phenanthrimidazole-bridged triphenylamine monomers and polyamides, their preparation methods and applications

Abstract

This invention relates to a method for preparing and applying polyamides containing phenanthrimidazole-bridged triphenylamine monomers N1,N1'-((1H-phenanthrimidazole-1,2-diyl)bis(4,1-phenyl))bis(N1-(4-methoxyphenyl)benzene-1,4-diamine) and polyamides. To address the problems of poor solubility, poor electrochemical cycling stability, slow response speed, and limited functionality in polyamide materials, this invention uses the bipolar phenanthrimidazole group as a bridge to connect two triphenylamine units. The large volume of the triphenylamine groups prevents the formation of a tightly packed polymer backbone, allowing solvent molecules to easily enter, thereby improving the polymer's solubility and facilitating solution film formation. The phenanthrimidazole introduced in this invention increases the charge transport capacity between polymer films through tight stacking, while the group also exhibits the ability to bind ferric ions. This invention can be applied to fields such as smart displays, electrochromic smart windows, military camouflage, and specific detection of ferric ions.

Description

Technical Field

[0001] This invention relates to a phenanthrimidazole-bridged triphenylamine diamine monomer and a polyamide, as well as their preparation methods and applications. Background Technology

[0002] The growing energy crisis has spurred research and innovation in the field of functional materials. Electrochromic materials, as functional materials with optically modulated properties, have become a research hotspot in materials science and electrochemistry due to their stable and reversible color changes under an applied electric field. In recent years, significant progress has been made in combining electrochromic materials with other functional properties, particularly in the development of multifunctional optoelectronic materials with uniquely customized molecular-level aromatic polyamides. Aromatic polyamides exhibit low conjugation between monomers, thus their optoelectronic properties are influenced by the molecular structure of the modified electroactive groups.

[0003] Triphenylamine and its derivatives exhibit a unique non-planar propeller structure, accelerating electrochemical response rates by inhibiting polymer chain stacking and promoting ion transport. Simultaneously, triphenylamine possesses multiple modifiable sites, allowing for the combination of electrochromic properties with other functional characteristics through molecular design. This opens up possibilities for expanding the application potential of electrochromic, chemical sensors, and other smart optoelectronic devices. Phenanimazole, a typical fluorescent chromophore, possesses a π-conjugated planar structure that facilitates the delocalization of the molecular electron cloud and is widely used in optoelectronics. Phenanimazole can not only be used as a typical fluorescent group, but the carbon-nitrogen double bond in its imidazole moiety can also act as a recognition group to bind to specific metal ions.

[0004] This invention relates to a polyamide comprising two triphenylamine units constructed on a phenanthreneimidazole structure. Substituting the imidazole group at different positions with two propeller-shaped triphenylamine groups reduces inter-chain stacking, thereby creating pores that facilitate ion transport. The phenanthrene structure within the phenanthreneimidazole group exhibits a strong stacking tendency, thus promoting electron hopping processes in the polyamide film. The combination of these two factors enhances the response rate of electrochemical reactions and charge transfer efficiency. Furthermore, the introduction of phenanthreneimidazole groups into the polymer structure endows the invented polymer with photoluminescence and chemiluminescence properties. Summary of the Invention

[0005] This invention addresses the problems of low solubility, poor processability, poor electrochemical cycling stability, slow response time, and narrow application range of aromatic polyamides in organic solvents. It proposes a monomer (PIBTPA-A) containing phenanthreneimidazole and triphenylamine, along with polyamides, their preparation methods, and applications. Ultimately, a class of electrochemically stable and fast-responding polyamides was obtained, and their application in electrochromic devices and explosive detection was explored, investigating their feasibility for practical use.

[0006] This invention uses the polyamide synthesized from PIBTPA-A as the polyamide synthesized from the diamine monomer of PIBTPA-A and a dicarboxylic acid monomer (the dicarboxylic acid can be cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxylic acid, 4,4''-sulfonyldibenzoic acid, terephthalic acid, benzophenone-4,4'-dicarboxylic acid, 4,4"-(perfluoropropane-2,2-diyl)dibenzoic acid, biphenyl dicarboxylic acid, 1,1'-di(cyclohexyl)-4,4'-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, 2,2'-bipyridine-5,5'-dicarboxylic acid, stilbene-4,4-dicarboxylic acid, etc.).

[0007] The structural formulas of the prepared polyamides P1 to P12 are as follows: In the formula, n is an integer from 8 to 30.

[0008] The preparation method of the polyamide containing phenanthreneimidazole and triphenylamine structures of the present invention is carried out according to the following steps:

[0009] I. Synthesis of monomer PIBTPA-A:

[0010] ① Under a nitrogen atmosphere, 9,10-phenanthrenequinone, 4-bromobenzaldehyde, 4-bromoaniline, ammonium acetate, and glacial acetic acid were added to a three-necked flask. The mixture was then heated and stirred at a constant temperature of 120°C. Thin-layer chromatography was used to determine whether the isothermal reaction was complete. After the reaction was complete, the solution was cooled to room temperature and poured into a saturated sodium chloride solution to precipitate the precipitate. The precipitate was then quenched, filtered, and vacuum dried to obtain the crude product. Next, the crude product was separated by silica gel column chromatography, and the product was vacuum dried to obtain a yellow solid 1,2-bis(4-bromophenyl)-1H-phenanthrene[9,10-d]imidazole, named M1.

[0011] The molar ratio of 9,10-phenanthrenequinone to 4-bromobenzaldehyde in step 1① is 1:1;

[0012] The molar ratio of 9,10-phenanthrenequinone to 4-bromoaniline in step 1① is 1:1.3;

[0013] The molar ratio of 9,10-phenanthrenequinone to ammonium acetate in step 1① is 1:12.5;

[0014] The ratio of the amount of 9,10-phenanthrenequinone to the volume of glacial acetic acid in step 1① is 1 mmol: 10 mL.

[0015] The volume ratio of the filtrate to the saturated sodium chloride solution in step 1① is 1:4;

[0016] The vacuum drying temperature in step 1① is 50°C, the vacuum drying time is 24 hours, and the vacuum drying pressure is -30~-29KPa;

[0017] ② Under a nitrogen atmosphere, a mixture of M1, 4-methoxy-4'-nitrodiphenylamine, potassium carbonate, 18-crown-6-ether, copper powder, and o-dichlorobenzene was heated to 160°C and refluxed. After the reaction was completed, the mixture was filtered. The filtrate was added to petroleum ether to precipitate the precipitate, which was then filtered again. The solid obtained by filtration was purified by silica gel column chromatography. After evaporation of the solution, it was dried under vacuum to obtain 4,4'-(1H-phenanthro[9,10-d]imidazol-1,2-diyl)bis(N-(4-methoxyphenyl)-N-(4-nitrophenyl)aniline), which was named M2.

[0018] In step 1②, the molar ratio of M1 to 4-methoxy-4'-nitrodiphenylamine is 1:2;

[0019] In step 1②, the molar ratio of M1 to potassium carbonate is 1:7;

[0020] The molar ratio of M1 to 18-crown-6 ether mentioned in step 1② is 1:1;

[0021] In step 1②, the molar ratio of M1 to copper powder is 1:7;

[0022] In step 1②, the volume ratio of o-dichlorobenzene to the molar amount of M1 is 5 mL: 1 mmol;

[0023] The volume ratio of petroleum ether to the molar amount of M1 in step 1② is 150 mL : 1 mmol;

[0024] The vacuum drying temperature described in step 1② is 40°C, the vacuum drying time is 36~48 hours, and the vacuum drying pressure is -30~-29KPa;

[0025] ③ Under a nitrogen atmosphere at room temperature, anhydrous ethanol, palladium on carbon, and M2 were added to a three-necked flask. Hydrazine hydrate was added dropwise to the mixed solution in the three-necked flask using a constant pressure funnel at a dropping rate of 1-2 drops per second. The temperature was raised to 80°C, and the reaction was stopped after 10-12 hours. The palladium on carbon was removed by filtration. The filtrate was poured into a saturated sodium chloride solution until no solid phase was precipitated. The solid phase was filtered out and washed with water. Then, it was dried under vacuum to obtain N1,N1'-((1H-phenanthro[9,10-d]imidazol-1,2-diyl)bis(4,1-phenyl))bis(N1-(4-methoxyphenyl)benzene-1,4-diamine), named PIBTPA-A.

[0026] The volume ratio of anhydrous ethanol to the amount of M2 in step 1③ is 80 mL: 1 mmol;

[0027] In step 1③, the mass ratio of palladium on carbon to the molar amount of M2 is 1 g: 5 mmol.

[0028] In step 1③, the volume ratio of hydrazine hydrate to the amount of M2 is 5 mL: 1 mmol.

[0029] The volume ratio of the filtrate to the sodium chloride solution in step 1, ③ is 1:4;

[0030] The palladium on carbon mentioned in step 1③ is a carbon-doped composite material of palladium, and the mass fraction of carbon in palladium on carbon is 10%.

[0031] The vacuum drying temperature described in step 1③ is 30°C, the vacuum drying time is 48~60 hours, and the vacuum drying pressure is -30~-29KPa;

[0032] II. Preparation of Polyamide:

[0033] Under a nitrogen atmosphere, PIBTPA-A, dicarboxylic acid monomer, triphenyl phosphite, calcium chloride, pyridine and N-methylpyrrolidone were mixed and stirred at 130°C for 8 hours. After cooling to room temperature, the mixture was poured into methanol to precipitate the solid. The product was collected by filtration, washed thoroughly with methanol, and finally extracted with acetone using a Soxhlet extractor.

[0034] The molar ratio of PIBTPA-A to dicarboxylic acid monomer in step two is 1:1;

[0035] In step two, the ratio of the amount of PIBTPA-A to the volume of triphenyl phosphite is 1 mmol: 2 mL.

[0036] In step two, the volume ratio of pyridine to the molar amount of PIBTPA-A is 2 mL: 1 mmol.

[0037] The volume ratio of N-methylpyrrolidone to the molar amount of PIBTPA-A in step two is 3 mL: 1 mmol;

[0038] The mass ratio of calcium chloride to N-methylpyrrolidone in step two is 1 g: 1 mL;

[0039] In step two, the volume ratio of methanol added to the amount of M4 during the precipitation of solid is 150 mL: 1 mmol.

[0040] The dicarboxylic acid monomers mentioned in step two are cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxylic acid, 4,4''-sulfonyl dibenzoic acid, terephthalic acid, benzophenone-4,4'-dicarboxylic acid, 4,4"-(perfluoropropane-2,2-diyl)dibenzoic acid, biphenyl dicarboxylic acid, 1,1'-di(cyclohexyl)-4,4'-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, 2,2'-bipyridine-5,5'-dicarboxylic acid, stilbene-4,4-dicarboxylic acid, and other dicarboxylic acid monomers.

[0041] The present invention has the following beneficial effects:

[0042] I. This invention contains phenanthrimidazole-bridged triphenylamine polyamides. Because phenanthrimidazole is directly bonded to diphenylamine, the non-planar structure between them can suppress inter-chain stacking in the polymer, thereby improving polymer solubility and enabling the formation of stable and uniform thin films. Simultaneously, it facilitates the formation of ion entry channels, effectively enhancing electrochemical reactivity and ion detection sensitivity. The aromatic structure significantly improves the polymer's thermal stability. The thermal stability of the polyamide was evaluated through thermogravimetric analysis. The polyamide begins to lose weight at 300°C; at 800°C, the residual carbon content is 29-37%, indicating that phenanthrimidazole-bridged triphenylamine polyamides possess good solubility and thermal stability.

[0043] II. The polymers of this invention exhibit excellent electrochromic properties. During the electrochromic process, the polymers of this invention exhibit multiple color changes; when a gradually increasing voltage is applied, polymers P1 and P2 change from colorless to yellowish-green and then to blackish-purple. The polymers of this invention have high optical contrast, with polymer P1 achieving a maximum optical contrast of 63%. Furthermore, the polymers exhibit good cycling stability; after 10,000 seconds of cycling, polymer P1 retains 70% of its optical contrast, demonstrating excellent electrochromic stability.

[0044] Third, polymer P1 in this invention exhibits strong fluorescence. When the N-methylpyrrolidone solution of the polymer of this invention comes into contact with a solution of ferric ions, the fluorescence of the polymer solution gradually decreases until it disappears. The polymer of this invention can be used to detect ferric ions. Attached Figure Description

[0045] Figure 1 The NMR spectrum of the N1,N1'-((1H-phenanthro[9,10-d]imidazol-1,2-diyl)bis(4,1-phenyl))bis(N1-(4-methoxyphenyl)benzene-1,4-diamine) monomer prepared in Example 1;

[0046] Figure 2 Fourier transform infrared spectra of phenanthrimidazole-bridged triphenylamine polyamides P1 and P2 prepared in Examples 1 and 2;

[0047] Figure 3 Thermogravimetric curves of phenanthrimidazole-bridged triphenylamine polyamides P1 and P2 prepared in Examples 1 and 2;

[0048] Figure 4 Cyclic voltammetry curves of phenanthrimidazole-bridged triphenylamine polyamides P1 and P2 prepared in Examples 1 and 2;

[0049] Figure 5 The electrochemical spectrograms of phenanthrimidazole-bridged triphenylamine polyamides P1 and P2 prepared in Examples 1 and 2 are shown.

[0050] Figure 6 Cyclic stability of the phenanthrimidazole-bridged triphenylamine polyamide P1 prepared in Example 1;

[0051] Figure 7 The response time of the phenanthrimidazole-bridged triphenylamine polyamide P1 prepared in Example 1;

[0052] Figure 8 The fluorescence intensity change curve of the trivalent iron ion-reactive polyamide P1 containing phenanthrimidazole bridged triphenylamine prepared in Example 1 is shown. Detailed Implementation

[0053] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments.

[0054] Specific implementation method one: The phenanthrimidazole-bridged triphenylamine polyamide in this implementation method is phenanthrimidazole-bridged triphenylamine polyamide P1 or P2.

[0055] The structural formula of polyamide P1 containing phenanthrimidazole-bridged triphenylamine is as follows: In the formula, n is an integer from 8 to 30.

[0056] The structural formula of the phenanthrimazole-bridged triphenylamine polyamide P2 is as follows: In the formula, n is an integer from 8 to 30.

[0057] The phenanthrimidazole-bridged triphenylamine polyamide prepared in this embodiment has significantly improved polymer solubility due to the non-planar structure of triphenylamine and phenanthrimidazole, which reduces inter-chain stacking. It also improves the electrochromic response and the sensitivity of ion detection.

[0058] Specific Implementation Method Two: The preparation method of the phenanthrimidazole-bridged triphenylamine polyamide in this implementation method is as follows:

[0059] I. Synthesis of monomer PIBTPA-A:

[0060] ① Under a nitrogen atmosphere, 9,10-phenanthrenequinone, 4-bromobenzaldehyde, 4-bromoaniline, ammonium acetate, and glacial acetic acid were added to a three-necked flask. The mixture was then heated and stirred at a constant temperature of 120°C. Thin-layer chromatography was used to determine whether the isothermal reaction was complete. After the reaction was complete, the solution was cooled to room temperature and poured into a saturated sodium chloride solution to precipitate the precipitate. The precipitate was then quenched, filtered, and vacuum dried to obtain the crude product. Next, the crude product was separated by silica gel column chromatography, and the product was vacuum dried to obtain a yellow solid 1,2-bis(4-bromophenyl)-1H-phenanthrene[9,10-d]imidazole, named M1.

[0061] The molar ratio of 9,10-phenanthrenequinone to 4-bromobenzaldehyde in step 1① is 1:1;

[0062] The molar ratio of 9,10-phenanthrenequinone to 4-bromoaniline in step 1① is 1:1.3;

[0063] The molar ratio of 9,10-phenanthrenequinone to ammonium acetate in step 1① is 1:12.5;

[0064] The ratio of the amount of 9,10-phenanthrenequinone to the volume of glacial acetic acid in step 1① is 1 mmol: 10 mL.

[0065] The volume ratio of the filtrate to the saturated sodium chloride solution in step 1① is 1:4;

[0066] The vacuum drying temperature in step 1① is 50°C, the vacuum drying time is 24 hours, and the vacuum drying pressure is -30~-29KPa;

[0067] ② Under a nitrogen atmosphere, a mixture of M1, 4-methoxy-4'-nitrodiphenylamine, potassium carbonate, 18-crown-6-ether, copper powder, and o-dichlorobenzene was heated to 160°C and refluxed. After the reaction was completed, the mixture was filtered. The filtrate was added to petroleum ether to precipitate the precipitate, which was then filtered again. The solid obtained by filtration was purified by silica gel column chromatography. After evaporation of the solution, it was dried under vacuum to obtain 4,4'-(1H-phenanthro[9,10-d]imidazol-1,2-diyl)bis(N-(4-methoxyphenyl)-N-(4-nitrophenyl)aniline), which was named M2.

[0068] In step 1②, the molar ratio of M1 to 4-methoxy-4'-nitrodiphenylamine is 1:2;

[0069] In step 1②, the molar ratio of M1 to potassium carbonate is 1:7;

[0070] The molar ratio of M1 to 18-crown-6 ether mentioned in step 1② is 1:1;

[0071] In step 1②, the molar ratio of M1 to copper powder is 1:7;

[0072] In step 1②, the volume ratio of o-dichlorobenzene to the molar amount of M1 is 5 mL: 1 mmol;

[0073] The volume ratio of petroleum ether to the molar amount of M1 in step 1② is 150 mL : 1 mmol;

[0074] The vacuum drying temperature described in step 1② is 40°C, the vacuum drying time is 36~48 hours, and the vacuum drying pressure is -30~-29KPa;

[0075] ③ Under a nitrogen atmosphere at room temperature, anhydrous ethanol, palladium on carbon, and M2 were added to a three-necked flask. Hydrazine hydrate was added dropwise to the mixed solution in the three-necked flask using a constant pressure funnel at a dropping rate of 1-2 drops per second. The temperature was raised to 80°C, and the reaction was stopped after 10-12 hours. The palladium on carbon was removed by filtration. The filtrate was poured into a saturated sodium chloride solution until no solid phase was precipitated. The solid phase was filtered out and washed with water. Then, it was dried under vacuum to obtain N1,N1'-((1H-phenanthro[9,10-d]imidazol-1,2-diyl)bis(4,1-phenyl))bis(N1-(4-methoxyphenyl)benzene-1,4-diamine), named PIBTPA-A.

[0076] The volume ratio of anhydrous ethanol to the amount of M2 in step 1③ is 80 mL: 1 mmol;

[0077] In step 1③, the mass ratio of palladium on carbon to the molar amount of M2 is 1 g: 5 mmol.

[0078] In step 1③, the volume ratio of hydrazine hydrate to the amount of M2 is 5 mL: 1 mmol.

[0079] The volume ratio of the filtrate to the sodium chloride solution in step 1, ③ is 1:4;

[0080] The palladium on carbon mentioned in step 1③ is a carbon-doped composite material of palladium, and the mass fraction of carbon in palladium on carbon is 10%.

[0081] The vacuum drying temperature described in step 1③ is 30°C, the vacuum drying time is 48~60 hours, and the vacuum drying pressure is -30~-29KPa;

[0082] II. Preparation of Polyamide:

[0083] Under a nitrogen atmosphere, PIBTPA-A, cyclohexane-1,4-dicarboxylic acid, triphenyl phosphite, calcium chloride, pyridine, and N-methylpyrrolidone were mixed and stirred at 130°C for 8 hours. After cooling to room temperature, the mixture was poured into methanol to precipitate a solid. The product was collected by filtration, washed thoroughly with methanol, and finally extracted with acetone using a Soxhlet extractor.

[0084] The molar ratio of PIBTPA-A to cyclohexane-1,4-dicarboxylic acid in step two is 1:1.

[0085] In step two, the ratio of the amount of PIBTPA-A to the volume of triphenyl phosphite is 1 mmol: 2 mL.

[0086] In step two, the volume ratio of pyridine to the molar amount of PIBTPA-A is 2 mL: 1 mmol.

[0087] The volume ratio of N-methylpyrrolidone to the molar amount of PIBTPA-A in step two is 3 mL: 1 mmol;

[0088] The mass ratio of calcium chloride to N-methylpyrrolidone in step two is 1 g: 1 mL;

[0089] In step two, the volume ratio of methanol added to the amount of M4 during the precipitation of solid is 150 mL: 1 mmol.

[0090] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 2 in that the dicarboxylic acid monomer mentioned in step 2 is 4,4'-dicarboxylic acid diphenyl ether, and polymer P2 is obtained.

[0091] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method Two in that the Soxhlet extraction solvent in step two is 400 mL of dichloromethane, the extraction temperature is 70°C, and the extraction time is 48 hours.

[0092] Specific Implementation Method 5: This implementation method uses polyamide synthesized from PIBTPA-A as the electrochromic layer in an electrochromic device.

[0093] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method Five in that the application of polyamide synthesized with PIBTPA-A as the electrochromic layer in the electrochromic device is carried out in the following steps: the polyamide synthesized with PIBTPA-A is used as the electrochromic layer in the electrochromic device, and the electrochromic layer is coated on a conductive transparent electrode to prepare an active electrode, which then undergoes electrochromic phenomenon under the action of an external electric field.

[0094] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method Five in that the voltage of the external electric field is 1~1.5V.

[0095] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method Five in that the transparent electrode is a silver nanowire electrode, while the rest is the same as Specific Implementation Method Six.

[0096] Specific Implementation Method Nine: In this implementation method, polyamide synthesized by PIBTPA-A is used for the fluorescence detection of ferric ions.

[0097] The beneficial effects of the present invention are verified using the following embodiments:

[0098] Example 1: The structural formula of polyamide P1 containing phenanthreneimidazole-bridged triphenylamine is as follows: In the formula, n is an integer from 8 to 30.

[0099] The preparation method of the phenanthrimidazole-bridged triphenylamine polyamide P1 in this embodiment is as follows:

[0100] I. Synthesis of monomer PIBTPA-A:

[0101] ① Under a nitrogen atmosphere, 9,10-phenanthrenequinone, 4-bromobenzaldehyde, 4-bromoaniline, ammonium acetate, and glacial acetic acid were added to a three-necked flask. The mixture was then heated and stirred at a constant temperature of 120°C. Thin-layer chromatography was used to determine whether the isothermal reaction was complete. After the reaction was complete, the solution was cooled to room temperature and poured into a saturated sodium chloride solution to precipitate the precipitate. The precipitate was then quenched, filtered, and vacuum dried to obtain the crude product. Next, the crude product was separated by silica gel column chromatography, and the product was vacuum dried to obtain a yellow solid 1,2-bis(4-bromophenyl)-1H-phenanthrene[9,10-d]imidazole, named M1.

[0102] The molar ratio of 9,10-phenanthrenequinone to 4-bromobenzaldehyde in step 1① is 1:1;

[0103] The molar ratio of 9,10-phenanthrenequinone to 4-bromoaniline in step 1① is 1:1.3;

[0104] The molar ratio of 9,10-phenanthrenequinone to ammonium acetate in step 1① is 1:12.5;

[0105] The ratio of the amount of 9,10-phenanthrenequinone to the volume of glacial acetic acid in step 1① is 1 mmol: 10 mL.

[0106] The volume ratio of the filtrate to the saturated sodium chloride solution in step 1① is 1:4;

[0107] The vacuum drying temperature in step 1① is 50°C, the vacuum drying time is 24 hours, and the vacuum drying pressure is -30~-29KPa;

[0108] ② Under a nitrogen atmosphere, a mixture of M1, 4-methoxy-4'-nitrodiphenylamine, potassium carbonate, 18-crown-6-ether, copper powder, and o-dichlorobenzene was heated to 160°C and refluxed. After the reaction was completed, the mixture was filtered. The filtrate was added to petroleum ether to precipitate the precipitate, which was then filtered again. The solid obtained by filtration was purified by silica gel column chromatography. After evaporation of the solution, it was dried under vacuum to obtain 4,4'-(1H-phenanthro[9,10-d]imidazol-1,2-diyl)bis(N-(4-methoxyphenyl)-N-(4-nitrophenyl)aniline), which was named M2.

[0109] In step 1②, the molar ratio of M1 to 4-methoxy-4'-nitrodiphenylamine is 1:2;

[0110] In step 1②, the molar ratio of M1 to potassium carbonate is 1:7;

[0111] The molar ratio of M1 to 18-crown-6 ether mentioned in step 1② is 1:1;

[0112] In step 1②, the molar ratio of M1 to copper powder is 1:7;

[0113] In step 1②, the volume ratio of o-dichlorobenzene to the molar amount of M1 is 5 mL: 1 mmol;

[0114] The volume ratio of petroleum ether to the molar amount of M1 in step 1② is 150 mL : 1 mmol;

[0115] The vacuum drying temperature described in step 1② is 40°C, the vacuum drying time is 36~48 hours, and the vacuum drying pressure is -30~-29KPa;

[0116] ③ Under a nitrogen atmosphere at room temperature, anhydrous ethanol, palladium on carbon, and M2 were added to a three-necked flask. Hydrazine hydrate was added dropwise to the mixed solution in the three-necked flask using a constant pressure funnel at a dropping rate of 1-2 drops per second. The temperature was raised to 80°C, and the reaction was stopped after 10-12 hours. The palladium on carbon was removed by filtration. The filtrate was poured into a saturated sodium chloride solution until no solid phase was precipitated. The solid phase was filtered out and washed with water. Then, it was dried under vacuum to obtain N1,N1'-((1H-phenanthro[9,10-d]imidazol-1,2-diyl)bis(4,1-phenyl))bis(N1-(4-methoxyphenyl)benzene-1,4-diamine), named PIBTPA-A.

[0117] The volume ratio of anhydrous ethanol to the amount of M2 in step 1③ is 80 mL: 1 mmol;

[0118] In step 1③, the mass ratio of palladium on carbon to the molar amount of M2 is 1 g: 5 mmol.

[0119] In step 1③, the volume ratio of hydrazine hydrate to the amount of M2 is 5 mL: 1 mmol.

[0120] The volume ratio of the filtrate to the sodium chloride solution in step 1, ③ is 1:4;

[0121] The palladium on carbon mentioned in step 1③ is a carbon-doped composite material of palladium, and the mass fraction of carbon in palladium on carbon is 10%.

[0122] The vacuum drying temperature described in step 1③ is 30°C, the vacuum drying time is 48~60 hours, and the vacuum drying pressure is -30~-29KPa;

[0123] II. Preparation of Polyamide:

[0124] Under a nitrogen atmosphere, PIBTPA-A, cyclohexane-1,4-dicarboxylic acid, triphenyl phosphite, calcium chloride, pyridine, and N-methylpyrrolidone were mixed and stirred at 130°C for 8 hours. After cooling to room temperature, the mixture was poured into methanol to precipitate a solid. The product was collected by filtration, washed thoroughly with methanol, and finally extracted with acetone using a Soxhlet extractor.

[0125] The molar ratio of PIBTPA-A to cyclohexane-1,4-dicarboxylic acid in step two is 1:1.

[0126] In step two, the ratio of the amount of PIBTPA-A to the volume of triphenyl phosphite is 1 mmol: 2 mL.

[0127] In step two, the volume ratio of pyridine to the molar amount of PIBTPA-A is 2 mL: 1 mmol.

[0128] The volume ratio of N-methylpyrrolidone to the molar amount of PIBTPA-A in step two is 3 mL: 1 mmol;

[0129] The mass ratio of calcium chloride to N-methylpyrrolidone in step two is 1 g: 1 mL;

[0130] In step two, the volume ratio of methanol added to the amount of M4 during the precipitation of solid is 150 mL: 1 mmol.

[0131] Example 2: The structural formula of polyamide P1 containing phenanthreneimidazole-bridged triphenylamine is as follows: In the formula, n is an integer from 8 to 30.

[0132] 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 replaced by 4,4"-dicarboxylic acid.

[0133] In Examples 1 and 2, the solvent used in step 1① of thin-layer chromatography was a mixture of ethyl acetate and petroleum ether, with a volume ratio of ethyl acetate to petroleum ether of 1:6; the solvent used in step 1② of silica gel column chromatography purification was a mixture of ethyl acetate and petroleum ether, with a volume ratio of ethyl acetate to petroleum ether of 1:12.

[0134] The preparation method of the phenanthrimidazole-bridged triphenylamine polyamide as an electrochromic material prepared in Examples 1 and 2 is as follows: 1 mg of phenanthrimidazole-bridged triphenylamine polyamide is dissolved in 1 mL of organic solvent to obtain a phenanthrimidazole-bridged triphenylamine polyamide solution. Then, the phenanthrimidazole-bridged triphenylamine polyamide is coated on conductive glass to obtain the electrochromic material. The organic solvent is N-methylpyrrolidone.

[0135] Figure 1 The image shows the proton NMR spectrum of the monomer PIBTPA-A prepared in Example 1, proving the successful synthesis of the monomer.

[0136] Figure 2 Fourier transform infrared spectra of phenanthreneimidazole-bridged triphenylamine polyamides P1 and P2 prepared in Examples 1 and 2; Figure 2 3270-3306cm -1 The characteristic absorption peak of -NH- in the amide bond is 1660 cm⁻¹. -1 The characteristic absorption peak of the carbonyl group in the amide bond is 1241 cm⁻¹. -1 The peaks represent the characteristic absorption peaks of NC in the amide bond, indicating that P1 and P2 were successfully synthesized in Example 2.

[0137] Figure 3 Thermogravimetric analysis spectra of phenanthreneimidazole-bridged triphenylamine polyamides prepared in Examples 1 and 2; from Figure 3 It is known that the initial thermal decomposition temperatures of phenanthrimidazole-bridged triphenylamine polyamides are 294°C and 345°C, respectively, indicating that these polymers have good thermodynamic stability. When heated to 800°C, the residual carbon content of the polymers is greater than 30%. This is due to the high content of aromatic structures in the polymers, which further demonstrates that the polymers have good thermal stability and can operate in high-temperature environments.

[0138] Figure 4 Cyclic voltammetry diagrams of phenanthrimidazole-bridged triphenylamine polyamides prepared in Examples 1 and 2; from Figure 6It can be seen that P1 showed oxidation peaks at 0.88V and 0.97V, and reduction peaks at 0.46V and 0.55V; P2 showed oxidation peaks at 0.83V and 0.92V, and reduction peaks at 0.58V and 0.63V. This indicates that the polyamides containing phenanthrimidazole bridged triphenylamine prepared in Examples 1 and 2 underwent redox reactions under applied voltage. During the redox process, the polyamides containing phenanthrimidazole bridged triphenylamine changed color, indicating that the polyamides containing phenanthrimidazole bridged triphenylamine prepared in Examples 1 to 4 have electrochromic properties.

[0139] Figure 5 The figures show the electrochromic spectra of phenanthrimidazole-bridged triphenylamine polyamides prepared in Examples 1 and 2. As can be seen from the figures, the UV-Vis spectra of the phenanthrimidazole-bridged triphenylamine polyamides change with increasing applied voltage. Taking the electrochromic properties of P2 as an example, the P2 film is pale yellow in the neutral state. As the voltage increases from 0.0V to 0.9V, oxidation of the P2 film reduces the intramolecular charge transfer effect, causing the peak at 340nm to gradually decrease, while the absorption peaks at 555nm and 830nm continue to increase, and the film color changes from pale yellow to yellowish-green. When the voltage increases to 1.1V, the absorption peaks at 555nm and 830nm continue to increase, and the film turns purplish-black.

[0140] Figure 6 The image shows the optical contrast of P1, a phenanthrimidazole-bridged triphenylamine polyamide prepared in Example 1. P1 has an optical contrast of 63%, and after 1000 cycles, it still maintains 70% of its initial value, indicating that the phenanthrimidazole-bridged triphenylamine polyamide has high optical contrast and good cycling stability.

[0141] Figure 7 The response time of the polyamide P1 containing phenanthrimidazole bridged triphenylamine prepared in Example 1 is 2.4s for coloring and 2.0s for bleaching, indicating that the polyamide containing phenanthrimidazole bridged triphenylamine has a fast switching response.

[0142] Figure 8 The fluorescence spectrum of the phenanthreneimidazole-bridged triphenylamine polyamide P1 prepared in Example 1 in response to ferric ions; Figure 8 The middle curves show the fluorescence intensity curves of the P1 solution without TNP and the fluorescence intensity curves of solutions with different concentrations of ferric ions added (1 μL each). Figure 8 It can be seen that as the concentration of ferric ions increases, the fluorescence intensity of the P1 solution gradually weakens; this indicates that the polymer can respond to ferric ions, and the presence of ferric ions can be determined by whether the fluorescence of the polymer solution decreases.

Claims

1. N1,N1'-((1H-phenanthro[9,10-d]imidazol-1,2-diyl)bis(4,1-phenyl))bis(N1-(4-methoxyphenyl)benzene-1,4-diamine), abbreviated as PIBTPA-A, has the following structural formula: 。 2. A polyamide synthesized from PIBTPA-A, characterized in that... Polyamides obtained by polymerizing PIBTPA-A monomers with dicarboxylic acid monomers; the dicarboxylic acid monomers include, but are not limited to, cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxylic acid, 4,4''-sulfonyl dibenzoic acid, terephthalic acid, benzophenone-4,4'-dicarboxylic acid, 4,4"-(perfluoropropane-2,2-diyl)dibenzoic acid, biphenyl dicarboxylic acid, 1,1'-di(cyclohexyl)-4,4'-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, 2,2'-bipyridine-5,5'-dicarboxylic acid, stilbene-4,4-dicarboxylic acid, etc. The structural formulas of the prepared polyamides P1 to P12 are as follows: In the formula, n is an integer from 8 to 30.

3. The method for preparing polyamide synthesized from PIBTPA-A as described in claim 2, characterized in that... The preparation method is as follows: I. Synthesis of monomer PIBTPA-A: ① Under a nitrogen atmosphere, 9,10-phenanthrenequinone, 4-bromobenzaldehyde, 4-bromoaniline, ammonium acetate, and glacial acetic acid were added to a three-necked flask. The mixture was then heated and stirred at a constant temperature of 120°C. Thin-layer chromatography was used to determine whether the isothermal reaction was complete. After the reaction was complete, the solution was cooled to room temperature and poured into a saturated sodium chloride solution to precipitate the precipitate. The precipitate was then quenched, filtered, and vacuum dried to obtain the crude product. Next, the crude product was separated by silica gel column chromatography, and the product was vacuum dried to obtain a yellow solid 1,2-bis(4-bromophenyl)-1H-phenanthrene[9,10-d]imidazole, named M1. The molar ratio of 9,10-phenanthrenequinone to 4-bromobenzaldehyde in step 1① is 1:1; The molar ratio of 9,10-phenanthrenequinone to 4-bromoaniline in step 1① is 1:1.3; The molar ratio of 9,10-phenanthrenequinone to ammonium acetate in step 1① is 1:12.5; The ratio of the amount of 9,10-phenanthrenequinone to the volume of glacial acetic acid in step 1① is 1 mmol: 10 mL. The volume ratio of the filtrate to the saturated sodium chloride solution in step 1① is 1:4; The vacuum drying temperature in step 1① is 50 ℃, the vacuum drying time is 24 hours, and the vacuum drying pressure is -30~-29KPa; ② Under a nitrogen atmosphere, a mixture of M1, 4-methoxy-4'-nitrodiphenylamine, potassium carbonate, 18-crown-6-ether, copper powder, and o-dichlorobenzene was heated to 160°C and refluxed. After the reaction was completed, the mixture was filtered. The filtrate was added to petroleum ether to precipitate the precipitate, which was then filtered again. The solid obtained by filtration was purified by silica gel column chromatography. After evaporation of the solution, it was dried under vacuum to obtain 4,4'-(1H-phenanthro[9,10-d]imidazol-1,2-diyl)bis(N-(4-methoxyphenyl)-N-(4-nitrophenyl)aniline), which was named M2. In step 1②, the molar ratio of M1 to 4-methoxy-4'-nitrodiphenylamine is 1:2; In step 1②, the molar ratio of M1 to potassium carbonate is 1:7; The molar ratio of M1 to 18-crown-6 ether mentioned in step 1② is 1:1; In step 1②, the molar ratio of M1 to copper powder is 1:7; In step 1②, the volume ratio of o-dichlorobenzene to the amount of M1 is 5 mL: 1 mmol; The volume ratio of petroleum ether to the amount of substance M1 in step 1② is 150 mL : 1 mmol; The vacuum drying temperature described in step 1② is 40°C, the vacuum drying time is 36~48 hours, and the vacuum drying pressure is -30~-29KPa; ③ Under a nitrogen atmosphere at room temperature, anhydrous ethanol, palladium on carbon, and M2 were added to a three-necked flask. Hydrazine hydrate was added dropwise to the mixed solution in the three-necked flask using a constant pressure funnel at a dropping rate of 1-2 drops per second. The temperature was raised to 80°C, and the reaction was stopped after 10-12 hours. The palladium on carbon was removed by filtration. The filtrate was poured into a saturated sodium chloride solution until no solid phase was precipitated. The solid phase was filtered out and washed with water. Then, it was dried under vacuum to obtain N1,N1'-((1H-phenanthro[9,10-d]imidazol-1,2-diyl)bis(4,1-phenyl))bis(N1-(4-methoxyphenyl)benzene-1,4-diamine), named PIBTPA-A. The volume ratio of anhydrous ethanol to the amount of M2 in step 1③ is 80 mL: 1 mmol. In step 1③, the mass ratio of palladium on carbon to the molar amount of M2 is 1 g: 5 mmol. The volume ratio of hydrazine hydrate to the amount of M2 in step 1③ is 5 mL: 1 mmol; The volume ratio of the filtrate to the sodium chloride solution in step 1, ③ is 1:4; The palladium on carbon mentioned in step 1③ is a carbon-doped composite material of palladium, and the mass fraction of carbon in palladium on carbon is 10%. The vacuum drying temperature described in step 1③ is 30°C, the vacuum drying time is 48~60 hours, and the vacuum drying pressure is -30~-29KPa; II. Preparation of Polyamide: Under a nitrogen atmosphere, PIBTPA-A, dicarboxylic acid monomer, triphenyl phosphite, calcium chloride, pyridine and N-methylpyrrolidone were mixed and stirred at 130°C for 8 hours. After cooling to room temperature, the mixture was poured into methanol to precipitate the solid. The product was collected by filtration, washed thoroughly with methanol, and finally extracted with acetone using a Soxhlet extractor. The molar ratio of PIBTPA-A to dicarboxylic acid monomer in step two is 1:1; In step two, the ratio of the amount of PIBTPA-A to the volume of triphenyl phosphite is 1 mmol: 2 mL. In step two, the volume ratio of pyridine to the molar amount of PIBTPA-A is 2 mL: 1 mmol. The volume ratio of N-methylpyrrolidone to the molar amount of PIBTPA-A in step two is 3 mL: 1 mmol; The mass ratio of calcium chloride to N-methylpyrrolidone in step two is 1 g: 1 mL; In step two, the ratio of the volume of methanol added to the amount of M4 during the precipitation of solid is 150 mL: 1 mmol. The dicarboxylic acid monomers mentioned in step two are cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxylic acid, 4,4''-sulfonyl dibenzoic acid, terephthalic acid, benzophenone-4,4'-dicarboxylic acid, 4,4"-(perfluoropropane-2,2-diyl)dibenzoic acid, biphenyl dicarboxylic acid, 1,1'-di(cyclohexyl)-4,4'-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, 2,2'-bipyridine-5,5'-dicarboxylic acid, stilbene-4,4-dicarboxylic acid, and other dicarboxylic acid monomers.

4. The method for preparing polyamide synthesized from PIBTPA-A according to claim 3, characterized in that... The dicarboxylic acid monomers mentioned in step two are cyclohexane-1,4-dicarboxylic acid, 4,4'-dicarboxylic acid, 4,4''-sulfonyldibenzoic acid, terephthalic acid, benzophenone-4,4'-dicarboxylic acid, 4,4"-(perfluoropropane-2,2-diyl)dibenzoic acid, biphenyl dicarboxylic acid, 1,1'-di(cyclohexyl)-4,4'-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, 2,2'-bipyridine-5,5'-dicarboxylic acid, and stilbene-4,4-dicarboxylic acid, respectively, to prepare polymers P1 to P12.

5. The method for preparing polyamide synthesized from PIBTPA-A according to claim 3, characterized in that... In step two, Soxhlet extraction was performed using acetone at a temperature of 70°C for 48 hours; the volume ratio of acetone to the molar amount of polyamide was 200 mL: 1 mmol.

6. The application of the phenanthrimidazole-bridged triphenylamine polyamide as described in claim 2 as the electrochromic layer in an electrochromic device.

7. The application of the phenanthrimidazole-bridged triphenylamine polyamide according to claim 6, characterized in that: A polyamide containing phenanthreneimidazole-bridged triphenylamine is used as the electrochromic layer in an electrochromic device. The electrochromic layer is coated on a transparent conductive electrode to prepare a polymer-modified electrode, which exhibits electrochromic phenomenon under the action of an applied electric field.

8. The application of the phenanthrimidazole-bridged triphenylamine polyamide according to claim 6, characterized in that... The voltage of the applied electric field is 0V~2V.

9. The application of the phenanthrimidazole-bridged triphenylamine polyamide according to claim 6, characterized in that... The transparent electrode is an indium tin oxide electrode or a silver nanowire electrode.

10. The phenanthrimidazole-bridged triphenylamine polyamide according to claim 2 for the fluorescence detection of ferric ions.

Images