An electrochromic monomer compound, polymer, material and their preparation methods and applications

Abstract

This application belongs to organic polymer compounds, and specifically relates to an electrochromic monomer compound, polymer, material and their preparation methods and applications. The present invention uses an acridine derivative as the central core and 3,4-ethylenedioxythiophene (EDOT) as the electroactive polymerization unit monomer, providing a three-branched material that is easy to form a network structure. Through electrochemical polymerization, a uniform and flat polymer film can be formed. This polymer film can achieve reversible switching from yellow to transparent, with an optical contrast of 32.4%. After 30,000 cycles, the optical contrast does not show significant attenuation, and the response times are 0.4 s and 0.42 s. It is an electrochromic material with good application prospects.

Description

Technical Field

[0001] This application belongs to organic polymer compounds, and specifically relates to an electrochromic monomer compound, polymer, material, and their preparation methods and applications. Background Art

[0002] Electrochromic materials refer to materials that can cause stable and reversible changes in optical properties such as reflectivity, transmittance, and absorbance due to the redox reactions occurring within them and the accompanying ion insertion and extraction processes when an external electric field is applied. As a new type of functional material, electrochromic materials have the advantages of self-color change and energy conservation, and have been vigorously developed in the context of the global promotion of energy conservation and emission reduction. They are widely used in fields such as smart glass, automotive anti-glare rearview mirrors, electronic tags, mobile phone accessories, displays, and thermal control.

[0003] Electrochromic materials can be divided into inorganic electrochromic materials and organic electrochromic materials. As one of the organic electrochromic materials, conductive polymers have the advantages of easy structural modification, low cost, easy processing, rich color changes, fast response time, etc., and have become the "star materials" of electrochromics, attracting much attention from researchers. In recent years, electrochromic materials with transitions from cyan to transparent and from magenta to transparent have been successively developed, but there are few reports on electrochromic materials with a transition from yellow to transparent.

[0004] Yellow is a basic component color of the three primary colors (cyan, magenta, yellow) and is very important in fields such as display and color. However, due to the poor optical stability of yellow-based electrochromic materials, this greatly limits the practical application of yellow-based electrochromic materials in the field of electrochromics. Therefore, how to prepare a conductive polymer electrochromic material with high stability and a yellow-to-transparent transition is an urgent problem to be solved at present. Summary of the Invention

[0005] The first object of this application is to provide an electrochromic monomer compound with high stability and capable of realizing a reversible transition from yellow to transparent, which is specifically achieved through the following technical solutions:

[0006] An electrochromic monomer compound, the structural formula of the electrochromic monomer compound is shown as formula (I):

[0007]

[0008] An electrochromic polymer, the structural formula of the electrochromic polymer is shown as formula (Ⅱ):

[0009]

[0010] In formula (Ⅱ), n represents the average degree of polymerization, and n takes values from 100 to 2000.

[0011] Preferably, it includes the following steps:

[0012] (1) 4,4,8,8,12,12-Hexamethyl-8,12-dihydro-4H-benzo[9,1]quinoxalino[3,4,5,6,7-defg]acridine undergoes a bromination reaction with N-bromosuccinimide to obtain compound HMAT-Br(Ⅲ), and the structural formula of HMAT-Br is as follows:

[0013]

[0014] (2) EDOT undergoes a substitution reaction with tributyltin chloride to obtain the tinated EDOT derivative EDOT-Sn(IV), and the structural formula of EDOT-Sn is as follows:

[0015]

[0016] (3) HMAT-Br(Ⅲ) and EDOT-Sn(IV) undergo a Stille coupling reaction under the catalysis of a palladium catalyst to obtain the target product HMAT-EDOT(I).

[0017] Preferably, step (1) includes: successively adding 4,4,8,8,12,12-hexamethyl-8,12-dihydro-4H-benzo[9,1]quinoxalino[3,4,5,6,7-defg]acridine, N-bromosuccinimide, and chloroform into a reaction vessel, stirring and reacting at room temperature under a nitrogen atmosphere, and performing post-treatment to obtain HMAT-Br(Ⅲ); the molar ratio of 4,4,8,8,12,12-hexamethyl-8,12-dihydro-4H-benzo[9,1]quinoxalino[3,4,5,6,7-defg]acridine to N-bromosuccinimide in the feed is 1:(3 - 3.2); the added volume of chloroform is 20 ml / g based on the mass of 4,4,8,8,12,12-hexamethyl-8,12-dihydro-4H-benzo[9,1]quinoxalino[3,4,5,6,7-defg]acridine.

[0018] The specific method of the post-treatment is as follows: after the reaction ends, pour the obtained reaction solution into deionized water and mix, filter to collect the precipitate, then extract the precipitate with saturated sodium chloride and dichloromethane, collect the organic phase and dry it with anhydrous sodium sulfate, and finally perform purification by silica gel column chromatography using petroleum ether and dichloromethane as the mobile phase; in the mobile phase, the volume ratio of petroleum ether to dichloromethane is (5 - 8):1.

[0019] Preferably, step (2) includes: dissolving EDOT in tetrahydrofuran under nitrogen protection, then adding n-butyllithium at -78 °C, stirring and then adding tributyltin chloride, restoring to room temperature and stirring, and performing post-treatment to obtain the compound EDOT-Sn(IV); the molar ratio of EDOT, n-butyllithium, and tributyltin chloride is 1:(1-1.2):(1-1.6); the added volume of tetrahydrofuran is 15-25 mL / g based on the mass of EDOT.

[0020] The specific method of the post-treatment is: after the reaction ends, subject the obtained reaction solution to separation and purification through an alumina chromatography column.

[0021] Preferably, step (3) includes: under nitrogen protection, sequentially adding the monomer HMAT-Br(III), EDOT-Sn(IV), and a palladium catalyst into a reaction vessel, then adding DMF, stirring and refluxing, and performing post-treatment to obtain the target product HMAT-EDOT(I); the molar ratio of HMAT-Br, EDOT-Sn, and the palladium catalyst is 1:(3-6):(0.001-0.01); the added volume of DMF is 15-25 mL / g based on the mass of monomer III.

[0022] The palladium catalyst is any one of palladium acetate, tetrakis(triphenylphosphine)palladium, or dichlorobis(triphenylphosphine)palladium.

[0023] The specific method of the post-treatment is: after the reaction ends, pour the obtained reaction solution into deionized water for mixing, filter and collect the precipitate, then extract the precipitate with saturated sodium chloride and dichloromethane, collect the organic phase and dry it with anhydrous sodium sulfate, and finally perform purification through silica gel column chromatography using petroleum ether and dichloromethane as the mobile phase; in the mobile phase, the volume ratio of petroleum ether to dichloromethane is (0.5-2):1.

[0024] The application of the above monomer compound in the preparation of a multifunctional electrochromic material.

[0025] A method for preparing an electrochromic material, including: dissolving HMAT-EDOT shown in formula (I) in a mixed chromatographic-grade solution of dichloromethane and acetonitrile, adding tetrabutylammonium perchlorate as an electrolyte, and electrochemically polymerizing to form a film through cyclic voltammetry to prepare a multifunctional electrochromic material.

[0026] Preferably, the volume ratio of dichloromethane to acetonitrile is (3-5):1; the concentration of HMAT-EDOT is 0.5-1 mmol / L; the concentration of tetrabutylammonium perchlorate is 0.05-0.1 mol / L.

[0027] The cyclic voltammetry electrochemical polymerization refers to that in a three - electrode system, ITO conductive glass serves as the working electrode, a platinum wire serves as the counter electrode, and Ag / AgCl serves as the reference electrode for electrochemical polymerization to obtain a film attached to the ITO glass, which is the electrochromic polymer material; the scanning speed of the cyclic voltammetry is 100 mV / s, the voltage is 0 - 1.2 V, and the number of cyclic scans is 5 - 10 cycles.

[0028] An electrochromic material is prepared by using the above - mentioned preparation method.

[0029] Compared with the prior art, the present application has the following beneficial effects:

[0030] The electrochromic material of the present invention has a novel structure representative not involved in current research. It is a monomer compound with an acridine derivative as the central core and 3,4 - ethylenedioxythiophene (EDOT) as the electroactive polymerization unit, providing a three - branched material that is easy to form a network structure. After electrochemical polymerization, it can form a uniform and flat polymer film (pHMAT - EDOT). The preparation is simple and effective, and it simultaneously exhibits good electrochromic and energy - storage and other electrochemical properties.

[0031] The polymer film prepared by electrochemically polymerizing the HMAT - EDOT compound shown in formula (I) of the present invention has excellent chemical stability, high sensitivity, short response time, can realize reversible switching from yellow to transparent under different voltage windows, with an optical contrast of 32.4%, and response times of 0.4 s and 0.42 s respectively, showing great development potential in electrochromic devices such as smart color - changing windows, display screens, supercapacitors, and smart materials.

[0032] The polymer film (pHMAT - EDOT) prepared by the present invention has a surface capacitance of 4.17 mF / cm 2 under a current density of 0.05 mA / cm 2 In addition, by combining electrochromism and energy storage through the polymer film, it provides a research idea for developing intelligent energy - storage devices for real - time monitoring of the energy - storage state, and also benefits the future intelligent production and life and the sustainable development of energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] To clearly illustrate the embodiments, the following will briefly introduce the drawings:

[0034] Figure 1 is the synthetic route diagram of the monomer compound (HMAT - EDOT) of the present invention;

[0035] Figure 2 is the electrochemical polymerization curve diagram of the monomer compound (HMAT - EDOT) of the present invention;

[0036] Figure 3 It is the ultraviolet-visible absorption spectrogram of the electrochromic polymer described in the present invention under different voltages;

[0037] Figure 4 It is the spectral kinetic stability diagram of the electrochromic polymer film described in the present invention at the 450 nm wavelength band;

[0038] Figure 5 It is the optical contrast and response time diagram of the electrochromic polymer film described in the present invention at the 450 nm wavelength band;

[0039] Figure 6 It is the charge-discharge curve diagram of the electrochromic polymer film described in the present invention under different current densities. Detailed implementation manners

[0040] The following will further describe the present application in the manner of specific embodiments. Those of ordinary skill in the art will be able to implement the present application based on these descriptions. In addition, the embodiments of the present application involved in the following description are usually only a part of the embodiments of the present application, rather than all of the embodiments. Therefore, all other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0041] Example 1: Synthesis of HMAT-Br

[0042] 4,4,8,8,12,12-Hexamethyl-8,12-dihydro-4H-benzo[9,1]quinoxalino[3,4,5,6,7-defg]acridine (1.0 g, 1 eq), N-bromosuccinimide (2.0 g, 3 eq), and 20 mL of chloroform solution were successively added to a 100 mL two-necked flask, and stirred at room temperature overnight under a nitrogen atmosphere. After the reaction was completed, the resulting reaction solution was poured into 100 mL of deionized water and mixed, and then extracted with saturated sodium chloride solution and dichloromethane. The organic phase was collected and dried with anhydrous sodium sulfate. Finally, using petroleum ether:dichloromethane (volume ratio 5:1) as the mobile phase, purification was carried out by silica gel column chromatography to obtain the product monomer HMAT-Br, and the structural formula of the monomer HMAT-Br is as shown in Formula III.

[0043]

[0044] In some embodiments, the molar ratio of 4,4,8,8,12,12-hexamethyl-8,12-dihydro-4H-benzo[9,1]quinoxalino[3,4,5,6,7-defg]acridine to N-bromosuccinimide is 1:(3 - 3.2); the volume ratio of petroleum ether to dichloromethane is (5 - 8):1.

[0045] Example 2: Synthesis of EDOT-Sn

[0046] Under nitrogen protection, 1 g (7.03 mmol) of EDOT was dissolved in 20 mL of anhydrous tetrahydrofuran, and then 3.37 mL (8.4 mmol, stored in a hexane solution at 2.5 mol / L) of n-butyllithium solution was added dropwise at -78 °C. After stirring at this temperature for 1 hour, 2.97 g (9.14 mmol) of tributyltin chloride was added. After the addition of tributyltin chloride was completed, the mixture was stirred at room temperature for 24 hours. After the reaction was completed, the resulting reaction solution was separated and purified by an alumina chromatography column to obtain a crude product of the compound EDOT-Sn with a yield of 80%. The structural formula of the compound EDOT-Sn is as shown in Formula IV.

[0047]

[0048] In some embodiments, the molar ratio of EDOT, n-butyllithium, and tributyltin chloride is 1:(1 - 1.2):(1 - 1.6); wherein, the n-butyllithium is an n-butyllithium solution with a concentration of 1 - 3 mol / L, and the tributyltin chloride is a tributyltin chloride solution with a concentration of 1 - 5 g / mL; the added volume of tetrahydrofuran is 15 - 25 mL / g based on the mass of EDOT.

[0049] Example 3: Synthesis of HMAT-EDOT

[0050] Under nitrogen protection, 0.35 g (0.58 mmol) of HMAT-Br, 0.88 g (2.04 mmol) of EDOT-Sn, and 40 mg (0.35 mmol) of tetrakis(triphenylphosphine)palladium were successively added to a two-necked round-bottom flask, and then 10 mL of anhydrous DMF was added. The reaction was refluxed with stirring for 48 hours. After the reaction was completed, the resulting reaction solution was poured into 100 mL of deionized water and mixed. The precipitate was collected by filtration, and then the precipitate was extracted with saturated sodium chloride solution and dichloromethane. The organic phase was collected and dried with anhydrous sodium sulfate. Finally, using petroleum ether:dichloromethane (volume ratio 1:1) as the mobile phase, purification was carried out by silica gel column chromatography to obtain the target product HMAT-EDOT. The structural formula of the monomer HMAT-EDOT is as shown in Formula I.

[0051]

[0052] In some embodiments, the molar ratio of the feed of HMAT-Br, EDOT-Sn, and the palladium catalyst is 1:(3 - 6):(0.001 - 0.01); wherein, the palladium catalyst is any one of palladium acetate, tetrakis(triphenylphosphine)palladium, or dichlorobis(triphenylphosphine)palladium; the added volume of DMF is 15 - 25 mL / g based on the mass of monomer III. The volume ratio of petroleum ether to dichloromethane is (0.5 - 2):1.

[0053] Example 4: Electrochemical Polymerization of HMAT-EDOT

[0054] Dissolve monomer HMAT-EDOT in a mixed chromatographic grade solution of dichloromethane and acetonitrile, with the volume ratio of dichloromethane to acetonitrile being 7:3 and the concentration of HMAT-EDOT being 1 mmol / L. Then add tetrabutylammonium perchlorate as the electrolyte with a concentration of 0.1 mol / L, and perform cyclic voltammetry electrochemical polymerization in a three-electrode system (ITO conductive glass as the working electrode, platinum wire as the counter electrode, and Ag / AgCl as the reference electrode) to obtain an electrochromic polymer film (pHMAT-EDOT) attached to the ITO glass, which is a multifunctional electrochromic polymer material; the scanning rate of the cyclic voltammetry is 100 mV / s, the voltage is 0 - 1.2 V, and the number of cycles is 5.

[0055] In some embodiments, the volume ratio of dichloromethane to acetonitrile is (3 - 5):1; the concentration of HMAT-EDOT is 0.5 - 1 mmol / L; the concentration of tetrabutylammonium perchlorate is 0.05 - 0.1 mol / L.

[0056] Example 5: Performance Test of Yellow to Transparent Multifunctional Electrochromic Material

[0057] Using a device combining an electrochemical workstation and an ultraviolet-visible spectrophotometer, in a 0.1 M tetrabutylammonium perchlorate / acetonitrile solution, respectively test the CV curve of the prepared film, the ultraviolet-visible light absorption at different voltages, the fading time and coloring time of the film at a specific wavelength, the relationship between the transmittance and time of the film at a specific wavelength, and the film stability test under a step voltage. The data processing results are shown in the figure. From Figure 2 It can be seen that the polymer film has two pairs of redox peaks, located at 0.65 V / 0.55 V and 0.95 V / 0.87 V. From Figure 3 It can be seen that the polymer film is yellow in the neutral state at 0 V and becomes transparent after oxidation at a voltage of 1.2 V. Figure 4 and Figure 5The spectral kinetic changes, optical contrast, and response time graphs of the polymer film at 450 nm under 0 V and 1.2 V were measured using a combined electrochemical workstation-UV-visible spectrophotometer. It can be seen that: after 30,000 cycles, the optical contrast of the film did not show obvious attenuation, indicating very excellent electrochemical stability. In addition to the stable color change behavior, from Figure 5 it can be seen that the optical contrast of the film at 450 nm is 32.4%, and the color response times are 0.4 s and 0.42 s, respectively.

[0058] Figure 6 The charge-discharge performance of the polymer film at different current densities in the voltage range of 0.4 - 1.2 V was measured using an electrochemical workstation. It can be seen from this figure that: at a current density of 0.05 mA / cm 2 the film exhibits a specific capacitance of 4.17 mF / cm 2 ; when the current density increases to 0.5 mA / cm 2 the specific capacitance is 4.16 mF / cm 2 , remaining 99.76% of the initial value.

Claims

1. An electrochromic monomer compound, characterized in that, The structural formula of the electrochromic monomer compound is shown in Formula (I):

2. An electrochromic polymer, characterized in that, The structural formula of the electrochromic polymer is shown in Formula (Ⅱ): In Formula (Ⅱ), n represents the average degree of polymerization, and n ranges from 100 to 2000.

3. The preparation method of the electrochromic monomer compound according to claim 1, characterized in that, It includes the following steps: (1) 4,4,8,8,12,12-Hexamethyl-8,12-dihydro-4H-benzo[9,1]quinoxalino[3,4,5,6,7-DEFG]acridine undergoes a bromination reaction with N-bromosuccinimide to obtain compound HMAT-Br(Ⅲ), and the structural formula of HMAT-Br is as follows: (2) EDOT undergoes a substitution reaction with tributyltin chloride to obtain a tinylated EDOT derivative EDOT-Sn(IV), and the structural formula of EDOT-Sn is as follows: (3) HMAT-Br(Ⅲ) and EDOT-Sn(IV) undergo a Stille coupling reaction under the catalysis of a palladium catalyst to obtain the target product HMAT-EDOT(I).

4. The method according to claim 3, wherein The said step (1) includes: adding 4,4,8,8,12,12-hexamethyl-8,12-dihydro-4H-benzo[9,1]quinoxalino[3,4,5,6,7-DEFG]acridine, N-bromosuccinimide, and chloroform into a reaction vessel in sequence, stirring and reacting at room temperature under a nitrogen atmosphere, and performing post-treatment to obtain HMAT-Br(Ⅲ); the molar ratio of 4,4,8,8,12,12-hexamethyl-8,12-dihydro-4H-benzo[9,1]quinoxalino[3,4,5,6,7-DEFG]acridine to N-bromosuccinimide in the feed is 1:(3 - 3.2); the added volume of chloroform is 20 ml / g based on the mass of 4,4,8,8,12,12-hexamethyl-8,12-dihydro-4H-benzo[9,1]quinoxalino[3,4,5,6,7-DEFG]acridine.

5. The method according to claim 3, characterized in that The said step (2) includes: under nitrogen protection, dissolving EDOT in tetrahydrofuran, then adding n-butyllithium at -78 °C, stirring and then adding tributyltin chloride, restoring to room temperature and stirring, and performing post-treatment to obtain compound EDOT-Sn(IV); the molar ratio of EDOT, n-butyllithium, and tributyltin chloride in the feed is 1:(1 - 1.2):(1 - 1.6); the added volume of tetrahydrofuran is 15 - 25 mL / g based on the mass of EDOT.

6. The method according to claim 3, wherein The said step (3) includes: under nitrogen protection, adding monomer HMAT-Br(III), EDOT-Sn(IV), and a palladium catalyst into a reaction vessel in sequence, then adding DMF, stirring and refluxing, and performing post-treatment to obtain the target product HMAT-EDOT(I); the molar ratio of HMAT-Br, EDOT-Sn, and the palladium catalyst in the feed is 1:(3 - 6):(0.001 - 0.01); the added volume of DMF is 15 - 25 mL / g based on the mass of monomer III.

7. The application of the monomer compound according to claim 1 in the preparation of a polymer thin film material.

8. A method for preparing an electrochromic polymer, characterized in that, It includes: Dissolve HMAT-EDOT shown in formula (I) of claim 1 in a mixed chromatographic grade solution of dichloromethane and acetonitrile, add tetrabutylammonium perchlorate as an electrolyte, and electrochemically polymerize it into a film by cyclic voltammetry to prepare an electrochromic polymer; the volume ratio of dichloromethane to acetonitrile is (3 to 5):1; the concentration of HMAT-EDOT is 0.5 to 1 mmol / L; the concentration of tetrabutylammonium perchlorate is 0.05 to 0.1 mol / L.

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