Electrochromic material based on pillararene and triphenylamine as well as preparation method and application of electrochromic material
By introducing columnar aromatic structures into triphenylamine derivatives, novel electrochromic materials were prepared, solving the problems of insufficient optical contrast and poor solubility in existing technologies, and realizing rapid and reversible color changes and long-life electrochromic devices.
Patent Information
- Application Number
- CN202511490962.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-17
- Publication Date
- 2026-02-13
AI Technical Summary
Existing electrochromic materials suffer from insufficient optical contrast and poor solubility in molecular design and synthesis techniques, and the problems of long-term stability and solute precipitation have not been effectively solved.
By introducing columnar aromatics structures into triphenylamine derivatives and employing solution-phase physical blending, electrochromic materials based on columnar aromatics and triphenylamine are prepared. The electron-rich rigid cavity and multiple benzene ring structures of columnar aromatics enhance molecular solubility and host-guest binding sites, thereby achieving color regulation.
It improves the color-changing speed and contrast of electrochromic materials, extends the service life of devices, solves the solute precipitation problem, and enhances the cycle stability and environmental reliability of devices.
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Figure CN121517701A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of organic photoelectric materials, and particularly relates to an electrochromic material based on a pillar arene and triphenylamine as well as a preparation method and application thereof. BACKGROUND
[0002] Electrochromism (EC) is a special photoelectrochemical phenomenon, which refers to that an electrochromic material can undergo an electrochemical redox reaction under the action of an applied potential, and is accompanied by a reversible change in optical properties (such as absorbance or transmittance), and macroscopically exhibits a reversible change in color. Due to this characteristic, electrochromic materials have potential application prospects in the fields of display technology and sensing.
[0003] In recent years, it has been found that a supramolecular system containing a pillar arene is stable itself, and due to the presence of the pillar arene structure, the supramolecular system also has special host-guest properties. At present, the research objects of organic electrochromic materials are mainly polymers such as polythiophene, polyaniline and polypyrrole, and modification researches on these polymers. In addition, new types of electrochromic materials such as organic-inorganic doped electrochromic materials have also been further researched. Triphenylamine compounds are often used as model units in electrochromic systems due to their easy derivatization, obvious color change signal and excellent electrochromic performance. Thiophene compounds, especially 3,4-ethylenedioxythiophene (EDOT) structure, can be selected as a construction module of an organic electrochromic material due to advantages such as adjustment of side chains, improvement of conjugation length, good compatibility with other color-changing components, etc. Finally, due to the easy derivatization property and rich host-guest performance of the pillar arene, which can be manifested as energy transfer and electron transfer, the pillar arene can be introduced into a supramolecular system with electrochromic performance. The above various components are used to develop and design a new type of electrochromic material based on a pillar arene supramolecule. This facilitates further research on the application of the pillar arene supramolecule in the field of electrochromism, and has important research value for widening the application field. At present, the design and development of electrochromic materials based on pillar arene polymers have been preliminarily explored, but there is no related literature report on electrochromic materials based on pillar arene small molecules. SUMMARY
[0004] One of the purposes of the present application is to expand the blank of electrochromic materials in organic supramolecular systems, and to provide a means for color regulation in the form of physical blending in solution phase for electrochromic materials. By introducing the structure of the pillar arene to the triphenylamine structure, the solubility of the electrochromic molecule in the organic solution can be improved, and the optical gap of the compound can be adjusted to obtain a color-changing material with more rich colors.
[0005] The second object of the present application is to provide a molecular design of electrochromic material and a preparation method thereof, and to develop the application of p-phenylene electrochromic compounds as electrochromic materials, the present application introduces p-phenylene structure into redox-type electrochromic small molecules to solve the problem of insufficient optical contrast of electrochromic materials or devices in the existing molecular design and synthesis technology.
[0006] The object of the present application is achieved by the following technical solutions: The present application provides an electrochromic material based on p-phenylene and triphenylamine, and the structural formula is:
[0007] The dotted line in the structural formula represents the p-phenylene cyclic structure in the compound.
[0008] The method of the present application derives compound 2 by symmetrically derivatizing triphenylamine benzene ring para-position and 3,4-propylenedioxythiophene (EDOT); then performs Suzuki reaction on the bis-OTf p-phenylene [5] arene and borate reagent to obtain compound 4; then performs substitution on sodium azide to obtain compound 5; finally, compound 2 and compound 5 undergo click reaction under the catalysis of cuprous to obtain an electrochromic material TPA-Th-P5 based on p-phenylene and triphenylamine. The reaction route is as follows:
[0009]
[0010]
[0011] The preparation method specifically comprises the following steps: (1) 5-6 equivalents of 2-bromo-5-ethynyl-3,4-ethylenedioxythiophene based on compound 1 are added to a reaction bottle, 10-12 equivalents of base based on compound 1 are added, and then a mixed solution of organic solvent and water is added, the volume ratio of organic solvent to distilled water is between 5:1 and 10:1, 0.02-0.08 molar amount of palladium catalyst based on compound 1 is added under inert gas protection, and the reaction is carried out at 72-86℃ for 6-12h, the solvent is removed by vacuum concentration, and compound 2 is separated by column chromatography; (2) adding 0.8-0.9 times of 1-boronic acid pinacol ester-4-aniline of the molar amount of compound 3 into a reaction bottle, adding 4-10 times of the molar amount of base of compound 3, adding a mixed solution of organic solvent and distilled water, the solvent volume ratio of organic solvent and distilled water is between 2:1 to 8:1, adding 0.01-0.1 times of the molar amount of palladium catalyst of compound 3 under inert gas protection, reacting at 70-90℃ for 6-24 h, removing the solvent by vacuum concentration, and obtaining compound 4 by column chromatography; (3) placing compound 4 in a reaction bottle, adding 3-5 times of the equivalent amount of acid of compound 4 under ice bath condition, adding 1.5-2 times of the equivalent amount of sodium nitrite, adding 1.5-2 times of the equivalent amount of sodium azide aqueous solution, reacting at room temperature for 6-10 h, extracting with dichloromethane, drying with anhydrous magnesium sulfate, removing the solvent by vacuum concentration, and obtaining compound 5 by column chromatography; (4) adding compound 2 and 3.5-4 times of the equivalent amount of compound 5 of compound 2 into a reaction bottle containing chloroform or tetrahydrofuran solvent, adding 0.04-0.1 times of the equivalent amount of stannous reagent of compound 2, adding 0.04-0.1 times of the equivalent amount of N,N,N',N",N"-pentamethyldipropylene triamine of compound 2, reacting at room temperature for 6-12 h under inert gas protection, quenching with water, extracting with dichloromethane, then drying with anhydrous magnesium sulfate, removing the solvent by vacuum concentration, and obtaining compound TPA-Th-P5 by column chromatography.
[0012] Further, the base in step (1) comprises one of Na2CO3, K2CO3, KOH or NaOH.
[0013] Further, the organic solvent in step (1) comprises one of toluene, 1,4-dioxane, ethanol.
[0014] Further, the palladium reagent in step (1) is Pd(PPh3)4.
[0015] Further, the base in step (2) comprises one of Na2CO3, K2CO3, potassium tert-butoxide, KOH or NaOH.
[0016] Further, the organic solvent in step (2) comprises toluene, 1,4-dioxane, ethanol, chloroform or tetrahydrofuran.
[0017] Further, the palladium reagent in step (2) is one of Pd(PPh3)4 or Pd(PPh2)Cl2.
[0018] Further, the acid in step (3) is one of dilute sulfuric acid or dilute hydrochloric acid.
[0019] Further, the cuprous reagent in step (4) is one of cuprous bromide or cuprous iodide.
[0020] Further, the inert gas in steps (1), (2) and (4) is one of argon or nitrogen.
[0021] The electrochromic material based on the pillar arene and triphenylamine obtained by the preparation method can be applied to the preparation of electrochromic devices, such as rearview mirrors of cars, smart windows and other smart display screens and the like.
[0022] Compared with the prior art, the present application has the following advantages and beneficial effects: (1) The present application introduces a pillar arene structure into the traditional triphenylamine derivative structure, and for the first time obtains a novel electrochromic molecule based on the pillar arene and triphenylamine, and applies it to electrochromic materials and devices. The pillar arene structure is introduced into the end of the triphenylamine derivative. The electron-rich rigid cavity of the pillar arene increases the electron cloud distribution of the conjugated fragment, so that the molecule itself is more easily oxidized and loses electrons, effectively reducing the band gap of the molecule and making the color change faster. Secondly, compared with the traditional ethylenedioxythiophene molecule, the introduction of the pillar arene introduces multiple benzene ring structures with methoxy groups into the end of the molecule, which improves the solubility of the molecule. In addition, the introduction of the pillar arene provides a site for the electrochromic molecule to bind to the guest, which can be used to introduce other electrochromic molecules, providing the possibility for physical blending means to adjust the color, and can be used as a new color control means for exploration.
[0023] (2) The present application uses the pillar arene and triphenylamine derivative to prepare an electrochromic molecule, and uses it to make an electrochromic device. The results show that the device exhibits completely different ultraviolet-visible absorption spectra and color changes before and after 0-2.4V voltage. Under the action of low voltage, the electrochromic device can realize reversible color change from light yellow to light blue, and the color can be restored. The electrochromic material has rapid response, high contrast and high reversibility. The electrochromic device based on the electrochromic molecule of the present application has more outstanding color changing performance, higher transmittance and longer service life.
[0024] In summary, the present application has the following significant advantages: 1. A more concise, milder and higher overall yield compound synthesis path is provided; 2. By introducing a clear host-guest binding site in the molecular structure, the possibility of combining with various functional guests is expanded, laying a material foundation for the diversification of device functions; 3. The solute precipitation problem that has long plagued polymer-based columnar arene electrochromic devices is effectively solved, significantly improving the cycle life and environmental reliability of the device; 4. The electrochromic device prepared in the present application has excellent performance in terms of optical contrast, response speed and long-term cycle stability when compared with similar products. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1 is the nuclear magnetic resonance spectrum of the columnar triphenylamine electrochromic molecule TPA-Ph-P5 synthesized in Example 1.
[0026] Figure 2 is the ultraviolet-visible absorption spectrum and fluorescence emission spectrum of the columnar triphenylamine electrochromic molecule TPA-Ph-P5 synthesized in Example 1.
[0027] Figure 3 is the thermogravimetric analysis graph of the columnar triphenylamine electrochromic molecule TPA-Ph-P5 synthesized in Example 1.
[0028] Figure 4 is the cyclic voltammogram of the columnar triphenylamine electrochromic molecule TPA-Ph-P5 synthesized in Example 1.
[0029] Figure 5 is the color change photo of the electrochromic device made of the columnar triphenylamine electrochromic molecule TPA-Ph-P5 synthesized in Example 1 under the action of external voltage in sunlight.
[0030] Figure 6 is the transmittance spectrum of the electrochromic device made of the columnar triphenylamine electrochromic molecule TPA-Ph-P5 synthesized in Example 1 under different voltages.
[0031] Figure 7 is the response time graph of the electrochromic device made of the columnar triphenylamine electrochromic molecule TPA-Ph-P5 synthesized in Example 1.
[0032] Figure 8 is the cycle stability graph of the electrochromic device made of the columnar triphenylamine electrochromic molecule TPA-Ph-P5 synthesized in Example 1. DETAILED DESCRIPTION
[0033] The technical solutions of the present application will be further described below in combination with the drawings and specific examples, but the scope of protection claimed by the present application is not limited to the scope expressed by the examples.
[0034] Example 1 The present example provides a preparation method of a columnar arene and triphenylamine-based electrochromic molecule, comprising the following steps: Synthesis of columnar arene and triphenylamine-based electrochromic material TPA-Th-P5, the synthesis route is as follows:
[0035]
[0036]
[0037] The synthesis steps are as follows: (1) Synthesis of compound 2:
[0038] Compound 1 (1.86 g, 3.0 mmol), 2-bromo-5-ethynyl-3,4-ethylenedioxythiophene (3.67 g, 15 mmol), potassium carbonate (4.14 g, 30 mmol) were weighed and added to a 50 mL two-necked flask under argon protection, a mixture solution of toluene, ethanol and water (V 甲苯 :V 乙醇 : V 水 = 36 mL: 9 mL: 9 mL) was added, and tetrakis triphenylphosphine palladium (180 mg, 0.16 mmol) was added to react at 80°C for 6 hours, and the reaction progress was monitored by TLC. After the reaction was completed, 50 mL x 3 dichloromethane was added, and 50 mL x 3 saturated brine was extracted three times, and the dichloromethane phase extract was collected, dried with anhydrous sodium sulfate, and concentrated. A chromatographic column was packed with 300-400 mesh silica gel, and a mixture solution of petroleum ether, dichloromethane and ethyl acetate (V 石油醚 :V 二氯甲烷 :V 乙酸乙酯 = 10:2:1) was used as the eluent for column chromatography separation, and a light yellow powder (compound 2, 2.02 g) was obtained, with a yield of 91.7%.
[0039] (2) Synthesis of compound 4:
[0040] Take compound 3 (800 mg, 0.81 mmol), 1-boronic acid pinacol-4-phenylamine (157 mg, 0.72 mmol), sodium carbonate (0.81 g, 8.1 mmol) into a 50 mL two-necked round-bottom flask under argon protection, add 20 mL of 1,4-dioxane and 2.5 mL of water into the reaction bottle, add tetrakis(triphenylphosphine)palladium (92.4 mg, 0.08 mmol), heat to 90°C for 6h, monitor the progress of the reaction by TLC, and stop the reaction when the borate is completely consumed. After cooling to room temperature, add 50 mL x 3 dichloromethane, 50 mL x 3 saturated brine extraction three times, collect the dichloromethane phase of the extraction, dry with anhydrous sodium sulfate, and concentrate. Use 300-400 mesh silica gel to pack the chromatography column, use a mixture of petroleum ether, dichloromethane and ethyl acetate (V 石油醚 :V 二氯甲烷 :V 乙酸乙酯 =10:2:1) as eluent, column chromatography separation, vacuum concentration, and the product is a yellow sticky material combined with dichloromethane solvent molecules, add 5 mL of n-hexane each time and continue to ultrasonic dissolution, then vacuum concentration until a light yellow powder solid is obtained (compound 4, 484 mg, 0.52 mmol), yield 64.0%.
[0041] (3) Synthesis of compound 5:
[0042] Take compound 4 (929.3 mg, 1 mmol) and stir in 20 mL of tetrahydrofuran solvent, inject 0.25 mL of concentrated hydrochloric acid (3 mmol) into the reaction system, stir in an ice bath for half an hour, prepare a solution of sodium nitrite with a concentration of 1.5 mol·L -1 (NaNO2: 103.5 mg, 1.5 mmol; H2O: 1.5 mL) and slowly add it to the reaction system (about 20 minutes to add), continue to stir in an ice bath for half an hour, then prepare a solution of sodium azide with a concentration of 1.5 mol·L -1 (NaN3: 97.5 mg, 1.5 mmol; H2O: 1.5 mL) and slowly add it to the reaction system (about 20 minutes to add). Continue to stir the reaction at room temperature for 6 hours. After the reaction of the raw material compound 4 is complete, the reaction system is concentrated under reduced pressure, and purified by column chromatography (V 石油醚 :V 二氯甲烷 :V 乙酸乙酯= 10:2:1), concentrated under reduced pressure, dried to obtain compound 5 (878.9 mg, 0.92 mmol) as a light brown solid powder, with a yield of 92.0%. 1 H NMR (400 MHz, CDCl3, 298 K), δ (ppm): 7.20 (s, 1H), 7.00 (s, 1H), 6.95 (m, 4H), 6.77 (m, 2H), 6.73 (m, 3H), 6.64 (s, 2H), 5.84 (s, 1H), 3.86 (s, 2H), 3.82 (s, 4H), 3.77 (s, 2H), 3.72 (s, 2H), 3.69 (m, 6H), 3.66 (s, 3H), 3.62 (s, 6H), 3.52 (s, 3H), 3.46 (s, 6H). (4) Synthesis of compound TPA-Th-P5:
[0043] The compound 2 (220 mg, 0.3 mmol) and compound 5 (1147.2 mg, 1.2 mmol) synthesized above were stirred and dissolved in 30 mL of dry tetrahydrofuran solvent, 1,1,4,7,7-pentamethyldiethylenetriamine (PMEDTA) (5.2 mg, 0.03 mmol), CuI (5.7 mg, 0.03 mmol) were added to the system, and the system was refluxed at room temperature under nitrogen protection for 12 hours. After the reaction was completed, the mixed solution after reaction was concentrated under reduced pressure, and column chromatography was used for separation and purification, using petroleum ether / dichloromethane / ethyl acetate mixed solvent (V 石油醚 :V 二氯甲烷 :V 乙酸乙酯 = 10:2:1) as eluent, concentrated under reduced pressure, dried to obtain compound TPA-Th-P5 (898 mg, 0.27 mmol) with a yield of 90.2%. The hydrogen spectrum is as follows: Figure 1 , 1H NMR (500 MHz, Chloroform-d) δ 7.31 - 7.23 (m, 4H), 6.87 - 6.82 (m, 2H), 6.75 - 6.67 (m, 4H), 6.62 (s, 2H), 4.36 (m, 2H), 4.17 (m, 2H), 3.78 (s, 4H), 3.72 (d, J = 2.9 Hz, 4H), 3.65 (s, 8H), 3.60 (d, J = 12.4 Hz, 14H), 3.54 (s, 4H), 1.13 (s, 2H), 1.21 - 1.04 (m, 4H), 0.77 (t, J = 7.1 Hz, 4H). Example 2 This example provides another method for preparing a columnar arene and triphenylamine-based electrochromic molecule, comprising the following steps: The synthesis of the columnar arene and triphenylamine-based electrochromic material is shown in the following synthesis route:
[0044]
[0045]
[0046] The synthesis steps are as follows: (1) Synthesis of compound 2:
[0047] Compound 1 (1.86 g, 3.0 mmol), 2-bromo-5-ethynyl-3,4-ethylenedioxythiophene (4.40 g, 18 mmol), sodium carbonate (3.82 g, 36 mmol) were weighed out and added to a 50 mL two-necked flask under argon protection, and a mixed solution of 1, 4-dioxane and water (V 二氧六环 : V 水 = 24 mL: 4 mL) was added, and tetrakis triphenylphosphine palladium (180 mg, 0.16 mmol) was added. The reaction was carried out at 80°C for 10 hours, and the progress of the reaction was monitored by TLC. After the reaction was completed, 50 mL x 3 dichloromethane was added, and 50 mL x 3 saturated brine was extracted three times. The dichloromethane phase was collected and dried over anhydrous sodium sulfate, and concentrated. A chromatographic column was packed with 300-400 mesh silica gel, and a mixed solution of petroleum ether, dichloromethane and ethyl acetate (V 石油醚 : V 二氯甲烷 : V 乙酸乙酯=10:2:1) as eluent, column chromatography separation, vacuum concentration, the column aromatic molecules will combine dichloromethane solvent molecules so that the product is a yellow viscous material, each time 5 mL of n-hexane ultrasonic dissolution after continue vacuum concentration until the yellow powder solid (compound 4, 510 mg, 0.55 mmol), the yield was 67.4%.
[0048] (2) Synthesis of compound 4:
[0049] Compound 3 (800 mg, 0.81 mmol), 1-boronic acid pinacol-4-phenylamine (157 mg, 0.72 mmol), potassium carbonate (1.12 g, 8.1 mmol) were weighed into a 50 mL two-necked round-bottom flask under argon protection, 20 mL of 1,4-dioxane and 2.5 mL of water were added to the reaction bottle, and tetrakis(triphenylphosphine)palladium (92.4 mg, 0.08 mmol) was added. Heat to 70°C for 18h, monitor the progress of the reaction by TLC, and stop the reaction after the borate is completely consumed. After cooling to room temperature, 50 mL of dichloromethane was added, and 50 mL of saturated brine was extracted three times. The dichloromethane phase was collected and dried over anhydrous sodium sulfate, and concentrated. The chromatographic column was packed with 300-400 mesh silica gel, and the mixture of petroleum ether, dichloromethane and ethyl acetate (V 石油醚 :V 二氯甲烷 :V 乙酸乙酯 =10:2:1) as eluent, column chromatography separation, vacuum concentration, the column aromatic molecules will combine dichloromethane solvent molecules so that the product is a yellow viscous material, each time 5 mL of n-hexane ultrasonic dissolution after continue vacuum concentration until the yellow powder solid (compound 4, 510 mg, 0.55 mmol), the yield was 67.4%.
[0050] (3) Synthesis of compound 5:
[0051] Compound 4 (929.3 mg, 1 mmol) was stirred in 20 mL of tetrahydrofuran solvent, and 2.5 mL of dilute sulfuric acid aqueous solution (2.5 mmol) was slowly added to the reaction system. Stir for half an hour in an ice bath, prepare a solution of sodium nitrite with a concentration of 1.5 mol·L -1 NaNO2: 138 mg, 2.0 mmol; H2O: 1.3 mL) and slowly drop into the reaction system (about 20 minutes to drop), continue to stir in the ice bath for half an hour, then prepare a solution of sodium azide with a concentration of 1.5 mol·L -1solution (NaN3: 130 mg, 2.0 mmol; H2O: 1.3 mL) was added slowly into the reaction system (about 20 minutes for dropwise addition). The reaction was continued to stir at room temperature for 8 hours. After the reaction of the starting compound 4 was completed, the reaction system was concentrated under reduced pressure, and column chromatography was used for separation and purification (V 石油醚 :V 二氯甲烷 :V 乙酸乙酯 = 10:2:1) to obtain compound 5 (888 mg, 0.93 mmol) in the form of light brown solid powder, with a yield of 93.2%.
[0052] (4) Synthesis of compound TPA-Th-P5:
[0053] The synthesized compound 2 (220 mg, 0.3 mmol) and compound 5 (1147.2 mg, 1.2 mmol) were stirred and dissolved in 30 mL of dry tetrahydrofuran solvent, 1,1,4,7,7-pentamethyl diethylene triamine (PMEDTA) (5.2 mg, 0.03 mmol), CuBr (5.4 mg, 0.03 mmol) were added into the system, and the reaction was continued to reflux at room temperature for 12 hours under nitrogen protection. After the reaction was completed, the mixed solution after the reaction was concentrated under reduced pressure, column chromatography was used for separation and purification, petroleum ether / dichloromethane / ethyl acetate mixed solvent (V 石油醚 :V 二氯甲烷 :V 乙酸乙酯 = 10:2:1) was used as the eluent, and compound TPA-Th-P5 (770 mg, 0.23 mmol) was obtained after concentration under reduced pressure and drying, with a yield of 77.4%.
[0054] Example 3 The columnar triphenylamine electrochromic molecule TPA-Th-P5 synthesized in Example 1 was subjected to ultraviolet-visible absorption spectrum test (the concentration was 5 x 10 -6 mol / L, and the solvent was tetrahydrofuran, at room temperature). The measured ultraviolet-visible absorption spectrum is shown in Figure 2 , the maximum ultraviolet-visible absorption wavelength of which is 464 nm, and the maximum fluorescence emission peak corresponds to a wavelength of 639 nm.
[0055] Meanwhile, the columnar triphenylamine electrochromic molecule TPA-Th-P5 synthesized in Example 1 was subjected to thermogravimetric analysis, as shown in Figure 3 , it can be seen that the initial thermal decomposition temperature of the molecule TPA-Th-P5 is 289°C, the terminal decomposition temperature is 344°C, and the mass loss is 66%.
[0056] The solid powder of the molecule TPA-Th-P5 was dissolved in tetrahydrofuran with a concentration of 72.1 mg / mL, and ultrasonic was used to help the molecule to be completely dissolved. A platinum electrode was used as the working electrode, a silver / silver chloride electrode was used as the reference electrode, and another platinum electrode was used as the auxiliary electrode. A tetrabutylammonium perchlorate (0.1 mol / L) tetrahydrofuran solution was used as the electrolyte. The molecule solution was subjected to cyclic voltammetry test at a rate of 100 mV / s in the range of -3 V~2 V in a three-electrode system. As shown in Figure 4 , two oxidation peaks and two reduction peaks can be seen. The initial oxidation potential is 1.199 V, and the initial reduction potential is -1.801 V. The closed cv curve shows that the electrochromic material has rapid response and reversibility, and can be applied to electrochromic devices. The columnar triphenylamine electrochromic molecule TPA-Th-P5 prepared in Example 2 also has rapid response and reversibility, and can also be applied to electrochromic devices.
[0057] Example 4 A tetrahydrofuran solution containing the columnar triphenylamine electrochromic molecule TPA-Th-P5 (0.02 M) and tetrabutylammonium perchlorate (0.01 M) was prepared. After being fully stirred and dissolved, a polymer electrochromic material electrolyte solution was obtained. An electrochromic device was assembled. First, an ITO conductive glass was taken, and a certain thickness of double-sided tape was attached to the conductive surface to form a cavity to control the thickness of the electrochromic active layer solution. Another ITO glass was taken, and the two ITO glasses were pasted together and tightly attached by applying pressure. Then, the prepared polymer solution was injected into the cavity, and hot melt adhesive was used to seal the four corners to form a liquid electrochromic device.
[0058] The device was tested by ultraviolet-visible absorption spectrum and electrochromic cycle tester. As shown in Figure 5 , the device is slightly yellow under natural light, and shows a light blue color under natural light after a voltage of 1.8 V is applied across the two ends. The transmittance change curve of the device under ultraviolet-visible absorption at a voltage of 0~2.0 V was tested, as shown in Figure 6 , it can be seen that the transmittance of the device between 580 nm and 660 nm decreases as the applied voltage increases, and the transmittance change at 680 nm reaches more than 50%. The color changes from light yellow to light blue, indicating that the device has color change and electrochromic performance.
[0059] The transmittance change of the device at a wavelength of 634 nm was measured when the applied voltage was intermittently changed between 0 V and 2.0 V. The time required for the transmittance change to reach a maximum change rate of 95% was defined as the response time, as shown in Figure 7As shown, the coloring time of the device is 4.1 s, and the bleaching time is 8.6 s.
[0060] Finally, the cyclic stability performance of the device is also determined, and each 30 s is set as a cycle, wherein the coloring time and the bleaching time are both set as 15 s. According to the response time determined above, this cyclic mode can meet the time requirement for complete color change during electrochromism, such as Figure 8 As shown, after 60 cycles, the optical contrast of the device can still be maintained at 85.1% of the initial maximum optical contrast.
[0061] The present application is not limited to the above optional embodiments, and anyone can derive other various forms of products under the inspiration of the present application, but regardless of any changes in the structure, any technical solutions falling within the scope defined by the claims of the present application fall within the protection scope of the present application.
Claims
1. An electrochromic material based on columnar aromatics and triphenylamine, characterized in that, Its structural formula is: The dashed lines in the structural formula represent the cyclic structure of aromatic hydrocarbons in the compound.
2. The method for preparing an electrochromic material based on columnar aromatics and triphenylamine as described in claim 1, characterized in that, The reaction route is as follows: The preparation method specifically includes the following steps: (1) Triphenylamine substituted with triboronic acid ester and 2-bromo-5-acetylene-3,4-ethylenedioxythiophene (based on compound 1) were added to a reaction flask. Then, 10-12 times the amount of base (based on compound 1) were added, followed by a mixed solution of organic solvent and water. The volume ratio of organic solvent to distilled water was between 5:1 and 10:
1. Under the protection of an inert gas, 0.02-0.08 times the molar amount of palladium catalyst (based on compound 1) were added. The reaction was carried out at 72-86 °C for 6-12 h. The solvent was removed by vacuum concentration, and compound 2 was obtained by column chromatography. (2) Add 0.8-0.9 molar amounts of 1-boronic acid pinacol ester-4-aniline (based on compound 3) to a reaction flask, add 4-10 molar amounts of base (based on compound 3), and then add a mixed solution of organic solvent and water. The volume ratio of organic solvent to distilled water is between 2:1 and 8:
1. Under inert gas protection, add 0.01-0.1 molar amounts of palladium catalyst (based on compound 3), and react at 70-90℃ for 6-24 h. Vacuum concentration is used to remove the solvent, and column chromatography is used to obtain compound 4. (3) Place compound 4 in a reaction flask, add 3-5 equivalents of acid, 1.5-2 equivalents of sodium nitrite, and 1.5-2 equivalents of sodium azide aqueous solution based on compound 4 under ice bath conditions, react at room temperature for 6-10 h, extract with dichloromethane, dry with anhydrous magnesium sulfate, concentrate under vacuum to remove solvent, and obtain compound 5 by column chromatography. (4) Compound 2 and 3.5-4 equivalents of Compound 5 (based on Compound 2) were added to a reaction flask containing chloroform or tetrahydrofuran solvent. 0.04-0.1 equivalents of cuprous reagent (based on Compound 2) were added, followed by 0.04-0.1 equivalents of N,N,N',N”,N”-pentamethyldipropylenetriamine (based on Compound 2). The reaction was carried out at room temperature for 6-12 hours under inert gas protection. After quenching with water, the mixture was extracted with dichloromethane, dried with anhydrous magnesium sulfate, concentrated under vacuum to remove the solvent, and column chromatography was used to obtain compound TPA-Th-P5.
3. The preparation method according to claim 2, characterized in that, The alkali mentioned in step (1) includes one of Na2CO3, K2CO3, KOH or NaOH; the organic solvent mentioned in step (1) includes one of toluene, 1,4-dioxane or ethanol.
4. The preparation method according to claim 2, characterized in that, The palladium reagent mentioned in step (1) is Pd(PPh3)4.
5. The preparation method according to claim 2, characterized in that, The alkali mentioned in step (2) includes one of Na2CO3, K2CO3, potassium tert-butoxide, KOH or NaOH; the organic solvent mentioned in step (2) includes toluene, 1,4-dioxane, ethanol, chloroform or tetrahydrofuran.
6. The preparation method according to claim 2, characterized in that, The palladium reagent mentioned in step (2) is either Pd(PPh3)4 or Pd(PPh2)Cl2.
7. The preparation method according to claim 2, characterized in that, The acid mentioned in step (3) is either dilute sulfuric acid or dilute hydrochloric acid.
8. The preparation method according to claim 2, characterized in that, The cuprous reagent mentioned in step (4) is either cuprous bromide or cuprous iodide.
9. The preparation method according to claim 2, characterized in that, The inert gas mentioned in steps (1), (2), and (4) is either argon or nitrogen.
10. The application of the electrochromic material based on columnar aromatics and triphenylamine as described in claim 1 in the preparation of electrochromic devices.