CN116903607A

CN116903607A - Polythiophene conductive polymer and preparation method and application thereof

Info

Publication number: CN116903607A
Application number: CN202310880835.XA
Authority: CN
Inventors: 吕晓静; 董俊成; 张�诚; 邵明发; 何阳
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Zhejiang University of Technology ZJUT
Priority date: 2023-07-18
Filing date: 2023-07-18
Publication date: 2023-10-20
Anticipated expiration: 2043-07-18
Also published as: CN116903607B

Abstract

The invention relates to the technical field of organic synthesis, and in particular to a polythiophene conductive polymer and its preparation method and application. Through reasonable structural design, the present invention provides a thiophene derivative monomer based on phenothiazine, which has relatively abundant active sites and can obtain a conductive polymer with a cross-linked network structure through simple electrochemical polymerization. At the same time, the polymer film has good electrochromic properties and can achieve reversible switching between orange and green at a lower voltage. It is a type of organic polymer electrochromic that has great application prospects in the field of military camouflage. Color changing material.

Description

Polythiophene conductive polymer and preparation method and application thereof

Technical Field

The invention relates to the technical field of organic synthesis, in particular to a polythiophene conductive polymer and a preparation method and application thereof.

Background

The high-molecular conductive polymer material has the properties of higher conductivity, lower equivalent circuit impedance, obvious optical adjustability and the like, and is widely applied to the field of organic photoelectric functional materials. In the electrochromic field, the conductive polymer materials still have the defects of poor cycle stability, high processing difficulty, monotonous color and the like, and the defects limit the practical application of the conductive polymer materials in the electrochromic field. Therefore, the molecular structure of the current conductive polymer material needs to be studied and improved, and the importance is to continuously improve the conductivity and stability of the current conductive polymer material.

The polythiophene conductive polymer has the characteristics of easily available raw materials, simple synthesis and the like, thiophene and derivatives thereof can be used as good electron acceptors to combine with proper electron donors to form a stable D-A type structure, and the structure has good environmental stability and thermal stability in the electrochemical doping and dedoping processes, so that the thiophene conductive polymer is always a research hot spot in the field of organic photoelectric materials. But the linear polythiophene-based conductive polymer has poor structural stability and ability to store electric charges. As in application number CN202011548856.4, a linear high-conductivity organic soluble thiophene polymer, and a preparation method and application thereof are disclosed, wherein it is proved that when the length of the flexible segment of the linear polythiophene-type conductive polymer increases, the conductivity of the copolymer decreases drastically. It is therefore necessary to modify the structure to some extent.

Phenothiazine and its derivatives are tricyclic azathia-heterocyclic compounds having a wide range of pharmaceutical properties, and have received great attention in the field of organic photoelectric functional materials because of their excellent photoelectric properties such as photoconduction, photochromism, electrochromic properties and low and highly reversible redox potentials. Because the structure of the phenothiazine contains nitrogen atoms and sulfur atoms rich in electrons, the phenothiazine can be used as a strong electron donor for a parent material of a conductive polymer. In addition, the phenothiazine has the characteristics of simple synthesis and easy modification, thiophene or a derivative thereof is modified at the periphery by taking the phenothiazine as a central unit and taken as a polymerization unit, and the phenothiazine can be processed into a film through simple electrochemical polymerization, so that the phenothiazine is expected to prepare a high-performance high-molecular conductive polymer material, and has wide application prospect in the electrochromic field.

Disclosure of Invention

The invention provides a polythiophene conductive polymer, a preparation method and application thereof, and aims to overcome the defect that the linear thiophene conductive polymer in the prior art has poor charge storage capacity.

In order to achieve the above object, the present invention provides a phenothiazine-based thiophene derivative monomer represented by formula (i):

the thiophene derivative monomer based on phenothiazine provided by the invention is a Y-type polymer monomer capable of undergoing cross-linking polymerization, wherein the center core is phenothiazine, and the periphery is three polymerizable bithiophene groups. Therefore, a reticular micropore structure is formed in the process of electropolymerization, the intercalation and deintercalation of electrolyte ions are very favorable in the electrochemical process, and the charge storage capacity is also greatly improved, so that excellent electrochemical performance is obtained. More importantly, the monomer increases the conjugation degree of the peripheral bithiophene polymerized units, and reduces the oxidation-reduction potential of the polymer.

The polythiophene conductive polymer film prepared by using thiophene derivative monomer based on phenothiazine as an active monomer through a constant potential deposition method is subjected to electrochemical impedance performance test and cyclic voltammetry performance test, and the effect of effectively doping and dedoping ions on the film can be proved, so that the electrochemical properties of the film are substantially improved.

The invention also provides a method for preparing the thiophene derivative monomer based on phenothiazine, which comprises the following steps:

s2.1, mixing 10-phenyl-10H-phenothiazine and N-bromosuccinimide, adding tetrahydrofuran, and carrying out bromination reaction to obtain an intermediate with a structure shown as a formula (II);

s2.2 at N ₂ Mixing the intermediate with 2-tributylstannyl bithiophene under the atmosphere, adding N, N-dimethylformamide and a catalyst, and performing Stille coupling reactionObtaining the thiophene derivative monomer based on phenothiazine;

wherein, the structural formula of the intermediate is:

specifically, the preparation method of the polythiophene derivative based on the phenothiazine as a central core comprises the following steps:

in the step S2.1, 10-phenyl-10H-phenothiazine (FSQ) and N-bromosuccinimide (NBS) are sequentially added into a single-neck round bottom flask, 20mL of anhydrous Tetrahydrofuran (THF) is added as a reaction solvent, and the reaction is carried out for 3-6 hours in an ice water mixed bath at 0-10 ℃, and after the reaction is finished, the reaction solution is purified to obtain a pure product FSQ-3Br (namely an intermediate).

In step S2.2, at N ₂ Under the protection, FSQ-3Br and 2-tributylstannyl bithiophene are added into a two-mouth round bottom flask, anhydrous N, N-dimethylformamide is used as a reaction solvent, bis (triphenylphosphine) palladium dichloride is used as a catalyst, heating reflux is carried out for 30-36 h, and after the reaction is finished, the reaction solution is purified to obtain a target product FSQ-3BT, namely the polythiophene derivative monomer based on phenothiazine as a central core.

Among them, tetrahydrofuran (THF) is used as a reaction solvent for the purpose of providing a suitable reaction environment to promote the progress of chemical reactions. Tetrahydrofuran can effectively dissolve 10-phenyl-10H-phenothiazine and N-bromosuccinimide to ensure that the 10-phenyl-10H-phenothiazine and the N-bromosuccinimide are fully mixed and contacted in the reaction, and the low polarity of the tetrahydrofuran is beneficial to nucleophilic substitution and other reactions; the lower boiling point and the higher boiling point range also make it easier to control the reaction conditions. In addition, tetrahydrofuran is capable of forming hydrogen bonds and van der waals interactions with many organic compounds, which may help regulate reaction rates and increase reaction yields; can also be used as proton donor or proton acceptor to participate in proton transfer process in reaction, and promote reaction.

N, N-Dimethylformamide (DMF) as a commonly used organic solvent has good solubility properties, especially for many organic compounds and metal complexes. It can effectively dissolve FSQ-3Br and 2-tributylstannyl bithiophene, so that they are fully mixed and contacted in the reaction.

In addition, DMF has certain solvent activity, which is helpful for the dissociation of reactants and the activation of catalysts; the rate and selectivity of the reaction can be controlled by stabilizing reaction intermediates or forming complexes and the like.

As for the addition of bis (triphenylphosphine) palladium dichloride (Pd (PPh) ₃ ) ₂ Cl ₂ ) The purpose of the catalyst is to promote a specific reaction. Bis (triphenylphosphine) palladium dichloride is a commonly used coordination catalyst and is widely used in many organic synthesis reactions. The main purpose is to promote the coupling reaction between the intermediate and 2-tributylstannyl bithiophene to form the target product or to perform other required chemical transformations.

Preferably, in the step S2.1, the molar ratio of the 10-phenyl-10H-phenothiazine to the N-bromosuccinimide is 1 (9-10), and the bromination reaction temperature is 0-10 ℃.

The bromination reaction can control the reaction rate and improve the selectivity of the reaction at low temperature. At lower temperatures, the reaction rate generally slows down. This helps to better control the progress of the reaction during the course of the reaction, avoiding possible side reactions or uncontrolled violent reactions. By lowering the temperature, the thermal movement of the reactant molecules can be reduced, reducing the frequency of collisions between them, and thus the reaction rate.

Meanwhile, the low-temperature condition is favorable for increasing the directionality of reactant molecules and improving the selectivity of the reaction. At low temperatures, the thermal motion of the reactant molecules slows down, making them more prone to collide with each other in a specific manner. This helps control the orientation and alignment of the reactant molecules to selectively perform the desired chemical reaction, reducing the occurrence of side reactions.

In conclusion, the bromination reaction is carried out at the temperature of 0-10 ℃ to help the reaction to proceed in the direction of generating FSQ-3Br, thereby preparing FSQ-3Br with higher purity and higher yield, and being beneficial to improving the generation quality of the final polythiophene conductive polymer film.

Preferably, in the step S2.2, the molar ratio of the intermediate to the 2-tributylstannyl bithiophene is 1 (9-10).

The invention provides a polythiophene conductive polymer prepared from thiophene derivative monomer based on phenothiazine shown in a formula (I), which has the following structural formula:

wherein n represents an average polymerization degree, and n is 10 to 2000.

The invention provides a polythiophene conductive polymer based on phenothiazine as a central core, wherein the central core is phenothiazine, and the periphery is three polymerizable bithiophene groups, and a reticular micropore structure can be formed in the polymerization process, so that the obtained polymer is very favorable for intercalation and deintercalation of electrolyte ions in the electrochemical process, and the charge storage capacity of the polymer is also greatly improved, so that excellent electrochemical performance is obtained.

The invention also provides a method for preparing the polythiophene conductive polymer, which comprises the following steps:

s6.1, dissolving thiophene derivative monomers based on phenothiazine and a supporting electrolyte in a solvent, and then adding the solution into a three-electrode electrolytic cell;

s6.2, electropolymerization is carried out by a constant potential electrodeposition method to obtain the polythiophene conductive polymer film.

The thiophene derivative monomer based on phenothiazine as a central core and a supporting electrolyte are dissolved in a solvent, ITO glass (0.9X4 cm) is used as a working electrode, a platinum sheet is used as a counter electrode, ag/AgCl is used as a reference electrode, and a constant potential electrodeposition method is adopted to obtain a polymer film, namely the polythiophene conductive polymer based on phenothiazine as a central core, wherein the chemical reaction schematic formula is shown as follows:

preferably, in the step S6.1, the thiophene derivative monomer concentration based on phenothiazine is 0.5-1 mmol/L.

Preferably, in the step S6.1, the supporting electrolyte is selected from any one of tetrabutylammonium hexafluorophosphate, tetrabutylammonium perchlorate, lithium tetrafluoroborate, and lithium perchlorate.

Further, tetrabutylammonium hexafluorophosphate is selected as the supporting electrolyte. The polymer is best prepared with tetrabutylammonium hexafluorophosphate as the supporting electrolyte.

Preferably, in the step S6.1, the solvent is selected from any one of dichloromethane, chromatographic grade acetonitrile, propylene carbonate.

Furthermore, the solvents are all of chromatographic grade, and the preparation effect of the polymer is optimal when the chromatographic grade dichloromethane is used as the solvent.

The invention also proves the application of the polythiophene conductive polymer in the electrochromic field.

The applicant of the invention detects ultraviolet-visible spectrum and electrochromic property of the prepared conductive polymer film, and discovers that the polymer film is orange yellow in color in a neutral state and green in an oxidation state, and has good electrochromic property. It can be confirmed that the polythiophene-type conductive polymer can be applied to the electrochromic field.

Therefore, the invention has the following beneficial effects:

(1) According to the invention, phenothiazine is taken as a central core, bithiophene is taken as a peripheral polymerization unit, a Y-type polymer monomer capable of performing cross-linking polymerization is constructed, a polymer film obtained through electrochemical polymerization can form a cross-linked reticular structure, the surface structure is loose, electrolyte ions are easy to insert and remove, and the electrochromic and energy storage properties of the material are excellent;

(2) According to the invention, the phenothiazine is introduced as the central core, so that the conjugation degree of the peripheral bithiophene polymerization unit is increased, and the oxidation-reduction potential of the polymer is reduced, and therefore, the obtained polymer film has good electrochemical performance;

(3) The polythiophene derivative monomer based on the phenothiazine as the center has the advantages of good reaction selectivity, simple preparation method flow, few byproducts, easy separation and high yield;

(4) The polythiophene derivative monomer based on the phenothiazine as the center core is prepared by a constant potential electrodeposition mode, and can be used for preparing a polymer film with lower driving voltage;

(5) The polymer film prepared by the invention can realize reversible switching between orange and green under different voltages, and has high application value in the field of military camouflage.

Drawings

FIG. 1 is an electrochemical impedance curve of a polythiophene-based conductive polymer film prepared in example 5;

FIG. 2 is a cyclic voltammogram of a polythiophene-based conductive polymer film prepared in example 5;

FIG. 3 is a graph showing the UV-visible absorption spectra of the polythiophene conductive polymer film prepared in example 5 at different voltages;

FIG. 4 is an electrochromic optical contrast diagram of the polythiophene-based conductive polymer film prepared in example 5 at different wavelengths.

Detailed Description

The invention is further described below in connection with specific embodiments. Those of ordinary skill in the art will be able to implement the invention based on these descriptions. In addition, the embodiments of the present invention referred to in the following description are typically only some, but not all, embodiments of the present invention. Therefore, all other embodiments, which can be made by one of ordinary skill in the art without undue burden, are intended to be within the scope of the present invention, based on the embodiments of the present invention.

[ preparation principle ]

The preparation process and reaction principle involved in the scheme are as follows:

1. preparation of 3Br-FSQ:

the 10-phenyl-10H-phenothiazine (FSQ) with the structure shown in the formula (a) and N-bromosuccinimide (NBS) are subjected to bromination reaction to obtain a compound FSQ-3Br with the structure shown in the formula (b),

wherein, the chemical reaction schematic formula is as follows:

2. preparation of 3BT-FSQ:

FSQ-3Br shown in the formula (b) and 2-tributylstannyl bithiophene shown in the formula (c) are subjected to coupling reaction to prepare FSQ-3BT shown in the formula (d), namely thiophene derivative monomer based on 10-phenyl-10H-phenothiazine,

wherein, the chemical reaction schematic formula is as follows:

3. preparation of Polymer p3BT-FSQ:

and (3) polymerizing a polythiophene derivative monomer with a structural formula shown in (d) and based on phenothiazine as a central core through constant potential electrodeposition to obtain the conductive polymer with the structure shown in (e).

Wherein, the chemical reaction schematic formula is as follows:

the following examples were carried out according to the reaction principle described above (preparation conditions slightly different):

[ example ]

Preparation of thiophene derivative monomer based on phenothiazine

Example 1

FSQ (500 mg,2.5 mmol) and NBS (4.02 g,22.6 mmol) were sequentially added into a single-neck round bottom flask, 20mL of anhydrous Tetrahydrofuran (THF) was added as a reaction solvent, the solution after the reaction was completed was poured into 200mL of deionized water, the solution was subjected to multiple extraction with 400mL of dichloromethane, the extract was concentrated and then dehydrated with anhydrous sodium sulfate, the crude silica gel was stirred, fine silica gel was used as a stationary phase, dichloromethane and petroleum ether were used as mobile phases (dichloromethane: petroleum ether=2:3), column chromatography purification was performed, eluent containing the target compound was collected, the solvent was removed by spin evaporation and drying was performed to obtain a pure product 3Br-FSQ with a yield of 82%.

Example 2

FSQ (500 mg,2.5 mmol) and NBS (4.24 g,23.8 mmol) were sequentially added into a single-neck round bottom flask, 20mL of anhydrous Tetrahydrofuran (THF) was added as a reaction solvent, the solution after the reaction was completed was poured into 200mL of deionized water, the solution was subjected to multiple extraction with 400mL of dichloromethane, the extract was concentrated and then dried over anhydrous sodium sulfate, the crude silica gel was used as a stationary phase, dichloromethane and petroleum ether were used as mobile phases (dichloromethane: petroleum ether=2:3), column chromatography purification was performed, eluent containing the target compound was collected, the solvent was removed by spin evaporation and drying was performed to obtain a pure product 3Br-FSQ with a yield of 80%.

Example 3

FSQ (500 mg,2.5 mmol) and NBS (4.45 g,25.0 mmol) are sequentially added into a single-neck round bottom flask, 20mL of anhydrous Tetrahydrofuran (THF) is added as a reaction solvent, the solution after the reaction is completed is poured into 200mL of deionized water, the solution is subjected to repeated extraction by using 400mL of dichloromethane, the extract is concentrated and dehydrated by using anhydrous sodium sulfate, crude silica gel is used for sample stirring, fine silica gel is used as a stationary phase, dichloromethane and petroleum ether are used as mobile phases (dichloromethane: petroleum ether=2:3), column chromatography purification is carried out, eluent containing a target compound is collected, the solvent is removed by spin evaporation and drying is carried out, and the pure product 3Br-FSQ is obtained, wherein the yield is 79%.

Preparation of polythiophene conductive polymer

Example 4

3Br-FSQ (500 mg,1.15 mmol) prepared in example 1, 2-tributylstannyl bithiophene (4.71 g,10.35 mmol) and bis (triphenylphosphine) palladium dichloride (0.1% W) were sequentially added to a 100mL two-necked round bottom flask at N ₂ Under protection, anhydrous DMF (20 mL) is added as a reaction solvent, heating and stirring are carried out for reflux for 48 hours at 120 ℃, after the reaction is finished, dichloromethane is used for extraction for 3 times, extract liquid is concentrated, anhydrous sodium sulfate is used for drying and dewatering, crude silica gel is used for sample mixing, column chromatography purification is carried out, fine silica gel is used as a stationary phase, dichloromethane and petroleum ether are used as mobile phases (dichloromethane: petroleum ether=1:3), eluent containing target compounds is collected, solvent is removed by rotary evaporation and drying is carried out, and a pure product 3BT-FSQ is obtained, and the yield is 74%.

Adding 4.26mg (0.5 mmol/L) of thiophene derivative 3BT-FSQ monomer based on phenothiazine into a 10mL volumetric flask, adding 0.387g (0.1 mol/L) of tetrabutylammonium hexafluorophosphate as a supporting electrolyte, using chromatographic grade dichloromethane to fix the volume, carrying out ultrasonic treatment for 3min, and carrying out potentiostatic electrodeposition after the solid is completely dissolved, wherein the specific process is as follows: ITO glass (0.9X4 cm) is used as a working electrode, a platinum wire is used as a counter electrode, ag/AgCl is used as a reference electrode, a deposited voltage window is 1.3V, and deposited electric quantity is 0.02C. After the deposition is completed, the polymer p3BT-FSQ is obtained by dedoping in a blank electrolyte solution (0.1 mol/L tetrabutylammonium hexafluorophosphate/dichloromethane) for 60s (voltage-0.5V), washing the polymer film with a dichloromethane solution for 2-3 times and then drying at 50 ℃ for 1 h.

Example 5

3Br-FSQ (500 mg,1.15 mmol) prepared in example 1, 2-tributylstannyl bithiophene (4.98 g,10.93 mmol) and bis (triphenylphosphine) palladium dichloride (0.1% W) were sequentially added to a 100mL two-necked round bottom flask in N ₂ Under protection, anhydrous DMF (20 mL) is added as a reaction solvent, heating and stirring are carried out for reflux for 48 hours at 120 ℃, after the reaction is finished, dichloromethane is used for extraction for 3 times, the extract is concentrated, anhydrous sodium sulfate is used for drying and dewatering, crude silica gel is used for sample mixing, column chromatography purification is carried out, fine silica gel is used as a stationary phase, dichloromethane and petroleum ether are used as mobile phases (dichloromethyl)Alkane: petroleum ether=1:3), eluent containing the target compound was collected, solvent was removed by rotary evaporation and drying was performed to obtain pure product 3BT-FSQ with a yield of 84%.

Adding 8.52mg (1 mmol/L) of thiophene derivative 3BT-FSQ monomer based on phenothiazine into a 10mL volumetric flask, adding 0.387g (0.1 mol/L) of tetrabutylammonium hexafluorophosphate as a supporting electrolyte, fixing the volume by using chromatographic grade dichloromethane, carrying out ultrasonic treatment for 3min, and carrying out constant potential electrodeposition after the solid is completely dissolved, wherein the specific process is as follows: ITO glass (0.9X4 cm) is used as a working electrode, a platinum wire is used as a counter electrode, ag/AgCl is used as a reference electrode, a deposited voltage window is 1.5V, and deposited electric quantity is 0.02C. After the deposition is completed, the polymer p3BT-FSQ is obtained by dedoping in a blank electrolyte solution (0.1 mol/L tetrabutylammonium hexafluorophosphate/dichloromethane) for 60s (voltage-0.5V), washing the polymer film with a dichloromethane solution for 2-3 times and then drying at 50 ℃ for 1 h.

Example 6

3Br-FSQ (500 mg,1.15 mmol) prepared in example 1, 2-tributylstannyl bithiophene (5.24 g,11.50 mmol) and bis (triphenylphosphine) palladium dichloride (0.1% W) were sequentially added to a 100mL two-necked round bottom flask at N ₂ Under protection, anhydrous DMF (20 mL) is added as a reaction solvent, heating and stirring are carried out for reflux for 48 hours at 120 ℃, after the reaction is finished, dichloromethane is used for extraction for 3 times, extract liquid is concentrated, anhydrous sodium sulfate is used for drying and dewatering, crude silica gel is used for sample mixing, column chromatography purification is carried out, fine silica gel is used as a stationary phase, dichloromethane and petroleum ether are used as mobile phases (dichloromethane: petroleum ether=1:3), eluent containing target compounds is collected, solvent is removed by rotary evaporation and drying is carried out, and a pure product 3BT-FSQ is obtained, and the yield is 84%.

Adding 6.82mg (0.8 mmol/L) of thiophene derivative 3BT-FSQ monomer based on phenothiazine into a 10mL volumetric flask, adding 0.387g (0.1 mol/L) of tetrabutylammonium hexafluorophosphate as a supporting electrolyte, using chromatographic grade dichloromethane to fix the volume, carrying out ultrasonic treatment for 3min, and carrying out potentiostatic electrodeposition after the solid is completely dissolved, wherein the specific process is as follows: ITO glass (0.9X4 cm) is used as a working electrode, a platinum wire is used as a counter electrode, ag/AgCl is used as a reference electrode, a deposited voltage window is 1.8V, and deposited electric quantity is 0.02C. After the deposition is completed, the polymer p3BT-FSQ is obtained by dedoping in a blank electrolyte solution (0.1 mol/L tetrabutylammonium hexafluorophosphate/dichloromethane) for 60s (voltage-0.5V), washing the polymer film with a dichloromethane solution for 2-3 times and then drying at 50 ℃ for 1 h.

[ Performance test ]

1. Electrochemical impedance performance test

Tetrabutylammonium hexafluorophosphate, 0.387g (0.1 mol/L), was added to a 10mL volumetric flask, and the volume was determined using chromatographic grade dichloromethane as a blank supporting electrolyte solution. The phenothiazine-based thiophene polymer p3BT-FSQ film prepared in example 5 is used as a working electrode, ag/AgCl is used as a reference electrode, a platinum wire is used as a counter electrode, and electrochemical impedance performance of the polymer film in different states is respectively tested, and the test result is shown in figure 1.

As can be seen from fig. 1, at 0V the polymer film only shows diffusion-controlled kinetics, whereas at 1.5V the polymer film almost only shows charge transfer-controlled kinetics, which suggests that ions can be efficiently doped and undoped on the film, thereby bringing about a change in the electrochemical properties of the film.

2. Cyclic voltammetry performance test

Tetrabutylammonium hexafluorophosphate, 0.387g (0.1 mol/L), was added to a 10mL volumetric flask, and the volume was determined using chromatographic grade dichloromethane as a blank supporting electrolyte solution. The thiophene polymer p3BT-FSQ film based on phenothiazine prepared in the embodiment 5 is used as a working electrode, ag/AgCl is used as a reference electrode, a platinum wire is used as a counter electrode, the cyclic voltammetry performance of the polymer film at different scanning speeds is tested, the voltage window is 0-1.5V, and the test result is shown in figure 2.

As can be seen from fig. 2, the polymer shows a distinct redox peak, which indicates that the polymer has good redox activity, and the area of the CV curve of the polymer is continuously increased with the increasing scanning rate, which indicates that the polymer film can be well adhered to the surface of the ITO conductive substrate, and the redox behavior is reversible and non-diffusion controlled.

3. Ultraviolet-visible absorption spectrum test

Tetrabutylammonium hexafluorophosphate, 0.387g (0.1 mol/L), was added to a 10mL volumetric flask, and the volume was determined using chromatographic grade dichloromethane as a blank supporting electrolyte solution. The phenothiazine-based thiophene polymer p3BT-FSQ film prepared in example 5 is used as a working electrode, ag/AgCl is used as a reference electrode, a platinum wire is used as a counter electrode, and the ultraviolet-visible absorption spectrum of the polymer film under different voltages is tested, and the test result is shown in figure 3.

As can be seen from the uv-vis absorption spectrum of fig. 3, the polymer film was orange-yellow in color in the neutral state and green in the oxidized state, with a significant color change.

4. Electrochromic Performance test

Tetrabutylammonium hexafluorophosphate, 0.387g (0.1 mol/L), was added to a 10mL volumetric flask, and the volume was determined using chromatographic grade dichloromethane as a blank supporting electrolyte solution. The phenothiazine-based thiophene polymer p3BT-FSQ film prepared in example 5 is used as a working electrode, ag/AgCl is used as a reference electrode, a platinum wire is used as a counter electrode, an optical contrast diagram of the polymer film is tested, and a test result is shown in FIG. 4.

As can be seen from the optical contrast chart of FIG. 4, the thin film has the coloring time of 2.5s, 3.0s, 1.5s and 3.0s at 380nm, 450nm, 687nm and 1100nm respectively, the fading time of 4.5s, 6.5s, 7.0s and 7.5s respectively, and the optical contrast can reach 18.2%, 36.5%, 58.0% and 65.5% respectively, and the thin film shows better electrochromic performance.

Claims

1. Thiophene derivative monomer based on phenothiazine as shown in formula (I):

2. a process for preparing phenothiazine-based thiophene derivative monomers according to claim 1,

the method comprises the following steps:

s2.2, mixing an intermediate with 2-tributylstannyl bithiophene in a nitrogen atmosphere, adding N, N-dimethylformamide and a catalyst, and performing a Stille coupling reaction to obtain a thiophene derivative monomer based on phenothiazine;

wherein, the structural formula of the intermediate is:

3. a process for the preparation of phenothiazine-based thiophene derivative monomers according to claim 2,

in the step S2.1, the molar ratio of the 10-phenyl-10H-phenothiazine to the N-bromosuccinimide is 1 (9-10), and the bromination reaction temperature is 0-10 ℃.

4. A process for the preparation of phenothiazine-based thiophene derivative monomers according to claim 2,

in the step S2.2, the molar ratio of the intermediate to the 2-tributylstannyl bithiophene is 1 (9-10).

5. A polythiophene conductive polymer prepared from thiophene derivative monomer based on phenothiazine shown in formula (I) has a structural formula as follows:

wherein n represents an average polymerization degree, and n is 10 to 2000.

6. A process for preparing the polythiophene-type conductive polymer as claimed in claim 5, wherein,

the method comprises the following steps:

7. The method for producing a polythiophene-based conductive polymer according to claim 6,

in the step S6.1, the concentration of thiophene derivative monomers based on phenothiazine is 0.5-1 mmol/L.

8. The method for producing a polythiophene-based conductive polymer according to claim 6 or 7,

in the step S6.1, the supporting electrolyte is selected from any one of tetrabutylammonium hexafluorophosphate, tetrabutylammonium perchlorate, lithium tetrafluoroborate, and lithium perchlorate.

9. The method for producing a polythiophene-based conductive polymer according to claim 6 or 7,

in the step S6.1, the solvent is selected from any one of dichloromethane, chromatographic grade acetonitrile and propylene carbonate.

10. The polythiophene conductive polymer according to claim 5 or the polythiophene conductive polymer prepared by the method according to any one of claims 6 to 9, and the application thereof in the electrochromic field.