Monomers containing 7-methyldibenzo[c,g]carbazole and triphenylamine and polyamides thereof, and methods of making and using the same

Abstract

This invention relates to a method for preparing and applying polyamides from a monomer containing 7-methyldibenzo[c,g]carbazole and triphenylamine: 4-({9-[(4-aminophenyl)(4-methoxyphenyl)amino]-7-methyldibenzo[c,g]carbazole-5-yl}(4-methoxyphenyl)amino)aniline. To address the problems of low solubility, difficulty in film formation, poor cycling stability, narrow color change range, and limited functionality in polyamide materials, this invention constructs two triphenylamine groups on 7-methyldibenzo[c,g]carbazole and introduces a methoxy group onto the triphenylamine to increase the polymer's solubility and stability. The polymer of this invention exhibits excellent electrochromic properties, including excellent cycling stability, fast switching time, and high optical contrast. Furthermore, to address the material's multifunctionality, a naphthalene unit is added to the molecular structure, resulting in a polymer with fluorescent emission. This invention can be applied to displays, rearview mirrors, camouflage applications, and the fluorescence detection of p-trinitrophenol.

Description

TECHNICAL FIELD

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

[0002] The electrochromic material is characterized by redox reaction under the driving of external voltage, or charge injection or extraction within the molecular structure, which causes reversible and persistent stable changes in optical properties, and the appearance shows color change or transparency change. With the progress of science and technology and the continuous upgrading of electronic products, people have higher requirements for electrochromic materials: higher optical contrast, richer color, faster response time, etc. However, it is still a great challenge to design and synthesize high-performance electrochromic materials.

[0003] Carbazole is a good color-changing unit and hole transport material, and 7-Hdibenzo[c,g]carbazole can increase the distance and conjugation degree of electron transport; triphenylamine derivatives exhibit non-planar molecular configuration and spatially twisted propeller structure, which provides a path for ion transport and diffusion. At the same time, it has excellent electron-donating properties and photo-physical and electrochemical properties, and is widely used as hole transport, memory device and electrochromic material. However, some key properties of triphenylamine still need to be improved to meet the requirements of commercial applications.

[0004] Aromatic polyamide has some very excellent properties: stable thermal performance, oxidation resistance, high mechanical strength, chemical corrosion resistance, etc., and has a wide range of applications in civil construction, transportation, national defense and military, aviation, electronics and other fields. However, due to the high content of benzene ring 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 polymer poor, thereby limiting its application range.

[0005] The present application constructs two triphenylamine units on the structure of 7-methyldibenzo[c,g]carbazole, which gives it a twisted spatial structure. On the one hand, it can improve the solubility and processability of the polyamide; on the other hand, it gives the film strong mechanical and anti-permeability properties. In addition, the introduction of the methoxy group with strong electron-donating ability and good solubility in 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 fluorescence emission property. SUMMARY

[0006] The application aims to solve the problems of low solubility in organic solvents, poor cycle stability and low optical contrast of aromatic polyamides, thereby resulting in a narrow application range, and provides a monomer (DCTPA-NH2) containing 7-methyl dibenzo[c,g]carbazole and triphenylamine, a polyamide and a preparation method and application thereof. Finally, a kind of polyamide with excellent electrochromic performance, including excellent cycle stability, fast switching time and high optical contrast, is obtained. The polyamide is applied to electrochromic devices and explosive detection, and the feasibility of practical application is discussed.

[0007] The polyamide synthesized from DCTPA-NH2 is a polyamide synthesized from DCTPA-NH2 diamino monomer and other diacid monomers (the diacid monomers are 4,4'-sulfonyldibenzoic acid, cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxy diphenyl ether, 4,4'-(perfluoropropane-2,2-diyl)dibenzoic acid, terephthalic acid and 1,4-naphthalene dicarboxylic acid).

[0008] The structural formulas of the polyamides P1, P2, P3, P4, P5, P6, P7 and P8 synthesized from DCTPA-NH2 are as follows:

[0009]

[0010] in the formula, n is an integer of 3-20;

[0011] 2. The preparation method of the polyamide synthesized from DCTPA-NH2 described above, characterized in that the preparation method is as follows:

[0012] I. Synthesis of monomer DCTPA-NH2:

[0013] ① Under a nitrogen atmosphere, 7-H dibenzo[c,g]carbazole and N,N-dimethylformamide solution are added to a three-necked flask, the reaction system is placed in an ice water bath to keep the temperature at 0°C, sodium hydride is slowly added, stirring is continued for 0.5 hours, iodomethane is added, and the obtained mixture is reacted at 25°C, and thin layer chromatography is used to determine whether the constant temperature reaction is completed; after the reaction is completed, the reaction liquid is cooled to room temperature, and is poured into a large amount of distilled water to precipitate a precipitate, the precipitate is filtered out and washed with a large amount of distilled water, and the product is vacuum dried to obtain white solid 7-methyl dibenzo[c,g]carbazole, which is named as M1;

[0014] The mass of 7-H dibenzo[c,g]carbazole and the volume of N,N-dimethylformamide in step I ① are 15 mmol: 20 mL;

[0015] The mass ratio of 7-H dibenzo[c,g]carbazole to sodium hydride in step I ① is 1:1.1;

[0016] The mass ratio of 7-H dibenzo[c,g]carbazole to iodomethane in step one 1 is 1:1.1;

[0017] In step one 2, the mass ratio of M1 to N,N-dimethylformamide is 5 mmol:40 mL;

[0018] In step one 2, the mass ratio of M1 to N-bromosuccinimide is 1:2.2;

[0019] In step one 2, the mass ratio of M1 to N-bromosuccinimide is 1:2.2;

[0020] In step one 2, the mass ratio of M1 to N-bromosuccinimide is 1:2.2;

[0021] In step one 2, the mass ratio of M1 to N-bromosuccinimide is 1:2.2;

[0022] In step one 2, the mass ratio of M1 to N-bromosuccinimide is 1:2.2;

[0023] In step one 2, the mass ratio of M1 to N-bromosuccinimide is 1:2.2;

[0024] In step one 2, the mass ratio of M1 to N-bromosuccinimide is 1:2.2;

[0025] In step one 2, the mass ratio of M1 to N-bromosuccinimide is 1:2.2;

[0026] The volume ratio of toluene to the amount of substance of M2 in step one ③ is 30 mL: 1 mmol;

[0027] ④ M3, Pd / C and anhydrous ethanol are added to a three-necked flask under a nitrogen atmosphere, hydrazine hydrate is added into the mixed solution in the three-necked flask using a constant pressure funnel at a drop rate of 1-2 drops per second; the temperature is raised to the boiling point of ethanol, and the reduction reaction is carried out for 10-14 hours; whether the constant temperature reaction is completed is determined by thin layer chromatography; after the reaction is completed, the filtrate is filtered, and the filtrate is stirred in distilled water until no precipitate is separated out, the precipitate is filtered and washed with distilled water, and then vacuum dried to obtain yellow solid DCTPA-NH2;

[0028] The volume ratio of anhydrous ethanol to the amount of substance of M3 in step one ④ is (100-120) mL: 1 mmol;

[0029] The mass ratio of Pd / C to the amount of substance of M3 in step one ④ is 1 g: 5 mmol;

[0030] The volume ratio of hydrazine hydrate to the amount of substance of M3 in step one ④ is 5 mL: 1 mmol;

[0031] The Pd / C in step one ④ is a C-doped composite material of Pd, and the mass fraction of Pd in Pd / C is 10%;

[0032] II. Preparation of a polyamide containing DCTPA-NH2:

[0033] DCTPA-NH2, a diacid monomer, triphenyl phosphite, CaCl2, pyridine and N-methyl pyrrolidone are mixed, and then stirred at 120°C for 6 hours; after cooling to room temperature, the solid is separated out by pouring into methanol, the product is collected by filtration, and Soxhlet extraction is performed using acetone, and the process is completed;

[0034] The amount of substance ratio of DCTPA-NH2 to the diacid monomer in step two is 1:1;

[0035] The volume ratio of triphenyl phosphite to the amount of substance of DCTPA-NH2 in step two is 1.5 mL: 1 mmol;

[0036] The volume ratio of pyridine to the amount of substance of DCTPA-NH2 in step two is 1.5 mL: 1 mmol;

[0037] The volume ratio of N-methyl pyrrolidone to the amount of substance of DCTPA-NH2 in step two is 1.5 mL: 1 mmol;

[0038] The mass ratio of CaCl2 to the volume of N-methyl pyrrolidone in step two is 0.15 g: 1.5 mL;

[0039] The diacid monomer in step two is 4,4'-sulfonyldibenzoic acid, cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxy diphenyl ether, 4,4'-(perfluoropropane-2,2-diyl)dibenzoic acid, terephthalic acid, 1,4-naphthalene dicarboxylic acid.

[0040] The present application has the following advantages:

[0041] One, the triarylamine compound is a propeller type molecule, due to its non-planar, can inhibit the accumulation of molecules, thereby improving the solubility of the polymer, the material can form a stable and uniform film, wherein the central nitrogen atom is easy to oxidize to form stable cationic radicals at low voltage, thereby improving the cycle stability. The polyamide synthesized by DCTPA-NH2 in the present application is directly connected with diphenylamine, which reduces the chain accumulation and significantly improves the solubility of the polymer, and also improves the contrast and cycle stability of the electrochromic.

[0042] Two, the polymer of the present application has excellent electrochromic performance; the color change of the polymer of the present application is obvious, and the simultaneous oxidation of the two triphenylamine units in the repeat 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 application is 1.5-3.1s; the bleaching time is 1.6-2.5s; the coloring time is blue-violet, and the bleaching time is yellow-green, the optical contrast is high, and the highest can reach 85%. Compared with the triphenylamine-containing naphthofuran polyamide with similar structure, the coloring time is 3.23s, and the optical contrast is only 35%. Moreover, the polyamide synthesized by DCTPA-NH2 prepared in the present application has good cycle stability, and the optical contrast basically does not change after 300 cycles, showing excellent electrochromic stability.

[0043] Three, the polymer P2 of the present application has strong fluorescence, and the fluorescence of the polymer gradually decreases until disappears after the solution of the polymer P2 and the explosive trinitrophenol (TNP) is contacted, and the polymer of the present application can be used for detecting the explosive TNP. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 The hydrogen nuclear magnetic spectrum of the monomer DCTPA-NH2 prepared for examples 1-4;

[0045] Figure 2 The Fourier infrared spectrum of the polyamide P1, P2, P3, P4 synthesized by DCTPA-NH2 prepared for examples 1-4;

[0046] Figure 3 The cyclic voltammogram of the polyamide P1, P2, P3, P4 synthesized by DCTPA-NH2 prepared for examples 1-4;

[0047] Figure 4 Thermogravimetric curve of polyamide P1, P2, P3, P4 synthesized with DCTPA-NH2 prepared for example 1 to 4;

[0048] Figure 5 Electrochromic graph of polyamide P1, P2, P3, P4 synthesized with DCTPA-NH2 prepared for example 1 to 4;

[0049] Figure 6 Optical contrast graph of polyamide P1 synthesized with DCTPA-NH2 prepared for example 1;

[0050] Figure 7 Switching time of polyamide P1 synthesized with DCTPA-NH2 prepared for example 1;

[0051] Figure 8 Fluorescence graph of polyamide P2 synthesized with DCTPA-NH2 prepared for example 2 responding to trinitrophenol; DETAILED DESCRIPTION

[0052] The technical solution of the present application is not limited to the following specific embodiments, but also includes any combination between the specific embodiments.

[0053] Specific embodiment one: the present embodiment is polyamide P1, P2, P3 or P4 synthesized with DCTPA-NH2.

[0054] The structure formula of polyamide P1 synthesized with DCTPA-NH2 is as follows:

[0055]

[0056] In the formula, n is an integer of 3 to 20.

[0057] The present application has the following beneficial effects:

[0058] One, the triarylamine compound is a propeller type molecule, due to its non-planar, can inhibit the accumulation of molecules, thereby improving the solubility of the polymer, so that the material can form a stable and uniform film, wherein the central nitrogen atom is easy to oxidize to form a stable cation radical at a lower voltage, thereby improving the cycle stability. In the present application, the polyamide synthesized with DCTPA-NH2 is directly connected with diphenylamine, which reduces the chain accumulation and significantly improves the solubility of the polymer, and also improves the contrast and cycle stability of the electrochromism.

[0059] Secondly, the polymer has excellent electrochromic performance; the polymer has obvious color change, and the oxidation of the 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 1.4 V, the polymer has a coloring time of 1.5-3.1 s, a bleaching time of 1.6-2.5 s, a blue-violet color in coloring, a yellow-green color in bleaching, a high optical contrast, and the highest optical contrast can reach 85%. Compared with the triphenylamine-containing naphthofuran polyamide having a similar structure, the coloring time is 3.23 s, and the optical contrast is only 35%. Moreover, the polyamide synthesized by DCTPA-NH2 has good cycle stability, and the optical contrast basically does not change after 500 cycles, which shows excellent electrochromic stability.

[0060] Thirdly, the polymer P2 has strong fluorescence, and the fluorescence of the polymer gradually decreases until disappears after the solution of the polymer and the explosive TNP is contacted, so that the polymer can be used for detecting the explosive TNP.

[0061] Specific embodiment two: the preparation method of the polyamide synthesized by DCTPA-NH2 is as follows:

[0062] Firstly, the monomer DCTPA-NH2 is synthesized as follows:

[0063] ①Under a nitrogen atmosphere, 7-H dibenzo[c,g]carbazole and N,N-dimethylformamide solution are added to a three-necked flask, the reaction system is placed in an ice water bath to keep the temperature at 0°C, sodium hydride is slowly added, stirring is continued for 0.5 hours, iodomethane is added, and the obtained mixture is reacted at 25°C, and thin layer chromatography is used to determine whether the constant temperature reaction is completed; after the reaction is completed, the reaction liquid is cooled to room temperature, and is poured into a large amount of distilled water to precipitate a precipitate, the precipitate is filtered out and washed with a large amount of distilled water, and the product is vacuum dried to obtain white solid 7-methyl dibenzo[c,g]carbazole, which is named as M1;

[0064] The mass of 7-H dibenzo[c,g]carbazole and the volume of N,N-dimethylformamide in step one ① are 15 mmol: 20 mL;

[0065] The mass ratio of 7-H dibenzo[c,g]carbazole and sodium hydride in step one ① is 1:1.1;

[0066] The mass ratio of 7-H dibenzo[c,g]carbazole and iodomethane in step one ① is 1:1.1;

[0067]

[0068] The mass of M1 and the volume of N,N-dimethylformamide in step one ② are 5 mmol and 40 mL, respectively;

[0069] The mass ratio of M1 and N-bromosuccinimide in step one ② is 1:2.2;

[0070] The volume of the small amount of N,N-dimethylformamide and the mass of M1 in step one ② are 5 mL and 5 mmol, respectively;

[0071]

[0072] The mass ratio of M2 and 4-methoxy-4'-nitroaniline in step one ③ is 1:2.2;

[0073] The mass ratio of M2 and sodium tert-butoxide in step one ③ is 1:0.2;

[0074] The mass ratio of M2 and tris(dibenzylideneacetone)dipalladium in step one ③ is 1:0.05;

[0075] The mass ratio of M2 and tri-tert-butylphosphine tetrafluoroborate in step one ③ is 1:0.1;

[0076] The volume of toluene and the mass of M2 in step one ③ are 30 mL and 1 mmol, respectively;​​

[0077] IV. In a nitrogen atmosphere, M3, Pd / C and anhydrous ethanol are added to a three-necked flask, hydrazine hydrate is added to the mixed solution in the three-necked flask using a constant pressure funnel at a drop rate of 1-2 drops per second; the temperature is raised to the boiling point of ethanol, and the reduction reaction is carried out for 10-14 hours, and thin layer chromatography is used to determine whether the constant temperature reaction is complete. After the reaction is complete, filtration is performed, the filtrate is poured into distilled water and stirred until no precipitate is separated out, the precipitate is filtered and washed with distilled water, and then vacuum drying is performed to obtain yellow solid DCTPA-NH2;

[0078] The volume of the anhydrous ethanol to the amount of substance of M3 in step I IV is (100-120) mL: 1 mmol;

[0079] The mass of the Pd / C to the amount of substance of M3 in step I IV is 1 g: 5 mmol;

[0080] The volume of the hydrazine hydrate to the amount of substance of M3 in step I IV is 5 mL: 1 mmol;

[0081] The Pd / C in step I IV is a C-doped composite material of Pd, and the mass fraction of Pd in the Pd / C is 10%;

[0082] II. Preparation of a polyamide containing DCTPA-NH2:

[0083] M4, a diacid monomer, triphenyl phosphite, CaCl2, pyridine and N-methyl pyrrolidone are mixed, and then stirred at 120°C for 6 hours, and after cooling to room temperature, the solid is separated out by pouring into methanol, the product is collected by filtration, and Soxhlet extraction is performed using acetone, and the process is complete;

[0084] The amount of substance ratio of the DCTPA-NH2 to the diacid monomer in step II is 1:1;

[0085] The volume of the triphenyl phosphite to the amount of substance of the DCTPA-NH2 in step II is 1.5 mL: 1 mmol;

[0086] The volume of the pyridine to the amount of substance of the DCTPA-NH2 in step II is 1.5 mL: 1 mmol;

[0087] The volume of the N-methyl pyrrolidone to the amount of substance of the DCTPA-NH2 in step II is 1.5 mL: 1 mmol;

[0088] The mass of the CaCl2 to the volume of the N-methyl pyrrolidone in step II is 0.15 g: 1.5 mL;

[0089] Specific embodiment three: the difference between this embodiment and specific embodiment two is that the diacid monomer in step two is 4,4'-sulfonyl benzoic acid, cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxy diphenyl ether, 4,4'-(perfluoropropane-2,2-diyl) benzoic acid, respectively, to prepare polymers P1, P2, P3, P4.

[0090] Specific embodiment four: the difference between this embodiment and specific embodiment two is that the Soxhlet extraction solvent in step two is 400 mL of acetone, and the extraction time is 72 hours.

[0091] Specific embodiment five: this embodiment uses the polyamide synthesized by DCTPA-NH2 as the electrochromic layer in the electrochromic device.

[0092] Specific embodiment six: the difference between this embodiment and specific embodiment five is that the application of the polyamide synthesized by DCTPA-NH2 as the electrochromic layer in the electrochromic device is carried out according to the following steps:

[0093] The polyamide synthesized by DCTPA-NH2 is used as the electrochromic layer in the electrochromic device, and the electrochromic layer is coated on the conductive transparent electrode to prepare an active electrode, which exhibits electrochromic phenomenon under the action of an external electric field.

[0094] Specific embodiment seven: the difference between this embodiment and specific embodiment five is that the voltage of the external electric field is 0-3V.

[0095] Specific embodiment eight: the difference between this embodiment and specific embodiment five is that the transparent electrode is ITO (indium tin oxide), transparent carbon nanotube, silver nanowire electrode.

[0096] Specific embodiment nine: this embodiment uses the polyamide synthesized by DCTPA-NH2 for fluorescent detection of trinitrophenol.

[0097] The following examples are used to verify the beneficial effects of the present application:

[0098] Example one: the structural formula of the polyamide P1 synthesized by DCTPA-NH2 is as follows:

[0099]

[0100] , wherein n is an integer of 3-20;

[0101] The preparation method of the polyamide P1 synthesized by DCTPA-NH2 in this embodiment is:

[0102] I. Synthesis of monomer DCTPA-NH2:

[0103]

[0104] The ratio of the amount of substance of the 7-H dibenzo[c,g]carbazole to the volume of N,N-dimethylformamide in step one ① is 15 mmol: 20 mL;

[0105] The ratio of the amount of substance of the 7-H dibenzo[c,g]carbazole to sodium hydride in step one ① is 1:1.1;

[0106] The ratio of the amount of substance of the 7-H dibenzo[c,g]carbazole to sodium hydride in step one ① is 1:1.1;

[0107] In step two ②, the ratio of the amount of substance of M1 to N,N-dimethylformamide is 5 mmol: 40 mL;

[0108] The ratio of the amount of substance of M1 to N-bromosuccinimide in step two ② is 1:2.2;

[0109] The ratio of the volume of the small amount of N,N-dimethylformamide to the amount of substance of M1 in step two ② is 5 mL: 5 mmol;

[0110] The ratio of the volume of the small amount of N,N-dimethylformamide to the amount of substance of M1 in step two ② is 5 mL: 5 mmol;

[0111] ​③Under nitrogen atmosphere, M2, 4-methoxy-4'-nitroaniline, sodium tert-butoxide, tris(dibenzylideneacetone)dipalladium, tri-tert-butylphosphonium tetrafluoroborate and toluene were added into a three-necked flask, and the reaction was carried out at 110°C, and the constant temperature reaction was determined by thin layer chromatography; after the reaction was completed, the reaction solution was cooled to room temperature, and then added into a large amount of petroleum ether to precipitate the sediment, which was filtered and vacuum dried to obtain the crude product; the crude product was separated by silica gel column chromatography, and the product was vacuum dried to obtain yellow solid 5,9-bis[(4-methoxyphenyl)(4-nitrophenyl)amino]-7-methyldibenzo[c,g]carbazole, named as M3;

[0112] The mass ratio of M2 to 4-methoxy-4'-nitroaniline in step one ③ is 1:2.2;

[0113] The mass ratio of M2 to sodium tert-butoxide in step one ③ is 1:0.2;

[0114] The mass ratio of M2 to tris(dibenzylideneacetone)dipalladium in step one ③ is 1:0.05;

[0115] The mass ratio of M2 to tri-tert-butylphosphonium tetrafluoroborate in step one ③ is 1:0.1;

[0116] The volume ratio of toluene to M2 in step one ③ is 30 mL:1 mmol;

[0117] ④Under nitrogen atmosphere, M3, Pd / C and anhydrous ethanol were added into a three-necked flask, and hydrazine hydrate was added into the mixed solution in the three-necked flask at a drop rate of 1-2 drops per second using a constant pressure funnel; the temperature was raised to the boiling point of ethanol, and the reduction reaction was carried out for 10-14 h, and the constant temperature reaction was determined by thin layer chromatography; after the reaction was completed, the solution was filtered, and the filtrate was poured into distilled water and stirred until no precipitate was precipitated, and then the precipitate was filtered and washed with distilled water, and then vacuum dried to obtain yellow solid DCTPA-NH2;

[0118] The volume ratio of anhydrous ethanol to M3 in step one ④ is (100-120) mL:1 mmol;

[0119] The mass ratio of Pd / C to M3 in step one ④ is 1 g:5 mmol;

[0120] The volume ratio of hydrazine hydrate to M3 in step one ④ is 5 mL:1 mmol;

[0121] The Pd / C in step one ④ is a C-doped composite material of Pd, and the mass fraction of Pd in Pd / C is 10%;

[0122] II. Preparation of polyamide containing DCTPA-NH2:

[0123] DCTPA-NH2, diacid monomer, triphenyl phosphite, CaCl2, pyridine and N- methylpyrrolidone were mixed, then stirred at 120℃ for 6 hours, after cooling to room temperature, the solid was precipitated by pouring into methanol, the product was collected by filtration, Soxhlet extraction with acetone was completed;

[0124] The molar ratio of DCTPA-NH2 to diacid monomer in step two is 1:1;

[0125] The volume ratio of triphenyl phosphite to the molar amount of DCTPA-NH2 in step two is 1.5 mL: 1 mmol;

[0126] The volume ratio of pyridine to the molar amount of DCTPA-NH2 in step two is 1.5 mL: 1 mmol;

[0127] The volume ratio of N-methylpyrrolidone to the molar amount of DCTPA-NH2 in step two is 1.5 mL: 1 mmol;

[0128] The mass ratio of CaCl2 to the volume of N-methylpyrrolidone in step two is 0.15 g:

[0129] 1.5 mL;

[0130] Examples two to four: the structural formula of polyamide P2-P4 synthesized with DCTPA-NH2 is similar to P1.

[0131] The specific preparation method of P2 is the same as that of P1 in Example one, except that the raw material cyclohexane-1, 4-dicarboxylic acid is used instead of 4, 4'-sulfonyldibenzoic acid in Example two.

[0132] The specific preparation method of P3 is the same as that of P1 in Example one, except that the raw material 4, 4'-dicarboxylic diphenyl ether is used instead of 4, 4'-sulfonyldibenzoic acid in Example two.

[0133] The specific preparation method of P4 is the same as that of P1 in Example one, except that the raw material 4, 4'- (perfluoropropane-2, 2- diyl) dibenzoic acid is used instead of 4, 4'-sulfonyldibenzoic acid in Example two.

[0134] Figure 1 The hydrogen nuclear magnetic resonance spectrum of the monomer DCTPA-NH2 prepared in Example one proves the successful synthesis of the monomer;

[0135] Figure 2 The Fourier infrared spectra of the four polyamides P1, P2, P3 and P4 synthesized with DCTPA-NH2 prepared in Examples one to four; Figure 2Mid 3299-3240 cm -1 Characteristic absorption peak of -NH- in amide bond, 1663 cm -1 Characteristic absorption peak of carbonyl in amide bond, 1256 cm -1 Characteristic absorption peak of N-C in amide bond; it indicates that the polyamides P1, P2, P3, P4 synthesized from DCTPA-NH2 in Example Two are successfully synthesized.

[0136] Figure 3 Cyclic voltammograms of the polyamides synthesized from DCTPA-NH2 prepared in Examples One to Four; from Figure 6 It can be seen that P1 has an oxidation peak at 0.79 V and a reduction peak at 0.54 V; P2 has an oxidation peak at 0.77 V and a reduction peak at 0.43 V; P3 has an oxidation peak at 0.81 V and a reduction peak at 0.48 V; P4 has an oxidation peak at 0.82 V and a reduction peak at 0.45 V; it indicates that the polyamides P1, P2, P3, P4 prepared in Examples One to Four have redox reactions under applied voltage.

[0137] Figure 4 Thermogravimetric curves of the polyamides synthesized from DCTPA-NH2 prepared in Examples One to Four; from Figure 4 It can be seen that the thermal decomposition temperatures of the polyamides P1, P2, P3, P4 synthesized from DCTPA-NH2 are all above 350℃ when the weight loss is 5% in air atmosphere, indicating that these polymers have good thermodynamic stability. When the temperature of the polymer is heated to 800℃, the carbon residue rate of the polymer is all greater than 30%. It proves that the polymer has good thermal stability.

[0138] Figure 5 Electrochromic graphs of the polyamides P1, P2, P3, P4 synthesized from DCTPA-NH2 prepared in Example Four; from the graph, it can be seen that the electrochromic properties of PAs change with the increase of linear applied voltage. Taking the electrochromic properties of P1 as an example, between 0.0 V and 1.2 V, with the increase of voltage, the absorption peak at 422 nm gradually decreases, and the absorption at 555 nm, 615 nm and 960 nm gradually increases; when applied to 1.2 V, the color of the film changes to blue-purple, and the prominent wave absorption at 555 nm, 615 nm does not change, which indicates that TPA is completely oxidized to TPA + .

[0139] Figure 6The optical contrast of the polyamide P1 synthesized with DCTPA-NH2 prepared in Example 1 is 85%, and remains 76% of the initial value after 500 cycles. In comparison with the triphenylamine-containing polyamide with similar structure containing naphthofuran, the optical contrast is only 35%. This shows that the polyamide synthesized with DCTPA-NH2 has high optical contrast and excellent cycle stability.

[0140] 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, which shows that the polyamide synthesized with DCTPA-NH2 has fast switching response.

[0141] Figure 8 The fluorescence graph of the polyamide P2 synthesized with DCTPA-NH2 prepared in Example 2 in response to trinitrophenol (TNP); 1 mg of the polyamide P2 is dissolved in 20 mL of N-methylpyrrolidone to obtain a solution with a concentration of 1 x 10 -5 M of the polyamide P2, and 5 μL of TNP is added to the polyamide solution; the graph shows the fluorescence intensity curve of the polyamide solution without adding TNP and the fluorescence intensity curves of the polyamide solution with 5 μL of TNP solution with different concentrations added in sequence; it can be seen from the graph that Figure 7 It can be seen that the fluorescence intensity of the polymer solution gradually decreases with the increase of the concentration of TNP; and it can be further shown that the polymer can respond to TNP, and whether TNP exists can be detected by whether the fluorescence of the polymer solution decreases.

Claims

1. A diamine monomer, 4-({9-[(4-aminophenyl)(4-methoxyphenyl)amino]-7-methyldibenzo[c,g]carbazole-5-yl}(4-methoxyphenyl)amino)aniline (abbreviated as DCTPA-NH2); characterized in that, The monomer is a monomer containing 7-methyldibenzo[c,g]carbazole and triphenylamine, DCTPA-NH2, as shown below:

2. The polyamide synthesized by DCTPA-NH2 according to claim 1, characterized in that, DCTPA-NH2 monomer is polymerized with diacid monomer to obtain polyamide; 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 according to claim 2, characterized in that, The preparation method is as follows: I. Synthesis of monomer DCTPA-NH2: ① Under a nitrogen atmosphere, 7-H-dibenzo[c,g]carbazole and N,N-dimethylformamide solution were added to a three-necked flask. The reaction system was placed in an ice-water bath to maintain the temperature at 0℃. Sodium hydride was slowly added, and stirring was continued for 0.5 hours. Iodomethane was then added, and the resulting mixture was reacted at 25℃. Thin-layer chromatography was used to determine whether the isothermal reaction was complete. After the reaction was completed, the reaction solution was cooled to room temperature and poured into a large amount of distilled water to precipitate the precipitate. The precipitate was filtered out and washed with a large amount of distilled water. The product was vacuum dried to obtain a white solid 7-methyldibenzo[c,g]carbazole, named M1. The ratio of the amount of 7-H dibenzo[c,g]carbazole to the volume of N,N-dimethylformamide in step 1① is 15 mmol: 20 mL. The molar ratio of 7-H dibenzo[c,g]carbazole to sodium hydride in step 1① is 1:1.1; The molar ratio of 7-H dibenzo[c,g]carbazole to iodomethane in step 1① is 1:1.1; ② Under a nitrogen atmosphere, M1 and N,N-dimethylformamide solution were added to a three-necked flask. The reaction system was kept in an ice-water bath at 0°C and protected from light. N-bromosuccinimide was dissolved in a small amount of N,N-dimethylformamide solution and slowly added dropwise to the three-necked flask while keeping the temperature at 0°C during the addition. After the addition was completed, the reaction was carried out at room temperature. Thin-layer chromatography was used to determine whether the isothermal reaction was complete. After the reaction was completed, an appropriate amount of water was added to the reaction solution for quenching. The product was extracted three times with dichloromethane. The combined organic phase was washed with brine, dried with anhydrous magnesium sulfate, and concentrated under vacuum to obtain the crude product. The crude product was separated by silica gel column chromatography and dried under vacuum to obtain a white solid 5,9-dibromo-7-methyldibenzo[c,g]carbazole, named M2. The amount of substance of M1 mentioned in step 1② and the volume ratio of N,N-dimethylformamide are 5 mmol: 40 mL; 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 mentioned in step 1② to the molar ratio of M1 is 5 mL: 5 mmol; ③ Under a nitrogen atmosphere, M2, 4-methoxy-4'-nitrodiphenylamine, sodium tert-butoxide, tris(dibenzylacetone)dipalladium, tri-tert-butylphosphine tetrafluoroborate, and toluene were added to a three-necked flask and reacted at 110°C. Thin-layer chromatography was used to determine whether the isothermal reaction was complete. After the reaction was completed, the reaction solution was cooled to room temperature and then added to a large amount of petroleum ether to precipitate. The precipitate was filtered, dried under vacuum, and the crude product was obtained. The crude product was separated by silica gel column chromatography and dried under vacuum to obtain a yellow solid 5,9-bis[(4-methoxyphenyl)(4-nitrophenyl)amino]-7-methyldibenzo[c,g]carbazole, named M3. The molar ratio of M2 to 4-methoxy-4'-nitrodiphenylamine mentioned in step 1③ is 1:2.2; In step 1, ③, the molar ratio of M2 to sodium tert-butoxide is 1:0.

2. The molar ratio of M2 to tris(dibenzylacetone)palladium in step 1③ is 1:0.05; The molar ratio of M2 to tri-tert-butylphosphine tetrafluoroborate mentioned in step 1③ is 1:0.1; In step 1③, the volume ratio of toluene to the molar ratio of M2 is 30 mL: 1 mmol. ④ Under a nitrogen atmosphere, add M3, Pd / C and anhydrous ethanol to a three-necked flask. Add hydrazine hydrate to the mixed solution in the three-necked flask at a dropping rate of 1-2 drops per second using a constant pressure funnel. Heat to the boiling point of ethanol to carry out the reduction reaction. Use thin-layer chromatography to determine whether the isothermal reaction has ended. After the reaction is complete, filter the solution and pour the filtrate into distilled water. Stir until no precipitate forms. Filter out the precipitate and wash it with distilled water. Then, vacuum dry to obtain a yellow solid DCTPA-NH2. The volume ratio of anhydrous ethanol to the amount of M3 in step 1, ④ is (100-120) mL: 1 mmol. In step 1, the mass ratio of Pd / C to the molar amount of M3 is 1 g: 5 mmol. The volume ratio of hydrazine hydrate to the amount of M3 in step 1, ④ is 5 mL: 1 mmol; The Pd / C mentioned in step 1④ is a Pd C-doped composite material, and the mass fraction of Pd in ​​Pd / C is 10%. II. Preparation of polyamides containing DCTPA-NH2: DCTPA-NH2, diacid monomer, triphenyl phosphite, CaCl2, pyridine and N-methylpyrrolidone were mixed and stirred at 120°C for 6 hours. After cooling to room temperature, the mixture was poured into methanol to precipitate the product. The product was collected by filtration and extracted with acetone using a Soxhlet extractor. The molar ratio of DCTPA-NH2 to the diacid monomer in step two is 1:1; The volume ratio of triphenyl phosphite to the molar amount of DCTPA-NH2 in step two is 1.5 mL: 1 mmol; In step two, the volume ratio of pyridine to the molar amount of DCTPA-NH2 is 1.5 mL: 1 mmol. The volume ratio of N-methylpyrrolidone to the molar amount of DCTPA-NH2 in step two is 1.5 mL: 1 mmol; The mass ratio of CaCl2 to the volume of N-methylpyrrolidone in step two is 0.15 g : 1.5 mL; The diacid monomers mentioned in step two are 4,4'-sulfonyl dibenzoic acid, cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxylic acid diphenyl ether, 4,4'-(perfluoropropane-2,2-diyl)dibenzoic acid, terephthalic acid, and 1,4-naphthalenedicarboxylic acid.

4. The method for preparing polyamide according to claim 3, characterized in that... The Soxhlet extraction solvent used in step two is 400 mL of acetone, and the extraction time is 72 hours.

5. The application of the polyamide according to claim 2 as an electrochromic layer in an electrochromic device.

6. The application of the polyamide according to claim 5, characterized in that: The polyamide 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, which undergoes electrochromic phenomenon under the action of an external electric field.

7. The application of the polyamide according to claim 6, characterized in that... The voltage of the applied electric field is 0V to 3V.

8. The application of the polyamide according to claim 6, characterized in that... The transparent electrode is ITO, transparent carbon nanotube, or silver nanowire electrode.

9. The polyamide according to claim 2 is used as a reagent for preparing fluorescence detection of p-trinitrophenol.

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