A pyrroloquinoxaline-triphenylamine electroactive material, its synthesis and application

Abstract

The present invention discloses a pyrroloquinoxaline-triphenylamine electroactive material and its synthesis and application, belonging to the technical field of organic semiconductor materials. The pyrroloquinoxaline-triphenylamine electroactive material improves the stability of triphenylamine radicals by introducing pyrroloquinoxaline groups and reduces their polymerization reaction; the stability is regulated by changing the spin density of arylamine positive ion radicals, and derivatives regulated by different position isomers and substituents are designed to ensure that the neutral state of the material presents a light color state and improve the stability; the material forms a D-A molecular structure to achieve intramolecular charge transfer, improve the photoelectric response speed, exhibit a broad and strong light absorption ability, and improve the photoelectric conversion efficiency; the electrochromic device synthesized based on this material has significant electrochromic performance, reasonable coloring and fading time, excellent cycle stability and high coloring efficiency, and this material has a wide application prospect in the field of electrochromics.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic semiconductor materials, and particularly relates to a pyrroloquinoxaline-triphenylamine electroactive material, its synthesis, and its application in the preparation of electrochromic devices. Background Art

[0002] Electrochromic (EC) materials can achieve controllable and reversible modulation of the absorption or photoluminescence (PL) properties of the materials in the visible light (400 - 700 nm) region by applying an external voltage. This unique property enables EC materials to exhibit great application potential in many fields such as displays, smart windows, electronic papers, optical sensors, and information encryption. Currently, intelligent materials with EC properties mainly focus on the optical changes in the visible light region because these materials can produce obvious color changes under electrical or optical stimulation, which is convenient for naked-eye observation and application. However, with the progress of technology and the expansion of application requirements, the research on EC materials is no longer limited to the optical changes in the visible light region, but is developing towards wider spectral ranges, faster response speeds, higher optical contrasts, etc.

[0003] EC materials mainly include inorganic electrochromic materials and organic electrochromic materials. Among them, organic electrochromic materials have attracted much attention due to their low cost, good cyclic reversibility, and good optical properties. Organic electrochromic materials mainly include two categories: organic small molecule electrochromic materials and conductive polymer electrochromic materials. The triphenylamine fragment, as a class of organic compounds with unique electronic structures and optoelectronic properties, is an important part of organic optoelectronic functional materials. Under the action of electrical or optical stimulation, the triphenylamine fragment can generate radical cations, thereby causing changes in the appearance color. This property enables the triphenylamine fragment to have broad application potential in the field of stimulus-induced color change. However, the radicals generated by the triphenylamine fragment have characteristics such as short lifetimes and high reactivity, which lead to problems such as instability and easy polymerization in the practical application of EC materials containing the triphenylamine fragment. Therefore, how to improve the stability of radicals is a frontier hot spot and key scientific issue in the field of EC materials containing the triphenylamine fragment. Pyrroloquinoxaline, as a nitrogen-containing heterocyclic compound, exhibits good stability and excellent optoelectronic properties due to its unique electronic structure. However, in the practical application of electrochromic devices, pyrroloquinoxaline-based materials face some problems that need to be solved urgently. On the one hand, during long-term use, pyrroloquinoxaline-based materials are prone to photo-degradation and thermal degradation, resulting in a decrease in their stability and a shortening of their service life, which seriously affects the performance and reliability of electrochromic devices. On the other hand, pyrroloquinoxaline-based materials have only two characteristic absorption peaks in the visible light region, resulting in a lack of diversity in color changes. Summary of the Invention

[0004] In view of the technical problems existing in the application of the existing electrochromic (EC) materials containing triphenylamine fragments and pyrroloquinoxaline in electrochromic devices alone, such as poor stability, few color changes, low optoelectronic response speed and efficiency, and short cycle life, the purpose of the present invention is to provide a pyrroloquinoxaline-triphenylamine electroactive material, its synthesis, and its application in the preparation of electrochromic devices.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] The present invention provides a pyrroloquinoxaline-triphenylamine electroactive material having a structure shown in Formula 1 or Formula 2:

[0007] ; ;

[0008] Among them, R1 is selected from a methyl group or a hydrogen atom; R2 is selected from any one of a hydrogen atom, a bromine atom, and a methyl group.

[0009] Further, it includes any one of the structures shown in Formulas 3 to 10:

[0010] .

[0011] The present invention provides a synthesis method of the above pyrroloquinoxaline-triphenylamine electroactive material, including the following steps:

[0012] (1) Under an inert atmosphere, dissolve Compound 1, Compound 2, and an auxiliary agent, add a ligand and a catalyst, react, quench with ice brine, extract, dry, and concentrate to obtain a crude product;

[0013] The structural formula of Compound 1 is , where R2 is selected from any one of a hydrogen atom, a bromine atom, and a methyl group;

[0014] The structural formula of Compound 2 is: , where R1 is a methyl group or a hydrogen atom;

[0015] The ligand is any one of 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl and triphenylphosphine, and the catalyst is any one of tris(dibenzylideneacetone)dipalladium, palladium acetate, and bis(tri-tert-butylphosphine)palladium; the auxiliary agent is any one of cesium carbonate, potassium carbonate, and sodium carbonate;

[0016] (2) Purify the crude product by silica gel column to obtain the pyrroloquinoxaline-triphenylamine electroactive material.

[0017] In step (1), Compound 1 is obtained by reacting Compound 3 with Compound 4;

[0018] The structural formula of the compound 3 is as follows: , where R2 is selected from any one of a hydrogen atom, a bromine atom, and a methyl group;

[0019] The compound 4 is any one of 4-bromobenzaldehyde, 3-bromobenzaldehyde, benzaldehyde, and 3-methylbenzaldehyde.

[0020] Furthermore, the molar ratio of the compound 3 to the compound 4 is 1: (1 to 2), the temperature of the reaction is 80 °C to 90 °C, and the reaction time is 10 h to 14 h.

[0021] In step (1), the molar ratio of the compound 1 to the compound 2 is 1: (1 to 1.6).

[0022] In step (1), the molar ratio of the auxiliary agent to the compound 1 is (2.5 to 1):1; the molar ratio of the catalyst to the compound 1 is (0.02 to 0.03):1, and the molar ratio of the ligand to the compound 1 is (0.1 to 0.2):1.

[0023] Furthermore, the ligand is 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl, the catalyst is tris(dibenzylideneacetone)dipalladium(0), and the auxiliary agent is cesium carbonate.

[0024] In step (1), the temperature of the reaction is 80 °C to 120 °C.

[0025] Furthermore, in step (1), the solvent used for dissolution is any one of toluene, acetonitrile, and dichloromethane.

[0026] Even further, the solvent used for dissolution is toluene.

[0027] In step (2), the eluent used for purification is a mixed solvent prepared by mixing petroleum ether and dichloromethane in a volume ratio of 2 to 5:1.

[0028] Furthermore, the eluent used for purification is a mixed solvent prepared by mixing petroleum ether and dichloromethane in a volume ratio of 2:1.

[0029] The present invention provides the application of the above-mentioned pyrroloquinoxaline-triphenylamine electroactive material in the preparation of an electrochromic device, and the electrochromic device uses the pyrroloquinoxaline-triphenylamine electroactive material as an electrochromic layer.

[0030] Furthermore, the concentration of the pyrroloquinoxaline-triphenylamine electroactive material is 2.0×10 -3 mol / L to 1×10 -5 mol / L.

[0031] Further, the electrochromic device adopts a sandwich structure. A liquid cavity is constructed between two glass plates covered with ITO, and the electrochromic active material is placed in the sandwich cavity to obtain the electrochromic device.

[0032] Furthermore, the resistance of the ITO glass is 10 - 15 Ω / square.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention provides a pyrroloquinoxaline-triphenylamine electroactive material. By introducing the pyrroloquinoxaline group, the stability of free radicals can be effectively improved. The nitrogen heterocyclic structure in the pyrroloquinoxaline group reduces the reactivity of free radicals through the electron conjugation effect and steric effect, thereby reducing the occurrence of polymerization reactions, helping to maintain the molecular structure stability of the material, and also reducing the decline of material performance and shortening of service life caused by polymerization reactions; changing the spin density of arylamine positive ion radicals to regulate stability, using methyl-capped diphenylamine as the donor structure, and 4-aryl pyrrolo[1,2- α quinoxaline as the acceptor structure, designing D-A type molecular structures with different position isomers and substituent regulations to ensure that the neutral state of the material presents a light color state, and dispersing the spin density of arylamine nitrogen positive ion radicals through different degrees of conjugation between the acceptor and the donor, thereby enhancing stability, providing a reference for neutral state colorless small molecule electrochromic materials; by combining pyrroloquinoxaline with triphenylamine to form a D-A type molecular structure, intramolecular charge transfer can be achieved, and the photoelectric response speed of the material can be improved; the pyrroloquinoxaline-triphenylamine electroactive material of the present invention exhibits a wide and strong light absorption ability, covering the visible light and near-infrared spectral ranges, and improving the photoelectric conversion efficiency.

[0035] Further, the optical energy gaps of the pyrroloquinoxaline-triphenylamine are 2.70 eV and 3.08 eV respectively, and the conjugation degree between the donor DPA and PQ is stronger; when the pyrroloquinoxaline-triphenylamine electroactive material (Formula 3 and Formula 4) reacts with copper perchlorate, cation radicals can be formed, and the EPR spectrum further confirms the formation of cation radicals, which indicates that the pyrroloquinoxaline-triphenylamine electroactive material provided by the present invention has the characteristic of forming cation radicals; the electrochromic device prepared by using it shows good electrochromic performance; the maximum transmittances at 700 nm and 675 nm are 42% and 39% respectively, the coloring times are 8.2 s and 13 s respectively, and the fading times are 60 s and 24 s respectively; the electrochromic device coloring efficiencies are 609.6 cm 2 / C and 269.8 cm 2 / C.

[0036] A synthesis method of a pyrroloquinoxaline-triphenylamine electroactive material provided by the present invention realizes a remarkable improvement in the optoelectronic properties, electrochromic properties and cycle stability of the pyrroloquinoxaline-triphenylamine electroactive material through reasonable molecular design. The synthesis method is simple and has good repeatability, and has broad application prospects and important research value.

[0037] An application of a pyrroloquinoxaline-triphenylamine electroactive material provided by the present invention in the preparation of an electrochromic device. The electrochromic device prepared by using the pyrroloquinoxaline-triphenylamine electroactive material of the present invention has remarkable electrochromic properties, reasonable coloring and fading times, excellent cycle stability and high coloring efficiency, making the material have broad application prospects in the field of electrochromics, such as displays, smart windows, electronic papers, etc. At the same time, by regulating the structure of the material, its performance can be further optimized to meet the requirements of different application scenarios. Description of the Drawings

[0038] Figure 1 It is the ultraviolet spectrum diagram of the pyrroloquinoxaline-triphenylamine electroactive material molecules of Example 1 (Formula 3) and Example 2 (Formula 4) of the present invention;

[0039] Figure 2 It is the cyclic voltammogram of the pyrroloquinoxaline-triphenylamine electroactive material molecule of Example 1 (Formula 3) of the present invention;

[0040] Figure 3 It is the cyclic voltammogram of the pyrroloquinoxaline-triphenylamine electroactive material molecule of Example 2 (Formula 4) of the present invention;

[0041] Figure 4 It is the test spectrogram of the ion radical characteristics of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) of the present invention;

[0042] Figure 5 It is the test spectrogram of the ion radical characteristics of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) of the present invention;

[0043] Figure 6 It is the electron paramagnetic resonance spectrogram of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) of the present invention;

[0044] Figure 7 It is the electron paramagnetic resonance spectrogram of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) of the present invention;

[0045] Figure 8 It is the test spectrogram of the color change phenomenon of the electrochromic device of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) of the present invention;

[0046] Figure 9It is the spectrogram of the electrochromic phenomenon test of the pyrroloquinoxaline-triphenylamine electroactive material in Example 2 (Formula 4) of the present invention;

[0047] Figure 10 It is the graph of the coloring time (Tc) and fading time (Tb) of the pyrroloquinoxaline-triphenylamine electroactive material in Example 1 (Formula 3) of the present invention;

[0048] Figure 11 It is the graph of the coloring time (Tc) and fading time (Tb) of the pyrroloquinoxaline-triphenylamine electroactive material in Example 2 (Formula 4) of the present invention;

[0049] Figure 12 It is the cyclic stability test graph of the pyrroloquinoxaline-triphenylamine electroactive material in Example 1 (Formula 3) of the present invention;

[0050] Figure 13 It is the cyclic stability test graph of the pyrroloquinoxaline-triphenylamine electroactive material in Example 2 (Formula 4) of the present invention;

[0051] Figure 14 It is the coloring efficiency graph of the pyrroloquinoxaline-triphenylamine electroactive material in Example 1 (Formula 3) of the present invention;

[0052] Figure 15 It is the coloring efficiency graph of the pyrroloquinoxaline-triphenylamine electroactive material in Example 2 (Formula 4) of the present invention. Detailed implementation mode

[0053] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0054] The present invention will be further described in detail below with reference to the accompanying drawings:

[0055] I. Embodiment

[0056] Embodiment 1

[0057] This embodiment provides a pyrroloquinoxaline-triphenylamine electroactive material, and the specific preparation process is as follows:

[0058] (1) Preparation of Compound 1 (7-bromo-4-phenylpyrrolo[1,2-α]quinoxaline)

[0059] Weigh 5-bromo-2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 795 mg) and 4-bromobenzaldehyde (3.0 mmol, 1.0 equivalent, 555 mg) separately, measure ethanol (10 mL), and add them successively to a round-bottom flask (25 mL). After adding acetic acid (0.6 mmol, 36 mg, 0.2 equivalent), a reaction mixture is obtained. Heat the reaction mixture to 85 °C and stir for 12 hours. After the reaction is completed, evaporate the solvent under reduced pressure to obtain a crude product. Purify the crude product by silica gel column chromatography (the eluent is petroleum ether and dichloromethane with a volume ratio of 1:2) to obtain compound 1 (7-bromo-4-phenylpyrrolo[1,2-α]quinoxaline).

[0060] The structural formula of compound 1 is: 。

[0061] (2) Preparation of pyrroloquinoxaline-triphenylamine electroactive material

[0062] In a glove box under a nitrogen atmosphere, weigh compound 1 (7-bromo-4-phenylpyrrolo[1,2-α]quinoxaline, 0.5 mmol, 164 mg) obtained in step (1), 4,4'-dimethyl diphenylamine (0.55 mmol, 1.1 equiv., 122 mg), cesium carbonate (1.0 mmol, 2.0 equiv. , 324 mg), tris(dibenzylideneacetone)dipalladium (Pd2(dba)3, 0.015 mmol, 0.03 equiv. , 10 mg) and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos, 0.06 mmol, 0.12 equiv. , 28.6 mg). After mixing the above raw materials, transfer them to a dry sealed tube. Pass nitrogen into the sealed tube, add 10 mL of toluene as the reaction solvent to the sealed tube to obtain a reaction mixture. Place the sealed tube in an oil bath preheated to 100 °C, heat and stir the reaction mixture for 8 hours to obtain a reaction mixture solution. After the reaction is completed, take out the sealed tube from the oil bath and let it cool naturally to room temperature. Add saturated brine to dilute the cooled reaction mixture solution. Use a separatory funnel to extract the aqueous phase three times with 20 mL of dichloromethane each time. After each extraction, shake the separatory funnel thoroughly, let it stand for layer separation, and then separate the organic phase. Combine the organic phases obtained from the three extractions, add anhydrous sodium sulfate Na2SO4 to the combined organic phase for drying for 5 h. Transfer the dried organic phase to a rotary evaporator and remove the dichloromethane solvent under reduced pressure. Purify the residual solid after removing the solvent under reduced pressure by silica gel column chromatography (the eluent volume ratio is petroleum ether:dichloromethane = 1:2), and concentrate under reduced pressure to obtain a pale yellow solid, which is the pyrroloquinoxaline-triphenylamine electroactive material with a yield of 85%.

[0063] The physical and chemical identification data of the corresponding pyrrolo[1,2 - a]quinoxaline - triphenylamine electroactive material are as follows:

[0064] 1 H NMR (600 MHz, Chloroform - d ) δ : 7.96 ~ 7.92 (m, 2H), 7.91 (d, J = 2.7Hz, 1H), 7.72 (d, J = 8.9 Hz, 1H), 7.66 (d, J = 2.6 Hz, 1H), 7.53 ~ 7.47 (m, 3H),7.29 (dd, J = 8.9, 2.5 Hz, 1H), 7.10 ~ 7.02 (m, 8H), 6.95 (d, J = 4.0 Hz, 1H),6.87 ~ 6.83 (m, 1H), 2.32 (s, 6H).

[0065] 13 C NMR (150 MHz, Chloroform - d ) δ : 154.6, 146.0, 145.3, 132.7, 130.0,129.7, 128.6, 128.5, 125.2, 124.6, 123.1, 122.8, 122.2, 114.3, 114.1, 113.7,108.4, 20.8.

[0066] HRMS - ESI (m / z) Theoretical: C 31 H 26 N3[M + H] + : 440.2121; Experimental: 440.2080.

[0067] The structural formula of the pyrrolo[1,2 - a]quinoxaline - triphenylamine electroactive material is determined as follows:

[0068] 。

[0069] Example 2

[0070] This example provides a pyrrolo[1,2 - a]quinoxaline - triphenylamine electroactive material, and the specific preparation process is as follows:

[0071] (1) Preparation of Compound 1 (4-(3'-bromophenyl)pyrrolo[1,2 - a]quinoxaline)

[0072] Weigh 2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 487 mg) and 3-bromobenzaldehyde (3.0 mmol, 1.0 equiv., 555 mg) separately, measure ethanol (10 mL) and add them successively into a round-bottom flask (25 mL); after adding acetic acid (0.6 mmol, 36 mg, 0.2 equiv.) simultaneously, a reaction mixture is obtained; the reaction mixture is heated to 85 °C and stirred for 12 hours. After the reaction is completed, the solvent is evaporated under reduced pressure to obtain a crude product. The crude product is purified by silica gel column chromatography (the eluent is petroleum ether:dichloromethane = 1:2 by volume ratio) to obtain compound 1 (4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline).

[0073] The structural formula of compound 1 is: 。

[0074] (2)Preparation of pyrroloquinoxaline-triphenylamine electroactive material

[0075] In a glove box under a nitrogen atmosphere, weigh compound 1 obtained in step (1) (4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline, 0.5 mmol, 163 mg), bis(4-methylphenyl)amine (0.5 mmol, 1.1 equiv., 99 mg) and Cs2CO3 (324 mg, 1.0 mmol, 2 equiv.), measure toluene (10 mL), place the above raw materials in a round-bottom flask, seal the round-bottom flask and connect it to a magnetic stirrer, start stirring to fully dissolve the reactants to obtain a mixture; under nitrogen protection, add Pd2(dba)3 (0.015 mmol, 0.03 equiv., 14 mg) and XPhos (0.06 mmol, 0.12 equiv., 28.6 mg) to the mixture to obtain a reaction mixture. The reaction mixture is heated to 100 °C for reaction, and the reaction process is monitored by thin-layer chromatography (TLC) until the reaction is completed; after the reaction is completed, it is cooled to room temperature, and the reaction is quenched with ice-saline; extract 3 times with dichloromethane to fully extract the product in the organic phase, and combine all organic phases; dry the organic layer with anhydrous magnesium sulfate, filter off the magnesium sulfate solid by suction, and concentrate the organic phase on a rotary evaporator to obtain a crude product; the crude product is purified by silica gel column chromatography (the eluent is petroleum ether and dichloromethane with a volume ratio of 1:2), collect the eluate containing the target product, and concentrate to obtain 158 mg of a white solid product with a yield of 78%, which is the pyrroloquinoxaline-triphenylamine electroactive material.

[0076] The corresponding physical and chemical identification data of the pyrroloquinoxaline-triphenylamine electroactive material are as follows:

[0077] 11H NMR (600 MHz, Chloroform- d ) δ : 7.92 (d, J J = 8.0 Hz, 1H), 7.87 (dd, J J=2.7, 1.4 Hz, 1H), 7.76 (dd, J J = 8.3, 1.5 Hz, 1H), 7.55 (q, J J = 2.1 Hz, 1H), 7.46(dt, J J = 7.6, 1.4 Hz, 1H), 7.44 ~ 7.38 (m, 1H), 7.35 ~ 7.32 (m, 1H), 7.31 ~7.25 (m, 1H), 7.10 (dq, J J = 8.2, 1.3 Hz, 1H), 6.99 (d, J J = 1.7 Hz, 8H), 6.79 (dd, J J = 4.1, 1.2 Hz, 1H), 6.76 (dd, J J = 4.1, 2.6 Hz, 1H), 2.32 (s, 6H).

[0078] 13 13C NMR (150 MHz, Chloroform- d ) δ : 154.4, 148.5, 145.3, 143.4, 134.8,132.6, 130.5, 130.2, 129.9, 129.4, 129.0, 128.4, 127.5, 127.2, 125.5, 125.4,125.2, 124.6, 124.1, 122.8, 122.0, 114.5, 113.9, 113.6, 108.7, 20.8.

[0079] HRMS-ESI (m / z) Calcd for C 31 H 26 N3[M+H] + : 440.2121; Found: 440.2084.

[0080] The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material was thus determined as follows:

[0081] 。

[0082] Example 3

[0083] This example provides a pyrroloquinoxaline-triphenylamine electroactive material, which is specifically prepared as follows:

[0084] (1) Preparation of Compound 1 (7-bromo-4-phenylpyrrolo[1,2-α]quinoxaline)

[0085] Weigh 5-bromo-2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 795 mg) and benzaldehyde (3.0 mmol, 1.0 equivalent, 318 mg) respectively, and measure ethanol (10 mL) and add them to a round-bottom flask (25 mL) in sequence; after adding acetic acid (0.6 mmol, 36 mg, 0.2 equivalent), a reaction mixture is obtained; the reaction mixture is heated to 85 °C and stirred for 12 hours. After the reaction is completed, the solvent is evaporated under reduced pressure to obtain a crude product, and the crude product is purified by silica gel column chromatography (the eluent is petroleum ether and dichloromethane with a volume ratio of 1:2) to obtain Compound 1 (7-bromo-4-phenylpyrrolo[1,2-α]quinoxaline).

[0086] The structural formula of Compound 1 is: 。

[0087] (2) Preparation of pyrroloquinoxaline-triphenylamine electroactive material

[0088] In a glove box under a nitrogen atmosphere, weigh Compound 1 (7-bromo-4-phenylpyrrolo[1,2-α]quinoxaline, 0.5 mmol, 164 mg) obtained in step (1), diphenylamine (0.55 mmol, 1.1 equiv., 93 mg), cesium carbonate (1.0 mmol, 2.0 equiv. , 324 mg), tris(dibenzylideneacetone)dipalladium (Pd2(dba)3, 0.015 mmol, 0.03 equiv. , 10 mg) and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos, 0.06 mmol, 0.12 equiv. , 28.6 mg). After mixing the above raw materials, transfer them to a dry sealed tube, introduce nitrogen into the sealed tube, add 10 mL of toluene as the reaction solvent to the sealed tube to obtain a reaction mixture; place the sealed tube in a preheated to 100 ∘In an oil bath at C, the reaction mixture was heated and stirred for 8 hours to obtain a reaction mixture solution; after the reaction was completed, the sealed tube was taken out of the oil bath and naturally cooled to room temperature. Saturated brine was added to the cooled reaction mixture solution for dilution. Using a separatory funnel, the aqueous phase was extracted three times with 20 mL of dichloromethane. After each extraction, the separatory funnel was shaken well, allowed to stand for phase separation, and then the organic phase was separated. The organic phases obtained from the three extractions were combined, and anhydrous sodium sulfate (Na2SO4) was added to the combined organic phase for drying for 5 h; the dried organic phase was transferred to a rotary evaporator, and the dichloromethane solvent was removed under reduced pressure; the residual solid after removing the solvent under reduced pressure was purified by silica gel column chromatography (the eluent was petroleum ether:dichloromethane = 1:2 by volume), and concentrated under reduced pressure to obtain a pale yellow solid of pyrroloquinoxaline-triphenylamine electroactive material with a yield of 88%.

[0089] The physical and chemical identification data of the corresponding pyrroloquinoxaline-triphenylamine electroactive material are as follows:

[0090] 1 H NMR (600 MHz, Chloroform- d ) δ : 7.96 ~ 7.92 (m, 2H), 7.91 (d, J = 2.7Hz, 1H), 7.72 (d, J = 8.9 Hz, 1H), 7.66 (d, J = 2.6 Hz, 1H), 7.53 ~ 7.47 (m, 3H),7.29 (dd, J = 8.9, 2.5 Hz, 1H), 7.10 ~ 7.02 (m, 10H), 6.95 (d, J = 4.0 Hz, 1H),6.87 ~ 6.83 (m, 1H).

[0091] 13 C NMR (150 MHz, Chloroform- d ) δ : 154.6, 146.0, 145.3, 132.7, 130.0,129.7, 128.6, 128.5, 125.2, 124.6, 123.1, 122.8, 122.2, 114.3, 114.1, 113.7,108.4.

[0092] HRMS-ESI (m / z) Theoretical: C 29 H 22 N3[M+H] +: 412.1814; Experiment: 412.1988.

[0093] The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material is determined as follows:

[0094] 。

[0095] Example 4

[0096] This example provides a pyrroloquinoxaline-triphenylamine electroactive material, which is specifically prepared as follows:

[0097] (1) Preparation of Compound 1 (4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline)

[0098] Weigh 2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 487 mg) and 3-bromobenzaldehyde (3.0 mmol, 1.0 equiv., 555 mg) respectively, measure 10 mL of ethanol and add them into a round-bottom flask (25 mL) in sequence; after adding acetic acid (0.6 mmol, 36 mg, 0.2 equiv.) at the same time, a reaction mixture is obtained; the reaction mixture is heated to 85 °C and stirred for 12 hours. After the reaction is completed, the solvent is evaporated under reduced pressure to obtain a crude product, and the crude product is purified by silica gel column chromatography (the eluent is petroleum ether and dichloromethane with a volume ratio of 1:2) to obtain Compound 1 (4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline).

[0099] The structural formula of Compound 1 is: 。

[0100] (2) Preparation of the pyrroloquinoxaline-triphenylamine electroactive material

[0101] In a glove box under a nitrogen atmosphere, weigh Compound 1 (4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline, 0.5 mmol, 163 mg), diphenylamine (0.5 mmol, 1.1 equiv., 93 mg) and Cs2CO3 (324 mg, 1.0 mmol, 2 equiv.) obtained in step (1), tris(dibenzylideneacetone)dipalladium (Pd2(dba)3, 0.015 mmol, 0.03 equiv. , 10 mg) and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos, 0.06 mmol, 0.12 equiv., 28.6 mg), the above raw materials were mixed and then transferred to a dry sealed tube. Nitrogen was introduced into the sealed tube, and 10 mL of toluene was added to the sealed tube as the reaction solvent to obtain a reaction mixture; the sealed tube was placed in an oil bath preheated to 100 °C, and the reaction mixture was heated and stirred for 8 hours to obtain a reaction mixture solution; after the reaction was completed, the sealed tube was taken out of the oil bath and naturally cooled to room temperature. Saturated brine was added to the cooled reaction mixture solution for dilution. Using a separatory funnel, the aqueous phase was extracted three times with 20 mL of dichloromethane. After each extraction, the separatory funnel was shaken well, allowed to stand for phase separation, and then the organic phase was separated. The organic phases obtained from the three extractions were combined, and anhydrous sodium sulfate Na2SO4 was added to the combined organic phase for drying for 5 h; the dried organic phase was transferred to a rotary evaporator, and the dichloromethane solvent was removed under reduced pressure; the residual solid after removing the solvent under reduced pressure was purified by silica gel column chromatography (the eluent was petroleum ether and dichloromethane with a volume ratio of 1:2), and concentrated under reduced pressure to obtain 158 mg of a white solid product with a yield of 71%, which was the pyrroloquinoxaline-triphenylamine electroactive material.

[0102] The physicochemical identification data of the pyrroloquinoxaline-triphenylamine electroactive material are as follows:

[0103] 1 H NMR (600 MHz, Chloroform- d ) δ : 7.92 (d, J = 8.0 Hz, 1H), 7.87 (dd, J =2.7, 1.4 Hz, 1H), 7.76 (dd, J = 8.3, 1.5 Hz, 1H), 7.55 (q, J = 2.1 Hz, 1H), 7.46(dt, J = 7.6, 1.4 Hz, 1H), 7.44 ~ 7.38 (m, 1H), 7.35 ~ 7.32 (m, 1H), 7.31 ~7.25 (m, 1H), 7.10 (dq, J = 8.2, 1.3 Hz, 1H), 6.99 (d, J = 1.7 Hz, 10H), 6.79(dd, J = 4.1, 1.2 Hz, 1H), 6.76 (dd, J = 4.1, 2.6 Hz, 1H).

[0104] 1313C NMR (150 MHz, Chloroform- d ) δ : 154.4, 148.5, 145.3, 143.4, 134.8, 132.6, 130.5, 130.2, 129.9, 129.4, 129.0, 128.4, 127.5, 127.2, 125.5, 125.4, 125.2, 124.6, 124.1, 122.8, 122.0, 114.5, 113.9, 113.6, 108.7.

[0105] HRMS-ESI (m / z) Theoretical: C 29 H 22 N3[M+H] + : 412.1814; Experimental: 412.1897.

[0106] The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material was thus determined as follows:

[0107] .

[0108] Example 5

[0109] This example provides a pyrroloquinoxaline-triphenylamine electroactive material, which is specifically prepared as follows:

[0110] (1) Preparation of Compound 1 (7-bromo-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline)

[0111] Weigh 5-bromo-2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 795 mg) and 3-bromobenzaldehyde (3.0 mmol, 1.0 equivalent, 555 mg) respectively, measure ethanol (10 mL) and add them into a round-bottom flask (25 mL) in turn; after adding acetic acid (0.6 mmol, 36 mg, 0.2 equivalent), a reaction mixture is obtained; the reaction mixture is heated to 85 °C and stirred for 12 hours. After the reaction is completed, the solvent is evaporated under reduced pressure to obtain a crude product, and the crude product is purified by silica gel column chromatography (the eluent is petroleum ether and dichloromethane with a volume ratio of 1:2) to obtain Compound 1 (7-bromo-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline).

[0112] The structural formula of Compound 1 is: .

[0113] (2) Preparation of the pyrroloquinoxaline-triphenylamine electroactive material

[0114] Weigh separately 1 (7-bromo-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline, 0.5 mmol, 202 mg) obtained in step (1), 4,4'-dimethyl diphenylamine (0.55 mmol, 1.1 equiv., 122 mg), cesium carbonate (1.0 mmol, 2.0 equiv. , 324 mg), tris(dibenzylideneacetone)dipalladium (Pd2(dba)3, 0.015 mmol, 0.03 equiv. , 10 mg) and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos, 0.06 mmol, 0.12 equiv. , 28.6 mg). Transfer the above raw materials to a dry sealed tube, introduce nitrogen into the sealed tube, add 10 mL of toluene as the reaction solvent to the sealed tube to obtain a reaction mixture; place the sealed tube in an oil bath preheated to 100 °C, heat and stir the reaction mixture for 8 hours to obtain a reaction mixture solution; after the reaction is completed, take out the sealed tube from the oil bath, naturally cool it to room temperature, dilute the cooled reaction mixture solution with saturated brine, use a separatory funnel, extract the aqueous phase three times with 20 mL of dichloromethane. After each extraction, shake the separatory funnel thoroughly, let it stand for layer separation, and then separate out the organic phase. Combine the organic phases obtained from the three extractions, add anhydrous sodium sulfate Na2SO4 to the combined organic phase for drying for 5 h; transfer the dried organic phase to a rotary evaporator and remove the dichloromethane solvent under reduced pressure; purify the residual solid after removing the solvent under reduced pressure by silica gel column chromatography (the eluent is petroleum ether and dichloromethane with a volume ratio of 1:2), concentrate under reduced pressure to obtain a pale yellow solid, which is the pyrroloquinoxaline-triphenylamine electroactive material, and the yield is 85%.

[0115] The corresponding physical and chemical identification data of the pyrroloquinoxaline-triphenylamine electroactive material are as follows:

[0116] 1 H NMR (600 MHz, Chloroform- d ) δ : 7.96 ~ 7.92 (m, 2H), 7.91 (d, J = 2.7Hz, 1H), 7.72 (d, J = 8.9 Hz, 1H), 7.66 (d, J = 2.6 Hz, 1H), 7.53 ~ 7.47 (m, 2H),7.29 (dd, J = 8.9, 2.5 Hz, 1H), 7.10 ~ 7.02 (m, 8H), 6.95 (d,J = 4.0 Hz, 1H), 6.87 ~ 6.83 (m, 1H), 2.32 (s, 6H).

[0117] 13 C NMR (150 MHz, Chloroform- d ) δ : 154.6, 146.0, 145.3, 132.7, 130.0, 129.7, 128.6, 128.5, 125.2, 124.6, 123.1, 122.2, 114.3, 114.1, 113.7, 108.4, 20.8.

[0118] HRMS-ESI (m / z) Calculated: C 31 H 25 BrN3[M+H] + : 518.1232; Found: 518.1180.

[0119] The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material is determined as follows:

[0120] 。

[0121] Example 6

[0122] This example provides a pyrroloquinoxaline-triphenylamine electroactive material, which is specifically prepared as follows:

[0123] (1) Preparation of Compound 1 (7-bromo-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline)

[0124] Weigh 5-bromo-2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 795 mg) and 3-bromobenzaldehyde (3.0 mmol, 1.0 equivalent, 555 mg) respectively, measure ethanol (10 mL) and add them into a round-bottom flask (25 mL) in sequence; after adding acetic acid (0.6 mmol, 36 mg, 0.2 equivalent), a reaction mixture is obtained; the reaction mixture is heated to 85 °C and stirred for 12 hours. After the reaction is completed, the solvent is evaporated under reduced pressure to obtain a crude product, and the crude product is purified by silica gel column chromatography (the eluent is petroleum ether and dichloromethane with a volume ratio of 1:2) to obtain Compound 1 (7-bromo-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline).

[0125] The structural formula of Compound 1 is: 。

[0126] (2) Preparation of the pyrroloquinoxaline-triphenylamine electroactive material

[0127] In a glove box under a nitrogen atmosphere, weigh out Compound 1 obtained in step (1) (7-bromo-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline, 0.5 mmol, 202 mg), bis(4-methylphenyl)amine (0.5 mmol, 1.1 equiv., 99 mg), cesium carbonate (1.0 mmol, 2.0 equiv. , 324 mg) and toluene (10 mL). Seal the round-bottom flask and connect it to a magnetic stirrer. Start stirring to fully dissolve the reactants to obtain a mixture. Under nitrogen protection, add tris(dibenzylideneacetone)dipalladium (Pd2(dba)3, 0.015 mmol, 0.03 equiv. , 10 mg) and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos, 0.06 mmol, 0.12 equiv. , 28.6 mg) to the mixture to obtain a reaction mixture. Heat the reaction mixture to 100 °C for reaction and monitor the reaction progress by thin-layer chromatography (TLC) until the reaction is complete. After the reaction is complete, cool to room temperature and quench the reaction with ice brine. Extract with dichloromethane 3 times to fully extract the product in the organic phase. Combine all organic phases. Dry the organic layer with anhydrous magnesium sulfate, filter off the magnesium sulfate solid by suction filtration, and concentrate the organic phase on a rotary evaporator to obtain a crude product. Purify the crude product by silica gel column chromatography (the eluent is petroleum ether and dichloromethane with a volume ratio of 1:2), collect the eluate containing the target product, and concentrate to obtain 158 mg of a white solid product with a yield of 75%, which is the pyrroloquinoxaline-triphenylamine electroactive material.

[0128] The physicochemical identification data of the pyrroloquinoxaline-triphenylamine electroactive material are as follows:

[0129] 1 H NMR (600 MHz, Chloroform- d ) δ : 7.92 (d, J = 8.0 Hz, 1H), 7.87 (dd, J = 2.7, 1.4 Hz, 1H), 7.76 (dd, J = 8.3, 1.5 Hz, 1H), 7.55 (q, J = 2.1 Hz, 1H), 7.46 (dt, J = 7.6, 1.4 Hz, 1H), 7.35 ~ 7.32 (m, 1H), 7.31 ~ 7.25 (m, 1H), 7.10 (dq, J= 8.2, 1.3 Hz, 1H), 6.99 (d, J = 1.7 Hz, 8H), 6.79 (dd, J = 4.1, 1.2 Hz, 1H),6.76 (dd, J = 4.1, 2.6 Hz, 1H), 2.32 (s, 6H).

[0130] 13 C NMR (150 MHz, Chloroform- d ) δ : 154.4, 148.5, 145.3, 143.4, 134.8,132.6, 130.5, 130.2, 129.9, 129.4, 129.0, 128.4, 127.5, 127.2, 125.5, 125.4,125.2, 124.6, 124.1, 122.8, 122.0, 114.5, 113.9, 113.6, 108.7, 20.8.

[0131] HRMS-ESI (m / z) Calculated: C 31 H 25 BrN3[M+H] + : 518.1232; Found: 518.1196.

[0132] The structural formula of the white solid was thus determined as follows:

[0133] 。

[0134] Example 7

[0135] This example provides a pyrroloquinoxaline-triphenylamine electroactive material, which is specifically prepared as follows:

[0136] (1) Preparation of Compound 1 (7-bromo-4-(3'-methylphenyl)pyrrolo[1,2-α]quinoxaline)

[0137] Weigh 5-bromo-2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 795 mg) and 3-methylbenzaldehyde (3.0 mmol, 1.0 equivalent, 360 mg) separately, measure ethanol (10 mL) and add them successively into a round-bottom flask (25 mL); after adding acetic acid (0.6 mmol, 36 mg, 0.2 equivalent), a reaction mixture is obtained; heat the reaction mixture to 85 °C and stir for 12 hours. After the reaction is completed, evaporate the solvent under reduced pressure and purify by silica gel column chromatography (the eluent is petroleum ether and dichloromethane with a volume ratio of 1:2) to obtain Compound 1 (7-bromo-4-(3'-methylphenyl)pyrrolo[1,2-α]quinoxaline).

[0138] The structural formula of Compound 1 is:

[0139] (2) Preparation of pyrroloquinoxaline-triphenylamine electroactive material

[0140] In a glove box under a nitrogen atmosphere, weigh Compound 1 (7-bromo-4-(3'-methylphenyl)pyrrolo[1,2-α]quinoxaline, 0.5 mmol, 169 mg) obtained in step (1), weigh 4,4'-dimethyl diphenylamine (0.55 mmol, 1.1 equiv. , 122 mg), cesium carbonate (1.0 mmol, 2.0 equiv. , 324 mg), tris(dibenzylideneacetone)dipalladium (Pd2(dba)3, 0.015 mmol, 0.03 equiv. , 10 mg) and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (0.06 mmol, 0.12 equiv. , 28.6 mg), mix them and transfer to a dry sealed tube. Pass nitrogen into the sealed tube, add 10 mL of toluene as the reaction solvent to the sealed tube to obtain a reaction mixture; place the sealed tube in an oil bath preheated to 100 °C, heat and stir the reaction mixture for 8 hours to obtain a reaction mixture solution; after the reaction is completed, take out the sealed tube from the oil bath and let it cool naturally to room temperature. Add saturated brine to dilute the cooled reaction mixture solution, use a separatory funnel, extract the aqueous phase three times with 20 mL of dichloromethane. After each extraction, shake the separatory funnel well, let it stand for layer separation, and then separate the organic phase. Combine the organic phases obtained from the three extractions, add anhydrous sodium sulfate Na2SO4 to the combined organic phase and dry for 5 h; transfer the dried organic phase to a rotary evaporator and remove the dichloromethane solvent under reduced pressure; purify the residual solid after removing the solvent under reduced pressure by silica gel column chromatography (the eluent is petroleum ether and dichloromethane with a volume ratio of 1:2), concentrate under reduced pressure to obtain a pale yellow solid, which is the pyrroloquinoxaline-triphenylamine electroactive material, and the yield is 83%.

[0141] The physical and chemical identification data of the corresponding pyrroloquinoxaline-triphenylamine electroactive material are as follows:

[0142] 1 H NMR (600 MHz, Chloroform- d ) δ : 7.96 ~ 7.92 (m, 2H), 7.91 (d, J = 2.7Hz, 1H), 7.72 (d, J = 8.9 Hz, 1H), 7.66 (d, J = 2.6 Hz, 1H), 7.53 ~ 7.47 (m, 3H),7.29 (dd, J = 8.9, 2.5 Hz, 1H), 7.10 ~ 7.02 (m, 8H), 6.95 (d, J = 4.0 Hz, 1H),2.32 (s, 6H), 2.8 (s, 3H).

[0143] 13 C NMR (150 MHz, Chloroform- d ) δ : 154.6, 146.0, 145.3, 132.7, 130.0,129.7, 128.6, 128.5, 125.2, 124.6, 123.1, 122.8, 122.2, 114.3, 114.1, 113.7,108.4, 20.8, 15.6.

[0144] HRMS-ESI (m / z) Theoretical: C 32 H 28 N3[M+H] + : 454.2283; Experimental: 454.2189.

[0145] The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material is determined as follows:

[0146] 。

[0147] Example 8

[0148] This example provides a pyrroloquinoxaline-triphenylamine electroactive material, which is specifically prepared as follows:

[0149] (1) Preparation of Compound 1 (7-methyl-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline)

[0150] Weigh 5-methyl-2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 517 mg) and 3-bromobenzaldehyde (3.0 mmol, 1.0 equiv., 555 mg) separately, measure ethanol (10 mL), and add them successively to a round-bottom flask (25 mL); after adding acetic acid (0.6 mmol, 36 mg, 0.2 equiv.), a reaction mixture is obtained; the reaction mixture is heated to 85 °C and stirred for 12 hours. After the reaction is completed, the solvent is evaporated under reduced pressure, and then purified by silica gel column chromatography (the eluent is petroleum ether and dichloromethane with a volume ratio of 1:2) to obtain Compound 1 (7-methyl-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline).

[0151] The structural formula of Compound 1 is as follows:

[0152] (2) Preparation of pyrroloquinoxaline-triphenylamine electroactive material

[0153] In a glove box under a nitrogen atmosphere, weigh Compound 1 (7-methyl-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline, 0.5 mmol, 169 mg) obtained in step (1), weigh bis(4-methylphenyl)amine (0.5 mmol, 1.1 equiv., 99 mg) and Cs2CO3 (324 mg, 1.0 mmol, 2 equiv.), measure toluene (10 mL), and add the above raw materials to a dry round-bottom flask. Seal the round-bottom flask and connect it to a magnetic stirrer, and start stirring to fully dissolve the reactants to obtain a mixture; under nitrogen protection, add Pd2(dba)3 (0.015 mmol, 0.03 equiv., 10 mg) and XPhos (0.06 mmol, 0.12 equiv., 2.85 mg) to the mixture to obtain a reaction mixture. Heat the reaction mixture to 100 °C for reaction, and monitor the reaction progress by thin-layer chromatography (TLC) until the reaction is completed; after the reaction is completed, cool to room temperature and quench the reaction with ice brine; extract 3 times with dichloromethane to fully extract the product in the organic phase, and combine all organic phases; dry the organic layer with anhydrous magnesium sulfate, filter off the magnesium sulfate solid by suction, and concentrate the organic phase on a rotary evaporator to obtain a crude product; purify the crude product by silica gel column chromatography (the eluent is petroleum ether and dichloromethane with a volume ratio of 1:2), collect the eluate containing the target product, and concentrate to obtain 158 mg of a white solid product with a yield of 69%, which is the pyrroloquinoxaline-triphenylamine electroactive material.

[0154] The physical and chemical identification data of the pyrroloquinoxaline-triphenylamine electroactive material are as follows:

[0155] 1 H NMR (600 MHz, Chloroform- d ) δ : 7.92 (d, J J = 8.0 Hz, 1H), 7.87 (dd, J J=2.7, 1.4 Hz, 1H), 7.76 (dd, J J = 8.3, 1.5 Hz, 1H), 7.46 (dt, J J = 7.6, 1.4 Hz, 1H),7.44 ~ 7.38 (m, 1H), 7.35 ~ 7.32 (m, 1H), 7.31 ~ 7.25 (m, 1H), 7.10 (dq, J J=8.2, 1.3 Hz, 1H), 6.99 (d, J J = 1.7 Hz, 8H), 6.79 (dd, J J = 4.1, 1.2 Hz, 1H), 6.76(dd, J J = 4.1, 2.6 Hz, 1H), 2.8 (s, 3H), 2.32 (s, 6H).

[0156] 13 C NMR (150 MHz, Chloroform- d ) δ : 154.4, 148.5, 145.3, 143.4, 134.8,132.6, 130.5, 130.2, 129.9, 129.4, 129.0, 128.4, 127.5, 127.2, 125.5, 125.4,125.2, 124.6, 124.1, 122.8, 122.0, 114.5, 113.9, 113.6, 108.7, 20.8, 19.8.

[0157] HRMS-ESI (m / z) Calculated: C 32 H 28 N3[M+H] + : 454.2283; Found: 454.2221.

[0158] The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material was thus determined as follows:

[0159] 。

[0160] II. Electrochemical Property Tests

[0161] On the basis of Examples 1 to 8, the properties of the pyrroloquinoxaline-triphenylamine electroactive material prepared by the present invention were tested.

[0162] 1. UV-Visible Absorption Spectroscopy Test

[0163] In this experiment, the UV-visible absorption spectroscopy test was carried out on the pyrroloquinoxaline-triphenylamine electroactive materials prepared in Examples 1 to 2. The solution-state UV-visible spectra of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) and the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) are as Figure 1 shown.

[0164] From the attached Figure 1 data, it can be seen that the main absorption peak of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) is 311 nm, which belongs to the π-π* transition, and the absorption at 410 nm belongs to the n-π* transition; for the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4), the main absorption peaks are located at 277 nm and 296 nm, which respectively belong to the absorption generated by the pyrroloquinoxaline fragment (PQ) and the donor DPA skeleton π-π* transition. At the same time, there is a shoulder peak at 358 nm in the absorption curve of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4), which belongs to the absorption generated by the PQ fragment n-π* ; comparing the pyrroloquinoxaline-triphenylamine electroactive materials prepared in Example 1 and Example 2, since the conjugation degree of DPA and PQ in the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) is higher, therefore, n-π* the transition redshifts to 410 nm, so the solution of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) shows light yellow, while the solution state of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) is colorless. In addition, using the formula E g = 1240 / λ onset the optical band gaps of the two compounds were calculated. The optical band gaps of the pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 (Formula 3) and Example 2 (Formula 4) are 2.70 eV and 3.08 eV respectively, which further indicates that in the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3), the conjugation degree between the donor DPA and PQ is stronger.

[0165] 2. Cyclic Voltammetry Test

[0166] In this experiment, the cyclic voltammetry test was carried out on the pyrroloquinoxaline-triphenylamine electroactive materials of Examples 1 to 2. For the specific results, see the attachedFigures 2 - 3 as shown

[0167] Using acetonitrile as the solvent and tetrabutylammonium hexafluorophosphate as the electrolyte (concentration: 0.1 mol / L), a three-electrode system (Pt wire as the working electrode, Pt sheet as the auxiliary electrode, Ag / AgCl as the reference electrode) was used, ferrocene was used as the reference substance, the scanning rate was set at 100 mV / s, and the concentration of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) or Example 2 (Formula 4) was 1.0×10 -3 mol / L. The cyclic voltammograms of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) and the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) are as Figures 2 - 3 shown

[0168] From the attached Figures 2 - 3 data, it can be seen that both the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) and the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) produced two pairs of redox peaks. The first oxidation peak of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) was 0.946 V (E HOMO = -5.22 eV), and the first oxidation peak of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) was 1.006 V (E HOMO = -5.28 eV). These two peaks correspond to the process of the lone pair electrons on the nitrogen atom in diphenylamine being oxidized to nitrogen cation radicals, and this process is reversible, that is, the oxidized substance can be reduced back to its original state during the reverse scan; the second oxidation peak of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) was 1.143 V, and the second oxidation peak of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) was 1.090 V. These two peaks are generated by the oxidation of the PQ fragment, indicating that the PQ fragment can also undergo redox reactions at higher potentials. Comparing the two compounds of Example 1 and Example 2, due to the difference in conjugation degree caused by their isomerism at different positions, the nitrogen charge density of diphenylamine in the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) is lower, which makes the position of its first oxidation peak shift 60 mV to the right compared with the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3). This shift reflects the influence of isomers on the redox properties of substances and also illustrates the importance of conjugation degree to the electrochemical properties of substances.

[0169] 3. Cation Radical Property Test

[0170] In this experiment, the pyrroloquinoxaline-triphenylamine electroactive materials obtained in Examples 1-2 were tested for cation radical properties. For specific results, see the attached Figures 4 - 5 shown

[0171] In an acetonitrile solution, copper perchlorate with different equivalents was used as an oxidant to react with the pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 (Formula 3) and Example 2 (Formula 4) respectively. The changes were recorded using ultraviolet-visible spectroscopy and electron paramagnetic resonance (EPR) spectroscopy. The results are shown in the appendix Figures 4 - 5 For the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3), as the equivalent of copper perchlorate increased from 0.0 equiv. to 2.0 equiv. , the absorption of the pyrroloquinoxaline-triphenylamine electroactive material at 311 nm gradually decreased, and new characteristic absorption peaks appeared at 353 nm and 700 nm. The color of the solution changed from light yellow to dark blue-green; for the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4), its absorption at 277 nm and 296 nm gradually decreased, and new characteristic absorption peaks appeared at 346 nm and 676 nm. The solution changed from colorless and transparent to blue. The absorption peaks of the two pyrroloquinoxaline-triphenylamine electroactive materials at 700 nm and 676 nm are attributed to the characteristic absorption generated by the transition of arylamine cation radicals π-π* . When the copper perchlorate increased from 1.0 equiv. to 2.0 equiv. , the intensity of the newly generated absorption peaks hardly changed any more, indicating that the stoichiometric ratio of the pyrroloquinoxaline-triphenylamine electroactive material to copper perchlorate is 1:1. In the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) and the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4), the diphenylamine nitrogen respectively forms the corresponding cation radicals, and the divalent copper ions are converted into monovalent copper ions. To further confirm the formation of the nitrogen cation radicals, the electron paramagnetic resonance spectra of the reaction of the pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 (Formula 3) or Example 2 (Formula 4) with copper perchlorate at a stoichiometric ratio of 1:1 were recorded in an acetonitrile solution. The results are shown in the appendix Figures 6 - 7 . In the range of 3330 - 3480 G, obvious EPR signals were observed. The g factor of the cation radicals of the pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 (Formula 3) and Example 2 (Formula 4) is 2.001, which is similar to the g factor of arylamine cation radicals. The experimental results show that when the pyrroloquinoxaline-triphenylamine electroactive materials (Formula 3 and Formula 4) react with copper perchlorate, cation radicals can be formed. The EPR spectra further confirm the formation of cation radicals, indicating that the pyrroloquinoxaline-triphenylamine electroactive materials provided by the present invention have the property of forming cation radicals, which is of great significance for understanding their optoelectronic properties and potential applications.

[0172] III. Application Examples

[0173] Based on Examples 1 - 8, electrochromic devices were prepared using the pyrroloquinoxaline - triphenylamine electroactive materials prepared in Examples 1 - 2, as follows:

[0174] 1. Preparation of electrochromic devices

[0175] Raw materials: ITO glass (resistance 10 Ω / square), multimeter, tweezers, scissors, syringe, 3M double - sided tape, ultraviolet curable glue, copper sticker; pyrroloquinoxaline - triphenylamine electroactive materials prepared in Example 1 (Formula 3) or Example 2 (Formula 4); acetonitrile solution of 0.1 mol / L tetrabutylammonium hexafluorophosphate.

[0176] Adopting a sandwich structure, a liquid cavity was constructed between two ITO - covered glass plates, and the electrochromic active material was placed in the sandwich cavity to obtain an electrochromic device. The specific preparation process is as follows: The ITO glass (2.0 cm×4.0 cm) was ultrasonically cleaned in acetone for thirty minutes and purged with nitrogen; a liquid groove was constructed on one piece of ITO glass using 3M double - sided tape and combined with another piece of ITO glass to obtain an ITO sandwich with a liquid cavity structure; the pyrroloquinoxaline - triphenylamine electroactive material of Example 1 (Formula 3) or the pyrroloquinoxaline - triphenylamine electroactive material of Example 2 (Formula 4) was added to an acetonitrile solution of 0.1 mol / L tetrabutylammonium hexafluorophosphate to prepare a solution with a molar concentration of 2.0×10 -3 mol / L, and the solution was injected into the liquid cavity to obtain a liquid electrochromic device.

[0177] 2. Performance testing of liquid electrochromic devices

[0178] An electrochemical workstation was connected in series with an in - situ ultraviolet - visible absorption spectrometer, and the absorption spectrum of the obtained liquid electrochromic device was measured at different voltages. The results are shown in the appendix Figures 8 - 9 As shown. When applying different magnitudes of positive voltage, the pyrroloquinoxaline - triphenylamine electroactive materials of Example 1 (Formula 3) and Example 2 (Formula 4) respectively produced new maximum absorption peaks at 700 nm and 675 nm; as the voltage increased, the absorption continuously enhanced, which belongs to the absorption generated when the two pyrroloquinoxaline - triphenylamine electroactive materials were oxidized from the neutral state to the cation radical (Formula 3→Formula 3 + · and Formula 4→Formula 4 +·), which is also consistent with the absorption produced by the oxidation of copper perchlorate. A voltage of 2.5 V was applied to the liquid electrochromic device prepared with the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3), and the liquid electrochromic device changed from the original yellow state to a dark green state. When a voltage of -0.1 V was applied, the liquid electrochromic device returned from the dark green state to the original yellow state. For the liquid electrochromic device prepared with the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4), when a voltage of 2.2 V was applied, the liquid electrochromic device changed from the original colorless state to a blue state. When a voltage of -0.1 V was applied, the liquid electrochromic device returned from the blue state to the original colorless state. The experimental results show that the pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 (Formula 3) and Example 2 (Formula 4) both exhibit good electrochromic properties.

[0179] The coloring time refers to the time required for the color-changing material to change from the neutral state to the colored state; the fading time refers to the time required for the color-changing material to return from the colored state to the neutral state. Generally, the coloring / fading time is taken as the time required when the transmittance reaches 90% of the maximum transmittance difference before and after color change. The cycle stability refers to the number of cycles of the device between the colored state and the faded state; the coloring efficiency refers to the change in optical density caused by the charge consumed per unit area. The higher the coloring efficiency, the smaller the amount of charge required for color change, and the more energy-efficient it is. Further investigate the coloring time (Tc) and fading time (Tb) of the above two liquid electrochromic devices, see Figure 10 and Figure 11 , for the liquid electrochromic devices prepared with the pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 (Formula 3) and Example 2 (Formula 4), the maximum transmittances at 700 nm and 675 nm are 42% and 39% respectively, the coloring times are 8.2 s and 13 s respectively, and the fading times are 60 s and 24 s respectively. It can be seen that the liquid electrochromic device prepared with the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) has a faster coloring time, indicating that the formation rate of its cation radical is faster. See Figure 12 and Figure 13 , the liquid electrochromic devices prepared with the two pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 and Example 2 were tested for cycle stability. The liquid electrochromic device of Example 1 (Formula 3) has stronger cycle stability than the liquid electrochromic device of Example 2 (Formula 4), indicating that the change in spin density caused by positional isomerism can regulate the stability of cation radicals, thereby affecting the cycle stability of the material. See Attachment Figure 14 and Attachment Figure 15 , the coloring efficiencies of the liquid electrochromic device of Example 1 (Formula 3) and the liquid electrochromic device of Example 2 (Formula 4) are 609.6 cm 2 / C and 269.8 cm2 / C indicates that the coloring efficiency of the pyrroloquinoxaline-triphenylamine electroactive material in Example 1 (Formula 3) is higher, the amount of charge consumed during the color change process is smaller, and it is more energy-efficient. In summary, the pyrroloquinoxaline-triphenylamine electroactive material in Example 1 (Formula 3) performs better in terms of coloring time, cycle stability, and coloring efficiency, and is a more promising electrochromic material.

[0180] The above content is only for explaining the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A pyrroloquinoxaline-triphenylamine electroactive material, characterized in that: Including any one of the structures shown in Formula 3 to Formula 4, Formula 6 to Formula 10: 。 2. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 1, characterized in that: The following steps are involved: (1) Under an inert atmosphere, compound 1, compound 2 and an auxiliary agent are dissolved, a ligand and a catalyst are added for reaction, and then the reaction is quenched with ice-salt water, extracted, dried and concentrated to obtain a crude product; The structural formula of the compound 1 is , wherein R2 is selected from any one of a hydrogen atom, a bromine atom and a methyl group; The structural formula of the compound 2 is: , wherein R1 is a methyl group or a hydrogen atom; The ligand is any one of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl and triphenylphosphine; the catalyst is any one of trisdibenzylideneacetone dipalladium, palladium acetate, and bis(tri-tert-butylphosphine)palladium; the auxiliary agent is any one of cesium carbonate, potassium carbonate, and sodium carbonate; (2) The crude product was purified by silica gel column to obtain pyrroloquinoxaline-triphenylamine electroactive material.

3. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 2, characterized in that: In step (1), the compound 1 is obtained by reacting compound 3 with compound 4; The structural formula of the compound 3 is: , wherein R2 is selected from any one of a hydrogen atom, a bromine atom and a methyl group; Compound 4 is any one of 4-bromobenzaldehyde, 3-bromobenzaldehyde, benzaldehyde and 3-methylbenzaldehyde.

4. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 2, characterized in that: The molar ratio of compound 3 to compound 4 is 1: (1-2), the reaction temperature is 80°C-90°C, and the reaction time is 10 h-14 h.

5. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 2, characterized in that: In step (1), the molar ratio of compound 1 to compound 2 is 1: (1-1.6).

6. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 2, characterized in that: In step (1), the molar ratio of the auxiliary agent to compound 1 is (2.5-1):1; the molar ratio of the catalyst to compound 1 is (0.02-0.03):1; and the molar ratio of the ligand to compound 1 is (0.1-0.2):

1.

7. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 2, characterized in that: In step (1), the reaction temperature is 80°C to 120°C.

8. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 2, characterized in that: In step (2), the eluent used for purification is a mixed solvent prepared by petroleum ether and dichloromethane in a volume ratio of 2 to 5:

1.

9. Use of a pyrroloquinoxaline-triphenylamine electroactive material according to claim 1 in preparing an electrochromic device, characterized in that: The electrochromic device uses the pyrroloquinoxaline-triphenylamine electroactive material as an electrochromic layer.

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