Anodic electrochromic material, method for preparing the same and use thereof

Abstract

The application discloses an anode electrochromic material and a preparation method and application thereof, and has a chemical structural formula as shown in the specification, wherein R is a substituted or unsubstituted alkyl group with C1-C20; and Ar is an electron-donating aryl group. The anode electrochromic material is prepared by alkylating phenoxazine as a raw material to obtain a first compound, double-brominating the first compound to obtain a second compound, and then performing carbon-carbon coupling on the second compound. The anode electrochromic material greatly improves the solubility of phenoxazine molecules in commonly used solvents (for example, propylene carbonate, PC) of electrochromism, and further improves the color changing effect, which is helpful to the transmittance regulation of the electrochromic device. In addition, by changing different coupling groups, the potential regulation and spectral regulation of the coloring state of the molecules can be realized.

Description

TECHNICAL FIELD

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

[0002] 5,10-dihydro-5,10-dimethylphenazine is the most commonly used anodic material in the field of electrochromic materials, and its colored state appears yellow. In the prior art, an electrochromic device usually changes the color state of a material by applying a voltage to achieve the purpose of optical modulation. In practical applications, the diversity of colors 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 try to introduce different electron-donating and electron-withdrawing groups on the anodic material, which can effectively adjust the oxidation-reduction potential of the molecule and the absorption spectrum of the colored state, thereby realizing the change of multiple colors.

[0003] However, it is difficult to modify 5,10-dihydro-5,10-dimethylphenazine on the aromatic ring, and it is not realistic to directly brominate it. Similarly, alkylphenothiazine can also be used as an electrochromic anodic material, but the sulfur atom in phenothiazine is easy to combine with oxygen, resulting in poor chemical stability, which limits its wide application. In addition, the solubility of the electrochromic material modified by introducing groups in the commonly used electrochromic solvent such as propylene carbonate (PC) is low, which also adversely affects the overall performance of the device.

[0004] In view of this, the present application is proposed. SUMMARY

[0005] The purpose of the present application is to provide an anodic electrochromic material and a preparation method thereof, an electrochromic medium solution, and the application of the anodic electrochromic material or the electrochromic medium solution in the preparation of an electrochromic device.

[0006] The present application is implemented as follows:

[0007] In a first aspect, the present application provides an anodic electrochromic material, and the chemical structural formula of the anodic electrochromic material is:

[0008]

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

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

[0011] In a second aspect, the present application further provides a preparation method of the anodic electrochromic material according to any one of the preceding embodiments, comprising: alkylating phenoxazine to obtain a first compound; then double-brominating 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 to the second compound for carbon-carbon coupling is 1:1.

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

[0014] In an optional embodiment, the synthesis route of the anodic electrochromic material is as follows:

[0015]

[0016] In a third aspect, the present application further provides an electrochromic medium solution, comprising an anodic electrochromic material, a cathodic electrochromic material and an electrochromic solvent, wherein the anodic electrochromic material is the anodic electrochromic material according to any one of the preceding embodiments.

[0017] In an optional embodiment, the concentration of the anodic electrochromic material is 1-100 mM, preferably 10-50 mM; and / or, the concentration of the cathodic electrochromic material is 1-100 mM, preferably 10-50 mM; and / or, the cathodic electrochromic material is selected from any one of methyl viologen, ethyl viologen, propyl viologen and butyl viologen.

[0018] In an optional embodiment, the anodic electrochromic material is any one of methyl viologen, ethyl viologen, propyl viologen and butyl viologen; and / or, the molar ratio of the anodic electrochromic material to the cathodic electrochromic material is 1:(0.5-1.5); and / or, the solvent is propylene carbonate.

[0019] In a fourth aspect, the present application provides use of the anodic electrochromic material according to any one of the preceding embodiments or the electrochromic medium solution according to the preceding embodiments in the preparation of an electrochromic device.

[0020] The present application has the following beneficial effects: by designing the anodic electrochromic material as an asymmetric structure of a bromine-phenoxazine-coupling group, the solubility of the phenoxazine molecule in the electrochromic commonly used solvent (such as propylene carbonate, PC) is greatly improved, and the color changing effect is improved, which is helpful to the transmittance regulation of the electrochromic device. In addition, by changing different coupling groups, the potential regulation and spectrum regulation of the coloring state of the molecule can be realized. Further, the anodic electrochromic material can be prepared from phenoxazine as a raw material through alkylation, dibromination and carbon-carbon coupling in three steps, and 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 application more clear, the technical scheme in the embodiments of the present application will be clearly and completely described below. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0022] The term "alkyl" is a linear or branched hydrocarbon group. For example, it can be listed as: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, n-heptyl, isohexyl, n-octyl, isooctyl, n-nonyl, n-decyl, etc.

[0023] The term "aryl" includes a monocyclic or 2 or more ring cyclic aromatic hydrocarbon group, or other polycyclic cyclic group with aromaticity. In some embodiments, the aryl group can be a 6-10 ring atom aryl group, i.e. a 6-10 membered aryl group. For example, it can be listed as: phenyl, naphthyl, anthryl, phenanthryl, etc., and can also be a five-membered heterocyclic group, such as thienyl, pyridyl, furanyl, etc.

[0024] The anodic electrochromic material provided by the present application and the preparation method and application thereof will be specifically described below.

[0025] Some embodiments of the present application provide an anodic electrochromic material, and the chemical structural formula of the anodic electrochromic material is:

[0026]

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

[0028] The inventors creatively propose, through a large amount of research and practice, a single coupling strategy, and design an asymmetric structure of a bromo-phenoxazine-coupling group, greatly improve the solubility of the phenoxazine molecule in a commonly used solvent for electrochromism, and further greatly improve the device performance. In addition, the potential and the spectrum of the coloring state of the molecule can be regulated by changing different coupling groups.

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

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

[0031] Some embodiments of the present application also provide a preparation method of the anodic electrochromic material as described in any one of the preceding embodiments, which comprises: alkylating phenoxazine as a raw material to obtain a first compound; then double-brominating the first compound to obtain a second compound; and then performing carbon-carbon coupling on the second compound to obtain the anodic electrochromic material.

[0032] The synthesis route of the embodiments of the present application has a smaller difficulty in modifying the aromatic ring compared with the existing anodic electrochromic material, and uses phenoxazine as a raw material, which is not easy to combine with oxygen and has better chemical stability, so that the application value is higher.

[0033] Based on the single coupling strategy, a single-side bromine-substituted phenoxazine derivative is prepared by controlling the proportion of the coupling group, 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 alkylating in the above embodiments comprises: subjecting the phenoxazine to a nucleophilic substitution reaction with a halogenated alkane under the action of a first catalyst. Preferably, the reaction is carried out under stirring, and the reaction temperature is room temperature. In some preferred embodiments, the phenoxazine and the first catalyst are first dissolved in an organic solvent at a certain temperature, and then the reaction with the halogenated alkane is carried out at room temperature. The temperature for dissolving the phenoxazine and the first catalyst can be selected as 50-80℃, for example, 50℃, 60℃, 70℃ or 80℃, etc., and the first catalyst can be selected as potassium tert-butoxide.

[0035] In some embodiments, after the reaction of the alkylating is completed, water is added to the system, and then a small amount of dichloromethane is extracted for multiple times, and the organic phase is combined and rotary evaporated. The crude product obtained after rotary evaporation is eluted on a silica gel column, and the developing agent is pure petroleum ether.

[0036] As a reference, in some embodiments, the dibromination comprises: bromination reaction of the first compound with a bromination agent. Specifically, the first compound is dissolved in an organic solvent, then the bromination agent is added for reaction. After the reaction is completed, water is added to the system, then dichloromethane is extracted a few times, and the organic phase is combined and rotary evaporated. The crude product obtained after rotary evaporation is eluted by silica gel column, and the developing agent is pure petroleum ether.

[0037] As a reference, the carbon-carbon coupling comprises: coupling reaction of the second compound with a coupling compound under the condition of a second catalyst and a base. Specifically, the second compound, the coupling compound and the base are dissolved in a mixed solvent, then the second catalyst is added for reaction. After the reaction is completed, water is added to the system, then dichloromethane is extracted a few times, and the organic phase is combined and rotary evaporated. The crude product obtained after rotary evaporation is eluted by 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 (PPh3)4Pd.

[0038] In some embodiments, the synthesis path of the anodic electrochromic material is as follows:

[0039]

[0040] Some embodiments of the present application also provide an electrochromic medium solution comprising an anodic electrochromic material, a cathodic electrochromic material and an electrochromic solvent, wherein the anodic electrochromic material is the anodic electrochromic material according to any one of the preceding embodiments.

[0041] By adjusting the ratio and concentration of the anodic and cathodic electrochromic materials, the depth of coloring can be controlled. The specific concentration can be selected according to the actual application. For example, the molar ratio of the anodic electrochromic material to the cathodic electrochromic 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 anodic electrochromic material in the electrochromic medium solution is 1-100 mM, preferably 10-50 mM; and the concentration of the cathodic electrochromic material in the electrochromic medium solution is 1-100 mM, preferably 10-50 mM.

[0043] Further, in some embodiments, the cathodic electrochromic material is selected from any one of methyl viologen, ethyl viologen, propyl viologen and butyl viologen.

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

[0045] Further, some embodiments of the present application also provide the use of the anodic electrochromic material according to any one of the preceding embodiments or the electrochromic medium solution according to the preceding embodiments in the preparation of an electrochromic device.

[0046] The features and nature of the present application will become more apparent from the detailed description set forth below, taken in conjunction with the accompanying drawings.

[0047] Example 1

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

[0049] Step one: synthesis of 10-methyl-10H-phenoxazine.

[0050] 1.83 g of phenoxazine and 1.12 g of potassium tert-butoxide (t-BuOK) were dissolved in 30 mL of tetrahydrofuran (THF) and stirred at 60°C for 1 h. After the solution was cooled to room temperature, 1.42 g of iodomethane was added and the reaction was continued at room temperature for 8 h. After the reaction was completed, 200 mL of water was added to the system, and the organic phase was extracted with dichloromethane in small amounts for several times, and then combined and rotary evaporated. The crude product obtained after rotary evaporation was eluted on a silica gel column with pure petroleum ether as the developing agent. 1.51 g (yield 76.6%) of the product was obtained. 1 HNMR (300 MHz, DMSO-d6): 6.91-6.82 (m, 2H), 6.69 (d, J = 6.4 Hz, 6H), 3.01 (s, 3H).

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

[0052] 1.97 g of 10-methyl-10H-phenoxazine was dissolved in 50 mL of THF, and 3.56 g of N-bromosuccinimide (NBS) was added at 0°C. After 2 h of reaction, 200 mL of water was added to the system, and the organic phase was extracted with dichloromethane in small amounts for several times, and then combined and rotary evaporated. The crude product obtained after rotary evaporation was eluted on a silica gel column with pure petroleum ether as the developing agent. 3.21 g (yield 90.4%) of the product was obtained. 1 HNMR (300 MHz, CDCl3): 6.94 (dd, J = 8.5, 2.0 Hz, 2H), 6.79 (d, J = 2.0 Hz, 2H), 6.34 (d, J = 8.5 Hz, 2H), 2.97 (s, 3H).

[0053] Step three: synthesis of 3-bromo-10-methyl-7-phenyl-10H-phenoxazine (compound 1).

[0054] A mixture of 3.55 g of 3,7-dibromo-10-methyl-10H-phenoxazine, 1.22 g of phenylboronic acid, 2.76 g of potassium carbonate, and 50 mL of THF and 10 mL of water was bubbled with nitrogen for 10 min, and then 100 mg of tetrakis(triphenylphosphine)palladium ((PPh3)4Pd) was added. The reaction was performed at 80°C for 12 h. After the reaction was completed, 200 mL of water was added to the system, and then a small amount of dichloromethane was added several times to extract the product. The combined organic phase was dried. The obtained crude product was washed with silica gel column, and the developing agent was a mixture of petroleum ether and dichloromethane (4:1). 2.39 g (yield 67.9%) of the product was obtained. 1 H NMR (300 MHz, DMSO-d6): 7.75 (d, J = 6.4 Hz, 2H), 7.49-7.27 (m, 7H), 7.10-7.03 (m, 2H), 3.20 (s, 3H).

[0055] Example 2

[0056] The present example provides an anodic electrochromic material (3-bromo-10-butyl-7-phenyl-10H-phenoxazine) and a method for preparing the same, the method comprising the following steps:

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

[0058]

[0059] A mixture of 1.83 g of phenoxazine and 1.12 g of potassium tert-butoxide (t-BuOK) was dissolved in 30 mL of tetrahydrofuran (THF) and stirred at 60°C for 1 h. After the solution was cooled to room temperature, 1.84 g of n-butyl iodide was added, and the reaction was continued at room temperature for 8 h. After the reaction was completed, 200 mL of water was added to the system, and then a small amount of dichloromethane was added several times to extract the product. The combined organic phase was dried. The obtained crude product was washed with silica gel column, and the developing agent was pure petroleum ether. 1.96 g (yield 81.9%) of the product was obtained. 1 H NMR (300 MHz, DMSO-d6): 7.14 (d, J = 6.4 Hz, 2H), 7.01-6.96 (m, 6H), 3.93 (t, J = 6.4 Hz, 2H), 1.49-1.30 (m, 4H), 0.89 (t, J = 6.2 Hz, 3H).

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

[0061]

[0062] To a solution of 2.37 g of 10-butyl-10H-phenoxazine in 50 mL of THF, 3.56 g of N-bromosuccinimide (NBS) was added at 0 °C. After 2 h of reaction, 200 mL of water was added to the system, and the organic phase was extracted with dichloromethane several times. The combined organic phase was dried. The crude product obtained after drying was eluted on a silica gel column with petroleum ether as the developing agent. 3.66 g (yield 92.1%) of the product was obtained. 1 HNMR (300 MHz, DMSO-d6): 7.30 (s, 2H), 7.10-7.03 (m, 4H), 3.87 (t, J = 6.8 Hz, 2H), 1.42-1.31 (m, 4H), 0.83 (t, J = 6.8 Hz, 3H).

[0063] Step three: synthesis of 3-bromo-10-butyl-7-phenyl-10H-phenoxazine (compound 2).

[0064]

[0065] To a solution of 3.97 g of 3,7-dibromo-10-butyl-10H-phenoxazine, 1.22 g of phenylboronic acid, 2.76 g of potassium carbonate in 50 mL of THF and 10 mL of water mixed solvent, 100 mg of tetrakis triphenylphosphine palladium ((PPh3)4Pd) was added after bubbling nitrogen for 10 min. The reaction was carried out at 80 °C for 12 h. After the reaction was completed, 200 mL of water was added to the system, and the organic phase was extracted with dichloromethane several times. The combined organic phase was dried. The crude product obtained after drying was eluted on a silica gel column with petroleum ether: dichloromethane = 4:1 mixed solvent as the developing agent. 2.51 g (yield 63.7%) of the product was obtained. 1 HNMR (300 MHz, DMSO-d6): 7.68 (d, J = 6.2 Hz, 2H), 7.45-7.33 (m, 7H), 7.08-7.01 (m, 2H), 3.87 (t, J = 7.2 Hz, 2H), 1.45-1.33 (m, 4H), 0.89 (t, J = 6.6 Hz, 3H).

[0066] Example 3

[0067] This example provides an anodic electrochromic material 3-bromo-7-(4- methoxyphenyl)-10-methyl-10H-phenoxazine (compound 3) and a preparation method thereof. The difference between this example and example 1 is only that step three is:

[0068]

[0069] To a solution of 3.55 g of 3,7-dibromo-10-methyl-10H-phenoxazine, 1.52 g of 4-methoxybenzeneboronic acid, 2.76 g of potassium carbonate in 50 mL of THF and 10 mL of water, 100 mg of palladium tetraphenylphosphine ((PPh3)4Pd) was added after bubbling nitrogen for 10 min, and the reaction was carried out at 80°C for 12 h. After the reaction was completed, 200 mL of water was added to the system, and the organic phase was extracted with dichloromethane in small amounts for several times, and then combined and dried. The obtained crude product was eluted by silica gel column, and the developing agent was a mixed solvent of petroleum ether:dichloromethane = 4:1. 2.57 g (yield 67.2%) of the product was obtained. 1 H NMR (300 MHz, DMSO-d6): 7.61 (d, J = 7.2 Hz, 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 example provides an anodic electrochromic material 3-bromo-10-methyl-7-(thiophen-2-yl)-10H-phenoxazine (compound 4) and a preparation method thereof. The difference between this example and example 1 is only that step three is:

[0072]

[0073] To a solution of 3.55 g of 3,7-dibromo-10-methyl-10H-phenoxazine, 1.52 g of 4-methoxybenzeneboronic acid, 2.76 g of potassium carbonate in 50 mL of THF and 10 mL of water, 100 mg of palladium tetraphenylphosphine ((PPh3)4Pd) was added after bubbling nitrogen for 10 min, and the reaction was carried out at 80°C for 12 h. After the reaction was completed, 200 mL of water was added to the system, and the organic phase was extracted with dichloromethane in small amounts for several times, and then combined and dried. The obtained crude product was eluted by silica gel column, and the developing agent was a mixed solvent of petroleum ether:dichloromethane = 4:1. 2.57 g (yield 67.2%) of the product was obtained. 1 H NMR (300 MHz, DMSO-d6): 7.61 (d, J = 7.2 Hz, 2H), 7.33-7.27 (m, 4H), 7.10-6.98 (m, 4H), 3.81 (s, 3H), 3.20 (s, 3H).

[0074] Example 5

[0075] This example provides an anodic electrochromic material 3-bromo-10-methyl-7-(thiophen-2-yl)-10H-phenoxazine (compound 4) and a preparation method thereof. The difference between this example and example 1 is only that step three is:

[0076]

[0077] To a solution of 3.55 g of 3,7-dibromo-10-methyl-10H-phenoxazine, 1.72 g of naphthalene-2-boronic acid, 2.76 g of potassium carbonate in 50 mL of THF and 10 mL of water, 100 mg of tetrakis(triphenylphosphine)palladium ((PPh3)4Pd) was added after bubbling nitrogen for 10 min, and the mixture was reacted at 80°C for 12 h. After the reaction was completed, 200 mL of water was added to the system, and the organic phase was extracted with dichloromethane several times, and then the combined organic phase was dried. The obtained crude product was eluted by silica gel column, and the developing agent was a mixture of petroleum ether and dichloromethane (4:1). 2.63 g (65.3% yield) of the product was obtained. 1 H NMR (300 MHz, DMSO-d6): 8.95 (d, J = 6.8 Hz, 2H), 8.50 (d, J = 6.3 Hz, 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).

[0078] Example 6

[0079] This example provides an anodic electrochromic material 3-bromo-10-methyl-7-(naphthalen-1-yl)-10H-phenoxazine (compound 6) and a method for preparing the same. The difference between this example and Example 1 is that the step three is as follows:

[0080]

[0081] To a solution of 3.55 g of 3,7-dibromo-10-methyl-10H-phenoxazine, 1.72 g of naphthalene-2-boronic acid, 2.76 g of potassium carbonate in 50 mL of THF and 10 mL of water, 100 mg of tetrakis(triphenylphosphine)palladium ((PPh3)4Pd) was added after bubbling nitrogen for 10 min, and the mixture was reacted at 80°C for 12 h. After the reaction was completed, 200 mL of water was added to the system, and the organic phase was extracted with dichloromethane several times, and then the combined organic phase was dried. The obtained crude product was eluted by silica gel column, and the developing agent was a mixture of petroleum ether and dichloromethane (4:1). 2.63 g (65.3% yield) of the product was obtained. 1 H NMR (300 MHz, DMSO-d6): 8.95 (d, J = 6.8 Hz, 2H), 8.50 (d, J = 6.3 Hz, 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] The present example provides an anodic electrochromic material 3-bromo-10-methyl-7- (pyridin-2-yl)-10H-phenoxazine (compound 7) and a preparation method thereof. The difference between the present example and example 1 is that step three is:

[0084]

[0085] A mixture of 3.55 g of 3,7-dibromo-10-methyl-10H-phenoxazine, 1.23 g of pyridine-2- boronic acid, 2.76 g of potassium carbonate, 50 mL of THF and 10 mL of water was prepared. After bubbling nitrogen for 10 min, 100 mg of tetrakis(triphenylphosphine)palladium ((PPh3)4Pd) was added. The reaction was carried out at 80°C for 12 h. After the reaction was completed, 200 mL of water was added to the system, and the organic phase was extracted with dichloromethane several times. The combined organic phase was dried. The obtained crude product was washed with silica gel column, and the developing agent was a mixture of petroleum ether and dichloromethane (4:1). 1.91 g (yield 53.8%) of the product was obtained. 1 H NMR (300 MHz, 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 = 6.9 Hz, 1H), 3.20 (s, 3H).

[0086] Detection Example 1

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

[0088] Example 8

[0089] The present example provides an electrochromic medium solution, which is denoted as 1a, 1b and 1c according to the different amounts of anodic electrochromic materials. The solvent used is propylene carbonate solution (PC). Specifically, the electrochromic material components are shown in the following table:

[0090]

[0091] Example 9

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

[0093]

[0094] Example 10

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

[0096]

[0097] Example 11

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

[0099]

[0100] Example 12

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

[0102]

[0103]

[0104] Comparative Example 1

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

[0106]

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

[0108]

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

[0110] 3.55 g of 3,7-dibromo-10-methyl-10H-phenoxazine, 3.08 g of 4-methoxyphenylboronic acid, 2.76 g of potassium carbonate, were dissolved in a mixed solvent of 50 mL of THF and 10 mL of water, 100 mg of tetrakis triphenylphosphine palladium ((PPh3)4Pd) was added after nitrogen bubbling for 10 min, and the reaction was carried out at 80°C for 12 h. After the reaction was completed, 200 mL of water was added to the system, and a small amount of dichloromethane was extracted several times, and the organic phase was combined and rotary evaporated. After rotary evaporation, the obtained crude product was eluted by silica gel column, and the developing agent was a mixed solvent of petroleum ether: dichloromethane = 4:1. 3.11 g (yield 75.9%) of product was obtained. 1 H NMR (300 MHz, DMSO-d6): d = 7.52 (d, J = 7.4 Hz, 4H), 7.31-7.24 (m, 6H), 6.95 (d, J = 7.0 Hz, 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, the compound introduced one methoxyphenyl group, and the potential was slightly negative.

[0112] Comparative Example 2

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

[0114]

[0115] 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] A mixture of 3.55 g of 3,7-dibromo-10-methyl-10H-phenoxazine, 3.64 g of 2,4-dimethoxybenzoic acid, 2.76 g of potassium carbonate, 50 mL of THF and 10 mL of water was bubbled with nitrogen for 10 min, and then 100 mg of tetrakis(triphenylphosphine)palladium ((PPh3)4Pd) was added. The reaction was carried out at 80°C for 12 h. After the reaction was completed, 200 mL of water was added to the system, and then a small amount of dichloromethane was extracted several times. The organic phase was combined and then rotary evaporated. The obtained crude product was eluted by silica gel column, and the developing agent was a mixture of petroleum ether and dichloromethane (4:1). 3.71 g (yield 79.0%) of the product was obtained. 1 H NMR (300 MHz, DMSO-d6): d = 7.71 (d, J = 6.4 Hz, 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 was measured by an electrochemical workstation to be 0.68 V, which was lower than that of compound 8, because the electron-donating ability of 2,4-dimethoxyphenyl was stronger than that of 4-methoxyphenyl.

[0120] Test Example 2

[0121] Two pieces of ITO-coated glass with a size of 40*40*0.4 mm were misaligned and spot-glued to be bonded, and the device box thickness was 125 microns. The electrochromic medium solution in the above examples and comparative examples was filled into the electrochromic device by vacuum filling, and the transmittance data at 550 nm under 1.2 V was measured by applying voltage to both ends, as shown in the following table:

[0122]

[0123] From the test results of Example 8 and Example 9, it can be seen that the transmittance gradually decreases as the concentration of the anode material increases, because more colored state ions are generated. From the test results of Example 10, it can be seen that the increase in the concentration of the cathode material also causes the transmittance to decrease, also due to the generation of more colored state ions. The test results of Example 11 show that compound 5 has a more obvious response at 550 nm after coloring than the compounds in other examples. In Example 12 after the combination of compound 5 and compound 2, the response of the device at 550 nm after coloring is between that of Example 8 and Example 11.

[0124] The transmittance change of Comparative Example 1 and Comparative Example 2 is very small, which is due to the very poor solubility of compound 8 and compound 9 in PC, and the low coloration efficiency. From the results of Example 8 and Comparative Example 1, it can be concluded that the asymmetric phenoxazine derivatives (such as compound 3 and compound 4) have better solubility than the symmetric structure (such as compound 8 and compound 9), and the prepared device has more excellent performance.

[0125] In summary, in the embodiments of the present application, based on the single coupling strategy, the anodic electrochromic material is designed as an asymmetric structure of bromo-phenoxazine-coupling group, which greatly improves the solubility of the phenoxazine molecule in the commonly used solvent (such as propylene carbonate, PC) of electrochromic, and further improves the coloration effect, which is helpful for the transmittance regulation of the electrochromic device. In addition, by changing different coupling groups, the potential regulation of the molecule and the spectral regulation of the colored state can be realized. Further, the anodic electrochromic material can be prepared from phenoxazine as raw material through alkylation, double bromination and carbon-carbon coupling in three steps, and the preparation method is simple and convenient, and the compound has high stability.

[0126] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An anodic electrochromic material, characterized in that, The chemical structural formula of the anodic electrochromic material is any one of the following structures: , , and .

2. A method for preparing the anodic electrochromic material as described in claim 1, characterized in that, It includes: Alkylation was performed using phenoxazine as a starting material to obtain the first compound; The first compound is then dibrominated to obtain the second compound; The second compound is then carbon-carbon coupled to obtain the anodic electrochromic material. The carbon-carbon coupling includes: coupling the second compound with a coupling compound under a second catalyst and alkaline conditions, wherein the second catalyst is tetra(triphenylphosphine)palladium; The structure of the first compound is as follows: ; The structure of the second compound is as follows: ; Where R stands for methyl.

3. The method for preparing the anodic electrochromic material according to claim 2, characterized in that, The molar ratio of the coupling compound used for carbon-carbon coupling to the second compound is 1:(0.5~1).

4. The method for preparing the anodic electrochromic material according to claim 2, characterized in that, The alkylation includes: nucleophilic substitution reaction of phenoxazine with a haloalkane in the presence of a first catalyst; And / or, the dibromination includes: brominating the first compound with a brominating agent.

5. The method for preparing the anodic electrochromic material according to claim 2, characterized in that, The synthesis route of the anodic electrochromic material is as follows: 。 6. An electrochromic medium solution, characterized in that, It includes an anodic color-changing material, a cathodic color-changing material, and an electrochromic solvent, wherein the anodic color-changing material is the anodic electrochromic material according to any one of claims 1 to 5.

7. The electrochromic medium solution according to claim 6, characterized in that, The concentration of the anodic color-changing material is 1~100mM; And / or, the concentration of the cathodic color-changing material is 1~100mM; 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 anodic color-changing material to the cathodic color-changing material is 1:(0.5~1.5); And / or, the solvent is propylene carbonate.

8. The use of the anodic electrochromic material as described in any one of claims 1 to 5 or the electrochromic medium solution as described in any one of claims 6 to 7 in the preparation of electrochromic devices.

Images