Pyrroloquinoxaline-triphenylamine electroactive material and synthesis and application thereof

Abstract

The invention discloses a pyrroloquinoxaline-triphenylamine electroactive material as well as synthesis and application thereof, and belongs to the technical field of organic semiconductor materials. According to the pyrroloquinoxaline-triphenylamine electroactive material, the stability of a triphenylamine free radical is improved by introducing a pyrroloquinoxaline group, and the polymerization reaction is reduced; the stability is regulated and controlled by changing the spin density of arylamine positive ion free radicals, derivatives regulated and controlled by isomers at different positions and substituent groups are designed, it is guaranteed that the material is in a light color state in a neutral state, and the stability is improved; the material forms a D-A type molecular structure, so that intramolecular charge transfer is realized, the photoelectric response speed is increased, wide and strong light absorption capability is shown, and the photoelectric conversion efficiency is improved; an electrochromic device synthesized on the basis of the material has remarkable electrochromic performance, reasonable coloring and fading time, excellent cycling stability and high coloring efficiency, and the material has wide application prospects in the field of electrochromism.

Description

Technical Field

[0001] The invention belongs to the technical field of organic semiconductor materials, and specifically relates to a pyrroloquinoxaline-triphenylamine electroactive material and its synthesis and application in preparing an electrochromic device. Background Art

[0002] Electrochromic (EC) materials can achieve controllable and reversible modulation of the absorption or photoluminescence (PL) properties of materials in the visible light region (400-700 nm) by applying external voltage. This unique property makes EC materials show great application potential in many fields such as displays, smart windows, electronic paper, optical sensors, and information encryption. At present, smart materials with EC properties mainly focus on optical changes in the visible light region. This is 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 advancement of science and technology and the expansion of application needs, the research on EC materials is no longer limited to optical changes in the visible light region, but is developing towards a wider spectral range, faster response speed, higher optical contrast, 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 advantages such as low cost, good cycle reversibility and good optical properties. Organic electrochromic materials mainly include two categories: organic small molecule electrochromic materials and conductive polymer electrochromic materials. Triphenylamine fragments, as a class of organic compounds with unique electronic structures and optoelectronic properties, are an important component of organic optoelectronic functional materials. Under the action of electrical or light stimulation, triphenylamine fragments can generate free radical cations, thereby producing changes in the appearance color. This feature makes triphenylamine fragments have a wide range of application potential in the field of stimulus-induced color change. However, the free radicals generated by triphenylamine fragments have the characteristics of short life and high reactivity, which leads to problems such as instability and easy polymerization in EC materials containing triphenylamine fragments in practical applications. Therefore, how to improve the stability of free radicals is a frontier hotspot and key scientific issue in the field of EC materials containing triphenylamine fragments. As a nitrogen-containing heterocyclic compound, pyrroloquinoxaline exhibits good stability and excellent photoelectric properties due to its unique electronic structure. However, in the actual application of electrochromic devices, pyrroloquinoxaline materials face some urgent problems to be solved. On the one hand, during long-term use, pyrroloquinoxaline materials are prone to photodegradation and thermal degradation, which leads to decreased stability and shortened service life, which seriously affects the performance and reliability of electrochromic devices. On the other hand, pyrroloquinoxaline materials have only two characteristic absorption peaks in the visible light region, which makes them lack diversity in color changes. Summary of the invention

[0004] In view of the technical problems that the existing EC materials containing triphenylamine fragments and pyrroloquinoxaline have poor stability, little color change, low photoelectric response speed and efficiency, and short cycle life when used alone in electrochromic devices, the purpose of the present invention is to provide a pyrroloquinoxaline-triphenylamine electroactive material and its synthesis and application in the preparation of electrochromic devices.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: The present invention provides a pyrroloquinoxaline-triphenylamine electroactive material having a structure shown in Formula 1 or Formula 2: ; ; Wherein, 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.

[0006] Further, it includes a structure shown in any one of Formula 3 to Formula 10: .

[0007] The present invention provides a method for synthesizing the above-mentioned pyrroloquinoxaline-triphenylamine electroactive material, comprising the following steps: (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.

[0008] 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.

[0009] Furthermore, the molar ratio of compound 3 to compound 4 is 1: (1~2), the reaction temperature is 80 ℃~90 ℃, and the reaction time is 10 h~14 h.

[0010] In step (1), the molar ratio of compound 1 to compound 2 is 1: (1-1.6).

[0011] 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.

[0012] Furthermore, the ligand is 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, the catalyst is tris dibenzylideneacetone dipalladium, and the auxiliary agent is cesium carbonate.

[0013] In step (1), the reaction temperature is 80°C to 120°C.

[0014] Furthermore, in step (1), the solvent used for dissolving is any one of toluene, acetonitrile and dichloromethane.

[0015] Furthermore, the solvent used for dissolution is toluene.

[0016] 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.

[0017] Furthermore, the eluent used for purification is a mixed solvent prepared by petroleum ether and dichloromethane in a volume ratio of 2:1.

[0018] The present invention provides an application of the above-mentioned pyrroloquinoxaline-triphenylamine electroactive material in preparing an electrochromic device, wherein the electrochromic device uses the pyrroloquinoxaline-triphenylamine electroactive material as an electrochromic layer.

[0019] Furthermore, the concentration of the pyrroloquinoxaline-triphenylamine electroactive material is 2.0×10 -3 mol / L~1×10 -5 mol / L.

[0020] Furthermore, the electrochromic device adopts a sandwich structure, a liquid cavity is constructed between two layers of ITO-covered glass plates, and the electrochromic active material is placed in the sandwich cavity to obtain the electrochromic device.

[0021] Furthermore, the resistance of the ITO glass is 10-15 Ω / square.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a pyrroloquinoxaline-triphenylamine electroactive material. The pyrroloquinoxaline-triphenylamine electroactive material can effectively improve the stability of free radicals by introducing pyrroloquinoxaline groups. The nitrogen heterocyclic structure in the pyrroloquinoxaline groups reduces the reactivity of free radicals through electronic conjugation effect and steric effect, thereby reducing the occurrence of polymerization reaction, which helps to maintain the molecular structure stability of the material and can also reduce the performance degradation and service life shortening of the material caused by polymerization reaction. The stability is regulated by changing the spin density of aromatic amine cation free radicals. Methyl-terminated diphenylamine is used as a donor structure, and 4-arylpyrrolo[1,2- α ] Quinoxaline is used as the acceptor structure, and a DA-type molecular structure regulated by isomers and substituents at different positions is designed to ensure that the neutral state of the material presents a light-colored state. The spin density of the aromatic amine nitrogen cation radical is dispersed through different degrees of conjugation between the acceptor and the donor, thereby improving the stability, providing a reference for neutral state colorless small molecule electrochromic materials; by combining pyrroloquinoxaline with triphenylamine to form a DA-type molecular structure, intramolecular charge transfer can be achieved, thereby improving the photoelectric response speed of the material; 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 range, and improving the photoelectric conversion efficiency.

[0023] Furthermore, the optical band 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; the pyrroloquinoxaline-triphenylamine electroactive materials (Formula 3 and Formula 4) can form cationic free radicals when reacting with copper perchlorate, and the EPR spectrum further confirms the formation of cationic free radicals, which indicates that the pyrroloquinoxaline-triphenylamine electroactive materials provided by the present invention have the characteristic of forming cationic free radicals; the electrochromic device prepared using the same exhibits good electrochromic performance; the maximum transmittance at 700 nm and 675 nm is 42% and 39%, the coloring time is 8.2 s and 13 s, and the fading time is 60 s and 24 s, respectively; the coloring efficiency of the electrochromic device is 609.6 cm 2 / C and 269.8 cm 2 / C.

[0024] The present invention provides a method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material. Through reasonable molecular design, the photoelectric performance, electrochromic performance and cycle stability of the pyrroloquinoxaline-triphenylamine electroactive material are significantly improved. The synthesis method is simple and has good repeatability, and has broad application prospects and important research value.

[0025] The present invention provides an application of a pyrroloquinoxaline-triphenylamine electroactive material in the preparation of an electrochromic device. The electrochromic device prepared using the pyrroloquinoxaline-triphenylamine electroactive material of the present invention has significant electrochromic performance, reasonable coloring and fading time, excellent cycle stability and high coloring efficiency, so that the material has a wide range of application prospects in the field of electrochromism, such as displays, smart windows, electronic paper, etc. At the same time, by regulating the structure of the material, its performance can be further optimized to meet the needs of different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The ultraviolet spectra of the pyrroloquinoxaline-triphenylamine electroactive material molecules of Example 1 (Formula 3) and Example 2 (Formula 4) of the present invention; Figure 2 The cyclic voltammogram of the pyrroloquinoxaline-triphenylamine electroactive material molecule of Example 1 (Formula 3) of the present invention; Figure 3 The cyclic voltammogram of the pyrroloquinoxaline-triphenylamine electroactive material molecule of Example 2 (Formula 4) of the present invention; Figure 4 This is a test spectrum of ion free radical characteristics of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) of the present invention; Figure 5 This is a test spectrum of ion free radical characteristics of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) of the present invention; Figure 6 This is an electron paramagnetic resonance spectrum of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) of the present invention; Figure 7 This is an electron paramagnetic resonance spectrum of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) of the present invention; Figure 8 This is a test spectrum of the color change phenomenon of the electrochromic device of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) of the present invention; Fig. 9 This is a test spectrum of the color change phenomenon of the electrochromic device of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) of the present invention; Fig.10 Graph showing the coloring time (Tc) and fading time (Tb) of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) of the present invention; Fig.11 Graph showing the coloring time (Tc) and fading time (Tb) of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) of the present invention; Fig.12This is a test diagram of the cycle stability of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) of the present invention; Fig.13 This is a test diagram of the cycle stability of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) of the present invention; Fig.14 This is a coloring efficiency diagram of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) of the present invention; Fig.15 This is a coloring efficiency diagram of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) of the present invention. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings: 1. Implementation Example 1 This embodiment provides a pyrroloquinoxaline-triphenylamine electroactive material, and the specific preparation process is as follows: (1) Preparation of Compound 1 (7-bromo-4-phenylpyrrolo[1,2-α]quinoxaline) 5-Bromo-2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 795 mg) and 4-bromobenzaldehyde (3.0 mmol, 1.0 equivalent, 555 mg) were weighed respectively, and ethanol (10 mL) was added into a round-bottom flask (25 mL) in sequence; after adding acetic acid (0.6 mmol, 36 mg, 0.2 equivalent), a reaction mixture was obtained; the reaction mixture was heated to 85°C and stirred for 12 hours. After the reaction was completed, the solvent was evaporated under reduced pressure to obtain a crude product, which was purified by silica gel column chromatography (the eluent was petroleum ether and dichloromethane in a volume ratio of 1:2) to obtain compound 1 (7-bromo-4-phenylpyrrolo[1,2-α]quinoxaline).

[0029] The structural formula of compound 1 is: .

[0030] (2) Preparation of pyrroloquinoxaline-triphenylamine electroactive materials In a glove box under nitrogen atmosphere, compound 1 (7-bromo-4-phenylpyrrolo[1,2-α]quinoxaline, 0.5 mmol, 164 mg) obtained in step (1), 4,4'-dimethyldiphenylamine (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), the above raw materials were mixed and transferred to a dry sealed tube, nitrogen was introduced into the sealed tube, and 10 mL of toluene was used as a reaction solvent to obtain a reaction mixture; the sealed tube was placed in an oil bath preheated to 100°C, the reaction mixture was heated and stirred for 8 hours to obtain a reaction mixture; after the reaction was completed, the sealed tube was taken out from the oil bath, cooled naturally to room temperature, saturated brine was added to the cooled reaction mixture for dilution, and a separatory funnel was used to extract the aqueous phase three times with 20 mL of dichloromethane, after each extraction, the separatory funnel was fully shaken, the layers were allowed to stand, and then the organic phase was separated, the organic phases obtained by the three extractions were combined, anhydrous sodium sulfate Na2SO4 was added to the combined organic phase, and dried for 5 hours; the dried organic phase was transferred to a rotary evaporator, and the dichloromethane solvent was removed under reduced pressure; the residual solid after the solvent was removed under reduced pressure was purified by silica gel column chromatography (the volume ratio of the eluent was petroleum ether: dichloromethane = 1:2), and concentrated under reduced pressure to obtain a light yellow solid, which was the pyrroloquinoxaline-triphenylamine electroactive material, with a yield of 85%.

[0031] The physicochemical characterization data of the corresponding pyrroloquinoxaline-triphenylamine electroactive materials are shown below: 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). 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. HRMS-ESI (m / z) Theoretical: C 31 H 26 N3[M+H] + : 440.2121; Experiment: 440.2080. The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material is determined as follows: .

[0032] Example 2 This embodiment provides a pyrroloquinoxaline-triphenylamine electroactive material, and the specific preparation process is as follows: (1) Preparation of compound 1 (4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline) 2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 487 mg) and 3-bromobenzaldehyde (3.0 mmol, 1.0 equivalent, 555 mg) were weighed respectively, and ethanol (10 mL) was added into a round-bottom flask (25 mL) in sequence; acetic acid (0.6 mmol, 36 mg, 0.2 equivalent) was added at the same time to obtain a reaction mixture; the reaction mixture was heated to 85 °C and stirred for 12 hours. After the reaction was completed, the solvent was evaporated under reduced pressure to obtain a crude product, which was purified by silica gel column chromatography (eluent: petroleum ether: dichloromethane in a volume ratio of 1:2) to obtain compound 1 (4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline).

[0033] The structural formula of compound 1 is: .

[0034] (2) Preparation of pyrroloquinoxaline-triphenylamine electroactive materials In a glove box under nitrogen atmosphere, compound 1 (4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline, 0.5 mmol, 163 mg) obtained in step (1), di(4-methylphenyl)amine (0.5 mmol, 1.1 equiv., 99 mg) and Cs2CO3 (324 mg, 1.0 mmol, 2 equiv.) were weighed, and toluene (10 mL) was added. The above raw materials were placed in a round-bottom flask, which was sealed and connected to a magnetic stirrer. Stirring was started to fully dissolve the reactants to obtain a mixture. Pd2(dba)3 (0.015 mmol, 0.03 equiv., 14 mg) and XPhos (0.06 mmol, 0.12 equiv., 28.6 mg), obtain a reaction mixture, heat the reaction mixture to 100°C for reaction, 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 with dichloromethane three times to fully extract the product in the organic phase, and combine all organic phases; dry the organic layer with anhydrous magnesium sulfate, filter to remove the magnesium sulfate solid, and concentrate the organic phase on a rotary evaporator to obtain a crude product; purify the crude product by silica gel column chromatography (eluent is petroleum ether and dichloromethane in 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.

[0035] The corresponding physicochemical identification data of the pyrroloquinoxaline-triphenylamine electroactive material are as follows: 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, 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). 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. HRMS-ESI (m / z) Theoretical: C 31 H 26 N3[M+H] + : 440.2121; Experiment: 440.2084. The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material is determined as follows: .

[0036] Example 3 This embodiment provides a pyrroloquinoxaline-triphenylamine electroactive material, which is specifically prepared as follows: (1) Preparation of Compound 1 (7-bromo-4-phenylpyrrolo[1,2-α]quinoxaline) 5-Bromo-2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 795 mg) and benzaldehyde (3.0 mmol, 1.0 equivalent, 318 mg) were weighed respectively, and ethanol (10 mL) was added into a round-bottom flask (25 mL) in sequence; after adding acetic acid (0.6 mmol, 36 mg, 0.2 equivalent), a reaction mixture was obtained; the reaction mixture was heated to 85°C and stirred for 12 hours to react. After the reaction was completed, the solvent was evaporated under reduced pressure to obtain a crude product, which was purified by silica gel column chromatography (the eluent was petroleum ether and dichloromethane in a volume ratio of 1:2) to obtain compound 1 (7-bromo-4-phenylpyrrolo[1,2-α]quinoxaline).

[0037] The structural formula of compound 1 is: .

[0038] (2) Preparation of pyrroloquinoxaline-triphenylamine electroactive materials In a glove box under nitrogen atmosphere, 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), the above raw materials were mixed and transferred to a dry sealed tube, nitrogen was introduced into the sealed tube, 10 mL of toluene was added to the sealed tube as a reaction solvent to obtain a reaction mixture; the sealed tube was placed in a preheated to 100 ∘ C, heating and stirring the reaction mixture for 8 hours to obtain a reaction mixture; after the reaction is completed, taking out the sealed tube from the oil bath, cooling it naturally to room temperature, adding saturated brine to the cooled reaction mixture for dilution, using a separatory funnel, extracting the aqueous phase three times with 20 mL of dichloromethane, fully shaking the separatory funnel after each extraction, standing to separate the layers, and then separating the organic phase, combining the organic phases obtained by the three extractions, adding anhydrous sodium sulfate Na2SO4 to the combined organic phase and drying it for 5 h; transferring the dried organic phase to a rotary evaporator, and removing the dichloromethane solvent under reduced pressure; purifying the residual solid after removing the solvent under reduced pressure by silica gel column chromatography (the eluent is petroleum ether: dichloromethane in a volume ratio of 1:2), and concentrating under reduced pressure to obtain a light yellow solid pyrroloquinoxaline-triphenylamine electroactive material with a yield of 88%.

[0039] The physicochemical characterization data of the corresponding pyrroloquinoxaline-triphenylamine electroactive materials are shown below: 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). 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. HRMS-ESI (m / z) Theoretical: C 29 H 22 N3[M+H] + : 412.1814; Experiment: 412.1988. The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material is determined as follows: .

[0040] Example 4 This embodiment provides a pyrroloquinoxaline-triphenylamine electroactive material, which is specifically prepared as follows: (1) Preparation of compound 1 (4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline) 2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 487 mg) and 3-bromobenzaldehyde (3.0 mmol, 1.0 equivalent, 555 mg) were weighed respectively, and ethanol (10 mL) was added into a round-bottom flask (25 mL) in sequence; acetic acid (0.6 mmol, 36 mg, 0.2 equivalent) was added at the same time to obtain a reaction mixture; the reaction mixture was heated to 85 °C and stirred for 12 hours. After the reaction was completed, the solvent was evaporated under reduced pressure to obtain a crude product, which was purified by silica gel column chromatography (the eluent was petroleum ether and dichloromethane in a volume ratio of 1:2) to obtain compound 1 (4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline).

[0041] The structural formula of compound 1 is: .

[0042] (2) Preparation of pyrroloquinoxaline-triphenylamine electroactive materials In a glove box under nitrogen atmosphere, compound 1 obtained in step (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.), 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 transferred to a dry sealed tube, nitrogen was introduced into the sealed tube, 10 mL of toluene was added to the sealed tube as a reaction solvent to obtain a reaction mixture; the sealed tube was placed in an oil bath preheated to 100 ° C, the reaction mixture was heated and stirred for 8 hours to obtain a reaction mixture; after the reaction was completed, the sealed tube was taken out from the oil bath, cooled naturally to room temperature, saturated brine was added to the cooled reaction mixture for dilution, and a separatory funnel was used to extract the aqueous phase three times with 20 mL of dichloromethane. After each extraction, the separatory funnel was fully shaken, the layers were allowed to stand, and then the organic phase was separated, the organic phases obtained from the three extractions were combined, anhydrous sodium sulfate Na2SO4 was added to the combined organic phase and dried 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 the solvent was removed under reduced pressure was purified by silica gel column chromatography (the eluent was petroleum ether and dichloromethane in a volume ratio of 1:2), and concentrated under reduced pressure to obtain 158 mg of white solid product with a yield of 71%, which is the pyrroloquinoxaline-triphenylamine electroactive material.

[0043] The physicochemical identification data of the pyrroloquinoxaline-triphenylamine electroactive material are as follows: 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). 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. HRMS-ESI (m / z) Theoretical: C 29 H 22 N3[M+H] + : 412.1814; Experimental: 412.1897. The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material is determined as follows: .

[0044] Example 5 This embodiment provides a pyrroloquinoxaline-triphenylamine electroactive material, which is specifically prepared as follows: (1) Preparation of compound 1 (7-bromo-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline) 5-Bromo-2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 795 mg) and 3-bromobenzaldehyde (3.0 mmol, 1.0 equivalent, 555 mg) were weighed respectively, and ethanol (10 mL) was added into a round-bottom flask (25 mL) in sequence; after adding acetic acid (0.6 mmol, 36 mg, 0.2 equivalent), a reaction mixture was obtained; the reaction mixture was heated to 85°C and stirred for 12 hours. After the reaction was completed, the solvent was evaporated under reduced pressure to obtain a crude product, which was purified by silica gel column chromatography (the eluent was petroleum ether and dichloromethane in a volume ratio of 1:2) to obtain compound 1 (7-bromo-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline).

[0045] The structural formula of compound 1 is: .

[0046] (2) Preparation of pyrroloquinoxaline-triphenylamine electroactive materials Weigh the compound 1 (7-bromo-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline, 0.5 mmol, 202 mg) obtained in step (1), 4,4'-dimethyldiphenylamine (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), the above raw materials were mixed and transferred to a dry sealed tube, nitrogen was introduced into the sealed tube, 10 mL of toluene was added to the sealed tube as a reaction solvent to obtain a reaction mixture; the sealed tube was placed in an oil bath preheated to 100°C, the reaction mixture was heated and stirred for 8 hours to obtain a reaction mixture; after the reaction was completed, the sealed tube was taken out from the oil bath, naturally cooled to room temperature, saturated brine was added to the cooled reaction mixture for dilution, a separatory funnel was used to extract the aqueous phase three times with 20 mL of dichloromethane, after each extraction, the separatory funnel was fully shaken, the layers were allowed to stand, and then the organic phase was separated, the organic phases obtained by the three extractions were combined, anhydrous sodium sulfate Na2SO4 was added to the combined organic phase, and dried 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 the solvent was removed under reduced pressure was purified by silica gel column chromatography (the eluent was petroleum ether and dichloromethane in a volume ratio of 1:2), and concentrated under reduced pressure to obtain a light yellow solid, which was the pyrroloquinoxaline-triphenylamine electroactive material, with a yield of 85%.

[0047] The corresponding physicochemical identification data of the pyrroloquinoxaline-triphenylamine electroactive material are as follows: 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). 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. HRMS-ESI (m / z) Theoretical: C 31 H 25 BrN3[M+H] + : 518.1232; Experimental: 518.1180. The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material is determined as follows: .

[0048] Example 6 This embodiment provides a pyrroloquinoxaline-triphenylamine electroactive material, which is specifically prepared as follows: (1) Preparation of compound 1 (7-bromo-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline) 5-Bromo-2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 795 mg) and 3-bromobenzaldehyde (3.0 mmol, 1.0 equivalent, 555 mg) were weighed respectively, and ethanol (10 mL) was added into a round-bottom flask (25 mL) in sequence; after adding acetic acid (0.6 mmol, 36 mg, 0.2 equivalent), a reaction mixture was obtained; the reaction mixture was heated to 85°C and stirred for 12 hours. After the reaction was completed, the solvent was evaporated under reduced pressure to obtain a crude product, which was purified by silica gel column chromatography (the eluent was petroleum ether and dichloromethane in a volume ratio of 1:2) to obtain compound 1 (7-bromo-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline).

[0049] The structural formula of compound 1 is: .

[0050] (2) Preparation of pyrroloquinoxaline-triphenylamine electroactive materials In a glove box under nitrogen atmosphere, compound 1 (7-bromo-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline, 0.5 mmol, 202 mg) obtained in step (1), di(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), the round-bottom flask was sealed and connected to a magnetic stirrer, stirring was started to fully dissolve the reactants to obtain a mixture; under nitrogen protection, 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 obtain a reaction mixture; the reaction mixture was heated to 100°C for reaction, and the reaction progress was monitored by thin layer chromatography (TLC) until the reaction was completed; after the reaction was completed, it was cooled to room temperature and quenched with ice brine; dichloromethane was used for extraction 3 times to fully extract the product in the organic phase, and all organic phases were combined; the organic layer was dried over anhydrous magnesium sulfate, the magnesium sulfate solid was removed by suction filtration, and the organic phase was concentrated on a rotary evaporator to obtain a crude product; the crude product was purified by silica gel column chromatography (the eluent was petroleum ether and dichloromethane in a volume ratio of 1:2), the eluate containing the target product was collected, and concentrated to obtain 158 mg of a white solid product with a yield of 75%, which was the pyrroloquinoxaline-triphenylamine electroactive material.

[0051] The physicochemical identification data of the pyrroloquinoxaline-triphenylamine electroactive material are as follows: 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). 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. HRMS-ESI (m / z) Theoretical: C 31 H 25 BrN3[M+H] + : 518.1232; Experimental: 518.1196. The structural formula of the white solid is determined as follows: .

[0052] Example 7 This embodiment provides a pyrroloquinoxaline-triphenylamine electroactive material, which is specifically prepared as follows: (1) Preparation of compound 1 (7-bromo-4-(3'-methylphenyl)pyrrolo[1,2-α]quinoxaline) 5-Bromo-2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 795 mg) and 3-methylbenzaldehyde (3.0 mmol, 1.0 equivalent, 360 mg) were weighed respectively, and ethanol (10 mL) was added into a round-bottom flask (25 mL) in sequence; after adding acetic acid (0.6 mmol, 36 mg, 0.2 equivalent), a reaction mixture was obtained; the reaction mixture was heated to 85°C and stirred for 12 hours. After the reaction was completed, the solvent was evaporated under reduced pressure and purified by silica gel column chromatography (the eluent was petroleum ether and dichloromethane in a volume ratio of 1:2) to obtain compound 1 (7-bromo-4-(3'-methylphenyl)pyrrolo[1,2-α]quinoxaline).

[0053] The structural formula of compound 1 is:

[0054] (2) Preparation of pyrroloquinoxaline-triphenylamine electroactive materials In a glove box under nitrogen atmosphere, compound 1 (7-bromo-4-(3'-methylphenyl)pyrrolo[1,2-α]quinoxaline, 0.5 mmol, 169 mg) obtained in step (1) and 4,4'-dimethyldiphenylamine (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), mixed and transferred to a dry sealed tube, nitrogen was passed through the sealed tube, 10 mL of toluene was added to the sealed tube as a reaction solvent to obtain a reaction mixture; the sealed tube was placed in an oil bath preheated to 100 °C, the reaction mixture was heated and stirred for 8 hours to obtain a reaction mixture; after the reaction was completed, the sealed tube was taken out from the oil bath, cooled naturally to room temperature, saturated brine was added to the cooled reaction mixture for dilution, a separatory funnel was used to extract the aqueous phase three times with 20 mL of dichloromethane, after each extraction, the separatory funnel was fully shaken, the layers were allowed to stand, and then the organic phase was separated, the organic phases obtained by the three extractions were combined, anhydrous sodium sulfate Na2SO4 was added to the combined organic phase, and dried 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 the solvent was removed under reduced pressure was purified by silica gel column chromatography (the eluent was petroleum ether and dichloromethane in a volume ratio of 1:2), and concentrated under reduced pressure to obtain a light yellow solid, which was the pyrroloquinoxaline-triphenylamine electroactive material, with a yield of 83%.

[0055] The physicochemical characterization data of the corresponding pyrroloquinoxaline-triphenylamine electroactive materials are shown below: 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). 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. HRMS-ESI (m / z) Theoretical: C 32 H 28 N3[M+H] + : 454.2283; Experiment: 454.2189. The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material is determined as follows: .

[0056] Example 8 This embodiment provides a pyrroloquinoxaline-triphenylamine electroactive material, which is specifically prepared as follows: (1) Preparation of Compound 1 (7-methyl-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline) 5-Methyl-2-(1H-pyrrol-1-yl)aniline (3.0 mmol, 517 mg) and 3-bromobenzaldehyde (3.0 mmol, 1.0 equivalent, 555 mg) were weighed respectively, and ethanol (10 mL) was added into a round-bottom flask (25 mL) in sequence; after adding acetic acid (0.6 mmol, 36 mg, 0.2 equivalent), a reaction mixture was obtained; the reaction mixture was heated to 85 °C and stirred for 12 hours to react. After the reaction was completed, the solvent was evaporated under reduced pressure and purified by silica gel column chromatography (the eluent was petroleum ether and dichloromethane in a volume ratio of 1:2) to obtain compound 1 (7-methyl-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline).

[0057] The structural formula of compound 1 is:

[0058] (2) Preparation of pyrroloquinoxaline-triphenylamine electroactive materials In a glove box under nitrogen atmosphere, compound 1 (7-methyl-4-(3'-bromophenyl)pyrrolo[1,2-α]quinoxaline, 0.5 mmol, 169 mg) obtained in step (1), di(4-methylphenyl)amine (0.5 mmol, 1.1 equiv., 99 mg) and Cs2CO3 (324 mg, 1.0 mmol, 2 equiv.) were weighed, and toluene (10 mL) was added to a dry round-bottom flask. The round-bottom flask was sealed and connected to a magnetic stirrer, and stirring was started to fully dissolve the reactants to obtain a mixture. Pd2(dba)3 (0.015 mmol, 0.03 equiv., 10 mg) and XPhos (0.06 mmol, 0.12 equiv., 2.85 mg), obtain a reaction mixture, heat the reaction mixture to 100°C for reaction, 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 with dichloromethane three times to fully extract the product in the organic phase, and combine all organic phases; dry the organic layer with anhydrous magnesium sulfate, filter to remove the magnesium sulfate solid, and concentrate the organic phase on a rotary evaporator to obtain a crude product; purify the crude product by silica gel column chromatography (eluent is petroleum ether and dichloromethane in a volume ratio of 1:2), collect the eluent 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.

[0059] The physicochemical identification data of the pyrroloquinoxaline-triphenylamine electroactive material are as follows: 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), 7.46 (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, 8H), 6.79 (dd, J= 4.1, 1.2 Hz, 1H), 6.76(dd, J = 4.1, 2.6 Hz, 1H), 2.8 (s, 3H), 2.32 (s, 6H). 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. HRMS-ESI (m / z) Theoretical: C 32 H 28 N3[M+H] + : 454.2283; Experiment: 454.2221. The structural formula of the pyrroloquinoxaline-triphenylamine electroactive material is determined as follows: .

[0060] 2. Electrochemical properties test Based on Examples 1 to 8, the performance of the pyrroloquinoxaline-triphenylamine electroactive material prepared by the present invention was tested.

[0061] 1. UV-visible absorption spectrum test In this experiment, the pyrroloquinoxaline-triphenylamine electroactive materials prepared in Examples 1 and 2 were subjected to UV-visible absorption spectroscopy test. The UV-visible spectra of the pyrroloquinoxaline-triphenylamine electroactive materials in Example 1 (Formula 3) and the pyrroloquinoxaline-triphenylamine electroactive materials in Example 2 (Formula 4) in solution were as follows: Figure 1 shown.

[0062] By the attached Figure 1 The data show that the main absorption peak of the pyrroloquinoxaline-triphenylamine electroactive material in Example 1 (Formula 3) is 311 nm, which belongs to π-π* The absorption at 410 nm is attributed to n-π* Transition; Example 2 (Formula 4) The main absorption peaks of the pyrroloquinoxaline-triphenylamine electroactive material are located at 277 nm and 296 nm, which are respectively attributed to the pyrroloquinoxaline fragment (PQ) and the donor DPA skeleton π-π*The absorption generated by the transition, at the same time, the absorption curve of the pyrroloquinoxaline-triphenylamine electroactive material in Example 2 (Formula 4) has a shoulder peak at 358 nm, which belongs to the PQ fragment n-π* Absorption generated; Comparing the pyrroloquinoxaline-triphenylamine electroactive materials prepared in Example 1 and Example 2, since the degree of conjugation of DPA and PQ in the pyrroloquinoxaline-triphenylamine electroactive material in Example 1 (Formula 3) is higher, therefore, n-π* The transition red shifts to 410 nm, so the pyrroloquinoxaline-triphenylamine electroactive material solution of Example 1 (Formula 3) appears light yellow, while the pyrroloquinoxaline-triphenylamine electroactive material solution of Example 2 (Formula 4) appears colorless. In addition, using the formula E g = 1240 / λ onset The optical energy gaps of the two compounds were calculated. The optical energy gaps of the pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 (Formula 3) and Example 2 (Formula 4) were 2.70 eV and 3.08 eV, respectively. This further illustrates that in the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3), the degree of conjugation between the donor DPA and PQ is stronger.

[0063] 2. Cyclic voltammetry test In this experiment, cyclic voltammetry was performed on the pyrroloquinoxaline-triphenylamine electroactive materials of Examples 1 and 2. The specific results are shown in the attached Figure 2~3 shown.

[0064] Acetonitrile was used as solvent, tetrabutylammonium hexafluorophosphate was used as electrolyte (concentration was 0.1 mol / L), a three-electrode system (Pt wire as working electrode, Pt sheet as auxiliary electrode, Ag / AgCl as reference electrode) was used, ferrocene was used as reference material, the scan rate was set to 100 mV / s, and the concentration of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) or Example 2 (Formula 4) was tested to be 1.0×10 -3 mol / L, the cyclic voltammetry curves of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) and the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) are as follows Figure 2~Figure 3 shown.

[0065] By the attached Figure 2-Figure 3 The data show that the pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 (Formula 3) and Example 2 (Formula 4) both produce two pairs of redox peaks. The first oxidation peak of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) is 0.946 V (E HOMO =-5.22 eV), the first oxidation peak of the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) is 1.006 V (EHOMO =-5.28 eV), these two peaks correspond to the process in which the lone pair of electrons on the nitrogen atom in diphenylamine is oxidized to nitrogen cation free radicals, and this process is reversible, that is, the oxidized substance can be reduced to its original state during reverse scanning; the second oxidation peak of the pyrroloquinoxaline-triphenylamine electroactive material in Example 1 (Formula 3) is 1.143 V, and the second oxidation peak of the pyrroloquinoxaline-triphenylamine electroactive material in Example 2 (Formula 4) is 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 in Example 1 and Example 2, due to the difference in the degree of conjugation caused by their isomerization at different positions, the nitrogen charge density of diphenylamine in the pyrroloquinoxaline-triphenylamine electroactive material in Example 2 (Formula 4) is lower, which makes its first oxidation peak position move 60 mV to the right compared with the pyrroloquinoxaline-triphenylamine electroactive material in Example 1 (Formula 3). This shift reflects the effect of isomers on the redox properties of the substance and also illustrates the importance of the degree of conjugation on the electrochemical properties of the substance.

[0066] 3. Cationic free radical characteristics test In this experiment, the pyrroloquinoxaline-triphenylamine electroactive material obtained in Examples 1 and 2 was tested for its cationic free radical properties. Figures 4 and 5 shown.

[0067] In acetonitrile solution, different equivalents of copper perchlorate were used as an oxidant to react with the pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 (Formula 3) and Example 2 (Formula 4), respectively, and the changes were recorded by UV-visible spectroscopy and electron paramagnetic resonance (EPR) spectroscopy. The results are shown in the attached Figures 4 and 5 As shown. For the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3), as the copper perchlorate equivalent increases from 0.0 equiv. Increased to 2.0 equiv. , the absorption of the pyrroloquinoxaline-triphenylamine electroactive material at 311 nm gradually decreased, new characteristic absorption peaks appeared at 353 nm and 700 nm, and the color of the solution changed from light yellow to dark blue-green; for the pyrroloquinoxaline-triphenylamine electroactive material in Example 2 (Formula 4), its absorption at 277 nm and 296 nm gradually decreased, new characteristic absorption peaks appeared at 346 nm and 676 nm, and 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 aromatic amine cationic free radicals. π-π* When copper perchlorate changes from 1.0 equiv. Increased to 2.0 equiv.When , the intensity of the newly generated absorption peak hardly changes, indicating that the stoichiometric ratio of the pyrroloquinoxaline-triphenylamine electroactive material and copper perchlorate is 1:1, and the diphenylamine nitrogen in the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) and the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) respectively forms corresponding cation radicals, and the divalent copper ions are converted into monovalent copper ions. In order to further confirm the formation of nitrogen cation radicals, the electron paramagnetic resonance spectrum of the reaction of the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) or Example 2 (Formula 4) with copper perchlorate in a stoichiometric ratio of 1:1 was recorded in acetonitrile solution, see the attached Figures 6 and 7 As shown in Figure 2, obvious EPR signals were observed in the range of 3330-3480 G. The cation radicals of the pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 (Formula 3) and Example 2 (Formula 4) g The factor is 2.001, which is consistent with the g The experimental results show that the pyrroloquinoxaline-triphenylamine electroactive material (Formula 3 and Formula 4) can form cationic free radicals when reacting with copper perchlorate, and the EPR spectrum further confirms the formation of cationic free radicals, which indicates that the pyrroloquinoxaline-triphenylamine electroactive material provided by the present invention has the characteristic of forming cationic free radicals, which is of great significance for understanding its photoelectric properties and potential applications.

[0068] 3. Application Examples On the basis of Examples 1 to 8, an electrochromic device was prepared using the pyrroloquinoxaline-triphenylamine electroactive material prepared in Examples 1 to 2, as follows: 1. Preparation of electrochromic devices Raw materials: ITO glass (resistance is 10 Ω / square), multimeter, tweezers, scissors, syringe, 3M double-sided tape, UV curing adhesive, copper sticker; pyrroloquinoxaline-triphenylamine electroactive material prepared in Example 1 (Formula 3) or Example 2 (Formula 4); 0.1 mol / L acetonitrile solution of tetrabutylammonium hexafluorophosphonate.

[0069] A sandwich structure is used to construct a liquid cavity between two layers of ITO-covered glass plates, and the electrochromic active material is placed in the interlayer cavity to obtain an electrochromic device. The specific preparation process is as follows: ITO glass (2.0 cm×4.0 cm) is ultrasonically cleaned in acetone for thirty minutes and purged with nitrogen; a liquid groove is constructed on one of the ITO glasses using 3M double-sided tape and combined with another ITO glass to obtain an ITO interlayer containing 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) is added to a 0.1 mol / L acetonitrile solution of tetrabutylammonium hexafluorophosphonate to prepare a molar concentration of 2.0×10 -3 mol / L solution, injecting the solution into the liquid cavity to obtain a liquid electrochromic device.

[0070] 2. Liquid electrochromic device performance test The electrochemical workstation was connected in series with the in-situ UV-visible absorption spectrum, and the absorption spectrum of the obtained liquid electrochromic device was tested at different voltages. The results are shown in the attached Figures 8 and 9 When different positive voltages are applied, the pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 (Formula 3) and Example 2 (Formula 4) produce new maximum absorption peaks at 700 nm and 675 nm, respectively; as the voltage increases, the absorption continues to increase, which belongs to the absorption generated by the oxidation of the two pyrroloquinoxaline-triphenylamine electroactive materials from the neutral state to the cationic free radicals (Formula 3→Formula 3 + · and formula 4 → formula 4 + ·), which is also consistent with the absorption produced by copper perchlorate oxidation. A voltage of 2.5 V was applied to the liquid electrochromic device prepared using the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3), and the liquid electrochromic device changed from the original yellow state to the dark green state. When a voltage of -0.1 V was applied, the liquid electrochromic device recovered from the dark green state to the original yellow state. A liquid electrochromic device prepared using the pyrroloquinoxaline-triphenylamine electroactive material of Example 2 (Formula 4) was applied with a voltage of 2.2 V, and the liquid electrochromic device changed from the original colorless state to the blue state. When a voltage of -0.1 V was applied, the liquid electrochromic device recovered 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 exhibited good electrochromic properties.

[0071] Coloring time refers to the time required for the color-changing material to change from a neutral state to a colored state; while fading time refers to the time required for the color-changing material to return to a neutral state from a colored state. Generally, the coloring / fading time is the time required for the transmittance to reach 90% of the maximum transmittance difference before and after the color change. Cyclic stability refers to the number of cycles of the device between the colored state and the faded state. 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 charge required for color change, and the more energy-efficient it is. For further investigation of the coloring time (Tc) and fading time (Tb) of the above two liquid electrochromic devices, see Fig.10 and Fig.11 The liquid electrochromic device prepared by the pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 (Formula 3) and Example 2 (Formula 4) has a maximum transmittance of 42% and 39% at 700 nm and 675 nm, respectively, a coloring time of 8.2 s and 13 s, and a fading time of 60 s and 24 s, respectively. It can be seen that the liquid electrochromic device prepared by the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) has a faster coloring time, indicating that the formation speed of its cationic radicals is faster. Fig.12 and Fig.13 The cycle stability test of the liquid electrochromic devices prepared from the two pyrroloquinoxaline-triphenylamine electroactive materials of Example 1 and Example 2 was carried out. 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 of spin density by positional isomerism can regulate the stability of cation radicals, thereby affecting the cycle stability of the material. See Appendix Fig.14 and attached Fig.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 cm 2 / C, indicating that the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) has higher coloring efficiency, consumes less charge in the color changing process, and is more energy-efficient. In summary, the pyrroloquinoxaline-triphenylamine electroactive material of Example 1 (Formula 3) performs better in coloring time, cycle stability, and coloring efficiency, and is a more promising electrochromic material.

[0072] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A pyrroloquinoxaline-triphenylamine electroactive material, characterized in that: It has a structure shown in Formula 1 or Formula 2: ； ； Wherein, 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.

2. A pyrroloquinoxaline-triphenylamine electroactive material according to claim 1, characterized in that: Including a structure shown in any one of Formula 3 to Formula 10: 。 3. A method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to any one of claims 1 to 2, 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.

4. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 3, 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.

5. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 4, 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.

6. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 3, characterized in that: In step (1), the molar ratio of compound 1 to compound 2 is 1: (1-1.6).

7. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 3, 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.

8. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 3, characterized in that: In step (1), the reaction temperature is 80°C to 120°C.

9. The method for synthesizing a pyrroloquinoxaline-triphenylamine electroactive material according to claim 3, 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.

10. Use of a pyrroloquinoxaline-triphenylamine electroactive material according to any one of claims 1 to 2 in the preparation of an electrochromic device, characterized in that: The electrochromic device uses the pyrroloquinoxaline-triphenylamine electroactive material as an electrochromic layer.

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