Monomer and polyamide containing 7-methyldibenzo [c, g] carbazole and triphenylamine as well as preparation method and application of monomer and polyamide

Abstract

The invention relates to a monomer containing 7-methyldibenzo [c, g] carbazole and triphenylamine, namely 4-({9-[(4-aminophenyl) (4-methoxyphenyl) amino]-7-methyldibenzo [c, g] carbazole-5-yl} (4-methoxyphenyl) amino) aniline and a preparation method and application of polyamide. In order to solve the problems that polyamide materials are low in solubility in organic solvents, difficult in film forming, poor in cycling stability, narrow in color changing range and single in function, two triphenylamine groups are constructed on 7-methyldibenzo [c, g] carbazole, and methoxyl is introduced to triphenylamine, so that the solubility and the stability of the polymer are improved; the polymer disclosed by the invention has excellent electrochromic performance, excellent cycling stability, fast switching time and high optical contrast. Meanwhile, in order to solve the multifunctionality of the material, a naphthalene unit is added into the molecular structure, and the polymer has fluorescence emission. The fluorescent probe can be applied to the fields of display, rearview mirrors and camouflage and fluorescence detection of p-trinitrophenol.

Description

Technical Field

[0001] The present invention relates to a monomer (DCTPA-NH2) containing 7-methyldibenzo[c,g]carbazole and triphenylamine, polyamide, and a preparation method and application thereof. Background Art

[0002] The characteristic of electrochromic materials is that they undergo a redox reaction under the drive of an external voltage, or charge injection or extraction occurs in the molecular structure, and their optical properties undergo reversible and lasting changes, which are manifested in color changes or changes in transparency. With the advancement of science and technology and the continuous upgrading of electronic products, people have put forward higher requirements for electrochromic materials: higher optical contrast, richer colors, faster response time, etc. However, designing and synthesizing high-performance electrochromic materials is still a huge challenge. Carbazole is a good color-changing element and hole transport material. 7-H dibenzo[c,g]carbazole increases the distance and degree of conjugation of electron transport. Triphenylamine derivatives present a non-planar molecular configuration and a spatially distorted propeller structure, providing a path for ion transport and diffusion. At the same time, they have excellent electron-donating properties as well as photophysical and electrochemical properties, so they are widely used as hole transport, memory devices and electrochromic materials. However, in order to meet the requirements of commercial applications, some key properties of triphenylamines still need to be improved. Aromatic polyamides have some very excellent properties: stable thermal properties, oxidation resistance, high mechanical strength, chemical corrosion resistance, etc., and are widely used in civil engineering, transportation, national defense, military, aviation, electronics, etc. However, due to the high content of benzene rings in the molecular structure of polyamide, the polyamide chain has strong rigidity, and the hydrogen bonding between molecules makes the solubility and processability of polyamide polymers poor, thus limiting its application range. The present invention constructs two triphenylamine units on the 7-methyldibenzo[c,g]carbazole structure to give it a twisted spatial structure, which can improve the solubility and processability of polyamide on the one hand, and give the film strong mechanical and anti-permeability properties on the other hand. In addition, the introduction of a methoxy group with strong electron-donating ability and good solubility into the structure of triphenylamine reduces the oxidation potential and enhances the cycle stability. At the same time, in order to solve the multifunctionality of the material, a naphthalene unit is added to the molecular structure, and the invented polymer has fluorescent emission. Summary of the invention

[0003] In order to solve the problem that aromatic polyamides have low solubility in organic solvents, poor cycle stability, and low optical contrast, which leads to a narrow application range, the present invention proposes a monomer (DCTPA-NH2) containing 7-methyldibenzo[c,g]carbazole and triphenylamine and polyamide, as well as a preparation method and application thereof. Finally, a class of polyamides with excellent electrochromic properties, including excellent cycle stability, fast switching time, and high optical contrast are obtained. It is applied to electrochromic devices and explosive detection, and the feasibility of its practical application is explored. The polyamide synthesized by using DCTPA-NH2 in the present invention is a polyamide synthesized by using a DCTPA-NH2 diamine monomer and other diacid monomers (the diacid can be 4,4'-sulfonyl dibenzoic acid, cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxy diphenyl ether, 4,4'-(perfluoropropane-2,2-diyl) dibenzoic acid, terephthalic acid, phthalic acid, adipic acid, 2,6-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, etc.) The structural formulas of polyamides P1, P2, P3, P4, P5, P6, P7 and P8 synthesized with DCTPA-NH2 are as follows: , where n is an integer from 3 to 20; 2. The method for preparing polyamide synthesized by using DCTPA-NH2 as claimed in claim 2, characterized in that the preparation method comprises: 1. Synthesis of monomer DCTPA-NH2: ① Under nitrogen atmosphere, add 7-H dibenzo[c,g]carbazole and N,N-dimethylformamide solution into a three-necked flask, place the reaction system in an ice-water bath to keep the temperature at 0°C, slowly add sodium hydride, continue stirring for 0.5 hours, then add iodomethane, and react the resulting mixture at 25°C. Use thin layer chromatography to determine whether the constant temperature reaction is complete. After the reaction is completed, cool the reaction solution to room temperature and pour it into a large amount of distilled water to precipitate. Filter the precipitate and wash it with a large amount of distilled water. Vacuum dry the product to obtain a white solid 7-methyldibenzo[c,g]carbazole, named M1; The ratio of the amount of 7-H dibenzo[c,g]carbazole in step 1① to the volume of N,N-dimethylformamide is 15mmol:20mL; In step 1①, the molar ratio of 7-H dibenzo[c,g]carbazole to sodium hydride is 1:1.1; In step 1①, the molar ratio of 7-H dibenzo[c,g]carbazole to methyl iodide is 1:1.1; ② Under a nitrogen atmosphere, add M1 and N, N-dimethylformamide solution to a three-necked flask, and place the reaction system in an ice-water bath to keep the temperature at 0°C in the dark. Dissolve N-bromosuccinimide in a small amount of N, N-dimethylformamide solution in the dark, and slowly add it dropwise to the three-necked flask in the dark. Keep the temperature at 0°C during the addition. After the addition is completed, react at room temperature, and use thin layer chromatography to determine whether the constant temperature reaction is completed. After the reaction is completed, add an appropriate amount of water to the reaction solution for quenching, extract the product three times with dichloromethane, wash the combined organic phase with brine, dry with anhydrous magnesium sulfate, and concentrate in vacuo to obtain a crude product. The crude product is separated by silica gel column chromatography, and the product is vacuum dried to obtain a white solid 5,9-dibromo-7-methyldibenzo[c,g]carbazole, named M2; The volume ratio of the amount of the substance M1 in step 1② to N,N-dimethylformamide is 5mmol:40mL; The molar ratio of M1 to N-bromosuccinimide in step 1② is 1:2.2; The volume ratio of the small amount of N,N-dimethylformamide described in step 1② to the amount of M1 is 5mL:5mmol; ③ Under nitrogen atmosphere, add M2, 4-methoxy-4'-nitrodiphenylamine, sodium tert-butoxide, tri(dibenzylideneacetone)dipalladium, tri-tert-butylphosphine tetrafluoroborate and toluene into a three-necked flask, react at 110°C, and use thin layer chromatography to determine whether the constant temperature reaction is completed. After the reaction is completed, the reaction solution is cooled to room temperature and added to a large amount of petroleum ether to precipitate. The precipitate is filtered and vacuum dried to obtain a crude product. The crude product is separated by silica gel column chromatography, and the product is vacuum dried to obtain a yellow solid 5,9-bis[(4-methoxyphenyl)(4-nitrophenyl)amino]-7-methyldibenzo[c,g]carbazole, named M3; In step 1③, the ratio of the amount of M2 to 4-methoxy-4'-nitrodiphenylamine is 1:2.2; The ratio of the amount of M2 to sodium tert-butoxide in step 1③ is 1:0.2; The ratio of the amount of M2 to tris(dibenzylideneacetone)dipalladium in step 1③ is 1:0.05; The ratio of the amount of M2 to tri-tert-butylphosphine tetrafluoroborate in step 1③ is 1:0.1; The volume ratio of toluene to M2 in step 1③ is 30mL:1mmol; ④ Under nitrogen atmosphere, add M3, Pd / C and anhydrous ethanol to a three-necked flask, and use a constant pressure funnel to drip hydrazine hydrate into the mixed solution in the three-necked flask at a dripping speed of 1 to 2 drops per second; heat to the boiling point of ethanol, carry out the reduction reaction for 10-14 hours, and use thin layer chromatography to determine whether the constant temperature reaction is completed. After the reaction is completed, filter, pour the filtrate into distilled water and stir until no precipitation is precipitated, filter the precipitate and rinse with distilled water, and then vacuum dry to obtain a yellow solid DCTPA-NH2; The ratio of the volume of anhydrous ethanol in step 1④ to the amount of substance of M3 is (100-120) mL:1 mmol; The ratio of the mass of Pd / C to the amount of M3 in step 1④ is 1 g:5 mmol; The ratio of the volume of hydrazine hydrate in step 1④ to the amount of substance of M3 is 5mL:1mmol; The Pd / C in step 1④ is a Pd C-doped composite material, and the mass fraction of Pd in ​​the Pd / C is 10%; 2. Preparation of polyamide containing DCTPA-NH2: DCTPA-NH2, diacid monomer, triphenyl phosphite, CaCl2, pyridine and N-methylpyrrolidone are mixed, and then stirred at 120°C for 6 hours, cooled to room temperature, poured into methanol to precipitate solid, filtered to collect the product, and subjected to Soxhlet extraction with acetone to complete; In step 2, the molar ratio of DCTPA-NH2 to the diacid monomer is 1:1; In step 2, the ratio of the volume of triphenyl phosphite to the amount of DCTPA-NH2 is 1.5 mL: 1 mmol; The ratio of the volume of pyridine to the amount of DCTPA-NH2 in step 2 is 1.5 mL: 1 mmol; In step 2, the ratio of the volume of N-methylpyrrolidone to the amount of DCTPA-NH2 is 1.5 mL: 1 mmol; The ratio of the mass of CaCl2 to the volume of N-methylpyrrolidone in step 2 is 0.15 g:1.5 mL; The diacid monomers described in step 2 are 4,4'-sulfonyl dibenzoic acid, cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxy diphenyl ether, 4,4'-(perfluoropropane-2,2-diyl) dibenzoic acid and other dicarboxylic acid monomers. The present invention has the following beneficial effects: 1. Triarylamine compounds are propeller-shaped molecules. Due to their non-planarity, they can inhibit the accumulation of molecules, thereby improving the solubility of polymers and allowing the material to form a stable and uniform film. The central nitrogen atom is easily oxidized to form stable cationic free radicals at a lower voltage, thereby improving the cycle stability. The polyamide synthesized with DCTPA-NH2 in the present invention, due to direct bonding with diphenylamine, reduces the interchain accumulation and significantly improves the solubility of the polymer, while also improving the contrast and cycle stability of the electrochromic. 2. The polymer of the present invention has excellent electrochromic properties; the color change of the polymer of the present invention is obvious, and the simultaneous oxidation of two triphenylamine units in the repeating unit makes the color change of the polymer more obvious. When the applied voltage changes between -0.2 and 1.4V, the coloring time of the polymer of the present invention is 1.5 to 3.1s; the bleaching time is 1.6 to 2.5s; it is blue-purple when colored and yellow-green when bleached, and the optical contrast is high, which can reach up to 85%. Compared with the triphenylamine polyamide containing naphthofuran with a similar structure, its coloring time is 3.23s and the optical contrast is only 35%. Moreover, the polyamide synthesized with DCTPA-NH2 prepared by the present invention has good cycle stability. After 300 cycles, the optical contrast has basically not changed, showing excellent electrochromic stability. 3. The polymer P2 of the present invention has a strong fluorescence. After the polymer P2 is in contact with a solution prepared with the explosive trinitrophenol (TNP), the fluorescence of the polymer gradually decreases until it disappears. The polymer of the present invention can be used to detect the explosive TNP. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 The hydrogen nuclear magnetic spectrum of the monomer DCTPA-NH2 prepared in Examples 1 to 4; Figure 2 Fourier transform infrared images of polyamides P1, P2, P3, and P4 synthesized with DCTPA-NH2 prepared in Examples 1 to 4; Figure 3 Cyclic voltammograms of polyamides P1, P2, P3, and P4 synthesized with DCTPA-NH2 prepared in Examples 1 to 4; Figure 4 The thermogravimetric curves of polyamides P1, P2, P3 and P4 synthesized with DCTPA-NH2 prepared in Examples 1 to 4; Figure 5 Electrochromic images of polyamides P1, P2, P3, and P4 synthesized with DCTPA-NH2 prepared in Examples 1 to 4; Figure 6 This is an optical contrast image of the polyamide P1 synthesized with DCTPA-NH2 prepared in Example 1; Figure 7The switching time of the polyamide P1 synthesized with DCTPA-NH2 prepared in Example 1; Figure 8 This is the fluorescence image of the polyamide P2 synthesized with DCTPA-NH2 prepared in Example 2 in response to trinitrophenol; DETAILED DESCRIPTION

[0005] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes. Specific embodiment 1: This embodiment is a polyamide P1, P2, P3 or P4 synthesized with DCTPA-NH2. The structural formula of polyamide P1 synthesized with DCTPA-NH2 is as follows: , where n is an integer from 3 to 20; The present invention has the following beneficial effects: 1. Triarylamine compounds are propeller-shaped molecules. Due to their non-planarity, they can inhibit the accumulation of molecules, thereby improving the solubility of polymers and allowing the material to form a stable and uniform film. The central nitrogen atom is easily oxidized to form stable cationic free radicals at a lower voltage, thereby improving the cycle stability. The polyamide synthesized with DCTPA-NH2 in the present invention, due to direct bonding with diphenylamine, reduces the interchain accumulation and significantly improves the solubility of the polymer, while also improving the contrast and cycle stability of the electrochromic. 2. The polymer of the present invention has excellent electrochromic properties; the color change of the polymer of the present invention is obvious, and the simultaneous oxidation of two triphenylamine units in the repeating unit makes the color change of the polymer more obvious. When the applied voltage changes between -0.2 and 1.4V, the coloring time of the polymer of the present invention is 1.5 to 3.1s; the bleaching time is 1.6 to 2.5s; it is blue-purple when colored and yellow-green when bleached, and the optical contrast is high, which can reach up to 85%. Compared with the triphenylamine polyamide containing naphthofuran with a similar structure, its coloring time is 3.23s and the optical contrast is only 35%. Moreover, the polyamide synthesized with DCTPA-NH2 prepared by the present invention has good cycle stability. After 500 cycles, the optical contrast has basically not changed, showing excellent electrochromic stability. 3. The polymer P2 of the present invention has a strong fluorescence. After the polymer of the present invention is in contact with a solution prepared from the explosive trinitrophenol (TNP), the fluorescence of the polymer gradually decreases until it disappears. Therefore, the polymer of the present invention can be used to detect the explosive TNP. Specific embodiment 2: The preparation method of polyamide synthesized by DCTPA-NH2 in this embodiment is: 1. Synthesis of monomer DCTPA-NH2: ① Under nitrogen atmosphere, add 7-H dibenzo[c,g]carbazole and N,N-dimethylformamide solution into a three-necked flask, place the reaction system in an ice-water bath to keep the temperature at 0°C, slowly add sodium hydride, continue stirring for 0.5 hours, then add iodomethane, and react the resulting mixture at 25°C. Use thin layer chromatography to determine whether the constant temperature reaction is complete. After the reaction is completed, cool the reaction solution to room temperature and pour it into a large amount of distilled water to precipitate. Filter the precipitate and wash it with a large amount of distilled water. Vacuum dry the product to obtain a white solid 7-methyldibenzo[c,g]carbazole, named M1; The ratio of the amount of 7-H dibenzo[c,g]carbazole in step 1① to the volume of N,N-dimethylformamide is 15mmol:20mL; In step 1①, the molar ratio of 7-H dibenzo[c,g]carbazole to sodium hydride is 1:1.1; In step 1①, the molar ratio of 7-H dibenzo[c,g]carbazole to methyl iodide is 1:1.1; ② Under a nitrogen atmosphere, add M1 and N, N-dimethylformamide solution to a three-necked flask, and place the reaction system in an ice-water bath to keep the temperature at 0°C in the dark. Dissolve N-bromosuccinimide in a small amount of N, N-dimethylformamide solution in the dark, and slowly add it dropwise to the three-necked flask in the dark. Keep the temperature at 0°C during the addition. After the addition is completed, react at room temperature, and use thin layer chromatography to determine whether the constant temperature reaction is completed. After the reaction is completed, add an appropriate amount of water to the reaction solution for quenching, extract the product three times with dichloromethane, wash the combined organic phase with brine, dry with anhydrous magnesium sulfate, and concentrate in vacuo to obtain a crude product. The crude product is separated by silica gel column chromatography, and the product is vacuum dried to obtain a white solid 5,9-dibromo-7-methyldibenzo[c,g]carbazole, named M2; The volume ratio of the amount of the substance M1 in step 1② to N,N-dimethylformamide is 5mmol:40mL; The molar ratio of M1 to N-bromosuccinimide in step 1② is 1:2.2; The volume ratio of the small amount of N,N-dimethylformamide described in step 1② to the amount of M1 is 5mL:5mmol; ③ Under nitrogen atmosphere, add M2, 4-methoxy-4'-nitrodiphenylamine, sodium tert-butoxide, tri(dibenzylideneacetone)dipalladium, tri-tert-butylphosphine tetrafluoroborate and toluene into a three-necked flask, react at 110°C, and use thin layer chromatography to determine whether the constant temperature reaction is completed. After the reaction is completed, the reaction solution is cooled to room temperature and added to a large amount of petroleum ether to precipitate. The precipitate is filtered and vacuum dried to obtain a crude product. The crude product is separated by silica gel column chromatography, and the product is vacuum dried to obtain a yellow solid 5,9-bis[(4-methoxyphenyl)(4-nitrophenyl)amino]-7-methyldibenzo[c,g]carbazole, named M3; In step 1③, the ratio of the amount of M2 to 4-methoxy-4'-nitrodiphenylamine is 1:2.2; The ratio of the amount of M2 to sodium tert-butoxide in step 1③ is 1:0.2; The ratio of the amount of M2 to tris(dibenzylideneacetone)dipalladium in step 1③ is 1:0.05; The ratio of the amount of M2 to tri-tert-butylphosphine tetrafluoroborate in step 1③ is 1:0.1; The volume ratio of toluene to M2 in step 1③ is 30mL:1mmol; ④ Under nitrogen atmosphere, add M3, Pd / C and anhydrous ethanol to a three-necked flask, and use a constant pressure funnel to drip hydrazine hydrate into the mixed solution in the three-necked flask at a dripping speed of 1 to 2 drops per second; heat to the boiling point of ethanol, carry out the reduction reaction for 10-14 hours, and use thin layer chromatography to determine whether the constant temperature reaction is completed. After the reaction is completed, filter, pour the filtrate into distilled water and stir until no precipitation is precipitated, filter the precipitate and rinse with distilled water, and then vacuum dry to obtain a yellow solid DCTPA-NH2; The ratio of the volume of anhydrous ethanol in step 1④ to the amount of substance of M3 is (100-120) mL:1 mmol; The ratio of the mass of Pd / C to the amount of M3 in step 1④ is 1 g:5 mmol; The ratio of the volume of hydrazine hydrate in step 1④ to the amount of substance of M3 is 5mL:1mmol; The Pd / C in step 1④ is a Pd C-doped composite material, and the mass fraction of Pd in ​​the Pd / C is 10%; 2. Preparation of polyamide containing DCTPA-NH2: M4, diacid monomer, triphenyl phosphite, CaCl2, pyridine and N-methylpyrrolidone were mixed, and then stirred at 120°C for 6 hours. After cooling to room temperature, the mixture was poured into methanol to precipitate solids. The product was collected by filtration and Soxhlet extraction was performed with acetone to complete the process. In step 2, the molar ratio of DCTPA-NH2 to the diacid monomer is 1:1; In step 2, the ratio of the volume of triphenyl phosphite to the amount of DCTPA-NH2 is 1.5 mL: 1 mmol; The ratio of the volume of pyridine to the amount of DCTPA-NH2 in step 2 is 1.5 mL: 1 mmol; In step 2, the ratio of the volume of N-methylpyrrolidone to the amount of DCTPA-NH2 is 1.5 mL: 1 mmol; The ratio of the mass of CaCl2 to the volume of N-methylpyrrolidone in step 2 is 0.15 g:1.5 mL; Specific embodiment three: This embodiment is different from specific embodiment two in that the diacid monomers described in step two are 4,4'-sulfonyldibenzoic acid, cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxy diphenyl ether, 4,4'-(perfluoropropane-2,2-diyl) dibenzoic acid, and polymers P1, P2, P3, and P4 are prepared respectively. Specific implementation method 4: This implementation method is different from specific implementation method 2 in that: the Soxhlet extraction solvent in step 2 is 400 mL of acetone, and the extraction time is 72 hours. Specific implementation method 5: In this implementation method, polyamide synthesized by DCTPA-NH2 is used as the electrochromic layer in the electrochromic device. Specific embodiment 6: This embodiment is different from the specific embodiment 5 in that the application of the polyamide synthesized with DCTPA-NH2 as the electrochromic layer in the electrochromic device is carried out according to the following steps: The polyamide synthesized with DCTPA-NH2 is used as the electrochromic layer in the electrochromic device. The electrochromic layer is coated on a conductive transparent electrode to prepare an active electrode, and the electrochromic phenomenon occurs under the action of an external electric field. Specific implementation method seven: This implementation method is different from specific implementation method five in that: the voltage of the external electric field is 0-3V. Specific implementation eight: This implementation differs from specific implementation five in that the transparent electrode is ITO (indium oxide tin oxide), transparent carbon nanotubes, and silver nanowire electrodes. Specific implementation method 9: In this implementation method, the polyamide synthesized with DCTPA-NH2 is used for the fluorescence detection of trinitrophenol. The following examples are used to verify the beneficial effects of the present invention: Example 1: The structural formula of polyamide P1 synthesized with DCTPA-NH2 is as follows: , where n is an integer from 3 to 20; The preparation method of polyamide P1 synthesized by DCTPA-NH2 in this embodiment is as follows: 1. Synthesis of monomer DCTPA-NH2: ① Under nitrogen atmosphere, add 7-H dibenzo[c,g]carbazole and N,N-dimethylformamide solution into a three-necked flask, place the reaction system in an ice-water bath to keep the temperature at 0°C, slowly add sodium hydride, continue stirring for 0.5 hours, then add iodomethane, and react the resulting mixture at 25°C. Use thin layer chromatography to determine whether the constant temperature reaction is complete. After the reaction is completed, cool the reaction solution to room temperature and pour it into a large amount of distilled water to precipitate. Filter the precipitate and wash it with a large amount of distilled water. Vacuum dry the product to obtain a white solid 7-methyldibenzo[c,g]carbazole, named M1; The ratio of the amount of 7-H dibenzo[c,g]carbazole in step 1① to the volume of N,N-dimethylformamide is 15mmol:20mL; In step 1①, the molar ratio of 7-H dibenzo[c,g]carbazole to sodium hydride is 1:1.1; In step 1①, the molar ratio of 7-H dibenzo[c,g]carbazole to methyl iodide is 1:1.1; ② Under a nitrogen atmosphere, add M1 and N, N-dimethylformamide solution to a three-necked flask, and place the reaction system in an ice-water bath to keep the temperature at 0°C in the dark. Dissolve N-bromosuccinimide in a small amount of N, N-dimethylformamide solution in the dark, and slowly add it dropwise to the three-necked flask in the dark. Keep the temperature at 0°C during the addition. After the addition is completed, react at room temperature, and use thin layer chromatography to determine whether the constant temperature reaction is completed. After the reaction is completed, add an appropriate amount of water to the reaction solution for quenching, extract the product three times with dichloromethane, wash the combined organic phase with brine, dry with anhydrous magnesium sulfate, and concentrate in vacuo to obtain a crude product. The crude product is separated by silica gel column chromatography, and the product is vacuum dried to obtain a white solid 5,9-dibromo-7-methyldibenzo[c,g]carbazole, named M2; The volume ratio of the amount of the substance M1 in step 1② to N,N-dimethylformamide is 5mmol:40mL; The molar ratio of M1 to N-bromosuccinimide in step 1② is 1:2.2; The volume ratio of the small amount of N,N-dimethylformamide described in step 1② to the amount of M1 is 5mL:5mmol; ③ Under nitrogen atmosphere, add M2, 4-methoxy-4'-nitrodiphenylamine, sodium tert-butoxide, tri(dibenzylideneacetone)dipalladium, tri-tert-butylphosphine tetrafluoroborate and toluene into a three-necked flask, react at 110°C, and use thin layer chromatography to determine whether the constant temperature reaction is completed. After the reaction is completed, the reaction solution is cooled to room temperature and added to a large amount of petroleum ether to precipitate. The precipitate is filtered and vacuum dried to obtain a crude product. The crude product is separated by silica gel column chromatography, and the product is vacuum dried to obtain a yellow solid 5,9-bis[(4-methoxyphenyl)(4-nitrophenyl)amino]-7-methyldibenzo[c,g]carbazole, named M3; In step 1③, the ratio of the amount of M2 to 4-methoxy-4'-nitrodiphenylamine is 1:2.2; The ratio of the amount of M2 to sodium tert-butoxide in step 1③ is 1:0.2; The ratio of the amount of M2 to tris(dibenzylideneacetone)dipalladium in step 1③ is 1:0.05; The ratio of the amount of M2 to tri-tert-butylphosphine tetrafluoroborate in step 1③ is 1:0.1; The volume ratio of toluene to M2 in step 1③ is 30mL:1mmol; ④ Under nitrogen atmosphere, add M3, Pd / C and anhydrous ethanol to a three-necked flask, and use a constant pressure funnel to drip hydrazine hydrate into the mixed solution in the three-necked flask at a dripping speed of 1 to 2 drops per second; heat to the boiling point of ethanol, carry out the reduction reaction for 10-14 hours, and use thin layer chromatography to determine whether the constant temperature reaction is completed. After the reaction is completed, filter, pour the filtrate into distilled water and stir until no precipitation is precipitated, filter the precipitate and rinse with distilled water, and then vacuum dry to obtain a yellow solid DCTPA-NH2; The ratio of the volume of anhydrous ethanol in step 1④ to the amount of substance of M3 is (100-120) mL:1 mmol; The ratio of the mass of Pd / C to the amount of M3 in step 1④ is 1 g:5 mmol; The ratio of the volume of hydrazine hydrate in step 1④ to the amount of substance of M3 is 5mL:1mmol; The Pd / C in step 1④ is a Pd C-doped composite material, and the mass fraction of Pd in ​​the Pd / C is 10%; 2. Preparation of polyamide containing DCTPA-NH2: DCTPA-NH2, diacid monomer, triphenyl phosphite, CaCl2, pyridine and N-methylpyrrolidone are mixed, and then stirred at 120°C for 6 hours, cooled to room temperature, poured into methanol to precipitate solid, filtered to collect the product, and subjected to Soxhlet extraction with acetone to complete; In step 2, the molar ratio of DCTPA-NH2 to the diacid monomer is 1:1; In step 2, the ratio of the volume of triphenyl phosphite to the amount of DCTPA-NH2 is 1.5 mL: 1 mmol; The ratio of the volume of pyridine to the amount of DCTPA-NH2 in step 2 is 1.5 mL: 1 mmol; In step 2, the ratio of the volume of N-methylpyrrolidone to the amount of DCTPA-NH2 is 1.5 mL: 1 mmol; The ratio of the mass of CaCl2 to the volume of N-methylpyrrolidone in step 2 is 0.15 g: 1.5mL; Examples 2 to 4: The structural formulas of polyamides P2-P4 synthesized with DCTPA-NH2 are similar to that of P1. The specific preparation method of P2 is the same as that of Example 1 P1, except that in Example 2, cyclohexane-1,4-dicarboxylic acid is used as the raw material to replace 4,4'-sulfonyldibenzoic acid. The specific preparation method of P3 is the same as that of Example 1 P1, except that in Example 2, the raw material 4,4'-dicarboxy diphenyl ether is used instead of 4,4'-sulfonyl dibenzoic acid. The specific preparation method of P4 is the same as that of Example 1 P1, except that in Example 2, the raw material 4,4'-(perfluoropropane-2,2-diyl)dibenzoic acid is used instead of 4,4'-sulfonyldibenzoic acid. Figure 1 This is the hydrogen nuclear magnetic spectrum of the monomer DCTPA-NH2 prepared in Example 1, proving the successful synthesis of the monomer; Figure 2 Fourier transform infrared images of four polyamides P1, P2, P3, and P4 synthesized with DCTPA-NH2 prepared in Examples 1 to 4; Figure 2 Medium 3299~3240cm -1 It is the characteristic absorption peak of -NH- in amide bond, 1663cm -1 The characteristic absorption peak of the carbonyl group in the amide bond is 1256 cm -1 It is the characteristic absorption peak of NC in the amide bond; it indicates that the polyamides P1, P2, P3 and P4 synthesized with DCTPA-NH2 were successfully synthesized in Example 2; Figure 3 The cyclic voltammograms of the polyamide synthesized with DCTPA-NH2 prepared in Examples 1 to 4; Figure 6It can be seen that P1 has an oxidation peak at 0.79V and a reduction peak at 0.54V; P2 has an oxidation peak at 0.77V and a reduction peak at 0.43V; P3 has an oxidation peak at 0.81V and a reduction peak at 0.48V; P4 has an oxidation peak at 0.82V and a reduction peak at 0.45V, which indicates that the polyamides P1, P2, P3, and P4 prepared in Examples 1 to 4 undergo redox reactions under applied voltage. Figure 4 The thermogravimetric curves of the polyamide synthesized with DCTPA-NH2 prepared in Examples 1 to 4; Figure 4 It can be seen that the thermal decomposition temperatures of polyamides P1, P2, P3, and P4 synthesized with DCTPA-NH2 in air atmosphere are all above 350°C when the weight loss is 5%, indicating that these polymers have good thermodynamic stability. When the polymer temperature is heated to 800°C, the residual carbon rate of the polymer is greater than 30%, proving that the polymer has good thermal stability. Figure 5 The electrochromic diagrams of polyamides P1, P2, P3, and P4 synthesized with DCTPA-NH2 prepared in Example 4 are shown in the figure. It can be seen from the figure that the electrochromic properties of PAs change with the increase of linear applied voltage and the UV-visible spectrum. Taking the electrochromic properties of P1 as an example, between 0.0V and 1.2V, as the voltage increases, the absorption peak at 422nm gradually decreases, and the absorption at 555nm, 615nm, and 960nm gradually increases; when applied to 1.2V, the color of the film changes to blue-purple, and the prominent wave absorption at 555nm and 615nm does not change, which indicates that TPA is completely oxidized to TPA + . Figure 6 This is an optical contrast diagram of the polyamide P1 synthesized with DCTPA-NH2 prepared in Example 1; the optical contrast of P1 is 85%, and after 500 cycles, it still maintains 76% of the initial value. Compared with the triphenylamine polyamide containing naphthofuran with a similar structure, its optical contrast is only 35%. It shows that the polyamide synthesized with DCTPA-NH2 has high optical contrast and excellent cycle stability. Figure 7 The switching time of the polyamide P1 synthesized with DCTPA-NH2 prepared in Example 2 is 1.6 s for coloring and 1.5 s for bleaching, indicating that the polyamide synthesized with DCTPA-NH2 has a fast switching response. Figure 8 The fluorescence image of the polyamide synthesized with DCTPA-NH2 prepared in Example 2 in response to trinitrophenol (TNP); 1 mg of polyamide P2 was dissolved in 20 mL of N-methylpyrrolidone to obtain a concentration of 1×10 -5M polyamide P2 solution, to which 5 microliters of TNP are added; the curves in the figure are the fluorescence intensity curves of the polyamide solution without TNP addition and the fluorescence intensity curves of the solutions to which 5 microliters of TNP of different concentrations are added in sequence; Figure 7 It can be seen that as the concentration of TNP increases, the fluorescence intensity of the polymer solution gradually weakens; this indicates that the polymer can respond to TNP, and the presence of TNP can be detected by whether the fluorescence of the polymer solution decreases.

Claims

1. Diamine monomer, 4-({9-[(4-aminophenyl)(4-methoxyphenyl)amino]-7-methyldibenzo[c,g]carbazole-5-yl}(4-methoxyphenyl)amino)aniline (abbreviated as DCTPA-NH2). The monomer characteristics are: a monomer containing 7-methyldibenzo[c,g]carbazole and triphenylamine, DCTPA-NH2, as shown in the figure:

2. A polyamide synthesized with DCTPA-NH2, characterized in that The polyamide is obtained by polymerizing DCTPA-NH2 monomer and diacid monomer; the diacid monomer includes but is not limited to 4,4'-sulfonyldibenzoic acid, cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxy diphenyl ether, 4,4'-(perfluoropropane-2,2-diyl)dibenzoic acid, terephthalic acid, phthalic acid, adipic acid, 2,6-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, etc. The structural formulas of the prepared polyamides P1, P2, P3, P4, P5, P6, P7 and P8 are as follows: ， In the formula, n is an integer from 3 to 20.

3. The method for preparing polyamide synthesized with DCTPA-NH2 as claimed in claim 2, characterized in that The preparation method is:

1. Synthesis of monomer DCTPA-NH2: ① Under nitrogen atmosphere, add 7-H dibenzo[c,g]carbazole and N,N-dimethylformamide solution into a three-necked flask, place the reaction system in an ice-water bath to keep the temperature at 0°C, slowly add sodium hydride, continue stirring for 0.5 hours, then add iodomethane, and react the resulting mixture at 25°C. Use thin layer chromatography to determine whether the constant temperature reaction is complete. After the reaction is completed, cool the reaction solution to room temperature and pour it into a large amount of distilled water to precipitate. Filter the precipitate and wash it with a large amount of distilled water. Vacuum dry the product to obtain a white solid 7-methyldibenzo[c,g]carbazole, named M1; The ratio of the amount of 7-H dibenzo[c,g]carbazole in step 1① to the volume of N,N-dimethylformamide is 15mmol:20mL; In step 1①, the molar ratio of 7-H dibenzo[c,g]carbazole to sodium hydride is 1:1.1; In step 1①, the molar ratio of 7-H dibenzo[c,g]carbazole to methyl iodide is 1:1.1; ② Under a nitrogen atmosphere, add M1 and N, N-dimethylformamide solution to a three-necked flask, and place the reaction system in an ice-water bath to keep the temperature at 0°C in the dark. Dissolve N-bromosuccinimide in a small amount of N, N-dimethylformamide solution in the dark, and slowly add it dropwise to the three-necked flask in the dark. Keep the temperature at 0°C during the addition. After the addition is completed, react at room temperature, and use thin layer chromatography to determine whether the constant temperature reaction is completed. After the reaction is completed, add an appropriate amount of water to the reaction solution for quenching, extract the product three times with dichloromethane, wash the combined organic phase with brine, dry with anhydrous magnesium sulfate, and concentrate in vacuo to obtain a crude product. The crude product is separated by silica gel column chromatography, and the product is vacuum dried to obtain a white solid 5,9-dibromo-7-methyldibenzo[c,g]carbazole, named M2; The volume ratio of the amount of the substance M1 in step 1② to N,N-dimethylformamide is 5mmol:40mL; The molar ratio of M1 to N-bromosuccinimide in step 1② is 1:2.2; The volume ratio of the small amount of N,N-dimethylformamide described in step 1② to the amount of M1 is 5mL:5mmol; ③ Under nitrogen atmosphere, add M2, 4-methoxy-4'-nitrodiphenylamine, sodium tert-butoxide, tri(dibenzylideneacetone)dipalladium, tri-tert-butylphosphine tetrafluoroborate and toluene into a three-necked flask, react at 110°C, and use thin layer chromatography to determine whether the constant temperature reaction is completed. After the reaction is completed, the reaction solution is cooled to room temperature and added to a large amount of petroleum ether to precipitate. The precipitate is filtered and vacuum dried to obtain a crude product. The crude product is separated by silica gel column chromatography, and the product is vacuum dried to obtain a yellow solid 5,9-bis[(4-methoxyphenyl)(4-nitrophenyl)amino]-7-methyldibenzo[c,g]carbazole, named M3; In step 1③, the ratio of the amount of M2 to 4-methoxy-4'-nitrodiphenylamine is 1:2.2; The ratio of the amount of M2 to sodium tert-butoxide in step 1③ is 1:0.2; The ratio of the amount of M2 to tris(dibenzylideneacetone)dipalladium in step 1③ is 1:0.05; The ratio of the amount of M2 to tri-tert-butylphosphine tetrafluoroborate in step 1③ is 1:0.1; The volume ratio of toluene to M2 in step 1③ is 30mL:1mmol; ④ Under nitrogen atmosphere, add M3, Pd / C and anhydrous ethanol to a three-necked flask, and use a constant pressure funnel to drop hydrazine hydrate into the mixed solution in the three-necked flask at a drop rate of 1 to 2 drops per second; heat to the boiling point of ethanol, carry out reduction reaction, and use thin layer chromatography to determine whether the constant temperature reaction is completed. After the reaction is completed, filter, pour the filtrate into distilled water and stir until no precipitation is precipitated, filter the precipitate and rinse with distilled water, and then vacuum dry to obtain yellow solid DCTPA-NH2; The ratio of the volume of anhydrous ethanol in step 1④ to the amount of substance of M3 is (100-120) mL:1 mmol; The ratio of the mass of Pd / C to the amount of M3 in step 1④ is 1 g:5 mmol; The ratio of the volume of hydrazine hydrate in step 1④ to the amount of substance of M3 is 5mL:1mmol; The Pd / C in step 1④ is a Pd C-doped composite material, and the mass fraction of Pd in ​​the Pd / C is 10%; 2. Preparation of polyamide containing DCTPA-NH2: DCTPA-NH2, diacid monomer, triphenyl phosphite, CaCl2, pyridine and N-methylpyrrolidone are mixed, and then stirred at 120°C for 6 hours, cooled to room temperature, poured into methanol to precipitate, the product is collected by filtration, and Soxhlet extraction is performed with acetone to complete; In step 2, the molar ratio of DCTPA-NH2 to the diacid monomer is 1:1; In step 2, the ratio of the volume of triphenyl phosphite to the amount of DCTPA-NH2 is 1.5 mL: 1 mmol; The ratio of the volume of pyridine to the amount of DCTPA-NH2 in step 2 is 1.5 mL: 1 mmol; In step 2, the ratio of the volume of N-methylpyrrolidone to the amount of DCTPA-NH2 is 1.5 mL: 1 mmol; The ratio of the mass of CaCl2 to the volume of N-methylpyrrolidone in step 2 is 0.15 g:1.5 mL; The diacid monomers described in step 2 are 4,4'-sulfonyl dibenzoic acid, cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxy diphenyl ether, 4,4'-(perfluoropropane-2,2-diyl) dibenzoic acid and other dicarboxylic acid monomers.

4. The method for preparing polyamide synthesized with DCTPA-NH2 according to claim 3, characterized in that The diacid monomers described in step 2 are 4,4'-sulfonyl dibenzoic acid, cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxy diphenyl ether, 4,4'-(perfluoropropane-2,2-diyl) dibenzoic acid and other dicarboxylic acid monomers, and polymers P1 to P8 are prepared respectively.

5. The method for preparing polyamide synthesized by using DCTPA-NH2 according to claim 3, characterized in that The Soxhlet extraction solvent in step 2 is 400 mL of acetone, and the extraction time is 72 hours.

6. Use of the polyamide synthesized with DCTPA-NH2 according to claim 2 as an electrochromic layer in an electrochromic device.

7. The use of polyamide synthesized with DCTPA-NH2 according to claim 6, characterized in that: The polyamide synthesized with DCTPA-NH2 is used as the electrochromic layer in the electrochromic device. The electrochromic layer is coated on a conductive transparent electrode to prepare an active electrode, and the electrochromic phenomenon occurs under the action of an external electric field.

8. The use of polyamide synthesized with DCTPA-NH2 according to claim 6, characterized in that The voltage of the external electric field is 0V to 3V.

9. The use of polyamide synthesized with DCTPA-NH2 according to claim 6, characterized in that The transparent electrode is ITO (indium oxide tin oxide), transparent carbon nanotube, and silver nanowire electrode.

10. The polyamide synthesized with DCTPA-NH2 according to claim 2 is used for fluorescence detection of trinitrophenol.

Images