Triphenylamine-based derivatized conjugated polymers, methods of making and using the same

Abstract

The application belongs to the technical field of polymers, and particularly relates to a triphenylamine derivative conjugated polymer and a preparation method and application thereof. The triphenylamine derivative conjugated polymer has a structure shown in formula (1): wherein X is an electron-withdrawing group; D is thiophene or 3,4-ethylenedioxythiophene; pi is thiophene or 3,4-ethylenedioxythiophene; and n is a positive integer. The triphenylamine derivative conjugated polymer has good optical contrast and coloring efficiency.

Description

Technical Field

[0001] This invention belongs to the field of polymer technology, and specifically relates to triphenylamine-derived conjugated polymers, their preparation methods, and applications. Background Technology

[0002] Electrochromism (EC) refers to the phenomenon where, under the influence of an applied driving voltage, a material undergoes an oxidation (reduction) reaction or experiences charge injection or extraction within its molecular structure. This causes a continuous and reversible change in the optical properties (including transmittance, absorptivity, or absorbance) of the polymer material within the visible and infrared spectral regions, manifesting as a change in color or transmittance in the material's appearance. Materials exhibiting this color-changing property are called electrochromic materials. These materials show commercial potential in various fields, including low-power display devices, electronic paper, color-changing skin, and information storage displays, and can be used for the upgrading and functional integration of various wearable electronic devices.

[0003] Existing electrochromic materials often employ halogen atoms to modify acceptor groups. However, the introduction of halogen atoms presents several challenges, including low photoelectron exchange yields, severe aggregation problems, difficult reaction steps, low yields, and the need for hazardous reagents. Therefore, how to better modify the material structure to reduce strong intermolecular interactions and packing density within the polymer chains, thereby increasing the polymer's processability and optical properties, is a problem that needs to be solved.

[0004] However, existing organic electrochromic materials still suffer from poor optical performance, such as high bandwidth, slow response time, and low coloring efficiency.

[0005] Therefore, there is an urgent need to provide an electrochromic polymer with good optical properties. Summary of the Invention

[0006] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a triphenylamine-derived conjugated polymer, its preparation method, and its application. The triphenylamine-derived conjugated polymer is a D-π-A-π-D type conjugated polymer. Triphenylamine (TPA) is a propeller-shaped molecule with good thermal stability, molecular morphological stability, and photoelectric properties. TPA's high oxidizing power, superior electroactivity and photoactivity, and the high stability of its corresponding free radical cations make it an excellent hole-transfer material. π-bridges are also crucial for regulating the electronic structure and electrochromic properties of D-π-A-π-D type polymers. Introducing π-bridges into conjugated polymers, such as thiophene and EDOT (3,4-ethylenedioxythiophene), makes the main chain more planar and the conjugated chain longer. Therefore, the molecular configuration, light absorption, oxidation potential, electrochemical properties, and film morphology of the conjugated polymer will be adjusted. Introducing π-bridges will redshift and extend the absorption spectra in the visible and NIR (near-infrared) regions, and result in a higher molar extinction coefficient. Meanwhile, the increased conjugation length of the polymer backbone facilitates electrochemical polymerization at lower potentials and the formation of high-quality polymer films.

[0007] The triphenylamine-derived conjugated polymers exhibit good processing and optical properties, with excellent optical contrast and coloring efficiency.

[0008] A first aspect of the present invention provides triphenylamine-derived conjugated polymers.

[0009] Specifically, triphenylamine-derived conjugated polymers have the structure shown in formula (1):

[0010]

[0011] Where X is an electron-withdrawing group;

[0012] π represents thiophene or 3,4-ethylenedioxythiophene;

[0013] D represents thiophene or 3,4-ethylenedioxythiophene;

[0014] n is a positive integer.

[0015] In formula (1), thiophene or 3,4-ethylenedioxythiophene is used as the donor unit D, and thiophene or 3,4-ethylenedioxythiophene is used as the π bridge.

[0016] Preferably, X is selected from one of nitro, cyano, aldehyde, carboxyl, thiol, amino, acyl, trifluoromethyl, and F atoms.

[0017] Preferably, n is an integer from 1 to 10000, such as 100-8000 or 500-5000.

[0018] Preferably, π has the following structure:

[0019] One of them.

[0020] Preferably, D has the following structure:

[0021] One of them.

[0022] Preferably, the structure of the triphenylamine-derived conjugated polymer is shown in formula (2), formula (3), formula (4) or formula (5):

[0023]

[0024] A second aspect of the present invention provides a method for preparing triphenylamine-derived conjugated polymers.

[0025] Specifically, the preparation method of triphenylamine-derived conjugated polymers includes the following steps:

[0026] The bromoaniline-based substance and the π-unit tin compound are subjected to a first-step Stille coupling reaction to obtain intermediate product A. Product A is then brominated to obtain product B. Product B is mixed with the D-unit tin compound and subjected to a Stille coupling reaction to obtain a polymerization precursor. The polymerization precursor is then subjected to electrochemical polymerization to obtain the triphenylamine-derived conjugated polymer.

[0027] Preferably, the bromoaniline compounds include 4-bromo-N-(4-bromophenyl)-N-(4-nitrophenyl)aniline.

[0028] Preferably, the D-unit tin compound is a thiophene tin compound or a 3,4-ethylenedioxythiophene tin compound.

[0029] In the preparation method, 4-bromo-N-(4-bromophenyl)-N-(4-nitrophenyl)aniline is first mixed with a π-unit-containing tin compound and subjected to a Stille coupling reaction to obtain a first intermediate containing a π unit (product A). Then, the first intermediate is brominated and added to a D-unit-containing tin compound and subjected to a Stille coupling reaction to obtain the polymerization precursor.

[0030] Preferably, the molar ratio of the bromoaniline substance to the π-unit tin compound is 1:(2-5); more preferably 1:(2-4); and even more preferably 1:(2.5-3).

[0031] Preferably, in the preparation method, the molar ratio of product B to tin oxide containing D unit is 1:(2-5); more preferably 1:(2-4); and even more preferably 1:(2.5-3).

[0032] Preferably, the Stille coupling reaction is carried out at a temperature of 100–140°C; more preferably 105–135°C; and even more preferably 110–130°C.

[0033] Preferably, the Stille coupling reaction takes 36–60 h; more preferably 40–56 h; and even more preferably 44–52 h.

[0034] Preferably, the Stille coupling reaction is carried out in a protective gas atmosphere. The protective gas in the Stille coupling reaction preferably includes at least one of nitrogen, argon, and helium; more preferably, argon.

[0035] Preferably, the Stille coupling reaction is carried out in a solvent and a catalyst; the solvent in the Stille coupling reaction preferably includes toluene, N,N-dimethylformamide or a mixture thereof, and more preferably a mixture of toluene and N,N-dimethylformamide.

[0036] Preferably, the catalyst in the Stille coupling reaction is bis(triphenylphosphine)palladium chloride.

[0037] Preferably, the electrochemical polymerization process is as follows: using a solution containing the polymerization precursor as an electrolyte, electrodeposition is performed in a three-electrode system consisting of a reference electrode, a counter electrode, and a working electrode to obtain the triphenylamine-derived conjugated polymer on the working electrode.

[0038] Preferably, during the electrochemical polymerization process, the concentration of the polymerization precursor in the electrolyte is 0.001–0.1 mol / L; more preferably, it is 0.005–0.05 mol / L; and even more preferably, it is 0.008–0.02 mol / L.

[0039] Preferably, during the electrochemical polymerization process, the solvent in the electrolyte includes at least one of dichloromethane (CH2Cl2), chloroform (CHCl3), or acetonitrile (MeCN); more preferably, dichloromethane.

[0040] Preferably, during the electrochemical polymerization process, the electrolyte also contains an electrolyte.

[0041] Preferably, the electrolyte in the electrolyte solution includes at least one of tetrabutylammonium hexafluoride phosphate (PF6), tetrabutylammonium tetrafluoroborate (BF4), or lithium perchlorate; more preferably, tetrabutylammonium hexafluoride phosphate.

[0042] Preferably, the concentration of the electrolyte in the electrolyte solution is 0.01–1 mol / L; more preferably, it is 0.05–0.5 mol / L; and even more preferably, it is 0.08–0.2 mol / L.

[0043] Preferably, during the electrochemical polymerization process, the reference electrode is preferably an Ag / AgCl electrode; the counter electrode is preferably a platinum electrode; and the working electrode is preferably a Pt / ITO conductive glass electrode.

[0044] Preferably, the electrodeposition method during the electrochemical polymerization process is a constant potential method; more preferably, the constant potential method is a constant current method or a cyclic voltammetry method.

[0045] Preferably, the electrodeposition potential is 1 to 2V; more preferably 1.1 to 1.5V.

[0046] Preferably, the electrodeposition is performed under a protective gas atmosphere. The protective gas in the electrodeposition preferably includes at least one of nitrogen, argon, and helium; more preferably, nitrogen.

[0047] A third aspect of the invention provides the application of triphenylamine-derived conjugated polymers.

[0048] An electrochromic device comprising the aforementioned triphenylamine-derived conjugated polymer.

[0049] Preferably, the electrochromic device includes a display device or a light-transmitting device.

[0050] More preferably, the electrochromic device includes at least one of a display, electrochromic glass, a smart window, or a rearview mirror.

[0051] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0052] This invention utilizes specific electron-withdrawing groups to modify the para position of triphenylamine, enhancing the electron-withdrawing ability of triphenylamine derivatives and thus improving their acceptor ability. Using these triphenylamine derivatives as A units, D-π-A-π-D type electrochromic materials based on this structure are synthesized and studied. These materials are advantageous for obtaining conjugated polymers with high optical contrast and coloring efficiency, and have wide applications in the preparation of high-performance electrochromic devices. The D-π-A-π-D structured triphenylamine-derived conjugated polymers of this invention exhibit high conjugation effects and electron transport rates, resulting in high electrochromic response speeds and high optical absorption efficiency. They also possess broad absorption bands and high molar absorptivity across the spectral range, giving them good absorption performance in the visible and near-infrared regions. Attached Figure Description

[0053] Figure 1 The image shows the spectroelectrochemical spectrum of the triphenylamine-derived conjugated polymer of Example 1 of this invention.

[0054] Figure 2 The color change results of the triphenylamine-derived conjugated polymer in Example 1 of this invention;

[0055] Figure 3 This is a kinetic diagram of the triphenylamine-derived conjugated polymer of Example 1 of the present invention;

[0056] Figure 4 This is a short-term memory diagram of the triphenylamine-derived conjugated polymer of Example 1 of the present invention;

[0057] Figure 5 The image shows the electrochemical spectrogram of the triphenylamine-derived conjugated polymer of Example 2 of this invention.

[0058] Figure 6 The color change results of the triphenylamine-derived conjugated polymer in Example 2 of this invention;

[0059] Figure 7 This is a kinetic diagram of the triphenylamine-derived conjugated polymer of Example 2 of the present invention;

[0060] Figure 8 This is a short-term memory diagram of the triphenylamine-derived conjugated polymer of Example 2 of the present invention;

[0061] Figure 9 The image shows the electrochemical spectrogram of the triphenylamine-derived conjugated polymer of Example 3 of this invention.

[0062] Figure 10 The color change results of the triphenylamine-derived conjugated polymer in Example 3 of the present invention;

[0063] Figure 11 This is a kinetic diagram of the triphenylamine-derived conjugated polymer of Example 3 of the present invention;

[0064] Figure 12 This is a short-term memory diagram of the triphenylamine-derived conjugated polymer of Example 3 of the present invention;

[0065] Figure 13 The image shows the electrochemical spectrogram of the triphenylamine-derived conjugated polymer of Example 4 of this invention.

[0066] Figure 14 The color change results of the triphenylamine-derived conjugated polymer in Example 4 of this invention.

[0067] Figure 15 This is a kinetic diagram of the triphenylamine-derived conjugated polymer of Example 4 of the present invention;

[0068] Figure 16 This is a short-term memory diagram of the triphenylamine-derived conjugated polymer of Example 4 of the present invention;

[0069] Figure 17 This is the spectroelectrochemical spectrum of the polymer in Comparative Example 1 of this invention;

[0070] Figure 18 The color change results of the polymer in Comparative Example 1 of this invention;

[0071] Figure 19 This is a kinetic diagram of the polymer in Comparative Example 1 of the present invention;

[0072] Figure 20 This is a short-term memory diagram of the polymer in Comparative Example 1 of the present invention. Detailed Implementation

[0073] To enable those skilled in the art to more clearly understand the technical solution described in this invention, the following embodiments are provided for illustration. Electrochromic materials have many data parameters that can be used to evaluate their performance in the laboratory stage, such as ultraviolet absorbance, transmittance, coloring efficiency, response time, and open-circuit memory effect, all of which are important parameters for evaluating whether a material is suitable for practical application.

[0074] Ultraviolet absorbance refers to the change in polymer properties during doping and dedoping processes. Macroscopically, this is manifested as a change in absorbance in the ultraviolet-visible spectrum. Different applied voltages and different degrees of polymer doping will result in corresponding changes in the color and brightness of the film. However, this property can only qualitatively analyze whether a material has electrochromic properties, and cannot subjectively judge or quantitatively analyze the quality of the material's electrochromic properties.

[0075] Transmittance refers to the change in the optical properties of a material under an applied voltage, which is quantitatively detected in an ultraviolet spectrometer and is represented by ΔT.

[0076] Coloring efficiency: refers to the ratio of the change in absorbance of an electrochromic material at a given wavelength to the change that results in the injection or extraction of all electrons.

[0077] For an electrochromic material, coloring efficiency is an important parameter for evaluating its performance. Studying the coloring efficiency of conductive polymers requires considering the electrochemical and spectral changes of the electrochromic film. The calculation formula is as follows:

[0078] ΔOD = log(Tox / Tred);

[0079] Qd = (Qox + Qred) / S;

[0080] CE = ΔOD / Qd;

[0081] Where Tox is the transmittance of the electrochromic material in the oxidized state; Tred is the transmittance of the electrochromic material in the reduced state; Qox is the charge amount during the oxidation process; Qred is the charge amount during the reduction process; and S is the area of ​​the working electrode.

[0082] Response time refers to the time required for a material to achieve a 95% change in transmittance when a square wave voltage changes its potential under an applied voltage. A shorter response time indicates a faster conversion time, which better meets the requirements of practical applications. However, this value is related to many factors, including the conductivity of the substrate, the inherent properties of the material, the conductivity of the system, the concentration of free ions in the system, and the ion migration rate. Furthermore, different working environments in applications require different conversion times.

[0083] The memory effect refers to the property of a material to maintain its doped or dedoped state under open-circuit conditions with an applied voltage. When a fully doped or fully dedoped voltage is applied to a material, and then the applied voltage is disconnected, the time-transmittance curve of the material in a UV spectrometer is observed. Under normal circumstances, because the dopant ions in the material are not bound under open-circuit conditions, they will automatically dissociate into the solution, causing changes in the material's color and transmittance, thus indicating the degree of change in the material's memory effect.

[0084] The absorption sites of a polymer determine its color, which is of great significance for the preparation of electrochromic polymers of various colors. Response time is also an important parameter of electrochromic materials, as it reveals the speed at which dopant ions enter the polymer backbone during the doping process.

[0085] Unless otherwise specified, the raw materials, reagents or devices used in the following examples are available from conventional commercial sources or can be obtained by existing known methods.

[0086] The embodiments disclose triphenylamine-derived conjugated polymers, their preparation methods, and applications. This invention utilizes different electron-withdrawing groups to modify the para-position of triphenylamine, enhancing the electron-withdrawing ability of the triphenylamine derivative, thereby improving its acceptor ability. Using such triphenylamine derivatives as A units facilitates the preparation of conjugated polymers with high optical contrast and coloring efficiency, which have wide applications in the preparation of high-performance electrochromic devices. D-π-A-π-D type electrochromic materials are a class of organic materials widely used in electrochromic devices. This structure consists of two electron donor (D) units connected to an electron acceptor (A) unit via a π-conjugated bridge, forming a π-electron conduction channel. D-π-A-π-D type materials typically possess good photoelectric properties and tunable absorption spectra, making them widely applicable in electrochromic devices, photoelectric conversion devices, and organic optoelectronic devices.

[0087] Example 1: Synthesis of triphenylamine-derived conjugated polymers

[0088] Preparation of a symmetrical D-π-A-π-D type monomeric compound a (TTTPA):

[0089] The chemical reaction process for the preparation of 4-([2,2'-bithiophene]-5-yl)-N-(4-([2,2'-bithiophene]-5-yl)phenyl)-N-(4-nitrophenyl)aniline is as follows:

[0090]

[0091] (1) Preparation of compound a (TTTPA)

[0092] 4-Bromo-N-(4-Bromophenyl)-N-(4-nitrophenyl)aniline (2 g, 4.46 mmol) was placed in a 250 mL round-bottom flask, and tributyl(thiophene-2-yl)tin (4.16 g, 11.15 mmol) and tetrakis(triphenylphosphine)palladium (Pd(pph3) 40.51 g, 0.446 mmol) were added. The round-bottom flask was rinsed with argon. Under negative pressure, a mixture of 80 mL toluene (Tol) and 20 mL N,N-dimethylformamide (DMF) was added to the round-bottom flask. The mixture was then heated to 120 °C and stirred under reflux for 12 hours. The resulting mixture was cooled to room temperature, and toluene was removed by rotary evaporation. The mixture was extracted with dichloromethane, washed with saturated sodium chloride solution, and dichloromethane was removed by rotary evaporation to obtain the crude product. The crude product was then subjected to column chromatography to obtain a red solid (1.51 g), with a yield of 75%.

[0093] 4-Nitro-N,N-bis(4-(thiophen-2-yl)phenyl)aniline (0.5 g, 1.1 mmol) was placed in a 100 mL round-bottom flask, and NBS (N-bromosuccinimide, 0.43 g, 2.42 mmol) was added. THF (tetrahydrofuran, 50 mL) was added in air, and the mixture was stirred at 0 °C for 12 h in the dark. The reaction was quenched with pure water, and the crude product was obtained by filtration. The crude product was then subjected to column chromatography to obtain a red solid (0.60 g), with a yield of 90%.

[0094] 4-(5-bromothiophen-2-yl)-N-(4-(5-bromothiophen-2-yl)phenyl)-N-(4-nitrophenyl)aniline (0.3 g, 0.49 mmol) was placed in a 50 mL round-bottom flask, and tributyl(thiophen-2-yl)tin (0.457 g, 1.225 mmol) and tetrakis(triphenylphosphine)palladium (0.056 g, 0.049 mmol) were added. The flask was rinsed with argon gas. Under negative pressure, a mixture of 20 mL toluene and 5 mL N,N-dimethylformamide was added to the flask. The mixture was then heated to 120 °C and stirred under reflux for 12 hours. The resulting mixture was cooled to room temperature, and toluene was removed by rotary evaporation. The product was extracted with dichloromethane, washed with saturated sodium chloride solution, and dichloromethane was removed by rotary evaporation to obtain the crude product. The crude product was then subjected to column chromatography to obtain a red solid compound a (TTTPA) (0.27 g) in 90% yield.

[0095] (2) Preparation of triphenylamine-derived conjugated polymers

[0096] Compound a (TTTPA) is electrochemically polymerized into the corresponding triphenylamine-derived conjugated polymer. The chemical reaction process is as follows:

[0097]

[0098] Under nitrogen protection, compound a (TTTPA) was dissolved in 10 mL of dichloromethane to prepare a concentration of 0.01 mol / L. Then, tetrabutylammonium hexafluorophosphate (TTPPA) with a concentration of 0.1 mol / L was added to obtain the electrolyte. The solution was stirred until homogeneous, and argon gas was continuously purged for 20 minutes. Maintaining the solution under an argon atmosphere, a triphenylamine-derived conjugated polymer (PTTTPA) film was deposited on the ITO conductive glass as the working electrode, a platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode, at a constant potential of 1.15 V. "Electrochemical Polymerization" refers to electrochemical polymerization.

[0099] Application Example 1

[0100] The properties of the triphenylamine-derived conjugated polymer obtained in Example 1 were tested.

[0101] (1) Spectroelectrochemistry

[0102] The ITO conductive glass coated with a triphenylamine-derived conjugated polymer prepared in Example 1 was placed in a three-electrode electrolytic cell containing a dichloromethane solution of tetrabutylammonium hexafluorophosphate. The working electrode was the ITO conductive glass coated with the triphenylamine-derived conjugated polymer, the counter electrode was a platinum sheet, and the reference electrode was an Ag / AgCl electrode. Using a potentiostatic method, the voltage applied to the working electrode was adjusted via an electrochemical workstation, and the changes in the absorption spectra of the triphenylamine-derived conjugated polymer at different voltages were recorded using a UV-Vis spectrometer, thus obtaining the electrochemical spectrogram of the triphenylamine-derived conjugated polymer. The results are as follows: Figure 1 As shown, and combined with visual observation of the color changes of triphenylamine-derived conjugated polymers (such as... Figure 2 As shown, "color" represents color, "Compound" represents substance, and L*, a*, and b* are used to measure color and brightness.

[0103] from Figure 1 , Figure 2 ( Figure 1 In the spectrum (where "Absorbance" represents absorbance and "Wavelength" represents wavelength), two absorption peaks appear at 441 nm and 632 nm, respectively, attributable to π-π* transitions and charge transfer between donor and acceptor molecules. With increasing voltage, the absorption peak intensity of the triphenylamine-derived conjugated polymer at 422 nm decreases, and new absorption peaks generated by polaron absorption gradually appear in the near-infrared region. The color of the triphenylamine-derived conjugated polymer changes from brownish-red to dark green.

[0104] (2) Study on the kinetic stability of polymer films

[0105] The transmittance of triphenylamine-derived conjugated polymer films in their oxidized and reduced states at a specific wavelength under a square-wave potential was measured using a UV-Vis spectrophotometer, thereby calculating optical contrast and influence time. The UV-Vis spectrophotometer recorded a time-transmittance curve, while the electrochemical workstation recorded a time-current curve. The coloring efficiency could also be calculated from these two curves, as shown in the results. Figure 3 ( Figure 3 In the figure, “Transmittance” represents transmittance and “Time” represents time.

[0106] The kinetic stability of the triphenylamine-derived conjugated polymer prepared in Example 1 was studied at 441 nm, 900 nm, and 1100 nm, with a square wave potential interval of 5 s. Figure 3It can be seen that the transmittance values ​​of the triphenylamine-derived conjugated polymers are approximately 23%, 25%, and 36%, and their transmittance remains basically unchanged after scanning for 500 seconds.

[0107] (3) Study on the short-term memory effect of triphenylamine-derived conjugated polymer films

[0108] Using a potentiostatic method, a voltage was applied to the working electrode using an electrochemical workstation for 10 seconds, followed by 2 seconds every 100 seconds. Simultaneously, the transmittance trends of the polymer in its oxidized and reduced states at the maximum absorption peak were recorded using a UV-Vis spectrometer, thus obtaining the short-term memory effect spectrum of the triphenylamine-derived conjugated polymer. Voltages of 0.2 V and 1.2 V were applied to the triphenylamine-derived conjugated polymer film at 1100 nm, and the results are as follows: Figure 4 ( Figure 4 As shown in the figure (where "Transmittance" represents transmittance and "Time" represents time), it was found that the transmittance of triphenylamine-derived conjugated polymers changed significantly in the oxidized state, while the transmittance changed less in the reduced state.

[0109] Example 2: Synthesis of triphenylamine-derived conjugated polymers

[0110] Preparation of a symmetrical D-π-A-π-D type monomer compound b (TETPA):

[0111] The chemical reaction process for the preparation of 4-([2,2'-bithiophene]-5-yl)-N-(4-([2,2'-bithiophene]-5-yl)phenyl)-N-(4-nitrophenyl)aniline is as follows:

[0112]

[0113] (1) Preparation of compound b (TETPA)

[0114] 4-Bromo-N-(4-Bromophenyl)-N-(4-nitrophenyl)aniline (4.46 mmol) was placed in a 250 mL round-bottom flask, and tributyl(2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)tin (11.15 mmol) and tetrakis(triphenylphosphine)palladium (Pd(pph3)4 0.446 mmol) were added. The round-bottom flask was rinsed with argon. Under negative pressure, a mixture of 80 mL toluene (Tol) and 20 mL N,N-dimethylformamide (DMF) was added to the round-bottom flask. The mixture was then heated to 120 °C and stirred under reflux for 12 hours. The resulting mixture was cooled to room temperature, and toluene was removed by rotary evaporation. The mixture was extracted with dichloromethane, washed with saturated sodium chloride solution, and dichloromethane was removed by rotary evaporation to obtain the crude product. The crude product was then subjected to column chromatography to obtain a red solid (1.2 g) in 50% yield.

[0115] 0.5 g (0.8 mmol) of 4-(2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)-N-(4-(2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)phenyl)-N-(4-nitrophenyl)aniline was placed in a 100 mL round-bottom flask, and NBS (N-bromosuccinimide, 0.33 g, 1.9 mmol) was added. THF (tetrahydrofuran, 50 mL) was added in air, and the mixture was stirred at 0 °C for 12 h in the dark. The reaction was quenched with pure water, and the crude product was obtained by filtration. The crude product was then subjected to column chromatography to obtain a red solid (0.52 g) with a yield of 90%.

[0116] 0.3 g (0.4 mmol) of 4-(7-bromo-2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)-N-(4-(7-bromo-2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)phenyl)-N-(4-nitrophenyl)aniline was placed in a 50 mL round-bottom flask. Tributyl(thiophene-2-yl)tin (0.384 g, 1 mmol) and tetrakis(triphenylphosphine)palladium (0.046 g, 0.04 mmol) were added. The flask was rinsed with argon gas. Under negative pressure, 20 mL of toluene and 5 mL of... A mixture of N,N-dimethylformamide was obtained, which was then heated to 120°C and stirred under reflux for 12 hours. The resulting mixture was cooled to room temperature, toluene was removed by rotary evaporation, and the mixture was extracted with dichloromethane, washed with saturated sodium chloride solution, and dichloromethane was removed by rotary evaporation to obtain a crude product. The crude product was then subjected to column chromatography to obtain a red solid compound b (TETPA) (0.23 g) in 90% yield.

[0117] (2) Preparation of triphenylamine-derived conjugated polymers

[0118] Compound b (TETPA) undergoes electrochemical polymerization to form the corresponding triphenylamine-derived conjugated polymer. The chemical reaction process is as follows:

[0119]

[0120] Under nitrogen protection, compound b (TETPA) was dissolved in 10 mL of dichloromethane to prepare a concentration of 0.01 mol / L. Then, tetrabutylammonium hexafluorophosphate (TETPA) with a concentration of 0.1 mol / L was added to obtain the electrolyte. The solution was stirred until homogeneous, and argon gas was continuously purged for 20 minutes. Maintaining the solution under an argon atmosphere, a triphenylamine-derived conjugated polymer (PTETPA) film was deposited on the ITO conductive glass using ITO conductive glass as the working electrode, a platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode at a constant potential of 1 V. "Electrochemical Polymerization" refers to electrochemical polymerization.

[0121] Application Example 2

[0122] The properties of the triphenylamine-derived conjugated polymer obtained in Example 2 were tested.

[0123] (1) Spectroelectrochemistry

[0124] The ITO conductive glass coated with a triphenylamine-derived conjugated polymer, prepared in Example 2, was placed in a three-electrode electrolytic cell containing a dichloromethane solution of tetrabutylammonium hexafluorophosphate. The working electrode was the ITO conductive glass coated with the triphenylamine-derived conjugated polymer, the counter electrode was a platinum sheet, and the reference electrode was an Ag / AgCl electrode. Using a potentiostatic method, the voltage applied to the working electrode was adjusted via an electrochemical workstation, and the changes in the absorption spectra of the triphenylamine-derived conjugated polymer at different voltages were recorded using a UV-Vis spectrometer, thus obtaining the electrochemical spectrogram of the triphenylamine-derived conjugated polymer. The results are as follows: Figure 5 ( Figure 5 The text refers to the absorption value and wavelength (as shown in the figure). It also mentions observing the color changes of triphenylamine-derived conjugated polymers with the naked eye (e.g.,...). Figure 6 As shown, "color" represents color, "Compound" represents substance, and L*, a*, and b* are used to measure color and brightness.

[0125] from Figure 5 , Figure 6 As can be seen, two absorption peaks appear at 447 nm and 675 nm in the spectrum, which are attributed to π-π* transitions and charge transfer between donor and acceptor molecules, respectively. With increasing voltage, the intensity of the absorption peak at 447 nm of the triphenylamine-derived conjugated polymer decreases, and new absorption peaks generated by polaron absorption gradually appear in the near-infrared region. The color of the triphenylamine-derived conjugated polymer changes from light brown to gray.

[0126] (2) Study on the kinetic stability of polymer films

[0127] The transmittance of triphenylamine-derived conjugated polymer films in their oxidized and reduced states at a specific wavelength under a square-wave potential was measured using a UV-Vis spectrophotometer, thereby calculating optical contrast and influence time. The UV-Vis spectrophotometer recorded a time-transmittance curve, while the electrochemical workstation recorded a time-current curve. The coloring efficiency could also be calculated from these two curves, as shown in the results. Figure 7 ( Figure 7 The text is incomplete and contains several errors. A more accurate translation would require the full context.

[0128] The kinetic stability of the triphenylamine-derived conjugated polymer prepared in Example 2 was studied at 447 nm, 920 nm, and 1100 nm, with a square wave potential interval of 5 s. Figure 7 It can be seen that the transmittance values ​​of the triphenylamine-derived conjugated polymers are approximately 4%, 3%, and 6%, and their transmittance remains basically unchanged after scanning for 500 seconds.

[0129] (3) Study on the short-term memory effect of triphenylamine-derived conjugated polymer films

[0130] Using a potentiostatic method, a voltage was applied to the working electrode using an electrochemical workstation for 10 seconds, followed by 2 seconds every 100 seconds. Simultaneously, the transmittance trends of the polymer in its oxidized and reduced states at the maximum absorption peak were recorded using a UV-Vis spectrometer, thus obtaining the short-term memory effect spectrum of the triphenylamine-derived conjugated polymer. Voltages of -0.3V and 1.1V were applied to the triphenylamine-derived conjugated polymer film at 1100 nm, and the results are as follows... Figure 8 ( Figure 8 As shown in the figure (where "Transmittance" represents transmittance and "Time" represents time), it was found that the transmittance of triphenylamine-derived conjugated polymers changed significantly in the oxidized state, while the transmittance remained basically unchanged in the reduced state.

[0131] Example 3: Synthesis of triphenylamine-derived conjugated polymers

[0132] Synthesis and preparation of a triphenylamine-derived conjugated polymer (ETTPA):

[0133] The chemical reaction process for the preparation of 4-(5-(2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)thiophene-2-yl)-N-(4-(5-(2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)thiophene-2-yl)phenyl)-N-(4-nitrophenyl)aniline is as follows:

[0134]

[0135] (1) Preparation of monomer (ETTPA)

[0136] 4-Bromo-N-(4-Bromophenyl)-N-(4-nitrophenyl)aniline (2 g, 4.46 mmol) was placed in a 250 mL round-bottom flask, and tributyl(thiophene-2-yl)tin (4.16 g, 11.15 mmol) and tetrakis(triphenylphosphine)palladium (Pd(pph3) 40.51 g, 0.446 mmol) were added. The round-bottom flask was rinsed with argon. Under negative pressure, a mixture of 80 mL toluene (Tol) and 20 mL N,N-dimethylformamide (DMF) was added to the round-bottom flask. The mixture was then heated to 120 °C and stirred under reflux for 12 hours. The resulting mixture was cooled to room temperature, and toluene was removed by rotary evaporation. The product was extracted with dichloromethane, washed with saturated sodium chloride solution, and dichloromethane was removed by rotary evaporation to obtain the crude product. The crude product was then subjected to column chromatography to obtain a red solid (1.51 g), with a yield of 75%.

[0137] 4-Nitro-N,N-bis(4-(thiophen-2-yl)phenyl)aniline (0.5 g, 1.1 mmol) was placed in a 100 mL round-bottom flask, and NBS (N-bromosuccinimide, 0.43 g, 2.42 mmol) was added. THF (tetrahydrofuran, 50 mL) was added in air, and the mixture was stirred at 0 °C for 12 h in the dark. The reaction was quenched with pure water, and the crude product was obtained by filtration. The crude product was then subjected to column chromatography to obtain a red solid (0.60 g), with a yield of 90%.

[0138] 4-(5-bromothiophen-2-yl)-N-(4-(5-bromothiophen-2-yl)phenyl)-N-(4-nitrophenyl)aniline (0.3 g, 0.49 mmol) was placed in a 50 mL round-bottom flask, and tributyl(2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)stannous (0.49 g, 1.225 mmol) and tetrakis(triphenylphosphine)palladium (0.056 g, 0.049 mmol) were added. The flask was rinsed with argon gas, and 20 mL of toluene and 5 mL of sodium hydroxide were added to the flask under negative pressure. A mixture of N,N-dimethylformamide was obtained, which was then heated to 120°C and stirred under reflux for 12 hours. The resulting mixture was cooled to room temperature, toluene was removed by rotary evaporation, and the mixture was extracted with dichloromethane, washed with saturated sodium chloride solution, and dichloromethane was removed by rotary evaporation to obtain a crude product. The crude product was then subjected to column chromatography to obtain a red solid monomer (ETTPA) (0.18 g) in 50% yield.

[0139] (2) Preparation of D-π-A-π-D type conjugated polymers

[0140] The monomer (ETTPA) is electrochemically polymerized into the corresponding D-π-A-π-D type conjugated polymer. The chemical reaction process is as follows:

[0141]

[0142] Under nitrogen protection, the monomer (ETTPA) was dissolved in 10 mL of dichloromethane to prepare an ETPA concentration of 0.01 mol / L. Then, tetrabutylammonium hexafluorophosphate (THP) with a concentration of 0.1 mol / L was added to obtain the electrolyte. The solution was stirred until homogeneous, and argon gas was continuously purged for 20 minutes. Maintaining the solution under an argon atmosphere, an ITO conductive glass was used as the working electrode, a platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode. Deposition was performed at a constant potential of 1.15 V on the ITO conductive glass to obtain a D-π-A-π-D type conjugated polymer (PETTPA) film. "Electrochemical Polymerization" refers to electrochemical polymerization.

[0143] Application Example 3

[0144] The properties of the triphenylamine-derived conjugated polymer obtained in Example 3 were tested.

[0145] (1) Spectroelectrochemistry

[0146] The ITO conductive glass coated with the prepared triphenylamine-derived conjugated polymer film from Example 3 was placed in a three-electrode electrolytic cell containing a dichloromethane solution of tetrabutylammonium hexafluorophosphate. The working electrode was the ITO conductive glass coated with the D-π-A-π-D type conjugated polymer, the counter electrode was a platinum sheet, and the reference electrode was an Ag / AgCl electrode. Using a potentiostatic method, the voltage applied to the working electrode was adjusted via an electrochemical workstation, and the changes in the absorption spectra of the D-π-A-π-D type conjugated polymer at different voltages were recorded using a UV-Vis spectrometer, thus obtaining the electrochemical spectrogram of the triphenylamine-derived conjugated polymer. The results are as follows: Figure 9 As shown, from Figure 9 ( Figure 9 In the spectrum (where "Absorbance" represents absorbance and "Wavelength" represents wavelength), two absorption peaks appear at 478 nm and 637 nm, respectively, attributable to π-π* transitions and charge transfer between donor and acceptor molecules. With increasing voltage, the absorption peak intensity of the triphenylamine-derived conjugated polymer at 478 nm decreases, and new absorption peaks generated by polaron absorption gradually appear in the near-infrared region. This is further illustrated by visual observation of the color changes of the triphenylamine-derived conjugated polymer (e.g., ...). Figure 10 As shown, "color" represents color, "Compound" represents substance, and L*, a*, and b* are used to measure color and brightness. The color of triphenylamine-derived conjugated polymers changes from brownish-red to gray.

[0147] (2) Study on the kinetic stability of polymer films

[0148] The transmittance of triphenylamine-derived conjugated polymer films in their oxidized and reduced states at a specific wavelength under a square-wave potential was measured using a UV-Vis spectrophotometer, thereby calculating optical contrast and influence time. The UV-Vis spectrophotometer recorded a time-transmittance curve, while the electrochemical workstation recorded a time-current curve. The coloring efficiency could also be calculated from these two curves, as shown in the results. Figure 11 ( Figure 11 In the figure, “Transmittance” represents transmittance and “Time” represents time.

[0149] The kinetic stability of the triphenylamine-derived conjugated polymer prepared in Example 3 was studied at 433 nm, 960 nm, and 1100 nm, with a square wave potential interval of 5 s. Figure 11 It can be seen that the transmittance values ​​of the triphenylamine-derived conjugated polymers are approximately 24%, 24%, and 41%, and their transmittance remains basically unchanged after scanning for 500 seconds.

[0150] (3) Study on the short-term memory effect of triphenylamine-derived conjugated polymer films

[0151] Using a potentiostatic method, a voltage was applied to the working electrode at 10-second intervals followed by 2-second intervals every 100-second intervals via an electrochemical workstation. Simultaneously, the transmittance trends of the polymer in its oxidized and reduced states at the maximum absorption peak were recorded using a UV-Vis spectrometer, thus obtaining the short-term memory effect spectrum of the triphenylamine-derived conjugated polymer. The triphenylamine-derived conjugated polymer film was subjected to voltages of -0.7V and 0.9V at 1100 nm, and the results are as follows... Figure 12 ( Figure 12 As shown in the figure (where "Transmittance" represents transmittance and "Time" represents time), it was found that the transmittance of triphenylamine-derived conjugated polymers changed significantly in the oxidized state, while the transmittance changed less in the reduced state.

[0152] Example 4: Synthesis of triphenylamine-derived conjugated polymers

[0153] Preparation of a symmetrical D-π-A-π-D type monomer EETPA:

[0154] The chemical reaction process for the preparation of 4-([2,2'-bithiophene]-5-yl)-N-(4-([2,2'-bithiophene]-5-yl)phenyl)-N-(4-nitrophenyl)aniline is as follows:

[0155]

[0156] (1) Preparation of monomer EETPA

[0157] 4-Bromo-N-(4-Bromophenyl)-N-(4-nitrophenyl)aniline (4.46 mmol) was placed in a 250 mL round-bottom flask, and tributyl(2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)tin (11.15 mmol) and tetrakis(triphenylphosphine)palladium (Pd(pph3)4, 0.446 mmol) were added. The round-bottom flask was rinsed with argon. Under negative pressure, a mixture of 80 mL toluene (Tol) and 20 mL N,N-dimethylformamide (DMF) was added to the round-bottom flask. The mixture was then heated to 120 °C and stirred under reflux for 12 hours. The resulting mixture was cooled to room temperature, and toluene was removed by rotary evaporation. The product was extracted with dichloromethane, washed with saturated sodium chloride solution, and dichloromethane was removed by rotary evaporation to obtain the crude product. The crude product was then subjected to column chromatography to obtain a red solid (1.2 g), with a yield of 50%.

[0158] 0.5 g (0.8 mmol) of 4-(2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)-N-(4-(2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)phenyl)-N-(4-nitrophenyl)aniline was placed in a 100 mL round-bottom flask, and NBS (N-bromosuccinimide, 0.33 g, 1.9 mmol) was added. THF (tetrahydrofuran, 50 mL) was added in air, and the mixture was stirred at 0 °C for 12 h in the dark. The reaction was quenched with pure water, and the crude product was obtained by filtration. The crude product was then subjected to column chromatography to obtain a red solid (0.52 g) with a yield of 90%.

[0159] 0.3 g (0.4 mmol) of 4-(7-bromo-2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)-N-(4-(7-bromo-2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)phenyl)-N-(4-nitrophenyl)aniline was placed in a 50 mL round-bottom flask. Tributyl(2,3-dihydrothiophene[3,4-b][1,4]dioxane-5-yl)stannous (0.432 g (1 mmol)) and tetrakis(triphenylphosphine)palladium (0.046 g (0.04 mmol)) were added. The flask was rinsed with argon gas. Under negative pressure, 20 mL of toluene and 5 mL of... A mixture of N,N-dimethylformamide was obtained, which was then heated to 120°C and stirred under reflux for 12 hours. The resulting mixture was cooled to room temperature, toluene was removed by rotary evaporation, and the mixture was extracted with dichloromethane, washed with saturated sodium chloride solution, and dichloromethane was removed by rotary evaporation to obtain a crude product. The crude product was then subjected to column chromatography to obtain a red solid monomer EETPA (0.23 g) in 90% yield.

[0160] (2) Preparation of triphenylamine-derived conjugated polymers

[0161] The monomer EETPA is electrochemically polymerized into the corresponding triphenylamine-derived conjugated polymers. The chemical reaction process is as follows:

[0162]

[0163] Under nitrogen protection, EETPA monomer was dissolved in 10 mL of dichloromethane to prepare an EETPA concentration of 0.01 mol / L. Then, tetrabutylammonium hexafluorophosphate (TEHFA) with a concentration of 0.1 mol / L was added to obtain the electrolyte. The solution was stirred until homogeneous, and argon gas was continuously purged for 20 minutes. Maintaining the solution under an argon atmosphere, a triphenylamine-derived conjugated polymer (PEETPA) film was deposited on the ITO conductive glass as the working electrode, a platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode at a constant potential of 1 V. "Electrochemical Polymerization" refers to electrochemical polymerization.

[0164] Application Example 4

[0165] The properties of the triphenylamine-derived conjugated polymer obtained in Example 4 were tested.

[0166] (1) Spectroelectrochemistry

[0167] The ITO conductive glass coated with a triphenylamine-derived conjugated polymer, prepared in Example 4, was placed in a three-electrode electrolytic cell containing a dichloromethane solution of tetrabutylammonium hexafluorophosphate. The working electrode was the ITO conductive glass coated with the triphenylamine-derived conjugated polymer, the counter electrode was a platinum sheet, and the reference electrode was an Ag / AgCl electrode. Using a potentiostatic method, the voltage applied to the working electrode was adjusted via an electrochemical workstation, and the changes in the absorption spectra of the triphenylamine-derived conjugated polymer at different voltages were recorded using a UV-Vis spectrometer, thus obtaining the electrochemical spectrogram of the triphenylamine-derived conjugated polymer. The results are as follows: Figure 13 ( Figure 13 In the figure, “Absorbance” represents absorbance and “Wavelength” represents wavelength.

[0168] from Figure 13 It can be seen that two absorption peaks appear at 493 nm and 726 nm in the spectrum, which are attributed to π-π* transitions and charge transfer between donor and acceptor molecules, respectively. With increasing voltage, the absorption peak intensity of the D-π-A-π-D type conjugated polymer at 493 nm decreases, and new absorption peaks generated by polaron absorption gradually appear in the near-infrared region. This is combined with visual observation of the color changes of triphenylamine-derived conjugated polymers (e.g., ...). Figure 14As shown, "color" represents color, "Compound" represents substance, and L*, a*, and b* are used to measure color and brightness. The color of triphenylamine-derived conjugated polymers changes from brownish-red to gray.

[0169] (2) Study on the kinetic stability of polymer films

[0170] The transmittance of triphenylamine-derived conjugated polymer films in their oxidized and reduced states at a specific wavelength under a square-wave potential was measured using a UV-Vis spectrophotometer, thereby calculating optical contrast and influence time. The UV-Vis spectrophotometer recorded a time-transmittance curve, while the electrochemical workstation recorded a time-current curve. The coloring efficiency could also be calculated from these two curves, as shown in the results. Figure 15 ( Figure 15 The text is incomplete and contains several errors. A more accurate translation would require the full context.

[0171] The kinetic stability of the triphenylamine-derived conjugated polymer prepared in Example 4 was studied at 493 nm, 937 nm, and 1100 nm, with a square wave potential interval of 5 s. Figure 15 It can be seen that the transmittance values ​​of the triphenylamine-derived conjugated polymers are approximately 34%, 37%, and 38%, and their transmittance remains basically unchanged after scanning for 500 seconds.

[0172] (3) Study on the short-term memory effect of triphenylamine-derived conjugated polymer films

[0173] Using a potentiostatic method, a voltage was applied to the working electrode at 10-second intervals, followed by 2-second intervals every 100-second intervals, via an electrochemical workstation. Simultaneously, the transmittance trends of the polymer in its oxidized and reduced states at the maximum absorption peak were recorded using a UV-Vis spectrometer, thus obtaining the short-term memory effect spectrum of the triphenylamine-derived conjugated polymer. Voltages of -0.5V and 1.1V were applied to the triphenylamine-derived conjugated polymer film at 1100 nm, and the results are as follows: Figure 16 ( Figure 16 As shown in the figure (where "Transmittance" represents transmittance and "Time" represents time), it was found that the transmittance of triphenylamine-derived conjugated polymers changed significantly in the oxidized state, while the transmittance remained basically unchanged in the reduced state.

[0174] Comparative Example 1

[0175] The structure of the polymer (PTTPA) in Comparative Example 1 is as follows:

[0176]

[0177] Following the test procedure of Application Example 1, the performance of the polymer (PTTPA) in Comparative Example 1 was tested, and the results are as follows: Figures 19 to 20 As shown.

[0178] Figure 17 This is the spectroelectrochemical spectrum of the polymer in Comparative Example 1 of this invention; Figure 18 The color change results of the polymer in Comparative Example 1 of this invention; Figure 19 This is a kinetic diagram of the polymer in Comparative Example 1 of the present invention; Figure 20 This is a short-term memory diagram of the polymer in Comparative Example 1 of the present invention.

[0179] The performance of the comparative example polymer (PTTPA) was tested.

[0180] (1) Spectroelectrochemistry

[0181] An ITO conductive glass coated with the polymer of Comparative Example 1 was placed in a three-electrode electrolytic cell containing a dichloromethane solution of tetrabutylammonium hexafluorophosphate. The working electrode was the ITO conductive glass coated with the polymer of Comparative Example 1, the counter electrode was a platinum sheet, and the reference electrode was an Ag / AgCl electrode. Using a potentiostatic method, the voltage applied to the working electrode was adjusted via an electrochemical workstation, and the changes in the absorption spectrum of the polymer of Comparative Example 1 at different voltages were recorded using a UV-Vis spectrometer, thus obtaining the spectroelectrochemical spectrum of the polymer of Comparative Example 1. The results are as follows: Figure 17 ( Figure 17 In the figure, "Absorbance" represents absorbance and "Wavelength" represents wavelength. The color change of the polymer in Comparative Example 1 was observed with the naked eye (e.g., ...). Figure 18 As shown, "color" represents color, "Compound" represents substance, and L*, a*, and b* are used to measure color and brightness.

[0182] from Figure 17 , Figure 18 As can be seen, two absorption peaks appear at 423 nm and 705 nm in the spectrum, which are attributed to π-π* transitions and charge transfer between donor and acceptor molecules, respectively. With increasing voltage, the intensity of the absorption peak at 423 nm of the polymer in Comparative Example 1 decreases, and new absorption peaks generated by polaron absorption gradually appear in the near-infrared region. The color of the polymer in Comparative Example 1 changes from brown to deep yellow.

[0183] (2) Study on the kinetic stability of polymer films

[0184] The transmittance of the polymer film in Comparative Example 1 at a specific wavelength under a square wave potential, in both oxidized and reduced states, was measured using a UV-Vis spectrophotometer. This allowed for the calculation of optical contrast and influence time. The UV-Vis spectrophotometer recorded a time-transmittance curve, while the electrochemical workstation recorded a time-current curve. The coloring efficiency could also be calculated from these two curves, as shown in the results. Figure 19 ( Figure 19 The text is incomplete and contains several errors. A more accurate translation would require the full context.

[0185] The kinetic stability of the polymer in Comparative Example 1 was studied at 423 nm, 900 nm, and 1100 nm, with a square wave potential interval of 5 s. From Figure 19 It can be seen that the transmittance values ​​of the polymer in Comparative Example 1 are approximately 4%, 13%, and 34%, and its transmittance remains basically unchanged after scanning for 500 seconds.

[0186] (3) Study on the short-term memory effect of polymer films in Comparative Example 1

[0187] Using a potentiostatic method, a voltage was applied to the working electrode using an electrochemical workstation for 10 seconds, followed by 2 seconds every 100 seconds. Simultaneously, the transmittance trends of the polymer in its oxidized and reduced states at the maximum absorption peak were recorded using a UV-Vis spectrometer, thus obtaining the short-term memory effect spectrum of the polymer in Comparative Example 1. Voltages of 0V and 1V were applied to the polymer film in Comparative Example 1 at 1100 nm, and the results are as follows... Figure 20 ( Figure 20 As shown in the figure, “Transmittance” represents transmittance and “Time” represents time. It was found that the transmittance of the polymer in Comparative Example 1 changed significantly in the oxidized state, while the transmittance remained basically unchanged in the reduced state.

[0188] Comparing the polymers of Examples 1-4 with those of Comparative Example 1, it can be observed that the polymers of Examples 1-4 with added π bridges exhibit richer and more pronounced color changes.

[0189] In addition, the response time and coloring efficiency calculated from the time-transmittance curve of the polymer (PTTTPA) in Example 1 are shown in Table 1; the response time and coloring efficiency calculated from the time-transmittance curve of the polymer (PTETPA) in Example 2 are shown in Table 2; the response time and coloring efficiency calculated from the time-transmittance curve of the polymer (PETTPA) in Example 3 are shown in Table 3; the response time and coloring efficiency calculated from the time-transmittance curve of the polymer (PEETPA) in Example 4 are shown in Table 4; and the response time and coloring efficiency calculated from the time-transmittance curve of the polymer (PTTPA) in Comparative Example 1 are shown in Table 5.

[0190] In addition, the response time and coloring efficiency calculated from the time-transmittance curve of the D-π-A-π-D type conjugated polymer (PTTTPA) of Example 1 are shown in Table 1, the response time and coloring efficiency calculated from the time-transmittance curve of the D-π-A-π-D type conjugated polymer (PTETPA) of Example 2 are shown in Table 2, and the response time and coloring efficiency calculated from the time-transmittance curve of the polymer (PTTPA) of Comparative Example 1 are shown in Table 3.

[0191] Table 1

[0192]

[0193] Table 2

[0194]

[0195]

[0196] Table 3

[0197]

[0198] Table 4

[0199]

[0200] Table 5

[0201]

[0202]

[0203] As can be seen from Tables 1-5, the polymers corresponding to the examples have high optical contrast and high coloring efficiency.

Claims

1. A triphenylamine-derived conjugated polymer, characterized in that, It has the structure shown in equation (1): Equation (1); Wherein, X is selected from one of nitro, cyano, aldehyde, and acyl groups; π represents thiophene or 3,4-ethylenedioxythiophene; D represents thiophene or 3,4-ethylenedioxythiophene; n is an integer between 1 and 10000.

2. The triphenylamine-derived conjugated polymer according to claim 1, characterized in that, The structures of the triphenylamine-derived conjugated polymers are shown in formulas (2), (3), (4), or (5): Equation (2), Equation (3) Equation (4) Equation (5).

3. The method for preparing the triphenylamine-derived conjugated polymer according to any one of claims 1-2, characterized in that, Includes the following steps: A first-step Stille coupling reaction is carried out on bromoaniline-based substances and π-unit tin compounds to obtain intermediate product A. Product A is then brominated to obtain product B. Product B is mixed with π-unit tin compounds and subjected to a Stille coupling reaction to obtain a polymerization precursor. The polymerization precursor is then subjected to electrochemical polymerization to obtain the triphenylamine-derived conjugated polymer.

4. The preparation method according to claim 3, characterized in that, The bromoaniline compounds include 4-bromo-N-(4-bromophenyl)-N-(4-nitrophenyl)aniline; And / or, the molar ratio of the bromoaniline to the π-unit tin compound is 1:(2~5); And / or, the molar ratio of product B to tin oxide containing D unit is 1:(2~5).

5. The preparation method according to claim 3, characterized in that, The electrochemical polymerization process is as follows: using a solution containing the polymerization precursor as an electrolyte, electrodeposition is performed in a three-electrode system consisting of a reference electrode, a counter electrode, and a working electrode to obtain the triphenylamine-derived conjugated polymer on the working electrode.

6. The preparation method according to claim 5, characterized in that, During the electrochemical polymerization process, the concentration of the polymerization precursor in the electrolyte is 0.001~0.1 mol / L; And / or, the electrolyte further contains an electrolyte, the electrolyte comprising at least one of tetrabutylammonium hexafluoride, tetrabutylammonium tetrafluoroborate, or lithium perchlorate.

7. The preparation method according to claim 5, characterized in that, During the electrochemical polymerization process, the electrodeposition method is a constant potential method; And / or, the electrodeposition potential is 1~2V.

8. An electrochromic device, characterized in that, Includes the triphenylamine-derived conjugated polymers as described in any one of claims 1-2.

9. The electrochromic device according to claim 8, characterized in that, The electrochromic device includes at least one of a display, electrochromic glass, a smart window, or a rearview mirror.

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