CN110655653B - A-D-A type polymer with main chain containing metal element, preparation method and application thereof - Google Patents

Abstract

The invention discloses a type of A-D-A type polymer containing metal elements in the main chain, a preparation method and application thereof. The preparation method takes the A-D-A unit as the core and the alkyne-metal compound-alkyne unit as the link to introduce metal atoms into the copolymer, and the prepared polymer has absorption in a wide spectral range and high carrier migration Rate. The present invention is based on such A-D-A-type polymers containing metal elements in the main chain, which can be used as active layers and applied in organic/polymer photodetectors or organic/polymer solar cells or organic/polymer field effect transistors.

Description

A class of A-D-A polymers containing metal elements in the main chain, preparation method and application thereof

technical field

The invention belongs to the field of organic semiconductors, and in particular relates to a type of A-D-A type polymer containing metal elements in the main chain and a preparation method thereof, and its application in organic/polymer photodetectors, organic/polymer solar cells, organic/polymer diodes, organic/polymeric applications in field effect transistors.

Background technique

Photodetectors are components that convert optical signals into electrical signals based on the photoelectric effect, and have important applications in optical communication, image sensing, biomedical sensing, environmental monitoring, meteorology, and military. Currently commonly used photodetectors are basically based on inorganic semiconductor materials, such as Si-based, Ge-based, and InGaAs.

Compared with inorganic materials, organic/polymer materials have the advantages of low cost, easy adjustment of absorption wavelength, and film formation by solution method, etc., which make the manufacturing process of organic/polymer photodiodes simple, low production cost, light weight, and easy to large area. The preparation and realization of flexible devices have broad application prospects. Gong et al. prepared a panchromatic photodetector with a spectral response range of 300-1150 nm by blending a narrow-band conjugated polymer PDDTT with a fullerene derivative PC ₆₁ BM. The detector has a detection rate of over 10 under zero bias. ¹³ cm Hz ^1/2 W ^-1 , its overall performance is already better than that of silicon-based devices [Science, 2009, 325(5948): 1665-1667].

The A-D-A type polymer with metal elements in the main chain involved in the present invention has better energy level structure and solution processing characteristics, which is beneficial to realize the requirement of the organic photodetector working in the short-wave infrared. Therefore, in the organic photodetector The field has huge development potential and prospects.

SUMMARY OF THE INVENTION

In order to solve the shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a type of A-D-A type polymer containing metal elements in the main chain. The introduction of metal atoms can provide supramolecular interactions between metals and induce molecular aggregation. Combined with the strong D-A interaction of electron-donating D units, the absorption spectrum of polymers can be effectively adjusted and the external quantum efficiency of polymers can be improved. The regular structure of type A-D-A makes the polymer molecules more orderly, which is more conducive to the stacking of polymer molecules, which can further improve the mobility and red-shift the absorption spectrum. stability.

Another object of the present invention is to provide a method for preparing the above-mentioned type of A-D-A type polymer containing metal elements in its main chain.

Another object of the present invention is to provide the application of the above-mentioned A-D-A type polymers containing metal elements in the main chain in the field of organic semiconductor devices.

In order to achieve the above objects, the present invention adopts the following technical solutions to achieve.

A class of A-D-A polymers whose main chain contains metal elements, the chemical structural formula satisfies the following general formula:

In the formula, n is the number of repeating units, and n=a positive integer from 2 to 1000;

A is an aromatic hydrocarbon group with 6 to 60 carbon atoms or an electron withdrawing unit of an aromatic heterocyclic group with 2 to 60 carbon atoms;

Each occurrence of M is identically or differently selected from groups containing metal atoms, preferably mercury atoms or platinum groups with phosphorus ligands Pt(P(R ¹ ) ₃ ) ₂ ;

R ¹ is a straight-chain alkyl group having 1-60 carbon atoms, a branched or cyclic alkyl group having 3-60 carbon atoms, an alkenyl or alkynyl group having 2-20 carbon atoms , an aromatic organic group with 6-60 carbon atoms or a heteroaromatic organic group with 3-60 carbon atoms, two or more groups R ¹ can be linked to each other and can form a ring;

Each occurrence of D is identically or differently selected from an aromatic organic group having 6 to 80 carbon atoms or a heteroaromatic organic group having 3 to 100 carbon atoms.

Further, the A group is preferably the following structure or a halogenated, deuterated, or alkyl-substituted derivative of the following structure:

wherein each occurrence of X is identically or differently selected from CR ² groups or N atoms;

Each occurrence of R ² is identically or differently selected from H, D, F, Cl, CN, NO ₂ , C(=O)R ³ , Si(R ³ ) ₃ , N(R ³ ) ₂ , P(= O)(R ³ ) ₂ , P(=S)(R ³ ) ₂ , OR ³ , SR ³ , S(=O)R ³ , S(=O) ₂ R ³ , with 1 to 20 carbon atoms Linear alkyl groups, branched or cyclic alkyl groups with 3 to 20 carbon atoms, alkenyl or alkynyl groups with 2 to 20 carbon atoms, aromatic organic groups with 6 to 60 carbon atoms group or a heteroaromatic organic group with 3 to 60 carbon atoms, wherein one or more -CH ₂ - groups that the R ² group may contain may be replaced by -R ³ C=CR ³ -,-C≡C -,Si(R ³ ) ₂ ,C=O,C=NR ³ ,-C(=O)O-,-C(=O)NR ³ -,NR ³ ,P(=O)(R ³ ), P(=S)(R ³ ), O, S, S(=O) or SO ₂ instead; two or more groups R ² can be linked to each other and can form a ring;

Each occurrence of R ³ is identically or differently selected from linear alkyl groups having 1 to 60 carbon atoms, branched or cyclic alkyl groups having 3 to 60 carbon atoms, alkyl groups having 2 to 20 carbon atoms Alkenyl or alkynyl groups, aromatic organic groups with 6 to 60 carbon atoms, or heteroaromatic organic groups with 3 to 60 carbon atoms; two or more groups ^R can be linked to each other and Rings can be formed.

Further, the electron-donating unit D is preferably one or more of the following structures or halogenated, deuterated, alkyl, alkoxy, and alkylthio substituted derivatives of the following structures:

Wherein, K is C(R ⁴ ) ₂ , NR ⁴ , BR ⁴ , C(R ⁴ ) ₂ O, Si(R ⁴ ) ₂ , Ge(R ⁴ ) ₂ , R ⁴ C=CR ⁴ , C(R ⁴ ) ₂ C(R ⁴ ) ₂ , C=O, C=NR ⁴ , C(=O)O, C(=O)NR ⁴ , P(=O)(R ⁴ ), P(=S)(R ⁴ ), O, S, Se, Te, S(=O) or SO ₂ ; Z is defined as above.

wherein each occurrence of R4 is identically or differently selected from straight ^- chain alkyl groups having 1-60 carbon atoms, branched or cyclic alkyl groups having 3-60 carbon atoms, alkyl groups having 2-20 carbon atoms alkenyl or alkynyl group, aromatic organic group with 6-60 carbon atoms or heteroaromatic organic group with 3-60 carbon atoms, wherein R ⁴ may contain one or more -CH ₂ The - group can be replaced by -R ⁵ C=CR ⁵ -, -C≡C-, Si(R ⁵ ) ₂ , C=O, C=NR ⁵ , -C(=O)O-, -C(=O ) NR ⁵ -, NR ⁵ , P(=O)(R ⁵ ), P(=S)(R ⁵ ), O, S, S(=O) or SO ₂ instead; the same for each occurrence of R ⁵ or Differently selected from straight chain alkyl groups having 1 to 60 carbon atoms, branched or cyclic alkyl groups having 3 to 60 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, An aromatic organic group having 6-60 carbon atoms or a heteroaromatic organic group having 3-60 carbon atoms; two or more groups R ⁴ , R ⁵ may be linked to each other and may form a ring.

Further, in the above-mentioned type of A-D-A type polymer containing metal elements in the main chain, the molecular dipoles of the two A units in each A-D-A repeating unit have opposite directions.

The present invention also provides the above-mentioned preparation method of a type of A-D-A type polymer containing metal elements in the main chain, comprising the following steps:

(1) The D unit containing the bis-alkyl tin functional group is Stille-coupling with the bis-bromo or iodo-substituted Ar to obtain the di-bromo or iodo-substituted A-D-A unit;

(2) react the A-D-A unit of dibromo or iodo with trialkylethynyl silicon in a solvent to obtain the A-D-A unit of two (trialkyl silicon) acetylene end groups; The A-D-A unit of the base reacts with the alkali solution to obtain the A-D-A unit of the diacetylene end group;

(3) After the A-D-A unit of the diacetylene end group is reacted with the metal compound, the A-D-A type polymer containing metal elements in the main chain is obtained.

Further, the molar ratio of the above-mentioned D containing the dialkyl tin functional group to the dibrominated or iodo A unit is 1:2 to 1:4, and the reaction solvent includes but is not limited to toluene, xylene, chlorobenzene, tetrahydrofuran, etc. , the reaction catalysts include but are not limited to tetrakis (triphenylphosphine) palladium, palladium acetate/tri-tert-butylphosphine, tris (dibenzylideneacetone) dipalladium/tris (o-methylphenylphosphine) etc., the reaction temperature is 20～140℃.

Further, the molar ratio of the dibromo or iodo A-D-A unit and trialkylethynyl silicon described in the above step (2) is 1:2～1:10, and the reaction solvent includes but is not limited to diisopropylamine , toluene, xylene, chlorobenzene, tetrahydrofuran, water, methanol, ethanol, isopropanol, etc., the reaction temperature is 0 ~ 150 ℃.

Further, the method for synthesizing a class of A-D-A type polymers whose main chain contains metal elements described in the above step (3), comprises the following steps:

(a) Under the protection of inert gas, the A-D-A monomer of the diacetylene end group is dissolved in an organic solvent, then the metal compound is added, and the reaction is performed at a temperature of 0 to 100 degrees Celsius for 0.1 to 36 hours;

(b) adding an alkaline solution, preferably a solution of an alkali metal or alkaline earth metal hydroxide, and continuing the reaction for 0.1 to 36 hours;

(c) after the reaction is completed, the obtained precipitate is purified to obtain the target product.

Further, the organic solvent described in the above-mentioned step (a) includes but is not limited to ethanol, isopropanol, glycerol, acetic acid, acetone, carbon disulfide, ether, ethyl acetate, pyridine, tetrahydrofuran, methyltetrahydrofuran, chlorobenzene, disulfide At least one of at least one of chlorobenzenes.

Further, the amount of the A-D-A monomer of the diacetylene end group and the metal compound monomer described in step (a) satisfies that the total molar amount of the diacetylene functional group-containing monomer is equal to the total molar amount of the metal compound monomer.

Further, the amount of the alkali described in step (b) is 0.1-100 times of the total molar amount of the reaction monomers.

Further, the purification described in step (c) means that the obtained precipitate is dried without filtration to obtain a crude product, the crude product is dissolved in a solvent, filtered again, concentrated, precipitated in methanol solution after concentration, filtered, and dried to obtain the target product. .

An electronic device selected from the group consisting of: organic thin film transistor (OFET), organic light-emitting transistor (OLET), organic solar cell (OSC), organic photodiode (OPD), organic phototransistor (OPT), organic light-emitting electrochemical cell ( OLEC), an organic electroluminescent diode device (OLED), the electronic device comprising at least one of the above-mentioned A-D-A type polymers containing metal elements in the main chain.

Further, the application of the above-mentioned A-D-A type polymer containing metal elements in the main chain in the preparation of electronic devices, the A-D-A type polymers containing metal elements in the main chain are dissolved in an organic solvent, and then by spin coating. , inkjet printing or printing film.

Compared with the prior art, the present invention has the following advantages and technical effects:

(1) The introduction of metal atoms can provide potential supramolecular effects to induce molecular aggregation.

(2) The A-D-A regular structure is conducive to the stacking of polymer molecules, further improving the mobility and red-shifting the absorption spectrum. In addition, the regular structure is conducive to improving the molecular weight and batch stability of the polymer.

Description of drawings

Figure 1 is a graph of current density-voltage characteristics of an organic/polymer photodetector device based on polymer P1.

Figure 2 is a graph showing the spectral responsivity characteristics of the organic/polymer photodetector device based on polymer P1 under -0.1V bias.

Detailed ways

The present invention will be described in further detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

The reagents used in the examples can be routinely purchased from the market unless otherwise specified.

Example 1

Preparation of compound D1

(1) Preparation of compound 1

In a nitrogen atmosphere, under an ice bath, dithienocyclopentadiene (1.78 g, 10 mmol), sodium tert-butoxide (2.88 g, 30 mmol), and bromo-n-hexadecane (6.67 g, 22 mmol) were added to 100 mL of tetrahydrofuran , and the reaction was stirred for 24 hours. THF was spin-dried under reduced pressure, extracted with dichloromethane, washed three times with saturated aqueous sodium chloride solution, and spin-dried with dichloromethane. The crude product was purified by column chromatography using petroleum ether as eluent to obtain a white solid product with a yield of 90%. The results of ¹ H NMR, ¹³ C NMR, MS and elemental analysis indicated that the obtained compound was the target product.

(2) Preparation of compound D1

Under nitrogen protection, compound 1 (3.14 g, 5 mmol) was dissolved in 150 mL of anhydrous tetrahydrofuran, cooled to -5 °C, n-butyllithium (8 mL, 20 mmol) was added dropwise, and the mixture was stirred at -5 °C for 2 hours. A solution of trimethyltin chloride in tetrahydrofuran (45 mL, 45 mmol) was injected, and the mixture was naturally warmed to room temperature to react for 12 hours. After the tetrahydrofuran was distilled off under reduced pressure, the product was extracted with dichloromethane, washed three times with deionized water, and the dichloromethane was spin-dried. Recrystallization from isopropanol gave the product as a white solid in 87% yield. The results of ¹ H NMR, ¹³ CNMR, MS and elemental analysis indicated that the obtained compound was the target product.

The chemical reaction equations for the synthesis of compounds 1 and D1 are shown below:

Example 2

Preparation of compound D2

(1) Preparation of compound 2

Under nitrogen protection, 3,3'-dibromo-2,2'-bithiophene (3.24g, 10mmol), 2-octyldodecylamine (3.57g, 12mmol) sodium tert-butoxide (2.40g, 25mmol), Tris(dibenzylideneacetone)dipalladium (0.46g, 0.5mmol), 2,2'-bis-(diphenylphosphino)-1,1'-binaphthyl (0.62g, 1mmol) were added to 100mL of anhydrous toluene middle. After heating to 100°C for 12 hours, washing with saturated aqueous sodium chloride solution 3 times, drying the solvent of the organic layer, the crude product was purified by column chromatography using petroleum ether as eluent to obtain a colorless oily product with a yield of 70%. %. The results of ¹ H NMR, ¹³ C NMR, MS and elemental analysis indicated that the obtained compound was the target product.

(2) Preparation of compound D2

The reaction and purification methods of compound D2 were similar to those of compound D1, and a light yellow oily product was obtained with a yield of 84%. The results of ¹ HNMR, ¹³ C NMR, MS and elemental analysis indicated that the obtained compound was the target product.

The chemical reaction equations for the synthesis of compounds 2 and D2 are shown below:

Example 3

Preparation of compound A1

Under nitrogen protection, 2,5-dibromo-3,4-diaminopyridine (2.67 g, 10 mmol) and selenium dioxide (2.78 g, 15 mmol) were dissolved in 50 mL of ethanol, and heated to reflux for 12 hours. After cooling, recrystallization from chloroform gave the product as a bright yellow solid in 70% yield. The results of ¹ H NMR, ¹³ C NMR, MS and elemental analysis indicated that the obtained compound was the target product.

The chemical reaction equation for the synthesis of compound A1 is shown below:

Example 4

Preparation of compound A2

Under nitrogen protection, 2,5-dibromo-3,4-diaminopyridine (2.67 g, 10 mmol) was dissolved in 30 mL of pyridine, cooled to 0 °C, thionyl chloride (1.79 g, 15 mmol) was added, and it was naturally raised to Stir at room temperature for 12 hours. The product was extracted with dichloromethane, the organic layer solvent was spin-dried under reduced pressure, and the crude product was purified by column chromatography using petroleum ether:ethyl acetate=4:1 (v/v) as the eluent to obtain a white solid product in a yield of 51%. The results of ¹ H NMR, ¹³ C NMR, MS and elemental analysis indicated that the obtained compound was the target product.

The chemical reaction equation for the synthesis of compound A2 is shown below:

Example 5

Preparation of compound A3

(1) Preparation of compound 3

Under nitrogen protection, compound A1 (3.42 g, 10 mmol) was dissolved in 50 mL of fuming sulfuric acid, 1 mL of fuming nitric acid was added, and the mixture was stirred at room temperature for 6 hours. The reaction solution was slowly poured into 500 mL of ice water, filtered, and the filter residue was recrystallized from chloroform to obtain a yellow solid product with a yield of 75%. The results of ¹ H NMR, ¹³ C NMR, MS and elemental analysis indicated that the obtained compound was the target product.

(2) Preparation of compound 4

Compound 3 (3.87 g, 10 mmol) and iron powder (1.12 g, 20 mmol) were added to 100 mL of ethanol, 5 mL of concentrated hydrochloric acid was added, and the reaction was stirred for 6 hours. The product was extracted with dichloromethane, washed three times with deionized water, and the solvent of the organic layer was spin-dried to obtain a brown solid product with a yield of 90%. The results of ¹ H NMR, ¹³ C NMR, MS and elemental analysis indicated that the obtained compound was the target product.

(3) Preparation of compound A3

Compound 4 (3.57 g, 10 mmol) was dissolved in 100 ml of dichloromethane containing a small amount of polyvinyl alcohol, 5 mL of hydrochloric acid was placed in an ice bath, stirred at 0 °C for 1 hour, and then sodium nitrite (1.38 g, 20 mmol) was added to continue stirring for 2 hours, and finally cuprous chloride was added to stir the reaction for 12 hours. The product was extracted with dichloromethane, washed 3 times with deionized water, the organic layer solvent was spin-dried, and the crude product was purified by column chromatography with petroleum ether:ethyl acetate=4:1 (volume ratio) as eluent to obtain bright yellow Solid product, 53% yield. The results of ¹ HNMR, ¹³ C NMR, MS and elemental analysis indicated that the obtained compound was the target product.

The chemical reaction equations for the synthesis of compounds 3, 4 and A3 are shown below:

Example 6

Synthesis of Polymer P1

(1) Preparation of compound 5

Under nitrogen atmosphere, compound A1 (7.52 g, 22 mmol), compound D1 (9.53 g, 10 mmol), tetrakis(triphenylphosphine)palladium (0.58 g, 0.5 mmol) were dissolved in 200 mL of anhydrous toluene, and heated to 100 °C The reaction was carried out for 8 hours. After spin-drying toluene, the crude product was purified by column chromatography using petroleum ether:ethyl acetate=1:1 (v/v) as eluent to obtain a solid product with a yield of 57%. The results of ¹ H NMR, ¹³ C NMR, MS and elemental analysis indicated that the obtained compound was the target product.

(2) Preparation of compound 6

Under nitrogen atmosphere, in a 500 mL two-neck round bottom flask, compound 5 (22.98 g, 20 mmol), bis(triphenylphosphine)palladium dichloride (0.475 g, 0.68 mmol) and cuprous iodide (0.052 g) were added in one portion , 0.28 mmol), 200 mL of degassed toluene, 60 mL of degassed diisopropylamine, and stirred to dissolve the solids and mix them uniformly. A solution of trimethylethynylsilicon (4.32 g, 44.0 mmol) in diisopropylamine (30 mL) was added dropwise under argon atmosphere at room temperature. After the dropwise addition, the temperature of the reaction solution was raised to 70 degrees Celsius, and the reaction was carried out under argon protection for 6 hours. The degree of reaction was monitored by thin-layer chromatography. After the reaction, the reaction solution was cooled to room temperature, and impurities such as solid salts were removed by suction filtration. The crude product was separated and purified by column chromatography (silica gel column, eluent is petroleum ether), further recrystallized from methanol to obtain a white solid, filtered and dried in vacuo with a yield of 70%. The results of ¹ H NMR, ¹³ C NMR, MS and elemental analysis indicated that the obtained compound was the target product.

(3) Preparation of compound 7

Under nitrogen atmosphere, 15 mL of 20 wt% potassium hydroxide aqueous solution was added to a solution of compound 6 (14.2 g, 12.0 mmol) in tetrahydrofuran (100 mL), and then 50 mL of methanol was added to dilute the reaction solution. The reaction was uniformly stirred for 1 hour under argon protection and room temperature. The degree of reaction was monitored by thin-layer chromatography. After the reaction, the reaction solution was poured into ice water, extracted with dichloromethane, the oil layer was washed with water and saturated aqueous sodium chloride solution, and concentrated to obtain the crude product. The crude product was separated and purified by column chromatography (silica gel column, eluent is petroleum ether), further recrystallized from methanol to obtain a white solid, filtered and dried in vacuo with a yield of 81%. The results of ¹ H NMR, ¹³ C NMR, MS and elemental analysis indicated that the obtained compound was the target product.

(4) Preparation of polymer P1

Under nitrogen protection, compound 7 (1039.3 mg, 1 mmol) was dissolved in 15 mL of ethyl acetate, mercuric dichloride (272 mg, 1 mmol) was added, the reaction was carried out for 10 minutes, and 10 mL of 0.1 M sodium hydroxide methanol solution was added dropwise, and the reaction was carried out for 10 minutes. , filtered to obtain the crude product, the crude product was dissolved in tetrahydrofuran, passed through a 0.45 μm polytetrafluoroethylene organic filter membrane, concentrated, and the concentrated solution was precipitated in methanol to obtain a filamentous polymer. The cake was dried in a vacuum oven at 45 degrees Celsius for 24 hours to obtain 984 mg of dark green flocculent polymer solid P1 with a yield of 68%.

The chemical reaction equation is as follows:

Example 7

Preparation of polymer P2

(1) Preparation of compound 8

The reaction and purification methods of compound 8 were similar to those of compound 5, and a solid product was obtained with a yield of 62%. The results of ¹ H NMR, ¹³ CNMR, MS and elemental analysis indicated that the obtained compound was the target product.

(2) Preparation of compound 9

The reaction and purification methods of compound 9 were similar to those of compound 6, and a solid product was obtained in a yield of 62%. The results of ¹ H NMR, ¹³ CNMR, MS and elemental analysis indicated that the obtained compound was the target product.

(3) Preparation of compound 10

The reaction and purification methods of compound 10 were similar to those of compound 7, and a solid product was obtained with a yield of 62%. The results of ¹ H NMR, ¹³ CNMR, MS and elemental analysis indicated that the obtained compound was the target product.

(4) Preparation of polymer P2

The reaction and purification methods of polymer P2 are similar to those of polymer P1, and a black fibrous polymer is obtained. The results of ¹ H NMR and elemental analysis indicated that the obtained compound was the target product.

The chemical reaction equation is as follows:

Example 8

Preparation of polymer P3

(1) Preparation of compound 11

The reaction and purification methods of compound 11 were similar to those of compound 5, and a solid product was obtained with a yield of 53%. The results of ¹ H NMR, ¹³ CNMR, MS and elemental analysis indicated that the obtained compound was the target product.

(2) Preparation of compound 12

The reaction and purification methods of compound 12 were similar to those of compound 6, and a solid product was obtained in a yield of 53%. The results of ¹ H NMR, ¹³ CNMR, MS and elemental analysis indicated that the obtained compound was the target product.

(3) Preparation of compound 13

The reaction and purification methods of compound 13 were similar to those of compound 7, and a solid product was obtained in a yield of 53%. The results of ¹ H NMR, ¹³ CNMR, MS and elemental analysis indicated that the obtained compound was the target product.

(4) Preparation of polymer P3

The reaction and purification methods of polymer P3 are similar to those of polymer P1, and a black fibrous polymer is obtained. The results of ¹ H NMR and elemental analysis indicated that the obtained compound was the target product.

The chemical reaction equation is as follows:

Example 9

Preparation of polymer P4

(1) Preparation of compound 14

The reaction and purification methods of compound 14 were similar to those of compound 5, and a solid product was obtained in a yield of 69%. The results of ¹ H NMR, ¹³ CNMR, MS and elemental analysis indicated that the obtained compound was the target product.

(2) Preparation of compound 15

The reaction and purification methods of compound 15 were similar to those of compound 6, and a solid product was obtained in a yield of 69%. The results of ¹ H NMR, ¹³ CNMR, MS and elemental analysis indicated that the obtained compound was the target product.

(3) Preparation of compound 16

The reaction and purification methods of compound 16 were similar to those of compound 7, and a solid product was obtained in a yield of 69%. The results of ¹ H NMR, ¹³ CNMR, MS and elemental analysis indicated that the obtained compound was the target product.

(4) Preparation of polymer P4

The reaction and purification methods of polymer P4 are similar to those of polymer P1, and a black fibrous polymer is obtained. The results of ¹ H NMR and elemental analysis indicated that the obtained compound was the target product. The reaction equation is as follows:

Example 10

Preparation of polymer photodetectors

Take pre-made indium tin oxide (ITO) glass with a square resistance of 15Ω, ultrasonically clean it with acetone, detergent, deionized water and isopropanol in sequence, and treat with plasma for 10 minutes. A polyethoxythiophene (PEDOT:PSS) film doped with polystyrene sulfonic acid was spin-coated on ITO with a thickness of 40 nm. The PEDOT:PSS films were dried in a vacuum oven at 80°C for 8 hours. Then a 1:1 mass ratio of polymer P1 and _PC71BM in o-dichlorobenzene solution (1 wt.%) was spin-coated on the surface of the PEDOT:PSS film with a thickness of 100 nm. Then a thin film of PFN-Br with a thickness of about 5 nm was spin-coated on the active layer. Finally, a metal Al layer with a thickness of 100 nm was evaporated, and the device structure was ITO/PEDOT:PSS/P1:PC ₇₁ BM/PFN-Br/Al.

Among them, Figure 1 is a current density-voltage characteristic diagram of an organic/polymer photodetector device based on polymer P1.

It can be seen that the device has good photodetection characteristics, and the current density at the same voltage under illumination is improved. Figure 2 shows the spectral responsivity characteristics of the organic/polymer photodetector device based on polymer P1 under -0.1V bias, it can be seen that the device has photoelectric response at 300-1000nm.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (11)

1. the A-D-A type polymer that a class of main chain contains metal element is characterized in that, its structural formula is as shown in P1～P4:

In the formula, n is the number of repeating units, and n=2-1000. 2 . The A-D-A type polymer with metal elements in its main chain according to claim 1 , wherein the molecular dipoles of the two A units in each A-D-A repeating unit have opposite directions. 3 . 3. the method for preparing the A-D-A type polymer of a kind of main chain containing metal element described in any one of claim 1～2, is characterized in that, comprises the steps: (1) The D unit containing the bisalkyl tin functional group carries out Stille coupling with the dibromo or iodo A unit to obtain the dibromo or iodo A-D-A unit; (2) react the A-D-A unit of dibromo or iodo with trialkylethynyl silicon in a solvent to obtain the A-D-A unit of two (trialkyl silicon) acetylene end groups; The A-D-A unit of the base reacts with the alkali solution to obtain the A-D-A unit of the diacetylene end group; (3) After the A-D-A unit of the diacetylene end group is reacted with the metal compound, the A-D-A type polymer containing metal elements in the main chain is obtained. 4. preparation method according to claim 3, is characterized in that, the mol ratio of the D of the described step (1) containing bisalkyl tin functional group and the A unit of double bromine or iodine generation is 1:2～1: 4; the Stille coupling reaction solvent in step (1) is toluene, xylene, chlorobenzene or tetrahydrofuran, and the reaction catalyst system is tetrakis(triphenylphosphine) palladium or palladium acetate with a mass ratio of 1:1 to 1:3 : tri-tert-butylphosphine or tris(dibenzylideneacetone)dipalladium:tris(o-methylphenylphosphine) in a mass ratio of 1:1 to 1:3, and the reaction temperature is 20 to 140°C. 5. preparation method according to claim 3, is characterized in that, the mol ratio of the A-D-A unit of step (2) or iodine generation and trialkylethynyl silicon is 1:2～1:10, The reaction solvent is diisopropylamine, toluene, xylene, chlorobenzene, tetrahydrofuran, water, methanol, ethanol or isopropanol, and the reaction temperature is 0-150°C. 6. preparation method according to claim 3 is characterized in that, step (3) specifically comprises following process: (a) Under the protection of inert gas, the A-D-A monomer of the diacetylene end group is dissolved in an organic solvent, then the metal compound is added, and the reaction is performed at a temperature of 0 to 100 degrees Celsius for 0.1 to 36 hours; (b) adding an alkaline solution, using a solution of an alkali metal or alkaline earth metal hydroxide, and continuing the reaction for 0.1 to 36 hours; (c) after the reaction is completed, the obtained precipitate is purified to obtain the target product. 7. the preparation method of the A-D-A type polymer of a class of main chain containing metal element according to claim 6, is characterized in that: the organic solvent described in the step (a) is ethanol, Virahol, glycerol, acetic acid, At least one of acetone, carbon disulfide, diethyl ether, ethyl acetate, pyridine, tetrahydrofuran, methyltetrahydrofuran, chlorobenzene, and dichlorobenzene. 8. the preparation method of the A-D-A type polymer of a class of main chain containing metal element according to claim 6, is characterized in that: the A-D-A monomer and the metal compound monomer of the diene end group described in the step (a) The consumption satisfies that the total molar amount of monomers containing diacetylene functional groups is equal to the total molar amount of metal compound monomers; 0.1 to 100 times. 9. the preparation method of the A-D-A type polymer of a class of main chain metal-containing elements according to claim 6, is characterized in that: the described purification of step (c) refers to the filtration drying of gained precipitate to obtain crude product, thick The product is dissolved in solvent, filtered again, concentrated, precipitated in methanol solution after concentration, filtered and dried to obtain the target product. 10. The application of a type of A-D-A type polymer containing metal elements in the main chain of any one of claims 1 to 2 in the preparation of electronic devices, wherein the electronic devices comprise organic thin film transistors OFET, organic light-emitting transistors OLET , Organic solar cell OSC, organic photodiode OPD, organic phototransistor OPT, organic light-emitting electrochemical cell OLEC, organic electroluminescent diode device OLED. 11. The application of the type of A-D-A type polymer containing metal elements in the main chain according to any one of claims 1 to 2 in the preparation of the electronic device according to claim 10, characterized in that: the type of The A-D-A type polymer containing metal elements in the main chain is dissolved in an organic solvent and then formed into a film by spin coating, inkjet printing or printing.

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