CN106832229A - Polymer and its application containing the hexa-atomic sulfuryl condensed ring unit of dibenzo - Google Patents

Abstract

The invention discloses a polymer containing a dibenzohexasulfone-based condensed ring unit and an application thereof. The polymer containing dibenzohexasulfone-based fused ring units of the present invention is obtained from dibenzohexasulfone-based fused-ring monomers through Suzuki, Stille or Yamamoto polymerization reactions, dibenzohexasulfone-based fused-ring monomers It has the advantages of simple structure and easy synthesis. The existence of sulfone group in the monomer is beneficial to increase electron affinity, promote electron injection and transport, and has high fluorescence efficiency and chemical stability. The polymer of the invention has good solubility in organic solvents, is suitable for solution processing, and has broad application prospects in the field of organic photoelectricity, especially deep blue organic electroluminescence.

Description

Polymer containing dibenzohexasulfone-based fused ring unit and its application

technical field

The invention relates to the field of organic photoelectric materials, in particular to polymers containing dibenzohexasulfone-based condensed ring units and applications thereof.

Background technique

The research on organic/polymer light-emitting diodes (O/PLEDs) began in the 1980s and 1990s. It is a type of light-emitting diodes based on organic small molecules and polymer materials. The advantages of cost, low energy consumption, easy fabrication, flexibility, and large-size panels have broad application prospects in the fields of organic flat panel displays and white lighting. Organic solar cell materials started in the 1990s. They are a new type of sustainable renewable low-cost green energy materials, and are easy to prepare large-area flexible batteries, so they have great application potential. Organic field-effect transistors are transistor devices that use organic semiconductor materials as the active layer, and have attracted widespread attention for their low cost, flexibility and bendability, and the ability to manufacture large-area devices. Therefore, the field of organic optoelectronics has attracted the attention and investment of many research institutions and scientific research teams in the world, and the development of new efficient and stable materials is the focus of attention in the field of organic optoelectronics.

The dibenzo-6-membered sulfone-based condensed ring is a three-membered ring, which has the advantages of simple structure, short synthesis steps, high yield, and low raw material prices, etc., and is easy to industrialize. Change the five-membered ring of oxidized thiophene in S,S-dioxy-dibenzothiophene to a six-membered ring, that is, a dibenzo-6-membered sulfone-based condensed ring. Like S, S-dioxy-dibenzothiophene, the dibenzo-6-membered sulfone-based fused ring can be modified at multiple positions on the benzene ring to obtain polymerized monomers; the sulfur atom in the sulfone group is in the highest chemical valence state, with Strong chemical and thermal stability; at the same time, due to the existence of the sulfone group, the electron affinity of the unit is improved, and the electron mobility of the material is also enhanced, so that the polymer based on this has the characteristics of bipolarity. In addition, compared with the S, S-dioxy-dibenzothiophene unit, the dibenzo-6-membered sulfone-based fused ring unit has its unique advantages: 1) The six-membered ring in the dibenzo-6-membered sulfone-based fused-ring unit It is a non-planar structure, and the dihedral angle of the two benzene rings is about 145°, which weakens its conjugation and blue-shifts the emission spectrum; 2) The 9-position atom in the dibenzo-6-membered sulfone-based fused ring unit is sp ³ hybridized , so that the conjugation of the entire fused ring is weakened. At the same time, the 9-position atom is varied, and a wide variety of derivatives with different conjugation strengths can be obtained, and it is easy to obtain polymers with different emission spectra, especially deep blue light emission. The above advantages make the dibenzohexasulfone-based condensed ring unit have a good application prospect in the field of organic optoelectronics, especially in deep blue photoluminescent devices and medium-band gap polymer solar cell donor materials.

Recently, some small-molecule light-emitting materials based on dibenzo-6-membered sulfone-based fused rings have been reported. Su Shijian's research group synthesized 10,10-dioxo-spiro[fluorene-9,9-thianthracene] brominated at the 2',7' position, and coupled with electron-rich units triphenylamine and carbazole to obtain blue light/dark blue Light-emitting small molecules, in which TPA-SO2 coupled with triphenylamine is in ITO(95nm)/HATCN(5nm)/NPB(30nm)/TCTA(10nm)/EML(30nm)/TPBI(30nm)/LiF(1nm ) Al (90nm) device structure, the current efficiency is 5.46cd/A, and the color coordinates are (0.154,0.168)[Chem.Mater.,2015,27,1100-1109.]. Since then, based on 2-bromo-5,5',10,10'-tetraoxythianthrene, a small molecule fluorescent material with high efficiency yellow-green light emission with TADF effect has been reported [Adv.Mater.2016,28,181-187.]. Lee and Santos also reported a small molecule luminescent material with high external quantum efficiency based on 2,7-dibromo-9,9'-dimethyl-S,S-dioxthioxanthene [Organic Electronics, 2016 , 29, 160-164; J. Mater. Chem. C, 2016, 4, 3815-3824.].

Compared with small molecule luminescent materials, polymer luminescent materials are easier to process (spin coating, inkjet printing, etc.), and the device is simple to manufacture; the material has a high glass transition temperature, is not easy to crystallize, and the stability of the device is improved; The ratio of bulk, main chain or side chain structure can be used to adjust the emission spectrum of the polymer to realize the three primary colors of red, green and blue. However, the polymer containing dibenzohexasulfone-based fused ring unit has good solubility, is suitable for solution processing, and has good fluorescence spectrum and high efficiency when used as a luminescent material.

Contents of the invention

The invention provides a dibenzohexasulfone-based fused ring monomer and a preparation method thereof, and introduces the dibenzohexasulfone-based fused ring monomer into a conjugated polymer, and synthesizes a main chain containing a dibenzohexamethylene A polymer of sulfone-based fused ring units.

The invention provides a polymer containing a dibenzohexasulfone-based condensed ring unit, which is applied to make an organic electroluminescent device, an organic solar battery or an organic field effect transistor.

The polymer containing dibenzohexasulfone-based fused ring units, the main chain contains dibenzohexavalent sulfone-based fused ring units, and has the following chemical structural formula:

In the formula, x and y are the mole fractions of unit components, satisfying: 0<x≤1, x+y=1; degree of polymerization n=1～300;

Y is C(R) ₂ , C=N(R), C=C(R) ₂ , Si(R) ₂ or SO ₂ ; R represents H, D, an alkyl group with 1 to 30 carbon atoms or a ring Alkyl, alkyl substituted aryl with 6 to 30 carbon atoms;

Ar is an alkyl-substituted aryl group with 6 to 60 carbon atoms or an alkyl-substituted aromatic heterocyclic group with 4 to 60 carbon atoms, and is one or more of the following chemical structures or derivatives of the following chemical structures:

Wherein, R ₁ and R ₂ are respectively H, D, an alkyl or cycloalkyl group with 1 to 30 carbon atoms, or an alkyl-substituted aryl group with 6 to 30 carbon atoms;

Z ₁ and Z ₂ are H, D, F, nitrile, nitro, acyl, alkoxy, carbonyl or sulfone.

Further, the monomer of the dibenzohexasulfone-based fused ring unit has the following chemical structural formula:

In the formula, X is Br or I atom; Y is C(R) ₂ , C=N(R), C=C(R) ₂ , Si(R) ₂ or SO ₂ ; R is represented by H, D, carbon An alkyl group or cycloalkyl group having 1 to 30 atoms, or an alkyl group having 6 to 30 carbon atoms substituted for an aryl group.

Further, the preparation method of the monomer of the dibenzohexasulfone-based fused ring unit comprises the following steps:

The raw material of dibenzohexasulfone-based condensed ring is dissolved in concentrated sulfuric acid, then N-bromosuccinimide (NBS) is added, and reacted at room temperature; after the reaction, extraction, drying, and purification are carried out to obtain The dibenzo-hexasulfone-based fused ring monomer; the preparation process is as follows:

Furthermore, the molar ratio of the dibenzohexasulfone-based fused ring raw material to N-bromosuccinimide is 1:2.2.

Furthermore, the reaction time is 24 hours.

Further, the preparation method of the dibenzohexasulfone-based fused ring monomer comprises the following steps:

4-bromo-2-iodothiophenol is reacted under the catalysis of palladium acetate and triphenylphosphine to obtain 2,7-dibromothianthrene; then in acetic acid, hydrogen peroxide is oxidized to obtain disulfone containing two sulfone groups. Benzohexasulfone-based condensed ring monomer - 2,7-dibromo-tetraxanthene monomer; the preparation process is as follows:

Furthermore, the temperature of the catalytic reaction is 60-80° C., and the reaction time is 24 hours.

Furthermore, the hydrogen peroxide oxidation temperature is 80-100° C., and the oxidation time is 8 hours.

The application of the polymer containing dibenzohexasulfone-based fused ring unit in the manufacture of organic electroluminescent devices, organic solar cells or organic field effect transistors.

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

(1) The present invention provides a simple and effective synthesis route of dibenzohexasulfone-based condensed ring monomer, and the raw material price is low, the synthesis route is short, the reaction yield is high, the monomer is easy to purify, and is conducive to large-scale production;

(2) The present invention obtains different dibenzo-6-membered sulfone-based fused-ring polymerization monomers by modifying multiple positions of the benzene ring of the dibenzo-6-membered sulfone-based fused ring;

(3) The presence of the sulfone group in the dibenzohexasulfone-based fused ring monomer of the present invention increases the electron affinity of the monomer, and enhances the electron mobility, so that the electron transport properties of the prepared polymer Improve, the polymer has bipolar characteristics;

(4) In the dibenzo-6-membered sulfone-based condensed ring of the present invention, the 9-position atom in the 6-membered ring is varied, and a wide variety of dibenzo-6-membered sulfone-based fused ring derivatives with different conjugation lengths can be obtained;

(5) In the polymer of the present invention, the introduction of dibenzo-hexasulfone-based fused ring unit endows the polymer with better thermal stability;

(6) The six-membered ring in the dibenzo six-membered sulfone-based fused ring monomer of the present invention is a non-planar structure, and the 9-position atom in the six-membered ring is _sp3 hybridized, so that the conjugation of the entire fused ring is weakened, It is easy to obtain high-efficiency deep-blue light-emitting polymers, which provides a new idea for the development of high-efficiency deep-blue light-emitting organic electroluminescent materials.

Description of drawings

Fig. 1 is the thermogravimetric analysis curve of polymer P1, P3 and P5;

Fig. 2 is the differential scanning calorimetry curve of polymer P1, P3 and P5;

Fig. 3 is the ultraviolet-visible absorption spectrum in polymer P1, P3 and P5 film;

Fig. 4 is the photoluminescence spectrum in polymer P1, P3 and P5 film;

Fig. 5 is the cyclic voltammetry characteristic curve of polymer P1, P3 and P5;

Fig. 6 is the device electroluminescence curve of polymer P1, P3 and P5;

Fig. 7 is the device lumen efficiency-current density curve of polymer P1, P3 and P5;

Fig. 8 is the device voltage-current density-brightness curve of polymer P1, P3 and P5;

Fig. 9 is the ultraviolet-visible absorption spectrum of polymer P30 film and polymer P30 in chloroform solution.

detailed description

The present invention will be further described below in conjunction with the examples and accompanying drawings, but the present invention is not limited to the following examples.

Example 1

3,6-Dibromo-9,9'-dimethyl-S,S-dioxythioxanthene (M-1)

Synthesis of 3,6-dibromo-9,9'-dimethyl-S,S-dioxthioxanthene (M-1): Under nitrogen protection, 9,9'-dimethyl-S,S- Dioxythioxanthene (1g, 3.87mmol) was dissolved in 10ml of concentrated sulfuric acid, and N-bromosuccinimide (NBS, 1.52g, 8.54mmol) was added in 3 times in a dark state, and reacted at room temperature for 24 hours; The reaction solution was poured into 100ml of ice water, the product was extracted with dichloromethane, the organic phase was washed 3 times with saturated sodium chloride solution; the solvent was spin-dried, and the crude product was recrystallized 3 times with a mixed solvent of tetrahydrofuran/n-hexane to obtain a colorless Crystalline product (1.01 g, yield 62%). ¹ H NMR (500 MHz, CDCl ₃ ) δ 8.29 (d, 2H), 7.72 (dd, 2H), 7.60 (d, 2H), 1.85 (s, 6H).

Example 2

2,7-Dibromo-9,9'-dimethyl-S,S-dioxthioxanthene (M-2)

(1) Synthesis of 2,7-dibromo-9,9'-dimethylthioxanthene (1): Dissolve 9,9'-dimethylthioxanthene (1g, 4.42mmol) in 10ml under nitrogen protection In acetic acid, add liquid bromine (0.56ml, 11mmol) dissolved in 2ml of acetic acid dropwise under ice-cooling, and the reaction solution naturally rose to room temperature to continue the reaction for 6 hours; the reaction was quenched with sodium bisulfite solution, the product was extracted with dichloromethane, saturated The organic phase was washed three times with sodium chloride solution; the solvent was spin-dried, and the crude product was purified by column chromatography using petroleum ether as the eluent to obtain a white solid (1.32 g, yield 78%). ¹ H NMR (500 MHz, CDCl ₃ ) δ 7.62 (d, 2H), 7.32 (dd, 2H), 7.28 (d, 2H), 1.64 (s, 6H).

(2) Synthesis of 2,7-dibromo-9,9'-dimethyl-S,S-dioxthioxanthene (M-2): Under nitrogen protection, 2,7-di-9,9' -Dimethylthioxanthene (1g, 2.60mmol) was dissolved in 20ml of acetic acid, stirred and heated to 100°C, slowly added dropwise 30wt% hydrogen peroxide solution (2ml, 20mmol), and continued to react at 100°C for 8 hours; cooled the reaction solution, and stopped stirring , stood still for 10 h, filtered to obtain a crude product, and then recrystallized three times from a tetrahydrofuran/n-hexane mixed solvent to obtain a colorless crystal product (0.81 g, yield 75%). ¹ H NMR (500 MHz, CDCl ₃ ) δ 8.03 (d, 2H), 7.87 (d, 2H), 7.67 (dd, 2H), 1.87 (s, 6H).

Example 3

2’,7’-Dibromo-10,10-dioxo-spiro[fluorene-9,9-thianthracene](M-3)

(1) Synthesis of 2',7'-dibromo-spiro[fluorene-9,9-thianthracene](2): Under nitrogen protection, a solution of 2-bromobiphenyl (1.17g, 5mmol) in tetrahydrofuran (5ml ) was slowly added dropwise to magnesium chips (0.19g, 8mmol), heated to 65°C and refluxed for 4 hours to obtain a biphenyl Grignard reagent; then 2,7-dibromothioxanthone (1g, 2.70mmol) was added to the The prepared biphenyl Grignard reagent was refluxed at 65°C for 8 hours; after the reaction solution was cooled, the tetrahydrofuran was spin-dried, and the obtained solid was dissolved in acetic acid without treatment, and heated to 118°C under nitrogen protection for reflux reaction for 12 hours; After the reaction was completed, the reaction solution was slowly poured into ice water, and the filter residue was obtained by suction filtration. The sample was loaded by dry method and purified by column chromatography with petroleum ether as eluent to obtain a white solid (0.82 g, yield: 60%). ¹ H NMR (500 MHz, CDCl ₃ ) δ 7.80 (d, 2H), 7.52 (d, 2H), 7.30 (dd, 2H), 7.26 (m, 6H), 6.60 (s, 2H).

(2) Synthesis of 2',7'-dibromo-10,10-dioxaspiro[fluorene-9,9-thianthracene](M-3): Under nitrogen protection, 2',7'-dibromo -Spiro[fluorene-9,9-thianthracene] (1g, 1.98mmol) was dissolved in 40ml of acetic acid/tetrahydrofuran (volume ratio 1:1) mixed solvent, stirred and heated to 70°C, slowly added dropwise 30wt% hydrogen peroxide solution (2ml , 20mmol), 70 ℃ continued to react for 8 hours; cooled the reaction solution, stopped stirring, stood still for 10 hours, filtered to obtain the crude product, and recrystallized 3 times with tetrahydrofuran/n-hexane mixed solvent to obtain a colorless crystal product (0.87 g, yield 82%). ¹ H NMR (500MHz, CDCl ₃ ) δ8.08(d, J=8.5Hz, 2H), 7.88(d, 2H), 7.61(dd, 2H), 7.48(td, J=7.6, 2H), 7.38- 7.26 (m, 4H), 6.66 (d, 2H).

Example 4

2,7-Dibromo-5,5’,10,10’-tetraoxythianthrene (M-4)

(1) Synthesis of 2,7-dibromothianthrene (3): Under nitrogen protection, 4-bromo-2 iodothiophenol (1g, 3.17mmol), palladium acetate (72mg, 0.32mmol), triphenyl Phosphine (0.26g, 1mmol) and sodium tert-butoxide (0.77g, 8mmol) were added to 10ml of anhydrous toluene, heated to 80°C and reacted for 24 hours; after the reaction solution was cooled, the product was extracted with dichloromethane, and the organic solution was washed with saturated brine. phase three times; the solvent was spin-dried, and the crude product was purified by column chromatography using petroleum ether as the eluent to obtain a white solid (0.49 g, yield 83%); (mass spectrum-APCI: 373.9).

(2) Synthesis of 2,7-dibromo-5,5',10,10'-tetraoxythianthrene (M-4): Under nitrogen protection, 2,7-dibromothianthrene (1g, 2.67mmol ) was dissolved in 20ml of acetic acid, stirred and heated to 100°C, slowly added dropwise 30wt% hydrogen peroxide solution (4ml, 40mmol), and continued to react at 100°C for 8 hours; cooling the reaction solution, stopping stirring, standing for 10h, filtering to obtain the crude product, and then Recrystallized 3 times with tetrahydrofuran/n-hexane mixed solvent to obtain colorless crystal product (0.91 g, yield 78%); (mass spectrum-APCI: 437.9).

Example 5

2,7-Dibromo-9-(propanedicyanomethylene)-S,S-dioxythioxanthene (M-5)

(1) Synthesis of 2,7-dibromo-9-(propanedicyanomethylene)-S,S-dioxythioxanthene (M-5): Under nitrogen protection, 2,7-dibromo-S , S-Dioxythioxanthone (1g, 2.49mmol) and propanedicyanide (0.18g, 2.74mmol) were dissolved in 10ml of dimethyl sulfoxide, and reacted at 110°C for 5 hours; after the reaction was stopped and cooled, it was obtained by suction filtration The red solid was washed with acetonitrile for 3 times to obtain a crude product; the crude product was recrystallized from a tetrahydrofuran/ethanol mixed solvent to obtain the product (0.96 g, yield 86%); (mass spectrum-APCI: 449.8).

Example 6

Preparation of Poly(2,7-Fluorene-co-3,6-S,S-Dioxythioxanthene)(P1-P6)

Synthesis of polymer P1: Under nitrogen protection, 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-dioctyl 2,7-dibromo-9,9-dioctylfluorene (147.9mg, 0.27mmol) and 3,6-dibromo-9,9'-dimethyl- S, S-Dioxythioxanthene (12.5mg, 0.03mmol) was dissolved in 8mL of toluene, and then added tetraethylhydroxylamine aqueous solution (1ml, wt% = 25%), palladium acetate (1mg), tricyclohexylphosphine (2mg ). After heating to 85°C and reacting for 24 hours, phenylboronic acid (20 mg) was added for capping for 6 hours, and bromobenzene (0.2 ml) was added for capping for 6 hours. After the reaction stopped, after cooling, the organic phase was precipitated in methanol (200ml), filtered, and after drying slightly, the crude product was extracted with methanol, acetone, and n-hexane successively. Dissolve the polymer in toluene, use toluene as eluent, and perform column chromatography purification with neutral alumina. The toluene solution of the polymer was concentrated, precipitated in methanol solution again, filtered, and dried to obtain a near-white fibrous polymer.

Polymer P1: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (147.9mg, 0.27mmol) and 3,6-dibromo-9,9'-dimethyl-S,S-dioxythiazide Tons (12.5mg, 0.03mmol). ¹ H NMR (500MHz, CDCl ₃ )δ(ppm): 8.56(br,ArH),7.94(br,ArH),7.89(br,ArH),7.85(br,ArH),7.68(br,ArH),2.13 (br, CH2), 2.02 (br, CH3), 1.26-1.05 (br, CH2), 0.85-0.75 (br, CH3).

Polymer P2: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (131.6mg, 0.24mmol) and 3,6-dibromo-9,9'-dimethyl-S,S-dioxythiazide Tons (25.0mg, 0.06mmol). ¹ H NMR (500MHz, CDCl ₃ )δ(ppm): 8.56(br,ArH),7.93(br,ArH),7.90(br,ArH),7.85(br,ArH),7.69(br,ArH),2.13 (br, CH2), 2.01 (br, CH3), 1.26-1.05 (br, CH2), 0.90-0.70 (br, CH3).

Polymer P3: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (115.2mg, 0.21mmol) and 3,6-dibromo-9,9'-dimethyl-S,S-dioxythiazide Tons (37.4mg, 0.09mmol). ¹ H NMR (500MHz, CDCl ₃ )δ(ppm): 8.56(br,ArH),7.94(br,ArH),7.89(br,ArH),7.85(br,ArH),7.68(br,ArH),2.12 (br, CH2), 2.01 (br, CH3), 1.26-1.05 (br, CH2), 0.85-0.75 (br, CH3).

Polymer P4: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (98.7mg, 0.18mmol) and 3,6-dibromo-9,9'-dimethyl-S,S-dioxythiazide Tons (49.9mg, 0.12mmol). ¹ H NMR (500MHz, CDCl ₃ )δ(ppm):8.55(br,ArH),7.94(br,ArH),7.89(br,ArH),7.85(br,ArH),7.67(br,ArH),2.12 (br, CH2), 2.01 (br, CH3), 1.25-1.05 (br, CH2), 0.85-0.75 (br, CH3).

Polymer P5: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (82.3mg, 0.15mmol) and 3,6-dibromo-9,9'-dimethyl-S,S-dioxythiazide Tons (62.4mg, 0.15mmol). ¹ H NMR (500MHz, CDCl ₃ )δ(ppm): 8.55(br,ArH),7.94(br,ArH),7.89(br,ArH),7.85(br,ArH),7.68(br,ArH),2.12 (br, CH2), 2.01 (br, CH3), 1.26-1.05 (br, CH2), 0.85-0.75 (br, CH3).

Polymer P6: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (65.8mg, 0.12mmol) and 3,6-dibromo-9,9'-dimethyl-S,S-dioxythiazide Tons (74.9mg, 0.18mmol). ¹ H NMR (500MHz, CDCl ₃ )δ(ppm):8.55(br,ArH),7.93(br,ArH),7.88(br,ArH),7.85(br,ArH),7.67(br,ArH),2.11 (br, CH2), 2.01 (br, CH3), 1.26-1.05 (br, CH2), 0.85-0.75 (br, CH3).

Among them, the thermogravimetric analysis curves of polymers P1, P3 and P5 are shown in Figure 1, and it can be seen from Figure 1 that the thermal decomposition temperatures (T _d , mass loss 5%) of polymers P1, P3 and P5 all exceed 400 ° C, It shows that the polymer has a relatively rigid molecular backbone, which endows the polymer with better thermal stability.

The differential scanning calorimetry curves of polymers P1, P3 and P5 are shown in Figure 2. It can be seen from Figure 2 that with the increase of 9,9'-dimethyl-S, S-dioxythioxanthene content, the polymer The glass transition temperature (Tg) of the polymer gradually increased (88°C to 140°C), indicating that the introduction of 9,9'-dimethyl-S,S-dioxythioxanthene can effectively improve the thermal stability of the polymer.

The ultraviolet-visible absorption spectra of polymers P1, P3 and P5 films are shown in Figure 3. It can be seen from Figure 3 that the polymers have only one broad absorption peak, and the absorption peaks are all between 360 and 385 nm. The π-π* transition absorption of the main chain of the molecule; with the increase of the content of 9,9'-dimethyl-S,S-dioxthioxanthene, the absorption peak has a significant blue shift, which is due to the non-conjugated 9, The 9'-dimethyl-S,S-dioxythioxanthene monomer interrupts the conjugation length of the polymer main chain, which reduces the conjugation degree of the polymer main chain.

The photoluminescence spectrum in polymer P1, P3 and P5 film is as shown in Figure 4, as can be seen from Figure 4, all polymers all present dark blue light emission, and emission peak is 426 and 446nm, and the half maximum width of emission peak is 44nm, And the increase of the content of non-conjugated charge-absorbing unit 9,9'-dimethyl-S, S-dioxthioxanthene will not cause the blue shift and broadening of the spectrum.

The cyclic voltammetry characteristic curves of polymers P1, P3 and P5 are shown in Figure 5. It can be seen from Figure 5 that the oxidation potential and reduction potential of polymers P1, P3 and P5 gradually shift to the right, and the energy levels of HOMO and LUMO gradually decrease, indicating that With the increase of 9,9'-dimethyl-S, S-dioxythioxanthene unit content, the electronegativity of the polymer gradually increases, which is beneficial to improve the electron transport performance of the polymer.

Example 7

Preparation of Poly(2,7-Fluorene-co-2,7-S,S-Dioxythioxanthene)(P7-P12)

The synthesis method of polymer P7-P12 is the same as the synthesis method of polymer P1 in Example 6, except that the monomer 3,6-dibromo-9,9'-dimethyl-S,S-dioxythiazide Ton was replaced by 2,7-dibromo-9,9'-dimethyl-S,S-dioxthioxanthene.

Polymer P7: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (147.9mg, 0.27mmol) and 2,7-dibromo-9,9'-dimethyl-S,S-dioxythiazide Tons (12.5mg, 0.03mmol). ¹ H NMR (500MHz, CDCl ₃ )δ(ppm): 8.33(br,ArH), 8.05(br,ArH), 7.92-7.78(br,ArH), 7.76-7.63(br,ArH), 7.61(br, ArH), 2.11 (br, CH2), 1.26-1.05 (br, CH2), 0.82 (br, CH3).

Polymer P8: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (131.6mg, 0.24mmol) and 2,7-dibromo-9,9'-dimethyl-S,S-dioxythiazide Tons (25.0mg, 0.06mmol). ¹ H NMR (500MHz, CDCl ₃ ) δ (ppm): 8.34 (br, ArH), 8.05 (br, ArH), 7.90-7.78 (br, ArH), 7.75-7.62 (br, ArH), 7.61 (br, ArH), 2.11 (br, CH2), 1.26-1.05 (br, CH2), 0.82 (br, CH3).

Polymer P9: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (115.2mg, 0.21mmol) and 2,7-dibromo-9,9'-dimethyl-S,S-dioxythiazide Tons (37.4mg, 0.09mmol). ¹ H NMR (500MHz, CDCl ₃ ) δ (ppm): 8.33 (br, ArH), 8.05 (br, ArH), 7.90-7.78 (br, ArH), 7.75-7.62 (br, ArH), 7.60 (br, ArH), 2.11 (br, CH2), 1.26-1.05 (br, CH2), 0.82 (br, CH3).

Polymer P10: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (98.7mg, 0.18mmol) and 2,7-dibromo-9,9'-dimethyl-S,S-dioxythiazide Tons (50.0mg, 0.12mmol). ¹ H NMR (500MHz, CDCl ₃ ) δ (ppm): 8.33 (br, ArH), 8.04 (br, ArH), 7.90-7.78 (br, ArH), 7.75-7.62 (br, ArH), 7.60 (br, ArH), 2.11 (br, CH2), 1.26-1.05 (br, CH2), 0.82 (br, CH3).

Polymer P11: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (82.3mg, 0.15mmol) and 2,7-dibromo-9,9'-dimethyl-S,S-dioxythiazide Tons (62.4mg, 0.15mmol). ¹ H NMR (500MHz, CDCl ₃ ) δ (ppm): 8.33 (br, ArH), 8.04 (br, ArH), 7.90-7.78 (br, ArH), 7.75-7.62 (br, ArH), 7.60 (br, ArH), 2.10 (br, CH2), 1.26-1.05 (br, CH2), 0.81 (br, CH3).

Polymer P12: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (65.8mg, 0.12mmol) and 2,7-dibromo-9,9'-dimethyl-S,S-dioxythiazide Tons (74.9mg, 0.18mmol). ¹ H NMR (500MHz, CDCl ₃ )δ(ppm): 8.33(br,ArH),8.04(br,ArH),7.92-7.78(br,ArH),7.75-7.63(br,ArH),7.61(br, ArH), 2.11 (br, CH2), 1.26-1.05 (br, CH2), 0.81 (br, CH3).

Similarly, the obtained polymers are all introduced with fused ring units of 9,9'-dimethyl-S, S-dioxythioxanthene, so that the polymers have higher thermal stability and higher electron transport performance.

Example 8

Preparation of poly(2,7-fluorene-co-2',7'-10,10-dioxo-spiro[fluorene-9,9-thianthracene])(P13-18)

Synthesis of polymer P13: Under nitrogen protection, 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-bis(4 -(2-Ethylhexyloxy)phenyl)fluorene (248.0mg, 0.3mmol), 2,7-dibromo-9,9-bis(4-(2-ethylhexyloxy)phenyl ) fluorene (197.8 mg, 0.27 mmol) and 2',7'-dibromo-10,10-dioxo-spiro[fluorene-9,9-thianthracene] (16.1 mg, 0.03 mmol) were dissolved in 8 mL of toluene, Tetraethylhydroxylamine aqueous solution (1 ml, wt% = 25%), palladium acetate (1 mg), and tricyclohexylphosphine (2 mg) were further added. After heating to 85°C and reacting for 24 hours, phenylboronic acid (20 mg) was added for capping for 6 hours, and bromobenzene (0.2 ml) was added for capping for 6 hours. After the reaction stopped, after cooling, the organic phase was precipitated in methanol (200ml), filtered, and after drying slightly, the crude product was extracted with methanol, acetone, and n-hexane successively. Dissolve the polymer in toluene, use toluene as eluent, and perform column chromatography purification with neutral alumina. The toluene solution of the polymer was concentrated, precipitated in methanol solution again, filtered, and dried to obtain a near-white fibrous polymer.

Polymer P13: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-bis(4-(2-ethylhexyl) Alkoxy)phenyl)fluorene (248.0mg, 0.3mmol), 2,7-dibromo-9,9-bis(4-(2-ethylhexyloxy)phenyl)fluorene (197.8mg, 0.27 mmol) and 2',7'-dibromo-10,10-dioxo-spiro[fluorene-9,9-thianthracene] (16.1 mg, 0.03 mmol). ¹ HNMR (500MHz, CDCl ₃ ) δ (ppm): 8.25 (br, ArH), 7.80 (br, ArH), 7.75 (br, ArH), 7.69 (br, ArH), 7.63 (br, ArH), 7.59 ( br,ArH),7.55-7.51(br,ArH),7.44-7.40(br,ArH),7.24(br,ArH),7.15(br,ArH),7.10(br,ArH),7.04(br,ArH) , 6.92 (br, ArH), 6.75 (br, ArH), 3.78 (br, CH ₂ ), 1.67 (br, CH ), 1.48-1.28 (br, CH ₂ ), 0.88 (br, CH ₃ ).

Polymer P14: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-bis(4-(2-ethylhexyl Alkoxy)phenyl)fluorene (248.0mg, 0.3mmol), 2,7-dibromo-9,9-bis(4-(2-ethylhexyloxy)phenyl)fluorene (175.8mg, 0.24 mmol) and 2',7'-dibromo-10,10-dioxo-spiro[fluorene-9,9-thianthracene] (32.3mg, 0.06mmol). ¹ HNMR (500MHz, CDCl ₃ ) δ (ppm): 8.25 (br, ArH), 7.80 (br, ArH), 7.75 (br, ArH), 7.69 (br, ArH), 7.63 (br, ArH), 7.59 ( br,ArH),7.55-7.51(br,ArH),7.44-7.40(br,ArH),7.24(br,ArH),7.15(br,ArH),7.10(br,ArH),7.04(br,ArH) , 6.90 (br, ArH), 6.75 (br, ArH), 3.77 (br, CH ₂ ), 1.68 (br, CH ), 1.48-1.26 (br, CH ₂ ), 0.88 (br, CH ₃ ).

Polymer P15: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-bis(4-(2-ethylhexyl Alkoxy)phenyl)fluorene (248.0mg, 0.3mmol), 2,7-dibromo-9,9-bis(4-(2-ethylhexyloxy)phenyl)fluorene (153.9mg, 0.21 mmol) and 2',7'-dibromo-10,10-dioxo-spiro[fluorene-9,9-thianthracene] (48.4mg, 0.09mmol). ¹ HNMR (500MHz, CDCl ₃ ) δ (ppm): 8.25 (br, ArH), 7.79 (br, ArH), 7.75 (br, ArH), 7.68 (br, ArH), 7.63 (br, ArH), 7.59 ( br,ArH),7.55-7.47(br,ArH),7.43-7.39(br,ArH),7.24(br,ArH),7.15(br,ArH),7.09(br,ArH),7.04(br,ArH) , 6.90 (br, ArH), 6.74 (br, ArH), 3.77 (br, CH ₂ ), 1.67 (br, CH ), 1.48-1.28 (br, CH ₂ ), 0.88 (br, CH ₃ ).

Polymer P16: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-bis(4-(2-ethylhexyl Alkoxy)phenyl)fluorene (248.0mg, 0.3mmol), 2,7-dibromo-9,9-bis(4-(2-ethylhexyloxy)phenyl)fluorene (131.9mg, 0.18 mmol) and 2',7'-dibromo-10,10-dioxo-spiro[fluorene-9,9-thianthracene] (64.6mg, 0.12mmol). ¹ HNMR (500MHz, CDCl ₃ ) δ (ppm): 8.25 (br, ArH), 7.79 (br, ArH), 7.75 (br, ArH), 7.69 (br, ArH), 7.63 (br, ArH), 7.59 ( br,ArH),7.55-7.47(br,ArH),7.44-7.39(br,ArH),7.24(br,ArH),7.15(br,ArH),7.09(br,ArH),7.04(br,ArH) , 6.90 (br, ArH), 6.75 (br, ArH), 3.77 (br, CH ₂ ), 1.67 (br, CH ), 1.48-1.28 (br, CH ₂ ), 0.88 (br, CH ₃ ).

Polymer P17: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-bis(4-(2-ethylhexyl Alkoxy)phenyl)fluorene (248.0mg, 0.3mmol), 2,7-dibromo-9,9-bis(4-(2-ethylhexyloxy)phenyl)fluorene (109.9mg, 0.15 mmol) and 2',7'-dibromo-10,10-dioxo-spiro[fluorene-9,9-thianthracene] (80.7 mg, 0.15 mmol). ¹ HNMR (500MHz, CDCl ₃ ) δ (ppm): 8.24 (br, ArH), 7.79 (br, ArH), 7.75 (br, ArH), 7.69 (br, ArH), 7.63 (br, ArH), 7.59 ( br,ArH),7.55-7.48(br,ArH),7.43-7.39(br,ArH),7.24(br,ArH),7.15(br,ArH),7.09(br,ArH),7.04(br,ArH) , 6.90 (br, ArH), 6.73 (br, ArH), 3.78 (br, CH ₂ ), 1.68 (br, CH ), 1.49-1.26 (br, CH ₂ ), 0.88 (br, CH ₃ ).

Polymer P18: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-bis(4-(2-ethylhexyl Alkoxy)phenyl)fluorene (248.0mg, 0.3mmol), 2,7-dibromo-9,9-bis(4-(2-ethylhexyloxy)phenyl)fluorene (87.9mg, 0.12 mmol) and 2',7'-dibromo-10,10-dioxo-spiro[fluorene-9,9-thianthracene] (96.9mg, 0.18mmol). ¹ HNMR (500MHz, CDCl ₃ ) δ (ppm): 8.25 (br, ArH), 7.80 (br, ArH), 7.75 (br, ArH), 7.69 (br, ArH), 7.63 (br, ArH), 7.59 ( br,ArH),7.57-7.47(br,ArH),7.44-7.37(br,ArH),7.24(br,ArH),7.15(br,ArH),7.08(br,ArH),7.04(br,ArH) , 6.92 (br, ArH), 6.73 (br, ArH), 3.76 (br, CH ₂ ), 1.67 (br, CH ), 1.48-1.28 (br, CH ₂ ), 0.88 (br, CH ₃ ).

Similarly, 10,10-dioxo-spiro[fluorene-9,9-thianthracene] condensed ring units are introduced into the obtained polymers, so that the polymers have higher thermal stability and higher electron transport performance.

Example 9

Preparation of poly(2,7-fluorene-co-2,7-tetraxanthylene)(P19-P23)

Synthesis of polymer P19: Under nitrogen protection, 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-dioctyl 2,7-dibromo-9,9-di-n-octylfluorene (192.6mg, 0.3mmol), 2,7-dibromo-9,9-di-n-octylfluorene (154.7mg, 0.282mmol) and 2,7-dibromo-5,5',10,10' -Tetraoxanthrene (7.9mg, 0.018mmol) was dissolved in 10mL of toluene, and tetraethylhydroxylamine aqueous solution (1ml, wt%=25%), palladium acetate (1mg) and tricyclohexylphosphine (2mg) were added. After heating to 85°C and reacting for 24 hours, phenylboronic acid (20 mg) was added for capping for 6 hours, and bromobenzene (0.2 ml) was added for capping for 6 hours. After the reaction stopped, after cooling, the organic phase was precipitated in methanol (200ml), filtered, and after drying slightly, the crude product was extracted with methanol, acetone, and n-hexane successively. Dissolve the polymer in toluene, use toluene as eluent, and perform column chromatography purification with neutral alumina. The toluene solution of the polymer was concentrated, precipitated in methanol solution again, filtered, and dried to obtain a light yellow-green fibrous polymer.

Polymer P19: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (154.7mg, 0.282mmol) and 2,7-dibromo-5,5',10,10'-tetraoxythianthrene (7.9 mg, 0.018mmol). (GPC: number average molecular weight M _n =9.52×10 ⁴ , polydispersity index PDI=2.08)

Polymer P20: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (148.1mg, 0.27mmol) and 2,7-dibromo-5,5',10,10'-tetraoxythianthrene (13.1 mg, 0.03mmol). (GPC: _Mn =11.05×10 ⁴ , PDI=2.25)

Polymer P21: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (141.5mg, 0.258mmol) and 2,7-dibromo-5,5',10,10'-tetraoxythianthrene (18.4 mg, 0.042mmol). (GPC: M _n = 13.20×10 ⁴ , PDI = 1.97)

Polymer P22: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (131.6mg, 0.24mmol) and 2,7-dibromo-5,5',10,10'-tetraoxythianthrene (26.3 mg, 0.06mmol). (GPC: _Mn =8.35×10 ⁴ , PDI=1.86)

Polymer P23: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-9,9-di-n-octylfluorene (192.6mg, 0.3 mmol), 2,7-dibromo-9,9-di-n-octylfluorene (115.2mg, 0.21mmol) and 2,7-dibromo-5,5',10,10'-tetraoxythianthrene (39.4 mg, 0.09mmol). (GPC: M _n = 14.50×10 ⁴ , PDI = 2.37)

Similarly, the obtained polymers all introduce fused ring units of 5,5',10,10'-tetraoxythianthrene, so that the polymers have higher thermal stability and higher electron transport performance.

Example 10

Preparation of poly(2,7-carbazole-co-2,7-S,S-dioxthioxanthene)(P24-P28)

Synthesis of polymer P24: Under nitrogen protection, 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-N-9'-heptadecane Alkylcarbazole (197.3mg, 0.3mmol), 2,7-dibromo-N-9'-heptadecylcarbazole (152.1mg, 0.27mmol) and 2,7-dibromo-9-(propanedi Cyanomethylene)-S,S-dioxythioxanthene (13.5mg, 0.03mmol) was dissolved in 10mL of toluene, and then tetraethylhydroxylamine aqueous solution (1ml, wt%=25%), palladium acetate (1mg), Tricyclohexylphosphine (2mg). After heating to 85°C and reacting for 24 hours, phenylboronic acid (20 mg) was added for capping for 6 hours, and bromobenzene (0.2 ml) was added for capping for 6 hours. After the reaction stopped, after cooling, the organic phase was precipitated in methanol (200ml), filtered, and after drying slightly, the crude product was extracted with methanol, acetone, and n-hexane successively. Dissolve the polymer in toluene, use toluene as eluent, and perform column chromatography purification with neutral alumina. The toluene solution of the polymer was concentrated, precipitated in methanol solution again, filtered and dried to obtain a light yellow fibrous polymer.

Polymer P24: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-N-9'-heptadecylcarbazole (197.3mg , 0.3mmol), 2,7-dibromo-N-9'-heptadecylcarbazole (152.1mg, 0.27mmol) and 2,7-dibromo-9-(propanedicyanomethylene)-S , S-Dioxythioxanthene (13.5mg, 0.03mmol). (GPC: _Mn =9.58×10 ⁴ , PDI=2.44)

Polymer P25: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-N-9'-heptadecylcarbazole (197.3mg , 0.3mmol), 2,7-dibromo-N-9'-heptadecylcarbazole (135.2mg, 0.24mmol) and 2,7-dibromo-9-(propanedicyanomethylene)-S , S-Dioxythioxanthene (27.0mg, 0.06mmol). (GPC: _Mn =8.51×10 ⁴ , PDI=2.21)

Polymer P26: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-N-9'-heptadecylcarbazole (197.3mg , 0.3mmol), 2,7-dibromo-N-9'-heptadecylcarbazole (101.4mg, 0.18mmol) and 2,7-dibromo-9-(propanedicyanomethylene)-S , S-Dioxythioxanthene (54.0mg, 0.12mmol). (GPC: _Mn =6.39×10 ⁴ , PDI=2.40)

Polymer P27: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-N-9'-heptadecylcarbazole (197.3mg , 0.3mmol), 2,7-dibromo-N-9'-heptadecylcarbazole (67.6mg, 0.12mmol) and 2,7-dibromo-9-(propanedicyanomethylene)-S , S-Dioxythioxanthene (81.0mg, 0.18mmol). (GPC: _Mn =7.52×10 ⁴ , PDI=2.16)

Polymer P28: 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-N-9'-heptadecylcarbazole (197.3mg , 0.3mmol) and 2,7-dibromo-9-(propanedicyanomethylene)-S,S-dioxythioxanthene (135.0mg, 0.30mmol). (GPC: _Mn =3.33×10 ⁴ , PDI=2.06)

Similarly, the obtained polymers are all introduced with fused ring units of 9-(propanedicyanomethylene)-S,S-dioxythioxanthene, so that the polymers have higher thermal stability and higher electron transport performance.

Example 11

Preparation of poly(2,7-carbazole-alt-2,7-tetraoxythianthrene)(P29)

Under nitrogen protection, 2,7-bis(4,4,5,5-tetramethyl-1,3-dioxo-2-boryl)-N-9'-heptadecylcarbazole (197.3 mg, 0.3mmol) and 2,7-dibromo-5,5',10,10'-tetraoxythianthrene (131.4mg, 0.3mmol) were dissolved in 12mL of toluene, and tetraethylhydroxylamine aqueous solution (1ml, wt%=25%), palladium acetate (1 mg), tricyclohexylphosphine (2 mg). The temperature was raised to 85° C. for 24 hours, then phenylboronic acid (20 mg) was added for capping for 6 hours, and bromobenzene (0.2 ml) was added for capping for 6 hours. After the reaction stopped, after cooling, the organic phase was precipitated in methanol (300ml), filtered, and after a little drying, the crude product was extracted with methanol, acetone, and n-hexane successively. Dissolve the polymer in toluene, use toluene as eluent, and perform column chromatography purification with neutral alumina. The toluene solution in which the polymer was dissolved was concentrated, precipitated in methanol solution again, filtered, and dried to obtain an orange-red fibrous polymer (GPC: M _n =3.66×10 ⁴ , PDI=2.48).

The obtained polymer has high thermal stability and high electron transport performance.

Example 12

Preparation of poly(benzobisindeno[1,2-b:5,6-b']-dithiophene-alt-2,7-tetraoxothianthrene) (P30)

Under nitrogen protection, 2,7-bis(trimethyltin)-4,9-dihydro-4,4,9,9-tetrakis(4-hexylphenyl)-benzobisindeno[1,2 -b: 5,6-b']-dithiophene (369.9mg, 0.3mmol) and 2,7-dibromo-5,5',10,10'-tetraoxythianthrene (131.4mg, 0.3mmol) dissolved In 12 ml of anhydrous toluene, tris(dibenzylideneacetone)dipalladium (4 mg) and tris(2-tolyl)phosphine (8 mg) were further added. After reacting at 100°C for 24 hours, 2-(tributyltin)thiophene (20 mg) was used for the first capping, and after 6 hours of reaction, 2-bromothiophene (30 mg) was used for the second capping, and the reaction was continued for 6 hours. After the reaction was completed, the reaction liquid was precipitated in methanol, and the polymer obtained by filtration was extracted with methanol and acetone successively, followed by column chromatography with chloroform as the eluent, and dried to obtain orange Red fibrous polymer. (GPC: _Mn =4.03×10 ⁴ , PDI=2.21)

The obtained polymer has high thermal stability and high electron transport performance.

Example 13

Poly(benzobisindeno[1,2-b:5,6-b']-dithiophene-alt-2,7-(9-propanedicyanomethylene)-S,S-dioxythioxanthene ) (P31) preparation

The synthesis method of polymer P31 is the same as the synthesis method of polymer P30 in Example 12, except that the monomer 2,7-dibromo-5,5',10,10'-tetraoxythianthrene is replaced by 2, 7-Dibromo-9-(malonylcyanomethylene)-S,S-dioxythioxanthene. The reaction gave an orange fibrous polymer (GPC: M _n =2.88×10 ⁴ , PDI=1.89).

The obtained polymer has high thermal stability and high electron transport performance.

Example 14

Fabrication of Polymer Electroluminescent Devices

Take the pre-made indium tin oxide (ITO) glass with a sheet resistance of 10Ω, clean it with acetone, detergent, deionized water and isopropanol in sequence, and treat it with plasma for 10 minutes. A film of polyethoxythiophene (PEDOT:PSS) doped with polystyrene sulfonic acid (PEDOT:PSS) was spin-coated on ITO with a thickness of 40 nm. The PEDOT:PSS film was dried in a vacuum oven at 80°C for 8 hours. Then the xylene solution (1wt.%) of the polymer is spin-coated on the surface of the PEDOT:PSS film with a thickness of 80nm; finally, a layer of 1.5nm thick CsF and a 120nm thick metal Al layer are successively evaporated on the light-emitting layer, Device structure: ITO/PEDOT:PSS/polymer/CsF/Al.

The properties of electroluminescent devices prepared by polymers P1, P3, P5, P7, P9 and P11 respectively are shown in Table 1.

Table 1 Performance of polymer electroluminescent device

It can be seen from Table 1 that the polymers based on 3,6- and 2,7-substituted 9,9'-dimethyl-S,S-dioxthioxanthene all exhibit good electroluminescent properties. All polymer devices have very low turn-on voltage (3.2V) and high maximum device brightness (greater than 2500 cd/m²). With the increase of 3,6- or 2,7-substituted 9,9'-dimethyl-S,S-dioxythioxanthene content, the maximum lumen efficiency and maximum external quantum efficiency of polymer devices gradually increased; at the same time, The color coordinate CIE _y of the device decreases gradually, and the deep blue light emission with CIE _y ≤ 0.1 is realized.

The device based on 3,6-substituted 9,9'-dimethyl-S,S-dioxythioxanthene polymer P5 with 25% content has a maximum lumen efficiency of 1.64 cd/A and a maximum external quantum efficiency of 3.36%, The maximum brightness is 2686 candela/square meter, and the color coordinates are (0.16,0.07). It is a high-efficiency deep blue photopolymer.

Among them, the device electroluminescence curves of polymers P1, P3 and P5 are shown in Figure 6. It can be seen from Figure 6 that all polymers exhibit deep blue light emission, and the main emission peaks are at 425 and 450nm, and there are shoulder peaks at 480 and 520nm Emission; from polymer P1 to P5, with the increase of 9,9'-dimethyl-S,S-dioxthioxanthene unit content, the emission at 425nm is enhanced, and the emission at 450nm, 480nm and 520nm is weakened, and the emission spectrum Narrowing, indicating that the introduction of 9,9'-dimethyl-S,S-dioxthioxanthene unit can blue-shift and narrow the electroluminescence spectrum of polyfluorene, and realize the emission of deep blue light.

The device lumen efficiency-current density curves of polymers P1, P3 and P5 are shown in Fig. 7. It can be seen from Fig. 7 that with the increase of 9,9'-dimethyl-S, S-dioxythioxanthene unit content, The lumen efficiency of polymer devices is significantly improved.

The device voltage-current density-brightness curves of polymers P1, P3 and P5 are shown in Figure 8. It can be seen from Figure 8 that the polymers have lower turn-on voltage and higher brightness, indicating that the material has better film-forming properties. The energy levels are relatively matched and have good fluorescence characteristics.

The ultraviolet-visible absorption spectrum of polymer P30 film and polymer P30 in chloroform solution is shown in Figure 9, as can be seen from Figure 9, the absorption peak of polymer has obvious broadening in film state than solution state, shows that polymer There are strong intermolecular interactions in the film state; the optical bandgap of the polymer is calculated to be 2.35eV according to the absorption edge, and it can be used as a medium-bandgap organic solar cell donor.

Claims (7)

1. the polymkeric substance that contains dibenzohexasulfone-based fused ring unit, is characterized in that, main chain contains dibenzohexamethylene sulfone-based condensed ring unit, and the structural formula of polymer is as follows: In the formula, x, y are the mole fractions of the unit components, satisfying: 0<x≤1, x+y=1; degree of polymerization n=1～300; Y is C(R) ₂ , C=N(R), C=C(R) ₂ , Si(R) ₂ or SO ₂ ; R represents H, D, an alkyl group with 1 to 30 carbon atoms or a ring Alkyl, alkyl substituted aryl with 6 to 30 carbon atoms; Ar is one or more of the following chemical structures or derivatives of the following chemical structures: Wherein, R ₁ and R ₂ are respectively H, D, an alkyl or cycloalkyl group with 1 to 30 carbon atoms, or an alkyl-substituted aryl group with 6 to 30 carbon atoms; Z ₁ and Z ₂ are H, D, F, nitrile, nitro, acyl, alkoxy, carbonyl or sulfone. 2. the polymkeric substance containing dibenzohexasulfone-based fused ring unit according to claim 1, is characterized in that, the monomer of described dibenzohexamethylene sulfone-based fused ring unit has following chemical structural formula: In the formula, X is Br or I atom; Y is C(R) ₂ , C=N(R), C=C(R) ₂ , Si(R) ₂ or SO ₂ ; R is represented by H, D, carbon An alkyl group or cycloalkyl group having 1 to 30 atoms, or an alkyl group having 6 to 30 carbon atoms substituted for an aryl group. 3. the polymkeric substance containing dibenzohexasulfone-based fused ring unit according to claim 1, is characterized in that, the preparation method of the monomer of described dibenzohexamethylene sulfone-based fused ring unit comprises the steps: Dissolve the dibenzo-6-membered sulfone-based fused ring raw material in concentrated sulfuric acid, then add N-bromosuccinimide, and react at room temperature; after the reaction, extract, dry, and purify to obtain meta-brominated dibenzo Six-membered sulfone-based fused ring monomer. 4. the polymkeric substance containing dibenzohexasulfone-based fused ring unit according to claim 3, is characterized in that, described dibenzohexamethylene sulfone-based condensed ring raw material and N-bromosuccinimide The molar ratio of is 1:2.2; The time of described reaction is 24 hours. 5. the polymkeric substance containing dibenzohexasulfone-based fused ring unit according to claim 1, is characterized in that, the preparation method of the monomer of described dibenzohexamethylene sulfone-based fused ring unit comprises the steps: 4-bromo-2-iodothiophenol is catalyzed by palladium acetate and triphenylphosphine to obtain 2,7-dibromothianthrene; then in acetic acid, hydrogen peroxide is oxidized to obtain 2,7-dibromothianthrene containing two sulfone groups ,7-Dibromo-tetraoxythianthrene monomer. 6. The polymer containing dibenzohexasulfone-based fused ring units according to claim 5, characterized in that, the temperature of the catalytic reaction is 60-80°C, and the reaction time is 24 hours; the hydrogen peroxide The oxidation temperature is 80-100°C, and the oxidation time is 8 hours. 7. The application of the polymer containing dibenzohexasulfone-based fused ring units according to claim 1 in the manufacture of organic electroluminescent devices, organic solar cells or organic field effect transistors.