Anode electrochromic material and preparation method and application thereof

Abstract

The invention discloses an anode electrochromic material as well as a preparation method and application thereof, the chemical structural formula of the anode electrochromic material is # imgabs0 #, in which R is substituted or unsubstituted alkyl of C1-C20; and Ar is an electron-donating aryl group. The anode electrochromic material is prepared by the following steps: alkylating phenoxazine serving as a raw material to obtain a first compound; carrying out dibromination on the first compound to obtain a second compound; and then carrying out carbon-carbon coupling on the second compound. According to the anode electrochromic material, the solubility of phenoxazine molecules in common electrochromic solvents (such as propylene carbonate and PC) is greatly improved, the color changing effect of the phenoxazine molecules is further improved, and transmittance regulation and control of an electrochromic device are facilitated. In addition, by changing different coupling groups, potential regulation and control of molecules and spectrum regulation and control of a coloring state can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochromic materials, and in particular to an anode electrochromic material and a preparation method and application thereof. Background Art

[0002] 5,10-Dihydro-5,10-dimethylphenazine is the most commonly used anode material in the electrochromic field, and its colored state appears yellow. In the prior art, electrochromic devices usually change the color state of the material by applying voltage to achieve the purpose of optical modulation. In practical applications, color diversity is particularly important for electrochromic devices, because a single color limits its applicability in different scenarios. In order to enrich the color performance of electrochromic devices, researchers have tried to introduce different electron-donating and electron-withdrawing groups on the anode materials. These groups can effectively adjust the redox potential of the molecules and the absorption spectrum of the colored state, thereby achieving a variety of color changes.

[0003] However, it is difficult to modify the aromatic ring of 5,10-dihydro-5,10-dimethylphenazine, and it is not realistic to directly brominate it. Similarly, alkyl phenothiazines can also be used as electrochromic anode materials, but the sulfur atoms in phenothiazines easily combine with oxygen, resulting in poor chemical stability, which limits their wide application. In addition, the solubility of electrochromic materials modified with groups is low in commonly used electrochromic solvents such as propylene carbonate (PC), which also has an adverse effect on the overall performance of the device.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The object of the present invention is to provide an anode electrochromic material and a preparation method thereof, an electrochromic medium solution, and the use of the anode electrochromic material or the electrochromic medium solution in the preparation of an electrochromic device.

[0006] The present invention is achieved in that:

[0007] In a first aspect, the present invention provides an anode electrochromic material, the chemical structure of the anode electrochromic material is:

[0008]

[0009] Wherein, R is a C1-C20 substituted or unsubstituted alkyl group; Ar is an electron donating aryl group.

[0010] In an optional embodiment, the aryl group is selected from any one of phenyl, naphthyl, anthracenyl, pyridyl, furanyl, and thienyl. In an optional embodiment, R is a C1-C4 alkyl group.

[0011] In a second aspect, the present invention also provides a method for preparing an anodic electrochromic material as described in any one of the aforementioned embodiments, comprising: alkylating phenoxazine as a raw material to obtain a first compound; then dibrominating the first compound to obtain a second compound; and then carbon-carbon coupling the second compound to obtain the anodic electrochromic material.

[0012] In an optional embodiment, the molar ratio of the coupling compound for carbon-carbon coupling to the second compound is 1:1.

[0013] In an optional embodiment, the alkylation comprises: subjecting phenoxazine to a nucleophilic substitution reaction with an alkyl halide under the action of a first catalyst; and / or, the dibromination comprises: subjecting the first compound to a bromination reaction with a brominating agent; and / or, the carbon-carbon coupling comprises: subjecting the second compound to a coupling reaction with a coupling compound under a second catalyst and alkaline conditions.

[0014] In an optional embodiment, the synthesis path of the anode electrochromic material is:

[0015]

[0016] In a third aspect, the present invention further provides an electrochromic medium solution, which includes an anodic electrochromic material, a cathodic electrochromic material and an electrochromic solvent, wherein the anodic electrochromic material is the anodic electrochromic material described in any one of the aforementioned embodiments.

[0017] In an optional embodiment, the concentration of the anode color-changing material is 1 to 100 mM, preferably 10 to 50 mM; and / or the concentration of the cathode color-changing material is 1 to 100 mM, preferably 10 to 50 mM; and / or the cathode color-changing material is selected from any one of methyl amethyst, ethyl amethyst, propyl amethyst and butyl amethyst.

[0018] Any one of the following; and / or, the molar ratio of the anode color-changing material to the cathode color-changing material is 1:(0.5-1.5); and / or, the solvent is propylene carbonate.

[0019] In a fourth aspect, the present invention provides use of the anode electrochromic material as described in any one of the aforementioned embodiments or the electrochromic medium solution as described in the aforementioned embodiments in the preparation of an electrochromic device.

[0020] The present invention has the following beneficial effects: by designing the anode electrochromic material into an asymmetric structure of bromine-phenoxazine-coupling group, the solubility of phenoxazine molecules in common electrochromic solvents (such as propylene carbonate, PC) is greatly improved, thereby improving its color change effect, which is helpful for the transmittance control of the electrochromic device. In addition, by changing different coupling groups, the potential control of the molecule and the spectral control of the coloring state can be achieved. Furthermore, the anode electrochromic material can be prepared by phenoxazine as a raw material through three steps of alkylation, double bromination, and carbon-carbon coupling. The preparation method is simple and convenient, and the compound has high stability. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0022] The term "alkyl" refers to a straight-chain or branched hydrocarbon group, and examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, n-heptyl, isoheptyl, n-octyl, isooctyl, n-nonyl, and n-decyl.

[0023] The term "aryl" includes a monocyclic or cyclic aromatic hydrocarbon group with more than two rings, or other polycyclic groups with aromaticity. In some embodiments, the aryl group may be an aryl group with 6-10 ring atoms, i.e., a 6-10-membered aryl group. Examples include: phenyl, naphthyl, anthracenyl, phenanthrenyl, etc., and may also be a five-membered heterocyclic group, such as thienyl, pyridyl, furanyl, etc.

[0024] The following is a detailed description of an anode electrochromic material provided by the present invention and its preparation method and application.

[0025] Some embodiments of the present invention provide an anode electrochromic material, the chemical structure of the anode electrochromic material is:

[0026]

[0027] Wherein, R is a C1-C20 substituted or unsubstituted alkyl group; Ar is an electron donating aryl group.

[0028] Through extensive research and practice, the inventor creatively proposed a single coupling strategy to design the molecule into an asymmetric structure of bromine-phenoxazine-coupling group, which greatly improved the solubility of phenoxazine molecules in common electrochromic solvents, thereby greatly improving the performance of the device. In addition, the potential regulation of the molecule and the spectral regulation of the coloring state can be achieved by changing different coupling groups.

[0029] In some embodiments, the aryl group is selected from any one of phenyl, naphthyl, anthracenyl, pyridyl, furanyl, and thienyl. In a preferred embodiment, the aryl group is selected from phenyl and thienyl. Among them, the phenyl group can be substituted or unsubstituted phenyl, for example, the substituted phenyl group can be methoxyphenyl, etc.

[0030] Furthermore, in some embodiments, R can be arbitrarily selected as a C1-C4 alkyl group, for example, methyl, ethyl, propyl, etc.

[0031] Some embodiments of the present invention also provide a method for preparing an anodic electrochromic material as described in any of the aforementioned embodiments, comprising: alkylating phenoxazine as a raw material to obtain a first compound; then dibrominating the first compound to obtain a second compound; and then carbon-carbon coupling the second compound to obtain the anodic electrochromic material.

[0032] Compared with the existing anode electrochromic materials, the synthetic route of the embodiment of the present invention is less difficult to modify on the aromatic ring, and uses phenoxazine as a raw material, which is not easy to combine with oxygen and has better chemical stability, making it more valuable in application.

[0033] Based on the single coupling strategy, unilaterally bromine-substituted phenoloxazine derivatives are prepared by controlling the ratio of the coupling groups, that is, in some embodiments, the molar ratio of the coupling compound used for carbon-carbon coupling to the second compound is 1:1.

[0034] For reference, in some embodiments, the alkylation in the above embodiments includes: reacting phenoxazine with an alkyl halide under the action of a first catalyst to undergo a nucleophilic substitution reaction. Preferably, the reaction is carried out under stirring conditions and the reaction temperature is room temperature. In some preferred embodiments, phenoxazine and the first catalyst are first dissolved in an organic solvent at a certain temperature, and then reacted with the alkyl halide at room temperature, wherein the temperature for dissolving phenoxazine and the first catalyst can be selected as 50°C to 80°C, such as 50°C, 60°C, 70°C or 80°C, and the first catalyst can be selected as potassium tert-butoxide.

[0035] In some embodiments, after the alkylation reaction is completed, water is added to the system, and then dichloromethane is used for multiple extractions in small amounts, and the organic phases are combined and then spin-dried. The crude product obtained after spin-dried is eluted with a silica gel column, and the developing solvent is pure petroleum ether.

[0036] For reference, in some embodiments, the double bromination includes: performing a bromination reaction on the first compound and the brominating agent. Specifically, the first compound is dissolved in an organic solvent, and then the brominating agent is added to react. After the reaction is completed, water is added to the system, and then a small amount of dichloromethane is used for multiple extractions, and the organic phases are combined and then spin-dried. The crude product obtained after spin-drying is eluted with a silica gel column, and the developing solvent is pure petroleum ether.

[0037] For reference, carbon-carbon coupling includes: coupling the second compound with the coupling compound under a second catalyst and alkaline conditions. Specifically, the second compound, the coupling compound and the base are dissolved in a mixed solvent, and then the second catalyst is added to react. After the reaction is completed, water is added to the system, and then a small amount of dichloromethane is used for multiple extractions, and the organic phases are combined and dried. The crude product obtained after drying is eluted with a silica gel column, and the developing agent is a mixed solvent of petroleum ether: dichloromethane = 4:1. The second catalyst is a palladium catalyst, such as tetrakistriphenylphosphine palladium ((PPh3)4Pd).

[0038] In some embodiments, the synthesis path of the anode electrochromic material is:

[0039]

[0040] Some embodiments of the present invention further provide an electrochromic medium solution, which includes an anodic color-changing material, a cathodic color-changing material, and an electrochromic solvent. The anodic color-changing material is the anodic electrochromic material described in any of the aforementioned embodiments.

[0041] By adjusting the ratio and concentration of the cathode and anode color-changing materials, the depth of coloring can be controlled, and the specific concentration can be selected according to the actual application. For example, the molar ratio of the anode color-changing material to the cathode color-changing material is 1: (0.5-1.5), such as 1:3, 2:3, 3:3, 2:1, 2:3, etc.

[0042] Specifically, in some embodiments, the concentration of the anode color-changing material in the electrochromic medium solution is 1 to 100 mM, preferably 10 to 50 mM; the concentration of the cathode color-changing material in the electrochromic medium solution is 1 to 100 mM, preferably 10 to 50 mM.

[0043] Furthermore, in some embodiments, the cathode color-changing material is selected from any one of methyl amethyst, ethyl amethyst, propyl amethyst and butyl amethyst.

[0044] In some embodiments, the solvent may be propylene carbonate.

[0045] Furthermore, some embodiments of the present invention also provide use of the anode electrochromic material as described in any of the aforementioned embodiments or the electrochromic medium solution as described in the aforementioned embodiments in the preparation of an electrochromic device.

[0046] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0047] Example 1

[0048] This embodiment provides an anode electrochromic material (3-bromo-10-methyl-7-phenyl-10H-phenoxazine) and a preparation method thereof, wherein the preparation method comprises the following steps:

[0049] Step 1: Synthesis of 10-methyl-10H-phenoxazine.

[0050] Dissolve 1.83g of phenoxazine and 1.12g of potassium tert-butoxide (t-BuOK) in 30mL of tetrahydrofuran (THF) and stir at 60°C for 1h. After the solution is cooled to room temperature, add 1.42g of methyl iodide and continue to react at room temperature for 8h. After the reaction is completed, add 200mL of water to the system, then extract with dichloromethane in small amounts for multiple times, combine the organic phases and spin dry. The crude product obtained after spin drying is eluted with a silica gel column, and the developing solvent is pure petroleum ether. 1.51g (yield 76.6%) of product is obtained. 1.51g (yield 76.6%) of product. 1 HNMR (300MHz, DMSO-d6): 6.91–6.82 (m, 2H), 6.69 (d, J = 6.4Hz, 6H), 3.01 (s, 3H).

[0051] Step 2: Synthesis of 3,7-dibromo-10-methyl-10H-phenoxazine.

[0052] Dissolve 1.97g of 10-methyl-10H-phenoxazine in 50mL of THF, add 3.56g of N-bromosuccinimide (NBS) at 0°C, react for 2h, add 200mL of water to the system, extract with dichloromethane in small amounts several times, combine the organic phases and spin dry. The crude product obtained after spin drying is eluted with a silica gel column, and the developing solvent is pure petroleum ether. 3.21g (yield 90.4%) of the product is obtained. 1 HNMR (300MHz, CDCl3): 6.94 (dd, J=8.5, 2.0Hz, 2H), 6.79 (d, J=2.0Hz, 2H), 6.34 (d, J=8.5Hz, 2H), 2.97 (s, 3H).

[0053] Step 3: Synthesis of 3-bromo-10-methyl-7-phenyl-10H-phenoxazine (Compound 1).

[0054] 3.55g 3,7-dibromo-10-methyl-10H-phenoxazine, 1.22g phenylboronic acid, 2.76g potassium carbonate, dissolved in a mixed solvent of 50mL THF and 10mL water, nitrogen bubbling for 10min, then 100mg tetrakistriphenylphosphine palladium ((PPh3)4Pd) was added, and the reaction was carried out at 80℃ for 12h. After the reaction, 200mL water was added to the system, and then extracted with dichloromethane in small amounts for multiple times, and the organic phases were combined and dried by spin drying. The crude product obtained after spin drying was eluted with a silica gel column, and the developing solvent was a mixed solvent of petroleum ether: dichloromethane = 4:1. 2.39g (yield 67.9%) of the product was obtained. 1 H NMR (300MHz, DMSO-d6): 7.75 (d, J=6.4Hz, 2H), 7.49-7.27 (m, 7H), 7.10-7.03 (m, 2H), 3.20 (s, 3H).

[0055] Example 2

[0056] This embodiment provides an anode electrochromic material (3-bromo-10-butyl-7-phenyl-10H-phenoxazine) and a preparation method thereof, wherein the preparation method comprises the following steps:

[0057] Step 1: Synthesis of 10-butyl-10H-phenoxazine.

[0058]

[0059] Dissolve 1.83g of phenoxazine and 1.12g of potassium tert-butoxide (t-BuOK) in 30mL of tetrahydrofuran (THF) and stir at 60°C for 1h. After the solution is cooled to room temperature, add 1.84g of n-butyl iodide and continue to react at room temperature for 8h. After the reaction is completed, add 200mL of water to the system, extract with dichloromethane in small amounts several times, combine the organic phases and spin dry. The crude product obtained after spin drying is eluted with a silica gel column, and the developing solvent is pure petroleum ether. 1.96g (yield 81.9%) of product is obtained. 1 H NMR (300MHz, DMSO-d6): 7.14 (d, J=6.4Hz, 2H), 7.01-6.96 (m, 6H), 3.93 (t, J=6.4Hz, 2H), 1.49-1.30 (m, 4H), 0.89 (t, J=6.2Hz, 3H).

[0060] Step 2: Synthesis of 3,7-dibromo-10-butyl-10H-phenoxazine.

[0061]

[0062] Dissolve 2.37g of 10-butyl-10H-phenoxazine in 50mL of THF, add 3.56g of N-bromosuccinimide (NBS) at 0°C, react for 2h, add 200mL of water to the system, extract with dichloromethane in small amounts several times, combine the organic phases and spin dry. The crude product obtained after spin drying is eluted with a silica gel column, and the developing solvent is pure petroleum ether. 3.66g (yield 92.1%) of the product is obtained. 1 HNMR (300MHz, DMSO-d6): 7.30 (s, 2H), 7.10-7.03 (m, 4H), 3.87 (t, J = 6.8Hz, 2H), 1.42-1.31 (m, 4H), 0.83 (t, J = 6.8Hz, 3H).

[0063] Step 3: Synthesis of 3-bromo-10-butyl-7-phenyl-10H-phenoxazine (Compound 2).

[0064]

[0065] 3.97g 3,7-dibromo-10-butyl-10H-phenoxazine, 1.22g phenylboronic acid, 2.76g potassium carbonate, dissolved in a mixed solvent of 50mL THF and 10mL water, nitrogen bubbling for 10min, then 100mg tetrakistriphenylphosphine palladium ((PPh3)4Pd) was added, and the reaction was carried out at 80℃ for 12h. After the reaction, 200mL water was added to the system, and then a small amount of dichloromethane was used for multiple extractions, and the organic phases were combined and dried by spin drying. The crude product obtained after spin drying was eluted with a silica gel column, and the developing solvent was a mixed solvent of petroleum ether: dichloromethane = 4:1. 2.51g (yield 63.7%) of the product was obtained. 1 H NMR (300MHz, DMSO-d6): 7.68 (d, J = 6.2Hz, 2H), 7.45-7.33 (m, 7H), 7.08-7.01 (m, 2H), 3.87 (t, J = 7.2Hz, 2H), 1.45-1.33 (m, 4H), 0.89 (t, J = 6.6Hz, 3H).

[0066] Example 3

[0067] This embodiment provides an anode electrochromic material 3-bromo-7-(4-methoxyphenyl)-10-methyl-10H-phenoxazine (Compound 3) and a preparation method thereof. This embodiment is different from Embodiment 1 only in that Step 3 is:

[0068]

[0069] 3.55g 3,7-dibromo-10-methyl-10H-phenoxazine, 1.52g 4-methoxyphenylboronic acid, 2.76g potassium carbonate, dissolved in a mixed solvent of 50mL THF and 10mL water, nitrogen bubbling for 10min, then 100mg tetrakistriphenylphosphine palladium ((PPh3)4Pd) was added, and the reaction was carried out at 80℃ for 12h. After the reaction, 200mL water was added to the system, and then extracted with dichloromethane in small amounts for multiple times, and the organic phases were combined and dried by spin drying. The crude product obtained after spin drying was eluted with a silica gel column, and the developing solvent was a mixed solvent of petroleum ether: dichloromethane = 4:1. 2.57g (yield 67.2%) of the product was obtained. 1 H NMR (300MHz, DMSO-d6): 7.61 (d, J = 7.2Hz, 2H), 7.33-7.27 (m, 4H), 7.10-6.98 (m, 4H), 3.81 (s, 3H), 3.20 (s, 3H).

[0070] Example 4

[0071] This embodiment provides an anode electrochromic material 3-bromo-10-methyl-7-(thiophene-2-yl)-10H-phenoxazine (Compound 4) and a preparation method thereof. This embodiment is different from Embodiment 1 only in that Step 3 is:

[0072]

[0073] 3.55g 3,7-dibromo-10-methyl-10H-phenoxazine, 1.28g 2-thiopheneboronic acid, 2.76g potassium carbonate, dissolved in a mixed solvent of 50mL THF and 10mL water, nitrogen bubbling for 10min, then 100mg tetrakistriphenylphosphine palladium ((PPh3)4Pd) was added, and the reaction was carried out at 80℃ for 12h. After the reaction, 200mL water was added to the system, and then extracted with dichloromethane in small amounts for multiple times, and the organic phases were combined and dried by spin drying. The crude product obtained after spin drying was eluted with a silica gel column, and the developing solvent was a mixed solvent of petroleum ether: dichloromethane = 4:1. 2.78g (yield 77.6%) of the product was obtained. 1 H NMR (300MHz, DMSO-d6): 7.70 (d, J = 7.1 Hz, 1H), 7.40-7.29 (m, 4H), 7.13-7.03 (m, 3H), 6.71 (d, J = 7.4 Hz, 1H), 3.18 (s, 3H).

[0074] Example 5

[0075] This embodiment provides an anode electrochromic material 3-bromo-10-methyl-7-(naphthalene-2-yl)-10H-phenoxazine (Compound 5) and a preparation method thereof. The difference between this embodiment and Embodiment 1 is that step three is:

[0076]

[0077] 3.55g 3,7-dibromo-10-methyl-10H-phenoxazine, 1.72g naphthalene-2-boric acid, 2.76g potassium carbonate, dissolved in a mixed solvent of 50mL THF and 10mL water, nitrogen bubbling for 10min, then 100mg tetrakistriphenylphosphine palladium ((PPh3)4Pd) was added, and the reaction was carried out at 80℃ for 12h. After the reaction, 200mL water was added to the system, and then extracted with dichloromethane in small amounts for multiple times, and the organic phases were combined and dried by spin drying. The crude product obtained after spin drying was eluted with a silica gel column, and the developing solvent was a mixed solvent of petroleum ether: dichloromethane = 4:1. 2.63g (yield 65.3%) of the product was obtained. 1 H NMR (300MHz, DMSO-d6): 8.09-7.99 (m, 3H), 7.63-7.55 (m, 3H), 7.38-7.27 (m, 5H), 7.10-7.03 (m, 2H), 3.20 (s, 3H).

[0078] Example 6

[0079] This embodiment provides an anode electrochromic material 3-bromo-10-methyl-7-(naphthalene-1-yl)-10H-phenoxazine (Compound 6) and a preparation method thereof. The difference between this embodiment and Embodiment 1 is that step three is:

[0080]

[0081] 3.55g 3,7-dibromo-10-methyl-10H-phenoxazine, 1.72g naphthalene-1-boric acid, 2.76g potassium carbonate, dissolved in a mixed solvent of 50mL THF and 10mL water, nitrogen bubbling for 10min, then 100mg tetrakistriphenylphosphine palladium ((PPh3)4Pd) was added, and the reaction was carried out at 80℃ for 12h. After the reaction, 200mL water was added to the system, and then extracted with dichloromethane in small amounts for multiple times, and the organic phases were combined and dried by spin drying. The crude product obtained after spin drying was eluted with a silica gel column, and the developing solvent was a mixed solvent of petroleum ether: dichloromethane = 4:1. 2.63g (yield 65.3%) of the product was obtained. 1 H NMR(300MHz,DMSO-d6):8.95(d,J=6.8Hz,2H),8.50(d,J=6.3Hz,2H),8.20-8 .09(m,2H),7.66(m,3H),7.52-7.27(m,6H),7.10-7.03(m,2H),3.20(s,3H).

[0082] Example 7

[0083] This embodiment provides an anode electrochromic material 3-bromo-10-methyl-7-(pyridin-2-yl)-10H-phenoxazine (Compound 7) and a preparation method thereof. This embodiment is different from Example 1 only in that step three is:

[0084]

[0085] 3.55g 3,7-dibromo-10-methyl-10H-phenoxazine, 1.23g pyridine-2-boric acid, 2.76g potassium carbonate, dissolved in a mixed solvent of 50mL THF and 10mL water, nitrogen bubbling for 10min, then 100mg tetrakistriphenylphosphine palladium ((PPh3)4Pd) was added, and the reaction was carried out at 80℃ for 12h. After the reaction, 200mL water was added to the system, and then extracted with dichloromethane in small amounts for multiple times, and the organic phases were combined and dried by spin drying. The crude product obtained after spin drying was eluted with a silica gel column, and the developing solvent was a mixed solvent of petroleum ether: dichloromethane = 4:1. 1.91g (yield 53.8%) of the product was obtained. 1 H NMR (300MHz, DMSO-d6): 8.37 (d, 2H), 7.84 (d, 2H), 7.68 (s, 1H), 7.38-7.30 (m, 3H), 7.14-7.03 (m, 3H), 6.90 (t, J = 6.9Hz, 1H), 3.20 (s, 3H).

[0086] Test Example 1

[0087] Oxidation-reduction potential test: The first oxidation-reduction potential of compound 1 measured by an electrochemical workstation was 0.88V (vs AgCl / Ag), the first oxidation-reduction potential of compound 2 was 0.83V, the first oxidation-reduction potential of compound 3 was 0.72V, and the first oxidation-reduction potential of compound 4 was 0.52V. The first oxidation-reduction potential of compound 5 was 0.91V, the first oxidation-reduction potential of compound 6 was 0.92V, and the first oxidation-reduction potential of compound 7 was 0.95V. The first oxidation-reduction potential of compound 2 was more negative than that of compound 1, because the electron-donating ability of butyl group was stronger than that of methyl group, and the change of alkyl chain played a role in regulating the oxidation-reduction potential. The first oxidation-reduction potential of compound 4 was lower than that of compound 3, because the electron-donating ability of thiophene was stronger than that of phenyl group. The oxidation-reduction potentials of compounds 5, 6, and 7 were all higher than 0.9V, because the electron-withdrawing ability of naphthalene and pyridine was stronger than that of benzene ring, thiophene and other groups.

[0088] Example 8

[0089] This embodiment provides an electrochromic medium solution, which is recorded as 1a, 1b and 1c according to the different amounts of the anode electrochromic material, and the solvent used is propylene carbonate solution (PC). Specifically, the composition of the electrochromic material is shown in the following table:

[0090]

[0091] Example 9

[0092] This embodiment provides an electrochromic medium solution, which is recorded as 2a, 2b and 2c according to the different amounts of the anode electrochromic material, and the solvent used is propylene carbonate solution (PC). Specifically, the composition of the electrochromic material is shown in the following table:

[0093]

[0094] Example 10

[0095] This embodiment provides an electrochromic medium solution, which is recorded as 3a, 3b and 3c according to the different amounts of cathode electrochromic materials, and the solvent used is propylene carbonate solution (PC). Specifically, the composition of the electrochromic material is shown in the following table:

[0096]

[0097] Embodiment 11

[0098] This embodiment provides an electrochromic medium solution, which is recorded as 4a, 4b and 4c according to the different amounts of cathode electrochromic materials. The solvent used is propylene carbonate solution (PC). Specifically, the composition of the electrochromic material is shown in the following table:

[0099]

[0100] Example 12

[0101] This embodiment provides an electrochromic medium solution, which is recorded as 5a, 5b and 5c according to the different amounts of cathode electrochromic materials, and the solvent used is propylene carbonate solution (PC). Specifically, the composition of the electrochromic material is shown in the following table:

[0102]

[0103]

[0104] Comparative Example 1

[0105] This comparative example provides an electrochromic medium solution, which is recorded as 6a, 6b and 6c according to the different amounts of the anode electrochromic material, and the solvent used is propylene carbonate solution (PC). Specifically, the composition of the electrochromic material is shown in the following table:

[0106]

[0107] Among them, compound 8 is 3,7-bis(4-methoxyphenyl)-10-methyl-10H-phenoxazine.

[0108]

[0109] The preparation process of compound 8 is as follows:

[0110] 3.55g 3,7-dibromo-10-methyl-10H-phenoxazine, 3.08g 4-methoxyphenylboronic acid, 2.76g potassium carbonate, dissolved in a mixed solvent of 50mL THF and 10mL water, nitrogen bubbling for 10min, then 100mg tetrakistriphenylphosphine palladium ((PPh3)4Pd) was added, and the reaction was carried out at 80℃ for 12h. After the reaction, 200mL water was added to the system, and then extracted with dichloromethane in small amounts for multiple times, and the organic phases were combined and dried by spin drying. The crude product obtained after spin drying was eluted with a silica gel column, and the developing solvent was a mixed solvent of petroleum ether: dichloromethane = 4:1. 3.11g (yield 75.9%) of the product was obtained. 1 H NMR (300MHz, DMSO-d6): d=7.52 (d, J=7.4Hz, 4H), 7.31-7.24 (m, 6H), 6.95 (d, J=7.0Hz, 4H), 3.72 (s, 6H), 3.12 (s, 3H).

[0111] The first redox potential of compound 8 was measured by an electrochemical workstation to be 0.71 V. Compared with compound 3, this compound introduced an additional methoxyphenyl group, and the potential shifted slightly negatively.

[0112] Comparative Example 2

[0113] This comparative example provides an electrochromic medium solution, which is recorded as 7a, 7b and 7c according to the different amounts of the anode electrochromic material, and the solvent used is propylene carbonate solution (PC). Specifically, the composition of the electrochromic material is shown in the following table:

[0114]

[0115] Among them, compound 9 is 3,7-bis(2,4-dimethoxyphenyl)-10-methyl-10H-phenoxazine.

[0116]

[0117] The preparation process of compound 9 is as follows:

[0118] 3.55g 3,7-dibromo-10-methyl-10H-phenoxazine, 3.64g 2,4-dimethoxyphenylboronic acid, 2.76g potassium carbonate were dissolved in a mixed solvent of 50mL THF and 10mL water. After nitrogen bubbling for 10min, 100mg tetrakistriphenylphosphine palladium ((PPh3)4Pd) was added and reacted at 80℃ for 12h. After the reaction, 200mL water was added to the system, and then extracted with dichloromethane in small amounts for multiple times. The organic phases were combined and dried by spin drying. The crude product obtained after spin drying was eluted with a silica gel column, and the developing solvent was a mixed solvent of petroleum ether: dichloromethane = 4:1. 3.71g (yield 79.0%) of the product was obtained. 1 H NMR (300MHz, DMSO-d6): d=7.71 (d, J=6.4Hz, 2H), 7.30-7.22 (m, 6H), 6.76-6.71 (m, 4H), 3.79 (s, 6H), 3.81 (s, 6H), 3.15 (s, 3H).

[0119] The first redox potential of compound 9 measured by an electrochemical workstation was 0.68 V. The first redox potential of compound 9 was lower than that of compound 8 because the electron donation ability of 2,4-dimethoxyphenyl was stronger than that of 4-methoxyphenyl.

[0120] Test Example 2

[0121] Two pieces of 40*40*0.4mm ITO-coated glass were glued together with offset points. The thickness of the device box was 125 microns. The electrochromic medium solution in the above embodiment and comparative example was filled into the electrochromic device by vacuum filling. A voltage was applied at both ends. The transmittance data at 550nm under 1.2V was measured, as shown in the following table:

[0122]

[0123] As can be seen from the test results of Example 8 and Example 9, the transmittance gradually decreases with the increase of the concentration of the anode material, which is due to the generation of more colored ions. As can be seen from the test results of Example 10, the increase in the concentration of the cathode material also causes the transmittance to decrease, which is also attributed to the generation of more colored ions. The test results of Example 11 illustrate that after coloring, the response of compound 5 at 550nm is more obvious than that of the compounds in other embodiments. In Example 12 after the combination of compound 5 and compound 2, the response of the device to 550nm after coloring is between Examples 8 and 11.

[0124] The transmittance changes of Comparative Example 1 and Comparative Example 2 are very small, which is due to the very poor solubility of Compound 8 and Compound 9 in PC and the low coloring efficiency. From the results of Example 8 and Comparative Example 1, it can be concluded that asymmetric phenoxazine derivatives (such as Compound 3 and Compound 4) have better solubility than symmetric structures (such as Compound 8 and Compound 9), and the prepared devices have better performance.

[0125] In summary, in the embodiment of the present invention, based on the single coupling strategy, the anode electrochromic material is designed to be an asymmetric structure of bromine-phenoxazine-coupling group, which greatly improves the solubility of phenoxazine molecules in common electrochromic solvents (such as propylene carbonate, PC), thereby improving its color change effect, which is helpful for the transmittance regulation of electrochromic devices. In addition, by changing different coupling groups, it is possible to achieve potential regulation of molecules and spectral regulation of coloring states. Furthermore, the anode electrochromic material can be prepared by phenoxazine as a raw material, through alkylation, double bromination, and carbon-carbon coupling in three steps. The preparation method is simple and convenient, and the compound has high stability.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An anode electrochromic material, characterized in that: The chemical structural formula of the anode electrochromic material is: Wherein, R is a C1-C20 substituted or unsubstituted alkyl group; Ar is an electron donating aryl group.

2. The anode electrochromic material according to claim 1, characterized in that: The aryl group is selected from any one of phenyl, naphthyl, anthracenyl, pyridyl, furyl and thienyl.

3. The anode electrochromic material according to claim 1, characterized in that: R is a C1-C4 alkyl group.

4. A method for preparing the anode electrochromic material according to any one of claims 1 to 3, characterized in that: It includes: Using phenoxazine as a raw material to carry out alkylation to obtain a first compound; Then, the first compound is subjected to dibromination to obtain a second compound; Then, the second compound is subjected to carbon-carbon coupling to obtain the anode electrochromic material.

5. The method for preparing an anode electrochromic material according to claim 4, characterized in that: The molar ratio of the coupling compound used for carbon-carbon coupling to the second compound is 1:(0.5-1).

6. The method for preparing an anode electrochromic material according to claim 4, characterized in that: The alkylation comprises: subjecting phenoxazine to a nucleophilic substitution reaction with an alkyl halide under the action of a first catalyst; And / or, the double bromination comprises: subjecting the first compound to a bromination reaction with a brominating agent; And / or, the carbon-carbon coupling comprises: subjecting the second compound to a coupling reaction with a coupling compound in the presence of a second catalyst and alkaline conditions.

7. The method for preparing an anode electrochromic material according to claim 4, characterized in that: The synthesis path of the anode electrochromic material is:

8. An electrochromic medium solution, characterized in that: The invention comprises an anode color-changing material, a cathode color-changing material and an electrochromic solvent, wherein the anode color-changing material is the anode electrochromic material according to any one of claims 1 to 7.

9. The electrochromic medium solution according to claim 8, characterized in that: The concentration of the anode color-changing material is 1 to 100 mM, preferably 10 to 50 mM; and / or, the concentration of the cathode color-changing material is 1 to 100 mM, preferably 10 to 50 mM; And / or, the cathode color-changing material is selected from any one of methyl amethyst, ethyl amethyst, propyl amethyst and butyl amethyst; and / or, the molar ratio of the anode color-changing material to the cathode color-changing material is 1:(0.5-1.5); And / or, the solvent is propylene carbonate.

10. Use of the anode electrochromic material according to any one of claims 1 to 7 or the electrochromic medium solution according to any one of claims 8 to 9 in the preparation of an electrochromic device.

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