Methylamine bistrifluoromethanesulfonimide compound structure, preparation method therefor and use thereof

Abstract

The present application relates to the technical field of organic synthesis, and provides a methylamine bistrifluoromethanesulfonimide compound structure, a preparation method therefor and a use thereof. The chemical formula of the compound is C3H6F6N2O4S2 or CH3NH3N(CF3SO2)2, the molecular weight of the compound is 312.2 g / mol, and the structural formula of the compound is as shown in formula 1 or formula 2. The preparation method therefor can be carried out in two manners, and in the two manners, a reaction can be completed within 20 minutes at room temperature. The compound is a white crystal or powder, does not contain active alkali metal elements, e.g., Li+, Na+, K+, and Ag+, contained in inorganic bistrifluoromethanesulfonimide salts such as common solar cell charge transport layer additives, and has the advantages of chemical inertness, environmental friendliness, rich raw materials, adjustable size, good crystallinity, high mobility and the like. The preparation method is simple and convenient, has good reproducibility and is beneficial to large-scale industrial preparation, and the compound can be used as a charge transport layer material and applied to a solar cell.

Description

Methylamine bis(trifluoromethanesulfonyl)imide compound structure, preparation method and application thereof

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on January 10, 2024, with application number 202410038097.9 and application name “Methylamine bis(trifluoromethanesulfonyl)imide) compound structure, preparation method and application thereof”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the technical field of organic synthesis, and in particular to a methylamine bis(trifluoromethanesulfonyl)imide compound structure, a preparation method and an application thereof. Background Art

[0003] Bistrifluoromethanesulfonimide (TSFI) salt compounds are a class of excellent charge transport layer additives for solar cells. - The special chemical structure of α-Hydroxy-1-nitropropene gives it high electrochemical stability and conductivity; and its cation part mostly uses active alkali metals such as Li + 、Na + , K + 、Ag + Therefore, the development of a methylamine bis(trifluoromethanesulfonyl imide) compound with chemical inertness, high reproducibility, simple synthesis, environmental friendliness, and high mobility to achieve solar cells with high photoelectric conversion efficiency is an urgent market need and is of great significance to the technical field. It is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0004] In view of this, the present application provides a methylamine bistrifluoromethanesulfonimide (MATSF) compound, whose chemical formula is C3H6F6N2O4S2 or CH3NH3N(CF3SO2)2, and whose molecular weight is 312.2 g / mol. The structural formula of the compound is shown in Formula 1 or Formula 2. Formula 1 and Formula 2 are two different structural expressions of the same compound.

[0005] The specific technical solutions are as follows:

[0006] The preparation method of methylamine bis(trifluoromethanesulfonyl imide) comprises the following steps:

[0007] A methylamine solution (CAS No. 74-89-5) and bis(trifluoromethanesulfonyl imide) (CAS No. 82113-65-3) are respectively dissolved in a solvent, and the two solutions are slowly mixed under stirring at room temperature. When the two raw materials are mixed in an equal stoichiometric ratio (molar ratio of 1:1), the reaction is terminated, and the solvent in the solution after the reaction is completely distilled off by reduced pressure distillation to obtain a target crude product. The target crude product is recrystallized at low temperature to prepare a methylamine bis(trifluoromethanesulfonyl imide) compound with a purity of up to 99.9%.

[0008] As a preferred embodiment, in the above-mentioned method for preparing methylamine bis(trifluoromethanesulfonyl)imide, the solvent in the methylamine solution is a solvent that can be easily distilled off by reduced pressure, such as water, alcohol solvents, ketone solvents, ether solvents, lipid solvents or benzene solvents.

[0009] As a preferred embodiment, in the above-mentioned method for preparing methylamine bis(trifluoromethanesulfonyl imide), the amounts of trifluoromethanesulfonyl imide and methylamine solution are in an equal stoichiometric ratio (molar ratio of 1:1) to ensure that only the target product and the solvent are produced after the reaction, so that all the solvent can be evaporated by reduced pressure distillation, thereby improving the yield.

[0010] As a preferred embodiment, when the solvent is ethanol, the above-mentioned preparation method of methylamine bis(trifluoromethanesulfonyl)imide has the following reaction formula:

[0011] Alternatively, the preparation method of methylamine bis(trifluoromethanesulfonyl imide) comprises the following steps:

[0012] Methylamine halide and silver bis(trifluoromethanesulfonyl imide) (CAS No. 189114-61-2) are respectively dissolved in a solvent, and the two solutions are slowly mixed under stirring at room temperature. The reaction is terminated when the two raw materials are mixed in an equal stoichiometric ratio (molar ratio of 1:1). The by-product silver halide precipitate obtained by the reaction is filtered out, and the solvent in the solution after the reaction is completely distilled off by vacuum distillation to obtain a target crude product. The target crude product is recrystallized at low temperature to prepare a methylamine bis(trifluoromethanesulfonyl imide) compound with a purity of up to 99.9%.

[0013] As a preferred embodiment, in the above-mentioned method for preparing methylamine bis(trifluoromethanesulfonyl)imide, the methylamine halide is methylamine chloride (CAS No. 593-51-1), methylamine bromide (CAS No. 6876-37-5) or methylamine iodide (CAS No. 14965-49-2).

[0014] As a preferred embodiment, in the above-mentioned method for preparing methylamine bis(trifluoromethanesulfonyl)imide, the solvent is a solvent that does not dissolve the silver halide precipitate, such as water, alcohol solvents, ketone solvents, ether solvents, lipid solvents or benzene solvents.

[0015] As a preferred embodiment, in the above-mentioned method for preparing methylamine bis(trifluoromethanesulfonyl)imide, the amounts of silver bis(trifluoromethanesulfonyl)imide and methylamine halide are in an equal stoichiometric ratio (molar ratio of 1:1) to ensure that only the target product and the by-product silver halide are precipitated after the reaction, to ensure that all by-products can be removed by filtration and all solvents can be evaporated by reduced pressure distillation, thereby improving the yield.

[0016] As a preferred embodiment, when the solvent is ethanol, the above-mentioned preparation method of methylamine bis(trifluoromethanesulfonyl)imide has the following reaction formula:

[0017] In the present application, the methylamine bis(trifluoromethanesulfonyl)imide (MATSFI) is a single crystal or powder.

[0018] Methylamine bis(trifluoromethanesulfonyl)imide (MATSFI) does not contain active alkali metal elements and is chemically inert, environmentally friendly, has abundant raw materials, is size-adjustable, has good crystallinity, and has high mobility. It can be prepared using two methods, both of which complete the reaction within 20 minutes at room temperature.

[0019] The present application also provides the use of the methylamine bis(trifluoromethanesulfonyl)imide (MATSFI) as a charge transport layer material in solar cells.

[0020] In this application, methylamine bis(trifluoromethanesulfonyl)imide (MATSFI) is doped and mixed with 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD) and 4-tert-butylpyridine (t-BP) in a certain proportion and then used as a charge transport layer material in solar cells.

[0021] In one embodiment, the molar ratio of the methylamine bis(trifluoromethanesulfonyl)imide compound (MATSFI) to 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD) is 1:0.1 to 1:100; the molar ratio of the methylamine bis(trifluoromethanesulfonyl)imide compound (MATSFI) to 4-tert-butylpyridine (t-BP) is 1:0.1 to 1:10.

[0022] The present application provides a charge transport layer material, comprising the methylamine bis(trifluoromethanesulfonyl)imide compound (MATSFI).

[0023] Compared with the prior art, this application has the following beneficial effects:

[0024] The present application provides a methylamine bis(trifluoromethanesulfonyl)imide (MATSFI) and its preparation method and application. The bis(trifluoromethanesulfonyl)imide salt does not contain active alkali metal elements such as Li contained in inorganic bis(trifluoromethanesulfonyl)imide salts such as common solar cell charge transport layer additives (LiTSFI, NaTSFI, KTSFI, AgTSFI). + 、Na + , K + 、Ag + , with advantages such as chemical inertness, environmental friendliness, abundant raw materials, adjustable size, good crystallinity, and high mobility. This preparation method is simple, convenient, and reproducible, which is conducive to large-scale industrial preparation and can be used as a charge transport layer material in solar cells.

[0025] Compared with known inorganic bis(trifluoromethanesulfonyl)imide salts such as LiTSFI, NaTSFI, KTSFI, and AgTSFI, the methylamine bis(trifluoromethanesulfonyl)imide compound (MATSFI) based on methylamine (MA) cation in this application has not been reported, and it has the advantages of 1) improving charge extraction of the photovoltaic layer; 2) stabilizing the interface of the photovoltaic layer; 3) enhancing charge transfer performance; 4) inhibiting water and oxygen corrosion; 5) improving high-temperature stability; and 6) improving photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is the general structural formula of methylamine bis(trifluoromethanesulfonyl)imide of the present application;

[0027] FIG2 is a melting point test graph of purified MATSFII according to Example 3 of the present application;

[0028] FIG3 is a diagram of purified MATSFI from Example 3 of the present application. 1 H NMR (DMSO) spectrum;

[0029] FIG4 is a diagram of the purified MATSFI of Example 3 of the present application. 19 F NMR (DMSO) spectrum;

[0030] FIG5 is a diagram of the purified MATSFI of Example 3 of the present application. 13 C NMR (DMSO) spectrum;

[0031] FIG6 is a differential scanning calorimetry (DSC) test curve of purified MATSFI in Example 3 of the present application;

[0032] FIG7 is a thermogravimetric analyzer (TGA) test curve of purified MATSFI according to Example 3 of the present application;

[0033] FIG8 is a scanning electron microscope (SEM) photograph of the top surface of the solar cell before and after coating with MATSFI as a charge transport layer material according to Example 4 of the present application;

[0034] FIG9 is a scanning electron microscope (SEM) photograph of a cross section of a solar cell before and after coating with MATSFI as a charge transport layer material according to Example 4 of the present application;

[0035] FIG10 is a charge mobility curve measured by space charge limited current method (SCLC) using MATSFI of Example 4 of the present application as a charge transport layer material;

[0036] FIG11 is a work function of MATSFI as a charge transport layer material in Example 4 of the present application measured by ultraviolet photoelectron spectroscopy (UPS);

[0037] FIG12 is a voltage-current (JV) curve measured for a solar cell using MATSFI as a charge transport layer material according to Example 4 of the present application. DETAILED DESCRIPTION

[0038] Below, the substantial features and advantages of the present application are further described with reference to examples, but the present application is not limited to the listed embodiments.

[0039] Example 1 Synthesis of methylamine bis(trifluoromethanesulfonyl)imide

[0040] In a stirred reactor, 281 g (1 mol, 99% purity) of bis(trifluoromethanesulfonyl)imide (CAS No. 82113-65-3) and 500 mL of anhydrous ethanol were added. After the raw materials were completely dissolved, 1 mol of methylamine solution (33% ethanol solution) was slowly added to the reactor while maintaining the reaction temperature at room temperature (25±10°C). The reaction was stirred at room temperature for 1 hour to complete. The ethanol solvent in the solution was completely distilled off under reduced pressure and vacuum dried at 60°C to obtain crude methylaminebis(trifluoromethanesulfonyl)imide as white crystals with a yield of no less than 95%.

[0041] Example 2 Synthesis of Methylamine Bis(Trifluoromethanesulfonyl)imide

[0042] In a reactor equipped with an agitator, 38.8 g (0.1 mol, 99% purity) of silver bis(trifluoromethanesulfonyl)imide (CAS No. 189114-61-2) and 200 mL of anhydrous ethanol were added. After the raw materials were completely dissolved, the reaction temperature was maintained at room temperature (25±10°C). 50 mL of anhydrous ethanol solution containing 15.9 g (0.1 mol, 99% purity) of methylamine iodide (CAS No. 14965-49-2) was slowly added to the reactor. The reaction was stirred at room temperature for 1 hour to complete the reaction. The silver iodide precipitate produced by the reaction was filtered out, and the ethanol solvent in the filtrate was completely distilled off under reduced pressure. The crude product of methylamine bis(trifluoromethanesulfonyl)imide was obtained as white crystals at 60°C, with a yield of not less than 95%.

[0043] The effects of different stoichiometric ratios of raw materials on the purity and yield of methylamine bis(trifluoromethanesulfonyl)imide are shown in Table 1.

[0044] Table 1 Effect of different raw material stoichiometric ratios on the purity and yield of methylamine bis(trifluoromethanesulfonyl)imide

[0045] Example 3 Purification of methylamine bis(trifluoromethanesulfonyl)imide

[0046] The crude methylamine bis(trifluoromethanesulfonyl)imide (MATSFI) obtained above was dissolved in an appropriately treated anhydrous polar solvent, and then anhydrous dichloromethane was slowly added dropwise to the solution under stirring until a small amount of crystals precipitated. After being stored in a refrigerator at -20°C for 24 hours, pure white needle-shaped MATSFI crystals were obtained by filtration. After testing, the purity of the product after two recrystallization treatments can reach 99.9%.

[0047] As shown in FIG2 , the melting point of methylamine bis(trifluoromethanesulfonyl)imide (MATSFI) after purification in Example 3 of the present application is 48° C.

[0048] As shown in FIG3 , the purified MATSFI of Example 3 of the present application is 1 H NMR (DMSO) spectrum; as shown in Figure 4, it is the purified MATSFI of Example 3 of the present application. 19 F NMR (DMSO) spectrum; as shown in Figure 5, it is the purified MATSFI of Example 3 of the present application. 13 CNMR (DMSO) spectrum.

[0049] 1 H NMR (DMSO) δ: 7.45 (3H, NH 3), 2.33 (3H, CH3);

[0050] 19 F NMR (DMSO) δ: -78.65 (6F, 2×CF3);

[0051] 13 C NMR (DMSO) δ: 124.80~115.20 (2C, 2×CF3), 24.95 (1C, CH3).

[0052] FIG6 is a differential scanning calorimetry (DSC) test curve of the purified MATSFI of Example 3 of the present application.

[0053] T m =46.3℃.

[0054] FIG7 is a thermogravimetric analyzer (TGA) test curve of the purified MATSFI of Example 3 of the present application.

[0055] T d =320.8℃.

[0056] Example 4 Application of Methylamine Bis(Trifluoromethanesulfonyl)imide (MATSFI) in the Preparation of Solar Cells

[0057] 6 mg of methylamine bis(trifluoromethanesulfonyl)imide (MATSFI), 28 mg of 4-tert-butylpyridine (t-BP), and 90 mg of 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD) were dissolved in 1 mL of chlorobenzene to obtain a MATSFI-based charge transport layer material solution.

[0058] The MATSFI-based charge transport layer material solution obtained above was spin-coated on the photovoltaic layer to form a thin film at a rotation speed of 4000 rpm, an acceleration of 2000 rpm, and a spin time of 30 seconds.

[0059] As shown in Figure 8, this is a scanning electron microscope (SEM) photograph of the top surface of the solar cell before and after coating with MATSFI as the charge transport layer material in Example 4 of the present application. The photograph shows that after coating with the MATSFI-based charge transport layer, the original photovoltaic layer is completely covered.

[0060] As shown in Figure 9, it is a cross-sectional scanning electron microscope (SEM) photograph of the solar cell before and after coating with MATSFI as the charge transport layer material in Example 4 of the present application. The photograph shows that the thickness of the MATSFI-based charge transport layer after coating is about 100 to 150 nm.

[0061] As shown in FIG10 , the charge mobility curve of MATSFI as the charge transport layer material in Example 4 of the present application is measured by the space charge limited current method (SCLC). The transfer rate of the charge transport layer based on MATSFI is calculated to be 1.58×10 -4 cm 2 v-1 s -1 .

[0062] As shown in FIG11 , the work function of MATSFI in Example 4 of the present application as a charge transport layer material is measured by ultraviolet photoelectron spectroscopy (UPS), with a Fermi edge of 16.57 eV and a cutoff edge of 0.34 eV.

[0063] As shown in Figure 12, the voltage-current (JV) curve of the solar cell with MATSFI as the charge transport layer material in Example 4 of the present application is measured. The positive scan open circuit voltage is 1.137V and the short circuit current is 25.85mA / cm 2 , fill factor is 81.09%, conversion efficiency is 23.84%; reverse scan open circuit voltage is 1.158V, short circuit current is 25.84mA / cm 2 , the fill factor is 81.10%, and the conversion efficiency is 24.25%.

[0064] It should be noted that the above preferred embodiments are merely illustrative of the technical concepts and features of this application. Their purpose is to enable those familiar with the art to understand the content of this application and implement it accordingly. They are not intended to limit the scope of protection of this application. Any equivalent changes or modifications made in accordance with the spirit and substance of this application shall be included within the scope of protection of this application.

Claims

1. Methylamine bis(trifluoromethanesulfonyl)imide compound, characterized in that, The chemical formula is C3H6F6N2O4S2 or CH3NH3N(CF3SO2)2, with a molecular weight of 312.2 g / mol. The structural formula of the compound is shown in Formula 1 or Formula 2:

2. The preparation method of the methylamine bis(trifluoromethanesulfonyl)imide compound according to claim 1, characterized in that, It includes the following steps: Dissolve methylamine solution and bis(trifluoromethanesulfonyl)imide in solvents respectively, slowly mix the two solutions under stirring at room temperature, end the reaction after the two raw materials are mixed in an equimolar ratio, and distill off all the solvents in the reaction solution by vacuum distillation to obtain the target crude product; the target crude product is recrystallized at low temperature to obtain a methylamine bis(trifluoromethanesulfonyl)imide compound with a purity as high as 99.9%.

3. The preparation method according to claim 2, characterized in that, The solvent is a solvent with a boiling point lower than 180°C and miscible with the by-product acetic acid.

4. The preparation method according to claim 3, characterized in that, The solvent is water, an alcohol solvent, a ketone solvent, an ether solvent, a lipid solvent or a benzene solvent.

5. The preparation method according to claim 2, characterized in that, The reaction time is 1 hour.

6. The preparation method according to claim 2, characterized in that, When the solvent is ethanol, the reaction formula of the preparation method is as follows:

7. The preparation method of the methylamine bis(trifluoromethanesulfonyl)imide compound according to claim 1, characterized in that, It includes the following steps: Dissolve methylamine halide and silver bis(trifluoromethanesulfonyl)imide in solvents respectively, slowly mix the two solutions under stirring at room temperature, end the reaction after the two raw materials are mixed in an equimolar ratio, filter and remove the by-product silver halide precipitate, and distill off all the solvents in the filtered solution by vacuum distillation to obtain the target crude product; the target crude product is recrystallized at low temperature to obtain a methylamine bis(trifluoromethanesulfonyl)imide compound with a purity as high as 99.9%.

8. The preparation method according to claim 7, characterized in that, The methylamine halide is methylamine chloride, methylamine bromide or methylamine iodide.

9. The preparation method according to claim 7, wherein, The solvent is a solvent that does not dissolve the silver halide precipitate.

10. The preparation method according to claim 9, characterized in that, The solvent is water, an alcohol solvent, a ketone solvent, an ether solvent, a lipid solvent or a benzene solvent.

11. The preparation method according to claim 7, wherein The reaction time is 1 hour.

12. The preparation method according to claim 7, characterized in that, When the solvent is ethanol, the reaction formula of the preparation method is as follows:

13. Application of the methylamine bis(trifluoromethanesulfonyl)imide compound according to claim 1 or the methylamine bis(trifluoromethanesulfonyl)imide compound prepared by the preparation method according to any one of claims 2 to 12 as a charge transport layer material in a solar cell.

14. The application according to claim 13, wherein The application is as follows: Mix the methylamine bis(trifluoromethanesulfonyl)imide compound with 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene and 4-tert-butylpyridine in proportion and dope them, and then apply them as a charge transport layer material in a solar cell.

15. The application according to claim 14, wherein The molar ratio of the methylamine bis(trifluoromethanesulfonyl)imide compound to 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene is 1:0.1 to 1:

100.

16. The application according to claim 14, characterized in that The molar ratio of the methylamine bis(trifluoromethanesulfonyl)imide compound to 4-tert-butylpyridine is 1:0.1 to 1:

10.

17. The application according to claim 14, wherein The thickness of the charge transport layer is 100 - 150 nm.

18. A charge transport layer material, characterized in that, It includes the methylamine bis(trifluoromethanesulfonyl)imide compound according to claim 1 or the methylamine bis(trifluoromethanesulfonyl)imide compound prepared by the preparation method according to any one of claims 2 to 12.

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