CN106588869B - Dialkyl-substituted naphthothiofluorene monomer and preparation method thereof, and dialkyl-substituted naphthothioxfluorene-containing polymer and application thereof - Google Patents

Abstract

The invention discloses a dialkyl-substituted naphthothiofluorene monomer, a preparation method thereof, a polymer containing a dialkyl-substituted naphthothiofluorene unit, and an application thereof. In the dialkyl-substituted naphthothiofluorene monomer, there is a strong electron withdrawing unit -SO2-, which is beneficial to improve the electron affinity of the molecule; the asymmetrically substituted fused ring structure and the introduction of the alkyl group are beneficial to reduce the monomer At the same time, the solubility of monomers in organic solvents is greatly improved. Dialkyl-substituted naphthothioxfluorene monomers are polymerized by Suzuki, Stille or Yamamoto to obtain homopolymers or copolymers containing dialkyl-substituted naphthothioxfluorene units, and the obtained polymers have good properties in organic solvents. Solubility, suitable for solution processing, and have broad application prospects in the preparation of electroluminescent devices, organic solar cells and organic field effect transistors.

Description

Dialkyl-substituted naphthothiofluorene monomer and preparation method thereof and dialkyl-substituted naphthalene Polymers of thiooxyfluorene units and their applications

technical field

The invention relates to the technical field of organic optoelectronic materials, in particular to a dialkyl-substituted naphthothiofluorene monomer, a preparation method thereof, a polymer containing a dialkyl-substituted naphthothioxfluorene unit, and an application thereof.

Background technique

In the past two decades, the organic electronics and optoelectronics industries, including organic/polymer light-emitting diodes, organic field effect transistors, organic solar cells, nonlinear optics, biosensors and lasers, have developed rapidly and gradually industrialization. Organic electronic products have the advantages of low price, light weight and portability, which make them have great market potential. Therefore, the development of organic electronic products with market attractiveness has attracted the attention and input of many research institutions and scientific research teams in the world. Among them, the development of new efficient and stable materials has undoubtedly become a key link.

S,S-dioxy-dibenzothiophene (SO) is an electron-deficient unit with many advantages. The strong electron-withdrawing group -SO ₂ - can improve the electron affinity of the molecule, higher electron mobility, and The S atom has reached the highest valence state and has oxidation resistance; the introduction of -SO ₂ - will not substantially reduce the fluorescence quantum efficiency of the material, especially those containing 3,7-substituted -S,S-dioxy-diphenyl The polymers of thiophene units exhibit excellent electroluminescence properties, and their light-emitting devices have attracted extensive attention due to their excellent spectral stability over a wide range of current densities and heat treatment temperatures. However, due to the poor solubility of S,S-dioxy-dibenzothiophene units, it is difficult to obtain polymers with high content of S,S-dioxy-dibenzothiophene units, and due to 3,7-substituted-S, The flatness of the S-dioxy-dibenzothiophene unit is good, and the obtained polymer emits sky blue light, which is slightly insufficient as a full-color display material. From the perspective of chemical synthesis, S,S-dioxy-dibenzothiophene is not as easily modified at C-9 or N-9 as fluorene or carbazole, which greatly limits its application in the field of optoelectronic materials . Therefore, it is necessary to develop new methods to modify S,S-dioxy-dibenzothiophene units.

The present invention develops a novel dialkyl-substituted naphthothiofluorene monomer, a preparation method, a polymer and an application thereof. The polymer containing the monomer has good solubility and is suitable for solution processing; its light-emitting device is not only efficient and stable, but also has a bluer saturated blue light, which can fully meet the requirements of full-color flat panel display. In addition, due to the steric hindrance effect of dialkyl-substituted S,S-dioxo-dibenzothiophene units, the triplet energy levels and electron transfer of copolymers and homopolymers based on dialkyl-substituted naphthothiofluorene units The rate will increase significantly, and as a phosphorescent host material and electron acceptor material, it will have great application potential in white light illumination and solar cells.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a dialkyl-substituted naphthothiofluorene monomer and a preparation method thereof in view of the deficiencies of the prior art. The monomer is easy to synthesize and purify, and the raw materials are cheap, which is conducive to mass production; at the same time, the introduction of asymmetric fused ring structure and long alkyl chain plays a key role in reducing the coplanarity of the monomer, improving solubility, and processability. the role of sex.

Another object of the present invention is to provide a conjugated polymer containing the structural unit of the dialkyl-substituted naphthothioxfluorene monomer.

Another object of the present invention is to provide the application of the conjugated polymer containing the dialkyl-substituted naphthothiofluorene unit in the preparation of electroluminescent devices, organic solar cells and organic field effect transistors.

Dialkyl-substituted naphthothiofluorene monomer has the following chemical structural formula:

In the formula, X is a Br or I atom; R is a straight-chain or branched-chain alkyl group with 1-30 carbon atoms.

The preparation method of the dialkyl-substituted naphthothiofluorene monomer comprises the following steps:

(1) Under chloroform environment, dibenzo[b,d]thiophene is brominated into 2-bromodibenzo[b,d]thiophene with liquid bromine;

(2) Dissolve 2-bromodibenzo[b,d]thiophene in THF, add butyllithium dropwise at -70～-80℃, and react for 2～3 hours; then keep the temperature at -70～- Under the condition of 80℃, add 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborane, continue to react for 1-2 hours, and then warm to room temperature for reaction 18-24 hours; prepare 2-(dibenzo[b,d]thiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborane;

(3) In toluene solvent, 2-(dibenzo[b,d]thiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborane With methyl 1-bromo-2-naphthoate as the reaction raw material, in an alkaline environment, with tetrakis (triphenylphosphine) palladium as a catalyst, at 120 ~ 150 ℃ through Suzuki, Stille or Yamamoto polymerization reaction 12-18 hours to prepare methyl 1-(dibenzo[b,d]thiophen-2-yl)-2-naphthoate;

(4) Dissolve methyl 1-(dibenzo[b,d]thiophen-2-yl)-2-naphthoate in THF, add alkylmagnesium bromide dropwise, and react at 100-120°C under reflux for 12 ~18 hours to produce 2-(1-(dibenzo[b,d]thiophen-2-yl)decalin)-isopropanol;

(5) Dissolve 2-(1-(dibenzo[b,d]thiophen-2-yl)decalin)-isopropanol in dichloromethane, and dropwise add trifluorotrifluorocarbon with a concentration of 46.5% to 48% Boronide-diethyl ether solution, ring-closing reaction at 0～5℃ for 1～2 hours to obtain 14,14-dialkyl-14H-benzo[b]benzo[5,6]fluorene[1,2-d ] thiophene;

(6) 14,14-dialkyl-14H-benzo[b]benzo[5,6]fluorene[1,2-d]thiophene was oxidized to monothiophene in acetic acid solvent with hydrogen peroxide as oxidant body 14,14-dialkyl-14H-benzo[b]benzo[5,6]fluorene[1,2-d]thiophene 9,9-dioxo;

(7) 14,14-Dialkyl-14H-benzo[b]benzo[5,6]fluorene[1,2-d]thiophene 9,9-dioxo in sulfuric acid with bromosuccinyl The imine is brominated to obtain the dialkyl-substituted naphthothiofluorene monomer.

Further, in step (1), the temperature of the bromination does not exceed 5°C, and the bromination time is 12 to 18 hours.

Further, in step (2), the molar ratio of the 2-bromodibenzo[b,d]thiophene to butyllithium is 1:1.5-1:2.

Further, in step (2), the 2-bromodibenzo[b,d]thiophene and 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-di The mass ratio of oxaborane is 1:0.9 to 1:1.5.

Further, in step (3), the 2-(dibenzo[b,d]thiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxa The molar ratio of borane and methyl 1-bromo-2-naphthoate is 1:1.2～1:1.5.

Further, in step (4), the molar ratio of the methyl 1-(dibenzo[b,d]thiophen-2-yl)-2-naphthoate to alkyl magnesium bromide is 1:3 ~1:5.

Further, in step (5), the mixture of 2-(1-(dibenzo[b,d]thiophen-2-yl)decalin-2-yl)isopropanol and boron trifluoride-diethyl ether solution The solid-liquid ratio is 4:1 to 4.5:1 g/mL.

Further, in step (6), the oxidation reaction is performed at 100-120° C. for 2-5 hours.

Further, in step (7), the 14,14-dialkyl-14H-benzo[b]benzo[5,6]fluorene[1,2-d]thiophene 9,9-dioxy and bromine The molar ratio of succinimide is 1:2 to 1:2.5.

Further, in step (7), the bromination reaction is carried out at 0-5° C. for 18-24 hours.

The polymer containing the structural unit of the dialkyl-substituted naphthothiofluorene monomer has the following chemical structural formula:

In the formula: R is a straight-chain or branched alkyl group with 1-30 carbon atoms, x, y are mole fractions, 0<x≤1, x+y=1, degree of polymerization n=1～300;

where: Ar has one of the following structures:

In the formula, R ₁ is a straight-chain or branched-chain alkyl group having 1-30 carbon atoms.

The application of the polymer containing the structural unit of the dialkyl-substituted naphthothioxfluorene monomer in the preparation of electroluminescent devices, organic solar cells and organic field effect transistors.

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

(1) On the basis of the S,S-dioxo-dibenzothiophene unit, the monomer of the present invention adds an asymmetric fused ring structure and introduces a long alkyl chain to reduce the planarity of the monomer and increase the mono The solvent properties of the polymer and its polymer are improved, the luminescence saturation and the molecular weight of the prepared polymer are improved, the terminal defects of the polymer molecular chain are reduced, and the film-forming property of the polymer is improved.

(2) The present invention provides an effective synthesis route of the dialkyl-substituted naphthothiofluorene monomer, the synthesis and purification are easy, the raw material price is low, and it is favorable for large-scale preparation and production.

(3) The conjugated polymer based on the dialkyl-substituted naphthothiofluorene monomer of the present invention has good solubility in organic solvents, and the device can be prepared by a solution processing method; at the same time, due to the good electron-deficient properties of the prepared polymer The balance of electron and hole injection and transport is ensured when it is used as a light-emitting layer, thereby significantly improving the light-emitting efficiency of the device.

Description of drawings

Fig. 1 is the nuclear magnetic image of dialkyl-substituted naphthothioxfluorene monomer;

Fig. 2 is the thermogravimetric curves of polymers P1, P2 and P3;

Fig. 3 is the electroluminescence spectrum of polymer P1;

Figure 4 is the electrochemical test curve of polymer P2.

Detailed ways

The following examples are only used to further illustrate the present invention, but do not limit the present invention.

Example 1

Preparation of 2,7-dibromofluorene

In a 1000mL three-necked flask, add fluorene (60g, 301mmol), iron powder (0.84g, 15mmol) and chloroform (400mL), and in an ice bath (5°C) protected from light, mix liquid bromine (35mL, 753mmol) and 115mL of chloroform The mixed solution was slowly added dropwise to the reaction solution, and after the addition was completed, the reaction was vigorously stirred at room temperature for 12 hours. 200 mL of saturated aqueous sodium bisulfite solution was added to the reaction flask to quench the reaction. The reaction mixture was suction filtered, and the filter residue was washed _three times with saturated aqueous sodium bisulfite solution, water and ethanol successively. After drying, the filter residue was recrystallized with CHCl for purification to obtain 77.8 g of white crystals, yield: 80%. ¹ H NMR (300 MHz, CDCl ₃ ) (ppm): 7.54 (d, 2H), 7.44 (d, 2H), 7.31 (d, 2H), 3.86 (m, 2H). ¹³ C NMR (75 MHz, CDCl ₃ ) (ppm): 152.91, 144.49, 134.89, 128.91, 121.31, 119.53, 76.54. Elemental analysis results: C ₁₃ H ₈ Br ₂ , theoretical value: C, 48.14%; H, 2.46%. Actual measured values: C, 48.21%; H, 2.63%.

Example 2

Preparation of 2,7-dibromo-9,9-dioctylfluorene (M-1)

Under argon protection, in a 500mL three-necked flask, add 2,7-dibromofluorene (32.4g, 100mmol) and dimethyl sulfoxide (250mL), under vigorous stirring, add tetrabutylammonium bromide (1.61g, 5mmol), then slowly dropwise added sodium hydroxide (40g, 1000mmol) 50wt% aqueous solution, after the addition was completed, the reaction was performed for 2 hours, and then 1-bromooctane (57.9g, 300mmol) was injected at one time. After continuing the reaction for 10 hours, the reaction was stopped, the reaction solution was poured into water, an aqueous hydrochloric acid solution was added for neutralization, extracted with dichloromethane, washed 7 times with saturated brine, dried, and the solvent was spin-dried, and the crude solution was analyzed by column chromatography. The product was purified using silica gel as the stationary phase and petroleum ether as the mobile phase to obtain 43.8 g of a white solid after purification, the yield: 80%. ¹ H NMR (300 MHz, CDCl ₃ ) (ppm): 7.53 (d, 2H), 7.46 (d, 2H), 7.41 (d, 2H), 1.94 (m, 4H), 1.20-1.04 (m, 20H), 0.84 (t, 6H), 0.53 (m, 4H). ¹³ C NMR (75 MHz, CDCl ₃ ) (ppm): 152.96, 139.46, 130.54, 126.56, 121.87, 121.54, 56.11, 40.52, 32.17, 30.26, 29.54, 24.04, 23.01, 14.51. Elemental analysis results: C ₂₉ H ₄₀ Br ₂ , theoretical value: C, 63.51%; H, 7.31%. Actual found values: C, 63.53%; H, 7.42%.

Example 3

Preparation of 2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)-9,9-dioctylfluorene (M-2)

Under argon protection, in a 500mL long there-necked flask, add 2,7-dibromo-9,9-dioctylfluorene (21.9g, 40mmol) and 250mL of anhydrous tetrahydrofuran, and cool the reaction solution to -78 with liquid nitrogen ℃, slowly add n-butyllithium n-hexane solution (48mL, 2.5M, 120mmol) dropwise, keep stirring at -78℃ for 2 hours, then inject 2-isopropyl-4,4,5,5-tetra Methyl-1,3,2-dioxaborane (26g, 140mmol) was allowed to rise to room temperature naturally, and the reaction was continued for 20h. An aqueous solution of ammonium chloride was added to quench the reaction, most of the solvent was evaporated by rotary evaporation, the reaction mixture was poured into water, extracted with dichloromethane, washed with water 5 times, the organic phase was separated, dried, filtered and rotated to dry the solvent, and the mixture was analyzed by column chromatography. The crude product was purified using silica gel as the stationary phase and petroleum ether/dichloromethane as the mobile phase to obtain 43.8 g of a white solid after purification, yield: 80%. ¹ H NMR (300 MHz, CDCl ₃ ) (ppm): 7.80 (d, 2H), 7.73 (s, 2H), 7.72 (d, 2H), 1.98 (m, 4H), 1.38 (s, 24H), 1.21- 1.01 (m, 20H), 0.80 (t, 6H), 0.55 (m, 4H). ¹³ C NMR (75 MHz, CDCl ₃ ) (ppm): 150.85, 144.31, 134.03, 129.28, 119.76, 84.10, 55.56, 40.48, 32.17, 30.32, 29.57, 25.32, 23.97, 22.98, 14.47. Elemental analysis results: C ₄₁ H ₆₄ O ₄ B ₂ , theoretical value: C, 76.73%; H, 10.05%. Actual found values: C, 76.43%; H, 9.91%.

Example 4

Preparation of 3,6-dibromocarbazole

In a 500mL three-necked flask, add carbazole (24.7g, 0.1mol), 200mL of dimethylformamide, stir until dissolved, NBS (49.84g, 0.28mol) is dissolved in 120mL DMF, ice bath to 0 ℃, slowly dropwise add NBS solution, the reaction was protected from light, and after the dropwise addition was completed, the temperature was automatically raised to room temperature, and the reaction was carried out for 6 hours. The reaction was added dropwise to water for precipitation, the crude product was obtained by suction filtration, the suction filtrate was recrystallized with absolute ethanol, and dried to obtain white needle-like crystals, yield: 85%. ¹ H NMR (300 MHz, CDCl ₃ ) δ (ppm): 8.11 (d, 2H), 8.03 (s, 1H), 7.51 (m, 2H), 7.29 (t, 2H). Elemental analysis results (%): _C12H7NBr2 , calculated: C, _44.31 %; H, _2.15 %; N, 4.31%; found: C, 44.28; H, 2.20; N, 4.26%.

Example 5

Preparation of 3,6-dibromo-N-octylcarbazole (M-3)

In a 250mL three-necked flask, add 3,6-dibromocarbazole (16.25g, 0.05mol), toluene (100mL), tetrabutylammonium bromide (0.8g, 3.5mmol), stir to dissolve, and slowly add 50wt% KOH dropwise (11 mL) solution, followed by nC ₈ H ₁₇ Br (19.3 g, 0.1 mol), heated for 24 h, water was added to terminate the reaction, the organic phase was separated by washing, the aqueous phase was extracted with CH ₂ Cl ₂ , washed twice with water, and combined The organic phase was dried over anhydrous _MgSO4 . The solvent was distilled off under reduced pressure to obtain a pale yellow solid, which was recrystallized from petroleum ether to obtain a white powdery solid. Yield: 95%. ¹ H NMR (300 MHz, CDCl ₃ ) δ (ppm): 8.18 (s, 2H), 7.56 (d, 2H), 7.24 (d, 2H), 4.21 (t, 2H), 1.83 (t, 2H) 1.33- 1.24(m, 10H), 0.85(t, 3H). Elemental analysis results (%) _{: C20H23Br2N} , calculated: C, _54.94 ; H, 5.30; N, 3.20; found: C, 54.88; H, 5.20; N, 3.26%.

Example 6

Preparation of 3,6-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborane-diyl)-N-octylcarbazole (M-4)

3,6-dibromo-N-octylcarbazole (13.11 g, 30 mmol) and 250 mL of freshly distilled diethyl ether were added to the three-necked flask, and the mixture was stirred to dissolve completely until it became clear and transparent. The reaction solution was cooled to -78°C, n-butyllithium (2.5M, 75 mmol) was slowly added dropwise, and stirring was continued at -78°C for 2 hours, at which time the reaction solution was a white paste. Then, the cold trap was removed and the reaction was slowly raised to room temperature, and the reaction solution was light yellow clear and transparent solution. The reaction was cooled to -78°C again, and then 2-isopropoxy-(4,4,5,5-tetramethyl)-1,3,2-ethylenedioxyboronic acid ester (37 mL, 180 mmol) was added in one portion. ), stirred at -78°C for 2 hours, and then raised the temperature to room temperature for 24 hours to complete the reaction. It was extracted with ether, washed 4 times with saturated brine, and dried over anhydrous magnesium sulfate. After filtration, the solvent was distilled off, and the product was purified by column chromatography using petroleum ether/ethyl acetate (10:1) as the eluent to obtain white crystals, yield: 45%. ¹ H NMR (300 MHz, CDCl ₃ ) δ (ppm): 8.67 (s, 2H), 7.91 (d, 2H), 7.40 (d, 2H), 4.31 (t, 2H), 1.88 (t, 2H), 1.31 -0.96(m, 34H), 0.85(t, 3H). Elemental analysis results (% _{) : C32H47B2NO4} , calculated: C, _72.33 ; H, 8.92; N, 2.64; found: C, 72.51; H, 9.02; N, 2.73.

Example 7

Preparation of 1,4-dioctyloxybenzene

Under argon protection, in a 250mL three-necked flask, add hydroquinone (2.2g, 20mmol), 5mL of saturated KOH aqueous solution, and 100mL of ethanol, then stir until dissolved, be warming up to reflux, react for 1 hour, and add bromoctane dropwise under reflux. Alkane (9.65g, 50mmol), after the dropwise addition, continued reflux reaction for 8 hours, cooled to room temperature, a large amount of scaly material was precipitated in the bottle, suction filtration, and the obtained crude product was recrystallized with ethanol to obtain pure product. ¹ H NMR (300 MHz, CDCl ₃ ) δ (ppm): 7.03 (d, 4H), 4.08 (t, 4H), 1.79-1.74 (m, 4H), 1.46 (m, 4H), 1.32-1.25 (m, 16H), 0.92-0.88 (m, 6H). Elemental analysis results (%): C ₂₂ H ₃₈ O ₂ , calculated: C, 78.99; H, 11.45; O, 9.56; found: C, 77.88; H, 11.39; O, 9.41.

Example 8

Synthesis of 1,4-dibromo-2,5-dioctyloxybenzene (M-5)

Dissolve 1,4-dioctyloxybenzene (3.35 g, 0.01 mol) in 100 mL of carbon tetrachloride, stir the reaction rapidly, keep away from light, and slowly add liquid bromine (4 g, 0.025 mol), stirred and reacted overnight, then poured the reaction solution into saturated NaHSO ₃ solution, extracted with ethyl acetate, washed with water, dried over anhydrous magnesium sulfate, evaporated the solvent, and the crude product was diluted with petroleum ether/dichloromethane (10:1 ) was purified by eluent column chromatography, and recrystallized with chloroform to obtain white needle-like crystals. ¹ H NMR (300 MHz, CDCl ₃ ) δ (ppm): 7.20 (s, 2H), 4.08 (t, 4H), 1.79-1.74 (m, 4H), 1.46 (m, 4H), 1.32-1.25 (m, 16H), 0.92-0.88 (m, 6H). Elemental analysis results (% _{) : C22H36Br2O2} , calculated: C, _53.67 ; H, 7.37; O, 6.50; found: C, 53.52; H, 7.29; O, 6.38.

Example 9

2,2'-(2,5-bis(octyloxy)-1,4-phenyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborane) Preparation of (M-6)

Dissolve 1,4-dibromo-2,5-dioctyloxybenzene (7.48g, 0.015mol) in 300mL of redistilled ether, cool to -78°C under nitrogen atmosphere, slowly add n-butyl dropwise Lithium (15.1mL, 2.5mol/L n-hexane solution, 0.038mol), at -78°C for 2h, add 2-isopropyl-4,4,5,5-tetramethyl-1,3,2- Dioxaborane (7.75 mL, 0.0375 mol) was reacted at room temperature for 48 h. After the reaction was completed, it was extracted with ether and distilled water, washed with water, and dried over anhydrous magnesium sulfate. The solvent was evaporated and recrystallized from n-hexane to obtain 3.1 g of white needle-like crystals, yield: 35.1%. ¹ H NMR (300 MHz, CDCl ₃ ) δ (ppm): 7.10 (s, 2H), 3.97-3.93 (t, 4H), 1.79-1.74 (m, 4H), 1.57-1.50 (m, 4H), 1.37- 1.30(m, 40H), 0.92-0.88(m, 6H). ¹³ C NMR (75 MHz, CDCl ₃ ) δ (ppm): 157.70, 119.96, 83.43, 69.80, 31.88, 29.68, 29.51, 29.35, 25.08, 24.85, 22.67, 14.07. Elemental analysis results (%): _C34H60B2O6 , calculated: C, _{69.63 ;} H, _10.31 ; O, 16.37; found: C, 69.55; H, 10.19; O, 16.23.

Example 10

Preparation of 2-Bromodibenzo[b,d]thiophene

In a 500 mL three-necked flask, add dibenzo[b,d]thiophene (22 g, 0.12 mol), iron powder (0.33 g, 6 mmol), and 200 mL of chloroform. After cooling in an ice-water bath, liquid bromine (6.2 mL, 0.12 mol) was injected into the flask with a syringe. The temperature in the bottle should not exceed 5°C during dropwise addition. After 12 hours of reaction, the reaction was stopped, filtered and recrystallized from chloroform to obtain 19.5 g of white solid, yield: 62%. ¹ H NMR (300 MHz, CDCl ₃ ) δ (ppm): 8.46(d,1H), 7.94(d,1H), 7.92(d,1H), 7.86(d,1H), 7.56(t,1H), 7.49 (t, 1H), 744(d, 1H). Elemental analysis results (%): C ₁₂ H ₇ B _r S, calculated: C, 54.77; H, 2.68; S, 12.18; found: C, 54.68; H, 2.55; S, 12.04.

Example 11

Preparation of 2-(dibenzo[b,d]thiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborane

2-Bromodibenzo[b,d]thiophene (12.0 g, 45.6 mmol) was dissolved in purified anhydrous THF (200 mL), and 1.6 mol/L n-butyllithium (1.6 mol/L) was gradually added dropwise at -78 °C. 57mL, 91.2mmol), reacted for 2 hours, then added dropwise 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborane 11.03g, at -78°C The reaction was continued for 1 hour, and the temperature was raised to room temperature for 24 hours. The reaction mixture was poured into water, extracted with ethyl acetate, and the organic layer was completely washed with brine, and dried over anhydrous magnesium sulfate. After the solution was concentrated, a pale yellow viscous crude product was obtained, which was purified by silica gel column chromatography (petroleum ether/dichloromethane=5/1, v/v as eluent) to obtain 8.2 g of a yellow oily liquid, yield: 58 %. ¹ H NMR (300MHz, CDCl ₃ )δ(ppm): 8.46(d,1H), 7.96(d,1H), 7.94(d,1H), 7.92(d,1H), 7.56(t,1H), 7.49 (t, 1H), 7.44 (t, 1H), 1.28 (t, 12H). Elemental analysis results (%) _{: C18H19BO2S} , calculated: C, _69.69 ; H, 6.17; S, 10.33; found: C, 69.57; H, 6.02; S, 10.14.

Example 12

Preparation of methyl 1-(dibenzo[b,d]thiophen-2-yl)-2-naphthoate

In a 500mL three-necked flask, add 2-(dibenzo[b,d]thiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborane (7.7g , 24.82 mmol), 200 mL of toluene was stirred and dissolved, followed by the addition of methyl 1-bromonaphthoate (8.55 g, 32.3 mmol), Na ₂ CO ₃ (13.15 g, 124.11 mmol), tetrabutylamine bromide (4 mg , 12.4umol), organic base (10mL), deionized water 30mL, catalyst tetrakis(triphenylphosphine)palladium (1.43g, 1.24mmol), heated to 150°C, and reacted for 12h. After the reaction solution was concentrated, silica gel column chromatography (petroleum ether, dichloromethane=5/1, v/v as eluent) was used to obtain 5.5 g of yellow oil, yield: 60%. ¹ H NMR (300MHz, CDCl ₃ )δ(ppm): 8.90(d,1H), 8.45(d,1H), 8.17(t,1H), 8.12(d,3H), 7.99(d,1H), 7.93 (d, 1H), 7.82 (s, 1H), 7.56 (t, 1H), 7.51 (t, 1H), 7.49 (t, 1H), 7.32 (t, 1H), 3.90 (t, 3H). Elemental analysis results (%): C ₂₄ H ₁₆ O ₂ S, calculated: C, 78.24; H, 4.38; S, 8.70; found: C, 78.11; H, 4.27; S, 8.55.

Example 13

Preparation of 2-(1-(dibenzo[b,d]thiophen-2-yl)decalin-2-yl)isopropanol

Methyl 1-(dibenzo[b,d]thiophen-2-yl)-2-naphthoate (5.0 g, 13.6 mmol) was dissolved in purified anhydrous THF (150 mL) and added dropwise 1.6 mol/L methylmagnesium bromide (25.4 g, 40.7 mmol) was heated to 100 °C and heated to reflux, and reacted for 12 h. After cooling to room temperature, the reaction mixture was poured into water, extracted with ethyl acetate, the organic layer was completely washed with brine, and dried over anhydrous magnesium sulfate. After the solution was concentrated, silica gel column chromatography (petroleum ether, dichloromethane=1/1, v/v as eluent) was used to obtain 2.5 g of white solid, yield: 50%. ¹ H NMR (300MHz, CDCl ₃ )δ(ppm): 8.92(d,1H), 8.45(d,1H), 8.12(t,3H), 7.98(d,2H), 7.93(d,1H), 7.56 (t, 1H), 7.48 (d, 2H), 7.34 (t, 1H), 7.09 (t, 1H), 5.52 (s, 1H), 1.41 (t, 6H). Elemental analysis results (%): _C25H20OS , calculated: C, _81.49 ; H, 5.47; S, 8.70; found: C, 81.32; H, 5.31; S, 8.55.

Example 14

Preparation of 14,14-dimethyl-14H-benzo[b]benzo[5,6]fluorene[1,2-d]thiophene

2-(1-(Dibenzo[b,d]thiophen-2-yl)decalin-2-yl)isopropanol (2.3 g, 6.24 mmol) was dissolved in 150 mL of dichloromethane, and 0.5 mL of trichloromethane was added. Boron fluoride-diethyl ether solution (concentration of 46.5%) was reacted at 3°C for 1 h. After the solution was concentrated, it was purified by silica gel column chromatography to obtain a white solid. It was recrystallized twice with ethanol and filtered to obtain 1.8 g of white crystals, yield: 82.6%. ¹ H NMR (300MHz, CDCl ₃ )δ(ppm): 8.85(d,1H), 8.45(d,1H), 8.08(t,1H), 7.93(d,1H), 7.91(t,2H), 7.88 (d,1H), 7.56(t,1H), 7.49(t,1H), 7.40(t,1H), 7.29(t,1H), 7.09(d,1H), 1.75(t,6H). Elemental analysis results (%): C ₂₅ H ₁₈ S, calculated: C, 85.68; H, 5.18; S, 9.15; found: C, 85.53; H, 5.10; S, 9.04.

Example 15

Preparation of 14,14-dimethyl-14H-benzo[b]benzo[5,6]fluorene[1,2-d]thiophene 9,9-dioxo

In a 250mL three-necked flask, add 14,14-dimethyl-14H-benzo[b]benzo[5,6]fluorene[1,2-d]thiophene (10.5g, 30mmol) and acetic acid (100mL), 30 mL of H ₂ O ₂ was added under stirring, and the reaction was heated to 100° C. under reflux for 2 hours. After the reaction was completed, the solvent was spun off. The crude product was recrystallized from methanol and purified to obtain a white solid, yield: 85%. ¹ H NMR (300 MHz, CDCl ₃ ) δ (ppm): 8.87 (dd, 2H), 8.56 (d, 1H), 7.98 (m, 2H), 7.91 (dd, 2H), 7.68 (m, 2H), 7.52 (m, 3H), 1.96 (t, 6H). Elemental analysis results (%): C ₂₅ H ₁₈ O ₂ S, calculated: C, 78.51; H, 4.74; S, 8.38; found: C, 78.36; H, 4.49; S, 8.12.

Example 16

Preparation of Dialkyl Substituted Naphthothiofluorenes (M-7)

In a 500mL single-necked flask, add 14,14-dimethyl-14H-benzo[b]benzo[5,6]fluorene[1,2-d]thiophene 9,9-dioxo (15.3g, 40mmol) and sulfuric acid (200 mL), NBS (17.8 g, 100 mmol) was added in the dark, and the reaction was carried out at room temperature. Test with a silica gel plate, until most of the raw materials are converted into double-substituted products, stop the reaction, slowly add the reaction solution to the ice water solution of sodium hydrogen sulfite, a large amount of solid is precipitated, suction filtration, and sequentially use sodium hydrogen carbonate aqueous solution. , water and methanol. Column chromatography using petroleum ether/dichloromethane as eluent gave a white solid. Yield: 70%. ¹ H NMR (300 MHz, CDCl ₃ ) δ (ppm): 8.87 (dd, 2H), 8.56 (d, 1H), 7.91 (dd, 2H), 7.68 (m, 2H), 7.52 (m, 3H), 1.96 (t, 6H). Elemental analysis results (% _{) : C25H16Br2O2S} , calculated: C, _55.58 ; H, 2.99; S, 5.93; found: C, 55.39; H, 2.84; S, 5.81.

Fig. 1 is the ¹ H NMR spectrum of the prepared dialkyl-substituted naphthothioxfluorene monomer. It can be seen from Fig. 1 that there are 10 Hs on the benzene ring and 6 Hs at δ1.96ppm, which completely conforms to the molecular structure. , indicating that the synthesized white solid is the target molecule.

Example 17

9,9-Dioctyl-substituted fluorene-co-14,14-dimethyl-14H-benzo[b]benzo[5,6]fluorene[1,2-d]thiophene 9,9-dioxopolymerization Synthesis of Compound (P1)

Under argon protection, add 2,7-bis(4,4,5,5-tetramethyl-1,3,2-ethylenedioxyborate-diyl)-9 to a 50mL two-necked flask, 9-bis(octyl)fluorene (M-2) (321.3 mg, 0.5 mmol), 2,7-dibromo-9,9-bis(octyl)fluorene (M-1) (268.4 mg, 0.49 mmol) , dialkyl-substituted naphthothioxfluorene (M-7) (5.40mg, 0.01mmol) and palladium acetate (2.24mg, 0.01mmol) and tricyclohexylphosphine (7.01mg, 0.025mmol), injected under argon protection 12 mL of toluene, stirred for half an hour, heated to 80°C under reflux, poured into tetraethylammonium hydroxide (20 wt%) aqueous solution (4 mL), reacted under argon atmosphere for 24 hours, then added phenylboronic acid (18.3 mg, 0.15 mmol) ) end-capping, continue to react for 8h, add bromobenzene (0.3mL, 3mmol) to end-cap again, stop the reaction after 8h, cool to room temperature; precipitate the product in methanol, extract methanol and acetone for 48 hours to remove oligomerization Then, it was dissolved in toluene and precipitated in methanol repeatedly; the polymer was further separated and purified by column chromatography, and 298 mg of pale yellow fibrous solid was obtained after vacuum drying, yield: 85%.

Figure 2 shows the thermal weight loss curve of the polymer P1. It can be seen from Figure 2 that the thermal decomposition temperature of the polymer P1 is 412 °C, indicating that the polymer has good thermal properties, which is very important for the preparation of electroluminescent devices.

Figure 3 shows the electroluminescence spectrum of polymer P1. It can be seen from Figure 3 that because the content of dialkyl-substituted naphthothiofluorene units in the polymer is relatively low, only 1 mol%, the polymer is mainly The electroluminescence spectrum of polyfluorene is shown, and its maximum emission peak is at 434 nm.

Example 18

3,6-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborane-diyl)-N-octylcarbazole-co-14,14-dimethyl Synthesis of -14H-benzo[b]benzo[5,6]fluorene[1,2-d]thiophene 9,9-dioxopolymer (P2)

Under argon protection, add 3,6-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborane-diyl)-N-octyl to a 50mL two-necked flask Carbazole (M-4) (265.7mg, 0.5mmol), 3,6-dibromo-N-octylcarbazole (M-3) (214.2mg, 0.49mmol), dialkyl-substituted naphthothiofluorene (M-7) (5.40 mg, 0.01 mmol) and tricyclohexylphosphine (7.01 mg, 0.025 mmol) were injected into 8 mL of toluene under argon protection, stirred for half an hour, heated to 82 °C under reflux, and injected with tetraethyl hydrogen Ammonium oxide (30wt%) aqueous solution (2mL) was reacted under argon atmosphere for 36 hours, then phenylboronic acid (19.5mg, 0.16mmol) was added to cap it, the reaction was continued for 10h, and bromobenzene (0.35mL, 3.5mmol) was added to cap it again. After 10 hours, the reaction was stopped and cooled to room temperature; the product was precipitated in methanol, extracted with methanol and acetone for 48 hours to remove oligomers and catalysts; then dissolved in toluene and repeatedly precipitated in methanol; using a column layer The polymer was further separated and purified by the analytical method, and 265 mg of light yellow powdery solid was obtained after vacuum drying, and the yield was 63%.

Figure 2 shows the thermal weight loss curve of polymer P2. It can be seen from Figure 2 that the thermal decomposition temperature of polymer P2 is 410 °C, indicating that the polymer has good thermal properties, which is very important for the preparation of electroluminescent devices.

Figure 4 shows the electrochemical test curve of the polymer P2. It can be seen from Figure 4 that the oxidation potential of the polymer P2 is 1.24V.

Example 19

2,5-Dioctyloxybenzene-co-14,14-dimethyl-14H-benzo[b]benzo[5,6]fluorene[1,2-d]thiophene 9,9-dioxopolymerization Synthesis of Compound (P3)

Under argon protection, add 2,2'-(2,5-bis(octyloxy)-1,4-phenyl)bis(4,4,5,5-tetramethyl- 1,3,2-dioxaborane) (M-6) (293.2mg, 0.5mmol), 1,4-dibromo-2,5-dioctyloxybenzene (M-5) (241.2mg, 0.49 mmol), dialkyl-substituted naphthothioxfluorene (M-7) (5.40 mg, 0.01 mmol) and palladium acetate (5.40 mg, 0.01 mmol) and tricyclohexylphosphine (7.01 mg, 0.025 mmol), argon Inject 12 mL of toluene under protection, stir for half an hour, heat to 85°C under reflux, inject tetraethylammonium hydroxide (20 wt%) aqueous solution (4 mL), react under argon atmosphere for 48 hours, add phenylboronic acid (20.7 mg , 0.17 mmol) end capping, continue the reaction for 12 h, add bromobenzene (0.4 mL, 4 mmol) to capping again, stop the reaction after 12 h, and cool to room temperature; the product is precipitated in methanol, and extracted with methanol and acetone for 48 hours, respectively Remove oligomer and catalyst; then dissolve in toluene and precipitate in methanol repeatedly; use column chromatography to further separate and purify the polymer, and obtain 280 mg of pale green fibrous solid after vacuum drying, yield: 64%.

Figure 2 shows the thermal weight loss curve of polymer P3. It can be seen from Figure 2 that the thermal decomposition temperature of polymer P3 is 411 °C, indicating that the polymer has good thermal properties, which is very important for the preparation of electroluminescent devices.

The compositions and properties of the prepared conjugated polymers P1 to P3 are listed in Table 1.

Table 1 Composition and properties of conjugated polymers P1～P3

It can be seen from Table 1 that the molecular weight of the conjugated polymer prepared with fluorene and benzene as the main body is relatively large, and the molecular weight of the conjugated polymer prepared with carbazole as the main body is relatively small. Low activity; all conjugated polymers prepared by Suzuki polycondensation have narrow dispersion coefficients between 1.9 and 2.2, and all polymers have higher photoluminescence quantum efficiencies, with photoluminescence quantum efficiencies at 59 -70%.

The following is the preparation of light-emitting device based on the dialkyl-substituted naphthothioxfluorene polymer

Example 20

Based on the polymer 9,9-dioctyl-substituted fluorene-co-14,14-dimethyl-14H-benzo[b]benzo[5,6]fluorene[1,2-d]thiophene 9,9- Preparation of Electroluminescent Devices of Dioxygen Polymer (P1)

On the pre-made indium tin oxide (ITO) glass with a sheet resistance of 15Ω/□, ultrasonically cleaned with acetone, detergent, deionized water and isopropanol in sequence, and plasma treated for 10 minutes; Polyethoxythiophene (PEDOT:PSS) film doped with polystyrene sulfonic acid with a thickness of 150 nm. The PEDOT:PSS film was dried in a vacuum oven at 80°C for 8 hours; then the xylene solution (1 wt%) of the polymer P1 was spin-coated on the surface of the PEDOT:PSS film with a thickness of 80 nm; finally, it was sequentially evaporated on the light-emitting layer A thin layer of CsF (1.5nm) and a 120nm thick metal Al layer.

Based on the single-layer device structure: ITO/PEDOT:PSS/emitter/CsF/Al, the single-layer device prepared by polymer P1 has a maximum lumen efficiency of 3.05cd/A and a maximum external quantum efficiency of 3.57%. Due to the single-layer device structure, The hole and electron transport is unbalanced, and the excitons are not efficiently used for light emission, so the performance is relatively low.

The work of further device optimization is still in progress. In the single-layer device structure, due to the unbalanced carrier transport, adding a hole transport layer or an electron transport layer to the device structure can effectively improve the carrier transport balance and at the same time. The excitons are confined in the light-emitting layer, thereby greatly improving the luminous efficiency of the device.

The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments, and any other changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principle of the present invention All should be equivalent replacement modes, which are all included in the protection scope of the present invention.

Claims (10)

1. dialkyl group replaces naphtho- sulphur dibenzofuran monomer, which is characterized in that have following chemical structural formula:

In formula, X is Br or I atom；R is the straight chain or branched alkyl of carbon atom number 1-30.

2. the preparation method that dialkyl group described in claim 1 replaces naphtho- sulphur dibenzofuran monomer, which is characterized in that including walking as follows It is rapid:

(1) under chloroform environment, with bromine by dibenzo [b, d] thiophene bromination at 2- bromine dibenzo [b, d] thiophene；

(2) 2- bromine dibenzo [b, d] thiophene is dissolved in THF, at -70~-80 DEG C, butyl lithium is added dropwise, reaction 2~3 is small When；Then it maintains the temperature under the conditions of -70~-80 DEG C, 2- isopropoxy -4,4,5,5- tetramethyls -1,3,2- dioxa is added Then borine is warmed to room temperature reaction 18~24 hours after the reaction was continued 1~2 hour；2- (dibenzo [b, d] thiophene -2- is made Base) -4,4,5,5- tetramethyl -1,3,2- dioxaborinate；

(3) in toluene solvant, with 2- (dibenzo [b, d] thiophene -2- base) -4,4,5,5- tetramethyls -1,3,2- dioxa boron Alkane and the bromo- 2- naphthoate of methyl 1- are reaction raw materials, under alkaline environment, using four (triphenylphosphines) conjunction palladium as catalyst, By Suzuki coupling reaction 12~18 hours at 120~150 DEG C, methyl 1- (dibenzo [b, d] thiophene -2- base) -2- is made Naphthoate；

(4) methyl 1- (dibenzo [b, d] thiophene -2- base) -2- naphthoate is dissolved in THF, methyl-magnesium-bromide is added dropwise, 100~120 DEG C back flow reaction 12~18 hours, be made 2- (1- (dibenzo [b, d] thiophene -2- base) naphthalane)-isopropanol；

(5) 2- (1- (dibenzo [b, d] thiophene -2- base) naphthalane)-isopropanol is dissolved in methylene chloride, concentration, which is added dropwise, is 46.5%~48% Eorontrifluoride etherate solution carries out ring closure reaction 1~2 hour at 0~5 DEG C, and 14,14- dioxane is made Base -14H- benzo [b] benzo [5,6] fluorenes [1,2-d] thiophene；

It (6) is oxidant with hydrogen peroxide in acetic acid solvent, by 14,14- dialkyl group -14H- benzo [b] benzo [5,6] fluorenes [1,2-d] thiophene is oxidized to monomer 14,14- dialkyl group -14H- benzo [b] benzo [5,6] fluorenes [1,2-d] thiophene 9,9- dioxy；

(7) 14,14- dialkyl group -14H- benzo [b] benzo [5,6] fluorenes [1,2-d] thiophene 9,9- dioxy is used into bromo in sulfuric acid Succimide bromination obtains the dialkyl group and replaces naphtho- sulphur dibenzofuran monomer.

3. the preparation method that dialkyl group according to claim 2 replaces naphtho- sulphur dibenzofuran monomer, which is characterized in that step (1) in, the brominated temperature is no more than 5 DEG C, and the brominated time is 12~18 hours.

4. the preparation method that dialkyl group according to claim 2 replaces naphtho- sulphur dibenzofuran monomer, which is characterized in that step (2) in, the molar ratio of 2- bromine dibenzo [b, the d] thiophene and butyl lithium is 1:1.5~1:2；The 2- bromine dibenzo [b, d] The mass ratio of thiophene and 2- isopropoxy -4,4,5,5- tetramethyl -1,3,2- dioxaborinate is 1:0.9~1:1.5.

5. the preparation method that dialkyl group according to claim 2 replaces naphtho- sulphur dibenzofuran monomer, which is characterized in that step (3) in, the 2- (dibenzo [b, d] thiophene -2- base) -4,4,5,5- tetramethyls -1,3,2- dioxaborinate and methyl 1- are bromo- The molar ratio of 2- naphthoate is 1:1.2~1:1.5；In step (4), the methyl 1- (dibenzo [b, d] thiophene -2- base) - The molar ratio of 2- naphthoate and methyl-magnesium-bromide is 1:3~1:5.

6. the preparation method that dialkyl group according to claim 2 replaces naphtho- sulphur dibenzofuran monomer, which is characterized in that step (5) in, the material of 2- (1- (dibenzo [b, d] thiophene -2- base) naphthalane -2- base) isopropanol and Eorontrifluoride etherate solution Liquor ratio is 4:1~4.5:1g/mL.

7. the preparation method that dialkyl group according to claim 2 replaces naphtho- sulphur dibenzofuran monomer, which is characterized in that step (6) in, the oxidation reaction is reacted 2~5 hours at 100~120 DEG C.

8. the preparation method that dialkyl group according to claim 2 replaces naphtho- sulphur dibenzofuran monomer, which is characterized in that step (7) in, 14,14- dialkyl group -14H- benzo [b] benzo [5,6] fluorenes [1, the 2-d] thiophene 9,9- dioxy and bromo succinyl The molar ratio of imines is 1:2~1:2.5；The bromination reaction is reacted 18~24 hours at 0~5 DEG C.

9. replacing the polymer of the structural unit of naphtho- sulphur dibenzofuran monomer containing dialkyl group described in claim 1, which is characterized in that With following chemical structural formula:

In formula: R is the straight chain or branched alkyl of carbon atom number 1-30, and x, y are molar fraction, 0 < x≤1, x+y=1, polymerization Spend n=1~300；

Wherein, Ar one of has the following structure:

In formula, R₁For the straight chain or branched alkyl of carbon atom number 1-30.

10. polymer as claimed in claim 9 is preparing electroluminescent device, organic photovoltaic cell and organic field effect tube In application.