continue to heat up to 90 °C and reflux for 24 hours. After the reaction is completed, detect that 2,2',7,7'-tetrabromo-9,9'-spirobifluorene has completely reacted. Cool it to room temperature, add saturated ammonium chloride aqueous solution to the reaction solution, stir for 20 minutes, stop the reaction, separate the organic phase, extract it with ethyl acetate and water, combine the organic phases, add anhydrous sodium sulfate for drying, evaporate the organic phase to dryness, and recrystallize it with a tetrahydrofuran and petroleum ether system to obtain 981.9 mg of light yellow solid powder Spiro-OMeTAD, with a yield of 80.12% and a purity > 99%. The structural characterization data of the obtained Spiro-OMe TAD are shown in Figure 1 。
[0024] Comparative Example
[0025] Add 917.2 mg (4 mmol) of 4,4'-dimethoxydiphenylamine, 631.9 mg (1 mmol) of 2,2',7,7'-tetrabromo-9,9'-spirobifluorene, 96 mg (4 mmol) of sodium hydride into a two-necked flask. Evacuate the air in the flask and fill it with nitrogen, repeating the operation three times. Then add 15 mL of toluene that has been dehydrated and deoxygenated. Heat it up under a nitrogen atmosphere. When the temperature reaches above 60 °C, add 7.977 mg (0.029 mmol) of bis-(1,5-cyclooctadiene)nickel and 33.80 mg (0.087 mmol) of 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene dissolved in 5 mL of toluene. Continue to heat up to 90 °C and reflux for 24 hours. After the reaction is completed, detect that 2,2',7,7'-tetrabromo-9,9'-spirobifluorene has completely reacted. Cool it to room temperature, add saturated ammonium chloride aqueous solution to the reaction solution, stir for 20 minutes, stop the reaction, separate the organic phase, extract it with ethyl acetate and water, combine the organic phases, add anhydrous sodium sulfate for drying, evaporate the organic phase to dryness, and purify it by silica gel column chromatography with an ethyl acetate and petroleum ether system to obtain 582.3 mg of light yellow solid powder Spiro-OMeTAD, with a yield of 47.51% and a purity > 99%.
[0026] Example 2
[0027] 917.2 mg (4 mmol) of 4,4'-dimethoxydiphenylamine, 631.9 mg (1 mmol) of 2,2',7,7'-tetrabromo-9,9'-spirobifluorene, 96 mg (4 mmol) of sodium hydride, and 1.517 mg (0.0232 mmol) of zinc powder were added to a two-necked flask. The air in the flask was evacuated and nitrogen was filled, and the operation was repeated three times. Then, 15 mL of toluene free of water and oxygen was added. When the temperature was raised above 60 °C under a nitrogen atmosphere, 11.00 mg (0.04 mmol) of bis-(1,5-cyclooctadiene)nickel dissolved in 5 mL of toluene and 31.09 mg (0.08 mmol) of 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene were added. The temperature was further raised to 90 °C and the mixture was refluxed for 24 hours. After the reaction was completed, it was detected that 2,2',7,7'-tetrabromo-9,9'-spirobifluorene had completely reacted. The reaction mixture was cooled to room temperature, and a saturated ammonium chloride aqueous solution was added thereto. The mixture was stirred for 20 minutes to stop the reaction. The organic phase was separated, extracted with ethyl acetate and water, the organic phases were combined, dried over anhydrous sodium sulfate, the organic phase was evaporated to dryness, and recrystallized from a tetrahydrofuran and petroleum ether system to obtain 958.97 mg of a light yellow solid powder, Spiro-OMeTAD, with a yield of 78.23% and a purity > 99%.
[0028] Example 3
[0029] 1.147 g (5 mmol) of 4,4'-dimethoxydiphenylamine, 631.9 mg (1 mmol) of 2,2',7,7'-tetrabromo-9,9'-spirobifluorene, 120 mg (5 mmol) of sodium hydride, and 1.517 mg (0.0232 mmol) of zinc powder were added to a two-necked flask. The air in the flask was evacuated and nitrogen was filled, and the operation was repeated three times. Then, 15 mL of toluene free of water and oxygen was added. When the temperature was raised above 60 °C under a nitrogen atmosphere, 7.977 mg (0.029 mmol) of bis-(1,5-cyclooctadiene)nickel dissolved in 5 mL of toluene and 33.80 mg (0.087 mmol) of 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene were added. The temperature was further raised to 105 °C and the mixture was refluxed for 24 hours. After the reaction was completed, it was detected that 2,2',7,7'-tetrabromo-9,9'-spirobifluorene had completely reacted. The reaction mixture was cooled to room temperature, and a saturated ammonium chloride aqueous solution was added thereto. The mixture was stirred for 20 minutes to stop the reaction. The organic phase was separated, extracted with ethyl acetate and water, the organic phases were combined, dried over anhydrous sodium sulfate, the organic phase was evaporated to dryness, and recrystallized from a tetrahydrofuran and petroleum ether system to obtain 1014.4 mg of a light yellow solid powder, Spiro-OMeTAD, with a yield of 82.78% and a purity > 99%.
[0030] Example 4
[0031] Add 1.147 g (5 mmol) of 4,4'-dimethoxydiphenylamine, 631.9 mg (1 mmol) of 2,2',7,7'-tetrabromo-9,9'-spirobifluorene, 120 mg (5 mmol) of sodium hydride, and 0.9481 mg (0.0145 mmol) of zinc powder into a two-necked flask. Evacuate the air in the flask and fill it with nitrogen, and repeat the operation three times. Then add 15 mL of toluene that has been dehydrated and deoxygenated. When the temperature is raised to above 60 °C under a nitrogen atmosphere, add 7.977 mg (0.029 mmol) of bis-(1,5-cyclooctadiene)nickel dissolved in 5 mL of toluene and 33.80 mg (0.087 mmol) of 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene. Continue to raise the temperature to 105 °C and reflux for 24 hours. After the reaction is completed, detect that 2,2',7,7'-tetrabromo-9,9'-spirobifluorene has completely reacted. Cool to room temperature, add saturated ammonium chloride aqueous solution to the reaction solution, stir for 20 minutes, stop the reaction, separate the organic phase, extract with ethyl acetate and water, combine the organic phases, add anhydrous sodium sulfate for drying, evaporate the organic phase to dryness, and recrystallize with a tetrahydrofuran and petroleum ether system to obtain 983.2 mg of light yellow solid powder Spiro-OMeTAD, with a yield of 80.23% and a purity > 99%.
[0032] Example 5
[0033] Add 1.147 g (5 mmol) of 4,4'-dimethoxydiphenylamine, 631.9 mg (1 mmol) of 2,2',7,7'-tetrabromo-9,9'-spirobifluorene, 120 mg (5 mmol) of sodium hydride, and 1.517 mg (0.0232 mmol) of zinc powder into a two-necked flask. Evacuate the air in the flask and fill it with nitrogen, and repeat the operation three times. Then add 15 mL of toluene that has been dehydrated and deoxygenated. When the temperature is raised to above 60 °C under a nitrogen atmosphere, add 11.00 mg (0.04 mmol) of bis-(1,5-cyclooctadiene)nickel dissolved in 5 mL of toluene and 31.09 mg (0.08 mmol) of 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene. Continue to raise the temperature to 105 °C and reflux for 24 hours. After the reaction is completed, detect that 2,2',7,7'-tetrabromo-9,9'-spirobifluorene has completely reacted. Cool to room temperature, add saturated ammonium chloride aqueous solution to the reaction solution, stir for 20 minutes, stop the reaction, separate the organic phase, extract with ethyl acetate and water, combine the organic phases, add anhydrous sodium sulfate for drying, evaporate the organic phase to dryness, and recrystallize with a tetrahydrofuran and petroleum ether system to obtain 995.4 mg of light yellow solid powder Spiro-OMeTAD, with a yield of 81.23% and a purity > 99%.
Claims
1. A method for synthesizing a hole transport material Spiro-OMeTAD using a nickel-based catalyst, characterized in that: 2,2',7,7'-tetrabromo-9,9'-spirobifluorene, 4,4'-dimethoxydiphenylamine, sodium hydride and zinc powder are added to toluene, and then bis-(1,5-cyclooctadiene)nickel and 1,3-bis(2,6-diisopropylphenyl)imidazole-2-ene are added, and reflux reaction is carried out under a nitrogen atmosphere. After the reaction is completed, the reaction solution is cooled to room temperature, extracted, dried and recrystallized to obtain a light yellow solid powder Spiro-OMeTAD.
2. The method for synthesizing hole transport material Spiro-OMeTAD using a nickel-based catalyst according to claim 1, characterized in that: The molar ratio of the 2,2',7,7'-tetrabromo-9,9'-spirobifluorene to 4,4'-dimethoxydiphenylamine is 1:4-6.
3. The method for synthesizing hole transport material Spiro-OMeTAD using a nickel-based catalyst according to claim 1, characterized in that: The molar ratio of the 4,4'-dimethoxydiphenylamine to sodium hydride is 1:1 to 1.
5.
4. The method for synthesizing hole transport material Spiro-OMeTAD using a nickel-based catalyst according to claim 1, characterized in that: The added amount of the bis-(1,5-cyclooctadiene) nickel is 2% to 5% of the molar amount of 2,2'-7,7'-tetrabromo-9,9'-spirobifluorene.
5. The method for synthesizing hole transport material Spiro-OMeTAD using a nickel-based catalyst according to claim 1 or 4, characterized in that: The molar ratio of the bis-(1,5-cyclooctadiene) nickel to 1,3-bis(2,6-diisopropylphenyl)imidazole-2-ene is 1:2-4.
6. The method for synthesizing hole transport material Spiro-OMeTAD using a nickel-based catalyst according to claim 1, characterized in that: The molar ratio of the bis-(1,5-cyclooctadiene) nickel to the zinc powder is 1:0.5-1.
7. The method for synthesizing hole transport material Spiro-OMeTAD using a nickel-based catalyst according to claim 1, characterized in that: When bis-(1,5-cyclooctadiene) nickel and 1,3-bis(2.6-diisopropylphenyl) imidazole-2-ene are added, the system temperature is controlled at 60°C to 90°C.
8. The method for synthesizing hole transport material Spiro-OMeTAD using a nickel-based catalyst according to claim 1, characterized in that: The temperature of the reflux reaction is 80° C. to 110° C., and the time is 12 to 24 hours.
9. The method for synthesizing hole transport material Spiro-OMeTAD using a nickel-based catalyst according to claim 1, characterized in that: The solvent for the recrystallization is selected from any one of dichloromethane, chloroform, tetrahydrofuran, ethyl acetate, and petroleum ether solvents, or a mixture of two of them.