Preparation and application of polyanthraquinone thiophene film

Abstract

The invention discloses preparation and application of a poly-anthraquinone thiophene film, the prepared film material can be used as a novel electrochromic material, and belongs to the field of intelligent discoloration, and the anthraquinone thiophene material is simple in synthetic route, mild in condition and low in cost. A novel D-A type monomer is synthesized by taking anthraquinone as an electron acceptor and thiophene derivatives as electron donors, and the monomer can be used for preparing a polymer film through electrochemical polymerization.

Description

Technical field:

[0001] The present invention belongs to the field of intelligent color change, and specifically relates to an organic small molecule monomer with anthraquinone as the core and the preparation of a polymer film thereof Background technology:

[0002] Electrochromism is a phenomenon in which the optical properties of a material change and cause macroscopic color changes due to charge intercalation or electrochemical oxidation when an external voltage is applied. The main application areas of electrochromism include smart windows for energy-saving buildings, electronic displays, electronic paper, energy storage, etc. Electrochromic materials can be divided into inorganic electrochromic materials, organic electrochromic materials and inorganic-organic hybrid electrochromic materials. Among them, organic electrochromic materials have been widely studied for their advantages such as low redox potential, high coloring efficiency, fast response time and flexibility.

[0003] Anthraquinone (AQ) is a three-membered fused ring system with two keto groups on the central six-membered ring, sandwiched between two benzene rings. It is mainly used in the field of dye preparation. Donor-acceptor (DA) polymers with AQ structure and used for electrochromic have not received due attention. Thiophene and its derivatives are a class of efficient electron donors, which are often introduced into organic conjugated DA polymers with excellent optical and electrical properties. Summary of the invention:

[0004] The present invention uses anthraquinone as the core, designs a new type of DA-type molecule through Stille coupling reaction, and prepares a polymer film with electrochromic properties through electrochemical polymerization. The synthetic route is simple, the conditions are mild, and the cost is low.

[0005] The present invention provides an organic small molecule monomer AQTh-EDOT with anthraquinone as the core, and its chemical structure is as shown in formula (I):

[0006]

[0007] The synthesis method of an organic small molecule monomer AQTh-EDOT with anthraquinone as the core is as follows: 2,6-dibromoanthraquinone undergoes a Stille coupling reaction with 2-tinbutyl-3-n-hexylthiophene to generate an intermediate 1, then undergoes a bromination reaction with N-bromosuccinimide to generate an intermediate 2, and finally undergoes a Stille coupling reaction with 2-tinbutyl-3,4-ethylenedioxythiophene to generate AQTh-EDOT.

[0008] (1) Under N2 atmosphere, 2,6-dibromoanthraquinone (5 g, 0.0137 mol) and 2-tinbutyl-3-n-hexylthiophene (18.74 g, 0.0409 mol) were added to 500 mL N,N-dimethylformamide (DMF) solution and stirred, and tetrakistriphenylphosphine palladium (1.5 g, 0.0013 mol) was added as a catalyst, and stirred at 90°C for 48 h. After the reaction was completed by spot plate monitoring, DMF was dried, and water was added after drying, and then extracted with dichloromethane, and then washed with saturated brine, and the organic phase was collected. The solvent was dried and purified by column chromatography. It was then washed with n-hexane and filtered and dried under vacuum to obtain intermediate 1.

[0009] (2) Intermediate 1 (500 mg, 0.92 mmol) and N-bromosuccinimide (NBS) (345.61 mg, 1.94 mmol) were dissolved in 30 mL of dichloromethane (DCM) solution. The reaction was stirred for 7 h. After the reaction was completed by spot plate observation, DCM was dried, extracted, and purified by column chromatography to finally obtain Intermediate 2.

[0010] (3) Under N2 atmosphere, intermediate 2 (500 mg, 0.72 mmol) and 2-tinbutyl-3,4-ethylenedioxythiophene (1.31 g, 2.86 mmol) were added to 100 ml of N,N-dimethylformamide (DMF) solution and stirred, and tetrakistriphenylphosphine palladium (80.8 mg, 0.072 mmol) was added as a catalyst and stirred at 90°C for 48 h. After the reaction was completed by spot plate monitoring, DMF was dried and water was added after drying. The mixture was extracted with dichloromethane and washed with saturated brine, and the organic phase was collected. The solvent was dried and purified by column chromatography. It was then washed with n-hexane and filtered and dried under vacuum to obtain AQTh-EDOT.

[0011] Synthesis process:

[0012] In step (1), the molar ratio of 2,6-dibromoanthraquinone, 2-tinbutyl-3-n-hexylthiophene and tetrakistriphenylphosphine palladium is 1:3:0.1, the reaction temperature is 90-100° C., and the reaction time is 24-48 hours.

[0013] In step (2), the molar ratio of intermediate 1 to N-bromosuccinimide is 1:2, the reaction temperature is 90-100° C., and the reaction time is 7-8 h.

[0014] In step (3), the molar ratio of intermediate 2, N-bromosuccinimide and tetrakistriphenylphosphine palladium is 1:3:0.1, the reaction temperature is 90-100° C., and the reaction time is 24-48 h.

[0015] The monomer represented by formula (I) is dissolved in dichloromethane solvent, tetrabutylammonium hexafluorophosphate is used as electrolyte, and cyclic voltammetry polymerization is performed at 0-1.6V, the polymerization scan rate is 0.1V / s, and the number of cycles is 5-30. After electrochemical polymerization, a polymer film is obtained; the initial concentration of tetrabutylammonium hexafluorophosphate is 0.1mol / L; the initial concentration of the monomer represented by formula (I) is 1mmol / L. Indium tin oxide (ITO) transparent conductive glass is used as a working electrode, a platinum wire is used as a counter electrode, and a silver wire is used as a reference electrode, and the monomer is polymerized into a film and deposited on the ITO surface.

[0016] Using an electrochemical workstation, UV-visible-near infrared absorption spectroscopy was used to characterize the electrochemical properties and electrochromic properties of the prepared polymer film. The study found that the polymer film has good electrochemical redox properties and can achieve reversible color changes from black to dark blue at different voltages.

[0017] Compared with the prior art, the advantages of the present invention are: a new type of polymer film is prepared by electrochemical polymerization, and it is applied to the field of electrochromism, which has potential application prospects in the fields of smart windows, displays, etc. Description of the drawings:

[0018] Figure 1 The molecular structure of AQTh-EDOT, an organic small molecule monomer with anthraquinone as the core, synthesized in Example 1.

[0019] Figure 2 This is the cyclic voltammetry curve of the electrochemical polymerization process of AQTh-EDOT, an organic small molecule monomer with anthraquinone as the core, synthesized in Example 1.

[0020] Figure 3 This is the absorption spectrum of a polyanthraquinonethiophene film PAQTh-EDOT synthesized in Example 2 under different voltages. Specific implementation method:

[0021] Implementation Example 1:

[0022] (1) Under N2 atmosphere, 2,6-dibromoanthraquinone (5 g, 0.0137 mol) and 2-tinbutyl-3-n-hexylthiophene (18.74 g, 0.0409 mol) were added to 500 mL N,N-dimethylformamide (DMF) solution and stirred, and tetrakistriphenylphosphine palladium (1.5 g, 0.0013 mol) was added as a catalyst, and stirred at 90°C for 48 h. After the reaction was completed by spot plate monitoring, DMF was dried, and water was added after drying, and then extracted with dichloromethane, and then washed with saturated brine, and the organic phase was collected. The solvent was dried and purified by column chromatography. It was then washed with n-hexane and filtered and dried under vacuum to obtain intermediate 1. 1H NMR (600MHz, CDCl3) δ8.52 (d, J=2.0Hz, 2H), 8.34 (d, J=8.1Hz, 2H), 7.99 (dd, J=8.1, 2.0Hz, 2H), 7.47 (d, J=1.4Hz, 2H ), 7.07 (q, J=1.1Hz, 2H), 2.68 (t, J=7.8Hz, 4H), 1.73-1.67 (m, 4H), 1.42-1.32 (m, 12H), 0.93 (td, J=5.8, 3.0Hz, 6H).

[0023] (2) Intermediate 1 (500 mg, 0.92 mmol) and N-bromosuccinimide (NBS) (345.61 mg, 1.94 mmol) were dissolved in 30 mL of dichloromethane (DCM) solution. The reaction was stirred for 7 h. After the reaction was completed by spot plate observation, DCM was dried, extracted, and purified by column chromatography to finally obtain Intermediate 2. 1 H NMR (600MHz, CDCl3) δ8.44 (d, J=2.0Hz, 2H), 8.34 (d, J=8.1Hz, 2H), 7.90 (dd, J=8.1, 2.0Hz, 2H) , 7.32 (s, 2H), 2.66-2.61 (m, 4H), 1.67 (t, J=7.5Hz, 4H), 1.41-1.30 (m, 12H), 0.95-0.91 (m, 6H).

[0024] (3) Under N2 atmosphere, intermediate 2 (500 mg, 0.72 mmol) and 2-tinbutyl-3,4-ethylenedioxythiophene (1.31 g, 2.86 mmol) were added to 100 mL N,N-dimethylformamide (DMF) solution and stirred, and tetrakistriphenylphosphine palladium (80.8 mg, 0.072 mmol) was added as a catalyst and stirred at 90°C for 48 h. After the reaction was completed, the DMF was dried by spin drying, and water was added after spin drying, and then extracted with dichloromethane, and then washed with saturated brine, and the organic phase was collected. The solvent was dried and purified by column chromatography. It was then washed with n-hexane and filtered and vacuum dried to obtain AQTh-EDOT. 1 H NMR (600MHz, CDCl3) δ8.52 (d, J=2.0Hz, 2H), 8.33 (d, J=8.2Hz, 2H), 7.99 (dd, J=8.2, 2.0Hz, 2H), 7.47 (s, 2H), 6.45 ( s, 2H), 4.40-4.29 (m, 8H), 2.83-2.77 (m, 4H), 1.72 (t, J=7.9Hz, 4H), 1.35 (q, J=5.4Hz, 12H), 0.92 (q, J=6.1Hz, 6H).

[0025] Example 2: Electrochemical polymerization of monomer AQTh-EDOT

[0026] 0.387g TBAPF6 was dissolved in 10mL dichloromethane to prepare the electrolyte. 8.21mg monomer AQTh-EDOT was dissolved in 10mL electrolyte to prepare the monomer solution (1mmol / L). The monomer solution was polymerized by 0-1.6V cyclic voltammetry with a polymerization scan rate of 0.1V / s. The polymer film was obtained by electrochemical polymerization and then dedoped in the electrolyte. All subsequent electrochemical tests were carried out in the electrolyte.

Claims

1. Preparation and application of a polyanthraquinonethiophene film, characterized in that: The polymer monomer has the chemical structure of formula (I):

2. The method for preparing an organic small molecule monomer AQTh-EDOT with anthraquinone as the core according to claim 1, comprising the following steps: 2,6-dibromoanthraquinone undergoes a Stille coupling reaction with 2-tinbutyl-3-n-hexylthiophene to generate intermediate 1, then undergoes a bromination reaction with N-bromosuccinimide to generate intermediate 2, and finally undergoes a Stille coupling reaction with 2-tinbutyl-3,4-ethylenedioxythiophene to generate AQTh-EDOT; (1) Preparation of intermediate 1: Under N2 atmosphere, 2,6-dibromoanthraquinone (5 g, 0.0137 mol) and 2-tinbutyl-3-n-hexylthiophene (18.74 g, 0.0409 mol) were added to 500 mL of N,N-dimethylformamide (DMF) solution and stirred, and tetrakistriphenylphosphine palladium (1.5 g, 0.0013 mol) was added as a catalyst, and stirred at 90°C for 48 h. After the reaction was completed, the DMF was dried by spin drying, and water was added after the drying, and the mixture was extracted with dichloromethane, and then washed with saturated brine, and the organic phase was collected. The solvent was dried by spin drying, and purified by column chromatography, and then washed with n-hexane and filtered and dried under vacuum to obtain intermediate 1; (2) Preparation of intermediate 2: Intermediate 1 (500 mg, 0.92 mmol) and N-bromosuccinimide (NBS) (345.61 mg, 1.94 mmol) were dissolved in 30 mL of dichloromethane (DCM) solution, and the reaction was stirred for 7 h. After the reaction was completed, the DCM was dried by spin drying, and then extracted and purified by column chromatography to finally obtain intermediate 2; (3) Preparation of AQTh-EDOT: Under N2 atmosphere, intermediate 2 (500 mg, 0.72 mmol) and 2-tinbutyl-3,4-ethylenedioxythiophene (1.31 g, 2.86 mmol) were added to 100 mL N,N-dimethylformamide (DMF) solution and stirred, and tetrakistriphenylphosphine palladium (80.8 mg, 0.072 mmol) was added as a catalyst, and stirred at 90°C for 48 h. After the reaction was completed, the DMF was dried by spin drying, and water was added after spin drying. The mixture was extracted with dichloromethane and then washed with saturated brine. The organic phase was collected, the solvent was dried by spin drying, and purified by column chromatography. It was then washed with n-hexane and filtered and dried in vacuo to obtain AQTh-EDOT.

3. The method for preparing an organic small molecule monomer AQTh-EDOT with anthraquinone as the core according to claim 2, characterized in that: In the synthesis method, in step (1), the molar ratio of 2,6-dibromoanthraquinone, 2-tinbutyl-3-n-hexylthiophene and tetrakistriphenylphosphine palladium is 1:3:0.1, the reaction temperature is 90-100° C., and the reaction time is 24-48 hours.

4. The method for preparing an organic small molecule monomer AQTh-EDOT with anthraquinone as the core according to claim 2, characterized in that: In the synthesis method: in step (2), the molar ratio of intermediate 1 to N-bromosuccinimide is 1:2, the reaction temperature is 90-100° C., and the reaction time is 7-8 hours.

5. The method for preparing an organic small molecule monomer AQTh-EDOT with anthraquinone as the core according to claim 2, characterized in that: In the synthesis method, in step (3), the molar ratio of intermediate 2, N-bromosuccinimide and tetrakistriphenylphosphine palladium is 1:3:0.1, the reaction temperature is 90-100° C., and the reaction time is 24-48 hours.

6. The polyanthraquinonethiophene film PAQTh-EDOT according to claim 1 is prepared by an electrochemical polymerization method.

7. The preparation of the polyanthraquinone thiophene film PAQTh-EDOT according to claim 6 comprises the following steps: The monomer AQTh-EDOT represented by formula (I) is dissolved in dichloromethane solvent, tetrabutylammonium hexafluorophosphate is used as electrolyte, and cyclic voltammetry polymerization is adopted at 0-1.6V, the polymerization scan rate is 0.1V / s, the number of cycles is 5-30, and a polymer film is obtained after electrochemical polymerization; the initial concentration of the tetrabutylammonium hexafluorophosphate is 0.1mol / L; the initial concentration of the monomer represented by formula (I) is 1mmol / L, indium tin oxide (ITO) transparent conductive glass is used as a working electrode, a platinum wire is used as a counter electrode, and a silver wire is used as a reference electrode, and the film is deposited on the ITO surface through electrochemical polymerization.

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