Boron-containing condensed ring carbon free radical compound as well as preparation method and application thereof

Abstract

The invention discloses a boron-containing condensed ring carbon free radical compound, a preparation method thereof and application of the boron-containing condensed ring carbon free radical compound in preparation of organic electronic devices, especially in organic light-emitting diodes. The invention also relates to an organic electronic device, in particular an organic light-emitting diode, containing the compound containing the boron-containing condensed ring carbon free radicals according to the invention, and application of the organic electronic device and the organic light-emitting diode in display and illumination technologies. By optimizing the structure of the device and changing the concentration of the boron-containing condensed ring carbon free radical compound in the matrix, the optimal device performance can be achieved, the OLED device with high efficiency, high brightness and high stability can be conveniently realized, and a better material option is provided for full-color display and illumination application.

Description

Technical Field

[0001] The present invention belongs to the technical field of new materials, and specifically relates to a boron-containing fused-ring carbon radical compound and a preparation method and application thereof, and in particular to an application in an organic light-emitting diode. Background Art

[0002] Organic light-emitting diodes (OLEDs) have great potential in the application of optoelectronic devices (such as flat panel displays and lighting) due to the diversity of organic semiconductor materials in synthesis, relatively low manufacturing costs, and excellent optical and electrical properties. In order to improve the luminous efficiency of organic light-emitting diodes, organic free radical luminescent materials based on open shells can achieve high device external quantum efficiency due to the use of 100% doublet excitons, which is comparable to traditional phosphorescent metal (iridium, platinum) complex materials.

[0003] In 2018, Professor Li Feng of Jilin University in China doped organic light-emitting materials containing trichlorotriphenylmethyl radical (TTM) units into N,N-dicarbazole biphenyl (CBP) and successfully prepared near-infrared electrophosphorescent devices with a maximum external quantum efficiency (EQE) of up to 27%. Since the free radical light-emitting material only forms doublet excitons in the light-emitting area of ​​OLED, and the doublet excitons do not have the problem of spin prohibition during the transition process, the internal quantum efficiency of the device is theoretically 100%, thus avoiding the long-standing problem of triplet exciton utilization. In addition, since such free radical light-emitting materials do not use heavy metals, are cheap and environmentally friendly, they have also aroused people's strong interest in stable free radical light-emitting materials.

[0004] However, most of the free radical luminescent materials reported so far introduce electron-donating groups, such as carbazole or aromatic amine groups, into the TTM unit, while large conjugated groups with electron-withdrawing effects are relatively rare. In addition, this type of free radical luminescent material is still insufficient in stability and luminescence efficiency. Therefore, new stable and high-performance free radical luminescent materials are urgently needed to be developed. Summary of the invention

[0005] Purpose of the invention: In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a new type of boron-containing fused-ring carbon free radical compound.

[0006] The technical problem that the present invention needs to solve is to provide a preparation method and application of a boron-containing condensed ring carbon radical compound.

[0007] Technical solution: In order to solve the above technical problems, the present invention provides a boron-containing fused ring carbon free radical compound, the general formula of which is shown in structure (I):

[0008]

[0009] in, It is a boron-containing fused ring organic unit, specifically selected from the following structures:

[0010]

[0011] Wherein, X is an O atom or an S atom, and R is a tert-butyl group or a H atom.

[0012] Wherein, the boron-containing fused ring carbon radical compound R1-R10:

[0013]

[0014]

[0015] The present invention also includes a method for preparing the boron-containing fused-ring carbon radical compound, comprising the following steps:

[0016] 1) First, 2,5-dibromo-1,3-difluorobenzene is used as a raw material to synthesize intermediates 1a-10a, and then monobrominated boron-containing fused ring compounds 1b-10b are synthesized through borylation reaction; and then the corresponding boron ester compounds 1c-10c are synthesized;

[0017] 2) then subjecting the boron ester compounds 1c-10c prepared in step 1) to Suzuki coupling reaction with tris(2,4,6-trichlorophenyl)methane to form free radical precursor compounds 1d-10d;

[0018] 3) Finally, under the action of potassium tert-butoxide and tetrachlorobenzoquinone, the free radical precursor prepared in step 2) is converted into free radical compounds R1-R10.

[0019] Among them, the synthesis step of the compound of intermediate 1a-10a in step 1) includes: reacting 2,5-dibromo-1,3-difluorobenzene with a phenyl-containing compound under a nitrogen atmosphere at high temperature for 12 to 24 hours to obtain, preferably, the phenyl-containing compound includes a phenolic compound, a carbazole compound or an aniline compound or phenoxazine; preferably, the phenolic compound includes phenol, 4-tert-butylphenol, thiophenol or 4-tert-butylthiophenol; preferably, the carbazole compound includes carbazole or di-tert-butylcarbazole; preferably, the aniline compound includes diphenylamine or bis(4-tert-butylphenyl)amine.

[0020] Among them, the synthesis process of compound 1b-10b in step 1) is as follows: dry m-xylene and n-butyl lithium are added to compound 1a-10a under a nitrogen atmosphere and stirred, then transferred to room temperature and continuously stirred, then boron tribromide is added and stirred, then the mixture is transferred to room temperature and stirred, then the mixture is heated and stirred, then cooled again, N,N-diisopropylethylamine is added, and finally the mixture is heated and stirred. After the reaction is completed, it is cooled to room temperature and the resulting solution is washed with a saturated sodium acetate solution, and then water and dichloromethane are added for extraction several times, respectively, and the combined organic phase is concentrated by rotary evaporation and dried, and finally the target products, namely compound 1b-10b, are obtained.

[0021] Among them, the synthesis process of intermediates 1c to 10c in step 1) is as follows: add pinacol borate and potassium acetate to compounds 1b to 10b respectively, evacuate and circulate with nitrogen, add 1,4-dioxane under nitrogen flow, add tetrakis(triphenylphosphine)palladium, stir at room temperature, heat the mixture under nitrogen atmosphere, and stir the reaction overnight, cool the reaction mixture to room temperature, concentrate, and purify by column chromatography to obtain the target product yellow solid intermediate, namely compounds 1c to 10c.

[0022] The present invention also includes the use of the boron-containing fused-ring carbon radical compound in the preparation of organic electronic devices.

[0023] Among them, the organic electronic device is one or more of an organic light emitting diode (OLED), an organic photovoltaic cell (OPV), an organic light emitting cell (OLEEC), an organic field effect transistor (OFET), an organic light emitting field effect transistor, an organic laser, an organic spin electronic device, an organic sensor and an organic plasmon emitting diode (Organic Plasmon Emitting Diode).

[0024] Wherein, the mass concentration of the boron-containing fused-ring carbon free radical compound in the matrix is ​​3-10wt%.

[0025] The present invention also includes an organic electronic device, which comprises the boron-containing fused-ring carbon radical compound.

[0026] Wherein, the mass concentration of the boron-containing fused-ring carbon radical compound is 3-10wt%.

[0027] Preferably, the mass concentration of the boron-containing fused-ring carbon radical compound is 5 wt %.

[0028] Beneficial effects: Compared with the prior art, the present invention has the following advantages: the boron-containing fused ring group contained in the free radical compound prepared by the present invention can effectively improve the stability of the free radical, the luminescence performance and the performance of the corresponding device due to its large conjugation and rigidity. The present invention also relates to an organic electronic device, in particular an organic light-emitting diode, comprising the boron-containing fused ring carbon free radical compound according to the present invention, and its application in display and lighting technology. By optimizing the device structure and changing the concentration of the boron-containing fused ring carbon free radical compound in the matrix, the best device performance can be achieved, which is convenient for realizing high-efficiency, high-brightness and high-stability OLED devices, and provides a better material option for full-color display and lighting applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 X-ray single crystal structure of the radical R1 precursor compound 1d;

[0030] Figure 2 Electron paramagnetic resonance (EPR) spectrum of free radical compound R1. DETAILED DESCRIPTION

[0031] Example 1 Synthesis of Boron-Containing Condensed Ring Carbon Radical Compound R1

[0032] Synthesis route of boron-containing fused ring carbon radical compound R1:

[0033]

[0034] 1. Synthesis of intermediate 1a:

[0035] Take a dry 250mL double-necked reaction bottle, add phenol (10.39g, 110.53mmol), 2,5-dibromo-1,3-difluorobenzene (10.21g, 36.80mmol) and potassium carbonate (15.30g, 110.70mmol), evacuate and fill with nitrogen for three cycles, and add N-methylpyrrolidone (55mL) under nitrogen protection. Heat the reaction to 170°C under nitrogen atmosphere protection and stir the reaction for 24 hours. After the reaction is completed, the reaction mixture is cooled to room temperature, concentrated, and then extracted with water and ethyl acetate three times. The combined organic phase is concentrated by rotary evaporation and purified by column chromatography (petroleum ether / dichloromethane=10 / 1, v / v) to obtain white solid intermediate 1a 13.22g, yield 86%. EI-MS (m / z): 421.1 (M + , 100%).

[0036] 2. Synthesis of intermediate 1b:

[0037] Intermediate 1a (1.22 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25.00 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and it was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain the target product, a white solid intermediate 1b, 0.78 g, with a yield of 76%. EI-MS (m / z): 350.3 (M+, 100%).

[0038] 3. Synthesis of intermediate 1c:

[0039] The intermediate 1b (0.200 g, 0.570 mmol), biboric acid pinacol ester (0.230 g, 0.570 mmol), potassium acetate (0.600 g, 6.110 mmol) were placed in a 100 mL two-necked bottle, vacuumed and nitrogen filled for three cycles, 1,4-dioxane (25 mL) was added under nitrogen flow, and an appropriate amount of tetrakis(triphenylphosphine)palladium was added. The mixture was stirred at room temperature for 10 minutes, and the mixture was heated to 90°C under nitrogen atmosphere and stirred overnight. The reaction mixture was cooled to room temperature. Concentrated and purified by column chromatography (petroleum ether / ethyl acetate = 5 / 1, v / v) to obtain the target product yellow solid intermediate 1c 0.200 g. The yield was about 88%. EI-MS (m / z): 398.3 (M + , 100%).

[0040] 4. Synthesis of intermediate 1d:

[0041] Add intermediate 1c (0.100 g, 0.250 mmol), tris(2,4,6-trichlorophenyl)methane (0.180 g, 0.320 mmol), potassium carbonate (0.138 g, 1.000 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, add an appropriate amount of tetrakis(triphenylphosphine)palladium under a nitrogen stream, and then add toluene (6 mL), methanol (2 mL), and deionized water (2 mL). After fully stirring for 10 minutes, the mixture was heated to 110°C under a nitrogen atmosphere and stirred to react overnight. The reaction mixture was cooled to room temperature. The organic phase was concentrated, concentrated by rotary evaporation, and purified by column chromatography (dichloromethane / petroleum ether = 1 / 10, v / v) to obtain the target product, white solid intermediate 1d 0.030 g. Yield 15%. EI-MS (m / z): 787.5 (M+, 100%).

[0042] The single crystal of the precursor compound 1d of the free radical R1 was obtained by slowly diffusing an ethanol solvent into its dichloromethane solution. Its structure is shown in Figure 1 shown.

[0043] 5. Synthesis of free radical compound R1:

[0044] Add intermediate 1d (0.020g, 0.025mmol) and potassium tert-butoxide (0.005g, 0.040mmol) to the Schlenck tube, evacuate and fill with nitrogen for three cycles, and add dry tetrahydrofuran solution (10mL) in a nitrogen atmosphere. Heat the mixture to 80°C under a nitrogen atmosphere and stir overnight in a dark environment. The solution color is purple. Cool to room temperature, add tetrachlorobenzoquinone (0.013g, 0.054mmol), and continue stirring for 2 hours in a dark environment at room temperature. After the reaction is completed, the organic solvent is removed in vacuo, and the target product is purified by column chromatography (dichloromethane / petroleum ether=1:10, v / v) to obtain the target product brown solid free radical compound R1 0.011g, with a yield of about 56%. EI-MS (m / z): 786.9 (M+, 100%).

[0045] The electron paramagnetic resonance spectrum (EPR) of the free radical compound R1 is as follows: Figure 2 shown.

[0046] Example 2 Synthesis of Boron-Containing Condensed Ring Carbon Radical Compound R2

[0047] Synthesis route of boron-containing fused ring carbon radical compound R2:

[0048]

[0049] 1. Synthesis of intermediate 2a:

[0050] Take a dry 250mL double-necked reaction bottle, add 4-tert-butylphenol (16.58g, 110.53mmol), 2,5-dibromo-1,3-difluorobenzene (10.21g, 36.80mmol) and potassium carbonate (15.30g, 110.70mmol), evacuate and fill with nitrogen for three cycles, and add N-methylpyrrolidone (55mL) under nitrogen protection. Heat the reaction to 170°C under nitrogen atmosphere protection and stir the reaction for 24 hours. After the reaction is completed, the reaction mixture is cooled to room temperature, concentrated, and then extracted with water and ethyl acetate three times. The combined organic phase is concentrated by rotary evaporation and purified by column chromatography (petroleum ether / dichloromethane=10 / 1, v / v) to obtain 15.6g of white solid intermediate 2a with a yield of 80%. EI-MS (m / z): 532.1 (M + , 100%).

[0051] 2. Synthesis of intermediate 2b:

[0052] Intermediate 2a (1.55 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25.00 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and it was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain 1.1 g of the target product, a white solid intermediate 2b, with a yield of 82%. EI-MS (m / z): 461.2 (M + , 100%).

[0053] 3. Synthesis of intermediate 2c:

[0054] The intermediate 2b (0.262 g, 0.570 mmol), biboric acid pinacol ester (0.230 g, 0.570 mmol), potassium acetate (0.600 g, 6.110 mmol) were placed in a 100 mL two-necked bottle, vacuumed and nitrogen filled for three cycles, 1,4-dioxane (25 mL) was added under nitrogen flow, and an appropriate amount of tetrakis(triphenylphosphine)palladium was added. The mixture was stirred at room temperature for 10 minutes, and the mixture was heated to 90°C under nitrogen atmosphere and stirred overnight. The reaction mixture was cooled to room temperature. Concentrated and purified by column chromatography (petroleum ether / ethyl acetate = 5 / 1, v / v) to obtain the target product yellow solid intermediate 2c 0.231 g. The yield was about 80%. EI-MS (m / z): 508.3 (M + , 100%).

[0055] 4. Synthesis of intermediate 2d:

[0056] Add intermediate 2c (0.127 g, 0.250 mmol), tris(2,4,6-trichlorophenyl)methane (0.180 g, 0.320 mmol), potassium carbonate (0.138 g, 1.000 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, add an appropriate amount of tetrakis(triphenylphosphine)palladium under a nitrogen stream, and then add toluene (6 mL), methanol (2 mL), and deionized water (2 mL). After fully stirring for 10 minutes, the mixture was heated to 110 ° C under a nitrogen atmosphere and stirred to react overnight. The reaction mixture was cooled to room temperature. The organic phase was concentrated, concentrated by rotary evaporation, and purified by column chromatography (dichloromethane / petroleum ether=1 / 10, v / v) to obtain the target product, white solid intermediate 2d 0.056 g. Yield 25%. EI-MS (m / z): 896.1 (M + , 100%).

[0057] 5. Synthesis of free radical compound R2:

[0058] Add intermediate 2d (0.022 g, 0.025 mmol) and potassium tert-butoxide (0.005 g, 0.040 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, and add dry tetrahydrofuran solution (10 mL) in a nitrogen atmosphere. Heat the mixture to 80 ° C under a nitrogen atmosphere, stir overnight in a dark environment, and the solution color turns purple. Cool to room temperature, add tetrachlorobenzoquinone (0.013 g, 0.054 mmol), and continue stirring for 2 hours in a dark environment at room temperature. After the reaction is completed, the organic solvent is removed in vacuo, and the target product is purified by column chromatography (dichloromethane / petroleum ether=1:10, v / v) to obtain the target product brown solid free radical compound R2 0.013 g, with a yield of about 60%. EI-MS (m / z): 900.2 (M +, 100%).

[0059] Example 3 Synthesis of Boron-Containing Condensed Ring Carbon Radical Compound R3

[0060] Synthesis route of boron-containing fused ring carbon radical compound R3:

[0061]

[0062] 1. Synthesis of intermediate 3a:

[0063] Take a dry 250mL double-necked reaction bottle, add thiophenol (12.16g, 110.53mmol), 2,5-dibromo-1,3-difluorobenzene (10.21g, 36.80mmol) and potassium carbonate (15.30g, 110.70mmol), evacuate and fill with nitrogen for three cycles, and add N-methylpyrrolidone (55mL) under nitrogen protection. The reaction was heated to 170°C under nitrogen atmosphere protection and stirred for 24 hours. After the reaction was completed, the reaction mixture was cooled to room temperature, concentrated, and then extracted with water and ethyl acetate three times. The combined organic phase was concentrated by rotary evaporation and purified by column chromatography (petroleum ether / dichloromethane=10 / 1, v / v) to obtain a light yellow solid intermediate 3a 13.31g, with a yield of 80%. EI-MS (m / z): 452.2 (M + , 100%).

[0064] 2. Synthesis of intermediate 3b:

[0065] Intermediate 3a (1.32 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25.00 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and it was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain 0.87 g of the target product, a yellow solid intermediate 3b, with a yield of 78%. EI-MS (m / z): 381.1 (M + , 100%).

[0066] 3. Synthesis of intermediate 3c:

[0067] The intermediate 3b (0.217 g, 0.570 mmol), biboric acid pinacol ester (0.230 g, 0.570 mmol), potassium acetate (0.600 g, 6.110 mmol) were placed in a 100 mL two-necked bottle, vacuumed and nitrogen filled for three cycles, 1,4-dioxane (25 mL) was added under nitrogen flow, and an appropriate amount of tetrakis(triphenylphosphine)palladium was added. The mixture was stirred at room temperature for 10 minutes, and the mixture was heated to 90°C under nitrogen atmosphere and stirred overnight. The reaction mixture was cooled to room temperature. Concentrated and purified by column chromatography (petroleum ether / ethyl acetate = 5 / 1, v / v) to obtain the target product yellow solid intermediate 3c 0.207 g. The yield was about 85%. EI-MS (m / z): 428.2 (M + , 100%).

[0068] 4. Synthesis of intermediate 3d:

[0069] Add intermediate 3c (0.107 g, 0.250 mmol), tris(2,4,6-trichlorophenyl)methane (0.180 g, 0.320 mmol), potassium carbonate (0.138 g, 1.000 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, add an appropriate amount of tetrakis(triphenylphosphine)palladium under a nitrogen stream, and then add toluene (6 mL), methanol (2 mL), and deionized water (2 mL). After fully stirring for 10 minutes, the mixture was heated to 110 ° C under a nitrogen atmosphere and stirred to react overnight. The reaction mixture was cooled to room temperature. The organic phase was concentrated, concentrated by rotary evaporation, and purified by column chromatography (dichloromethane / petroleum ether=1 / 10, v / v) to obtain the target product, white solid intermediate 3d 0.035 g. Yield 17%. EI-MS (m / z): 820.1 (M + , 100%).

[0070] 5. Synthesis of free radical compound R3:

[0071] Add intermediate 3d (0.021 g, 0.025 mmol) and potassium tert-butoxide (0.005 g, 0.040 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, and add dry tetrahydrofuran solution (10 mL) in a nitrogen atmosphere. Heat the mixture to 80 ° C under a nitrogen atmosphere, stir overnight in a dark environment, and the solution color is purple. Cool to room temperature, add tetrachlorobenzoquinone (0.013 g, 0.054 mmol), and continue stirring for 2 hours in a dark environment at room temperature. After the reaction is completed, the organic solvent is removed in vacuo, and the target product is purified by column chromatography (dichloromethane / petroleum ether=1:10, v / v) to obtain the target product brown solid free radical compound R3 0.013 g, with a yield of about 65%. EI-MS (m / z): 819.3 (M + , 100%).

[0072] Example 4 Synthesis of Boron-Containing Condensed Ring Carbon Radical Compound R4

[0073] Synthesis route of boron-containing fused ring carbon radical compound R4:

[0074]

[0075] 1. Synthesis of intermediate 4a:

[0076] Take a dry 250mL double-necked reaction bottle, add 4-tert-butylthiophenol (18.36g, 110.53mmol), 2,5-dibromo-1,3-difluorobenzene (10.21g, 36.80mmol) and potassium carbonate (15.30g, 110.70mmol), evacuate and fill with nitrogen for three cycles, and add N-methylpyrrolidone (55mL) under nitrogen protection. Heat the reaction to 170°C under nitrogen atmosphere protection and stir the reaction for 24 hours. After the reaction is completed, the reaction mixture is cooled to room temperature, concentrated, and then extracted with water and ethyl acetate three times. The combined organic phase is concentrated by rotary evaporation and purified by column chromatography (petroleum ether / dichloromethane=10 / 1, v / v) to obtain 17.65g of light yellow solid intermediate 4a with a yield of 85%. EI-MS (m / z): 564.4 (M + , 100%).

[0077] 2. Synthesis of intermediate 4b:

[0078] Intermediate 4a (1.65 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25.00 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and it was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain 1.04 g of the target product, a yellow solid intermediate 4b, with a yield of 72%. EI-MS (m / z): 493.3 (M + , 100%).

[0079] 3. Synthesis of intermediate 4c:

[0080] The intermediate 4b (0.281 g, 0.570 mmol), biboronic acid pinacol ester (0.230 g, 0.570 mmol), potassium acetate (0.600 g, 6.110 mmol) were placed in a 100 mL two-necked bottle, vacuumed and nitrogen filled for three cycles, 1,4-dioxane (25 mL) was added under nitrogen flow, and an appropriate amount of tetrakis(triphenylphosphine)palladium was added. The mixture was stirred at room temperature for 10 minutes, and the mixture was heated to 90°C under nitrogen atmosphere and stirred overnight. The reaction mixture was cooled to room temperature. Concentrated and purified by column chromatography (petroleum ether / ethyl acetate = 5 / 1, v / v) to obtain the target product yellow solid intermediate 4c 0.234 g. The yield was about 76%. EI-MS (m / z): 540.4 (M + , 100%).

[0081] 4. Synthesis of intermediate 4d:

[0082] Add intermediate 4c (0.135 g, 0.250 mmol), tris(2,4,6-trichlorophenyl)methane (0.180 g, 0.320 mmol), potassium carbonate (0.138 g, 1.000 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, add an appropriate amount of tetrakis(triphenylphosphine)palladium under a nitrogen stream, and then add toluene (6 mL), methanol (2 mL), and deionized water (2 mL). After fully stirring for 10 minutes, the mixture was heated to 110 ° C under a nitrogen atmosphere and stirred to react overnight. The reaction mixture was cooled to room temperature. The organic phase was concentrated, concentrated by rotary evaporation, and purified by column chromatography (dichloromethane / petroleum ether=1 / 10, v / v) to obtain the target product, white solid intermediate 4d 0.042 g. Yield 18%. EI-MS (m / z): 932.3 (M + , 100%).

[0083] 5. Synthesis of free radical compound R4:

[0084] Add intermediate 4d (0.023 g, 0.025 mmol) and potassium tert-butoxide (0.005 g, 0.040 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, and add dry tetrahydrofuran solution (10 mL) in a nitrogen atmosphere. Heat the mixture to 80 ° C under a nitrogen atmosphere, stir overnight in a dark environment, and the solution color is purple. Cool to room temperature, add tetrachlorobenzoquinone (0.013 g, 0.054 mmol), and continue stirring for 2 hours in a dark environment at room temperature. After the reaction is completed, the organic solvent is removed in vacuo, and the target product is purified by column chromatography (dichloromethane / petroleum ether=1:10, v / v) to obtain the target product brown solid free radical compound R4 0.014 g, with a yield of about 62%. EI-MS (m / z): 931.1 (M + , 100%).

[0085] Example 5 Synthesis of Boron-Containing Condensed Ring Carbon Radical Compound R5

[0086] Synthesis route of boron-containing fused ring carbon radical compound R5:

[0087]

[0088] 1. Synthesis of intermediate 5a:

[0089] Place carbazole (0.84 g, 5 mmol) and cesium carbonate (3.92 g, 12 mmol) in a dry two-necked bottle and evacuate for three cycles. Add dry DMF (15 mL) with a syringe under nitrogen flow, stir at room temperature for 30 min, add 2.5-dibromo-1.3-difluorobenzene (0.54 g, 2 mmol) under nitrogen flow, heat to 155 ° C for 12 hours, until the raw materials react completely. After the reaction, add a large amount of water to form a precipitate, filter, collect the precipitate and pass it through a column with dichloromethane: petroleum ether = 1:10. Obtain 0.68 g of white solid intermediate 5a with a yield of 60%. EI-MS (m / z): 566.3 (M + , 100%).

[0090] 2. Synthesis of intermediate 5b:

[0091] Intermediate 5a (1.65 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25.00 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and the temperature was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain 1.08 g of the target product, a white solid intermediate 5b, with a yield of 75%. EI-MS (m / z): 495.2 (M + , 100%).

[0092] 3. Synthesis of intermediate 5c:

[0093] The intermediate 5b (0.282 g, 0.570 mmol), biboric acid pinacol ester (0.230 g, 0.570 mmol), potassium acetate (0.600 g, 6.110 mmol) were placed in a 100 mL two-necked bottle, vacuumed and nitrogen filled for three cycles, 1,4-dioxane (25 mL) was added under nitrogen flow, and an appropriate amount of tetrakis(triphenylphosphine)palladium was added. The mixture was stirred at room temperature for 10 minutes, and the mixture was heated to 90°C under nitrogen atmosphere and stirred overnight. The reaction mixture was cooled to room temperature. Concentrated and purified by column chromatography (petroleum ether / ethyl acetate = 5 / 1, v / v) to obtain the target product yellow solid intermediate 5c 0.262 g. The yield was about 85%. EI-MS (m / z): 542.3 (M + , 100%).

[0094] 4. Synthesis of intermediate 5d:

[0095] Add intermediate 5c (0.136 g, 0.250 mmol), tris(2,4,6-trichlorophenyl)methane (0.180 g, 0.320 mmol), potassium carbonate (0.138 g, 1.000 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, add an appropriate amount of tetrakis(triphenylphosphine)palladium under a nitrogen stream, and then add toluene (6 mL), methanol (2 mL), and deionized water (2 mL). After fully stirring for 10 minutes, the mixture was heated to 110 ° C under a nitrogen atmosphere and stirred to react overnight. The reaction mixture was cooled to room temperature. The organic phase was concentrated, concentrated by rotary evaporation, and purified by column chromatography (dichloromethane / petroleum ether=1 / 10, v / v) to obtain the target product, white solid intermediate 5d 0.028 g. Yield 12%. EI-MS (m / z): 934.1 (M + , 100%).

[0096] 5. Synthesis of free radical compound R5:

[0097] Add intermediate 5d (0.023 g, 0.025 mmol) and potassium tert-butoxide (0.005 g, 0.040 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, and add dry tetrahydrofuran solution (10 mL) in a nitrogen atmosphere. Heat the mixture to 80 ° C under a nitrogen atmosphere, stir overnight in a dark environment, and the solution color turns purple. Cool to room temperature, add tetrachlorobenzoquinone (0.013 g, 0.054 mmol), and continue stirring for 2 hours in a dark environment at room temperature. After the reaction is completed, the organic solvent is removed in vacuo, and the target product is purified by column chromatography (dichloromethane / petroleum ether=1:10, v / v) to obtain the target product brown solid free radical compound R5 0.014 g, with a yield of about 60%. EI-MS (m / z): 933.3 (M +, 100%).

[0098] Synthesis route of boron-containing fused ring carbon radical compound R6:

[0099]

[0100] 1. Synthesis of intermediate 6a:

[0101] Place di-tert-butylcarbazole (1.39 g, 5 mmol) and cesium carbonate (3.92 g, 12 mmol) in a dry two-necked bottle and evacuate for three cycles. Add dry DMF (15 mL) with a syringe under nitrogen flow, stir at room temperature for 30 min, add 2.5-dibromo-1.3-difluorobenzene (0.54 g, 2 mmol) under nitrogen flow, heat to 155 ° C for 12 hours, until the raw materials react completely. After the reaction, add a large amount of water to generate a precipitate, filter, collect the precipitate and pass it through a column with dichloromethane: petroleum ether = 1:10. Obtain 0.87 g of white solid intermediate 6a with a yield of 55%. EI-MS (m / z): 790.7 (M + , 100%).

[0102] 2. Synthesis of intermediate 6b:

[0103] Intermediate 6a (2.31 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25.00 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and the temperature was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain 1.59 g of the target product, a white solid intermediate 6b, with a yield of 76%. EI-MS (m / z): 719.6 (M + , 100%).

[0104] 3. Synthesis of intermediate 6c:

[0105] The intermediate 6b (0.41 g, 0.570 mmol), biboric acid pinacol ester (0.230 g, 0.570 mmol), potassium acetate (0.600 g, 6.110 mmol) were placed in a 100 mL two-necked bottle, vacuumed and nitrogen filled for three cycles, 1,4-dioxane (25 mL) was added under nitrogen flow, and an appropriate amount of tetrakis(triphenylphosphine)palladium was added. The mixture was stirred at room temperature for 10 minutes, and the mixture was heated to 90°C under nitrogen atmosphere and stirred overnight. The reaction mixture was cooled to room temperature. Concentrated and purified by column chromatography (petroleum ether / ethyl acetate = 5 / 1, v / v) to obtain the target product yellow solid intermediate 6c 0.371 g. The yield was about 85%. EI-MS (m / z): 766.6 (M + , 100%).

[0106] 4. Synthesis of intermediate 6d:

[0107] Add intermediate 6c (0.192 g, 0.250 mmol), tris(2,4,6-trichlorophenyl)methane (0.180 g, 0.320 mmol), potassium carbonate (0.138 g, 1.000 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, add an appropriate amount of tetrakis(triphenylphosphine)palladium under a nitrogen stream, and then add toluene (6 mL), methanol (2 mL), and deionized water (2 mL). After stirring for 10 minutes, the mixture was heated to 110 ° C under a nitrogen atmosphere and stirred to react overnight. The reaction mixture was cooled to room temperature. The organic phase was concentrated, concentrated by rotary evaporation, and purified by column chromatography (dichloromethane / petroleum ether=1 / 10, v / v) to obtain the target product, white solid intermediate 6d 0.054 g. Yield 19%. EI-MS (m / z): 1143.5 (M + , 100%).

[0108] 5. Synthesis of free radical compound R6:

[0109] Add intermediate 6d (0.029 g, 0.025 mmol) and potassium tert-butoxide (0.005 g, 0.040 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, and add dry tetrahydrofuran solution (10 mL) in a nitrogen atmosphere. Heat the mixture to 80 ° C under a nitrogen atmosphere, stir overnight in a dark environment, and the solution color is purple. Cool to room temperature, add tetrachlorobenzoquinone (0.013 g, 0.054 mmol), and continue stirring for 2 hours in a dark environment at room temperature. After the reaction is completed, the organic solvent is removed in vacuo, and the target product is purified by column chromatography (dichloromethane / petroleum ether=1:10, v / v) to obtain the target product brown solid free radical compound R6 0.016 g, with a yield of about 55%. EI-MS (m / z): 1142.2 (M +, 100%).

[0110] Synthesis route of boron-containing fused ring carbon radical compound R7:

[0111]

[0112] 1. Synthesis of intermediate 7a:

[0113] Place diphenylamine (0.85 g, 5 mmol) and cesium carbonate (3.92 g, 12 mmol) in a dry two-necked bottle and evacuate for three cycles. Add dry DMF (15 mL) with a syringe under nitrogen flow, stir at room temperature for 30 min, add 2.5-dibromo-1.3-difluorobenzene (0.54 g, 2 mmol) under nitrogen flow, heat to 155 ° C for 12 hours, until the raw materials react completely. After the reaction, add a large amount of water to generate a precipitate, filter, collect the precipitate and pass it through a column with dichloromethane: petroleum ether = 1:10. Obtain 0.71 g of white solid intermediate 7a with a yield of 62%. EI-MS (m / z): 570.3 (M + , 100%).

[0114] 2. Synthesis of intermediate 7b:

[0115] 7a (1.67 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25.00 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and the temperature was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain 1.09 g of the target product, a white solid intermediate 7b, with a yield of 75%. EI-MS (m / z): 499.2 (M + , 100%).

[0116] 3. Synthesis of intermediate 7c:

[0117] The intermediate 7b (0.285 g, 0.570 mmol), biboric acid pinacol ester (0.230 g, 0.570 mmol), potassium acetate (0.600 g, 6.110 mmol) were placed in a 100 mL two-necked bottle, vacuumed and nitrogen filled for three cycles, 1,4-dioxane (25 mL) was added under a nitrogen flow, and an appropriate amount of tetrakis(triphenylphosphine)palladium was added. The mixture was stirred at room temperature for 10 minutes, and the mixture was heated to 90°C under a nitrogen atmosphere and stirred overnight. The reaction mixture was cooled to room temperature. Concentrated and purified by column chromatography (petroleum ether / ethyl acetate = 5 / 1, v / v) to obtain the target product, yellow solid intermediate 7c 0.265 g. The yield was about 85%. EI-MS (m / z): 546.3 (M + , 100%).

[0118] 4. Synthesis of intermediate 7d:

[0119] Add intermediate 7c (0.137 g, 0.250 mmol), tris(2,4,6-trichlorophenyl)methane (0.180 g, 0.320 mmol), potassium carbonate (0.138 g, 1.000 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, add an appropriate amount of tetrakis(triphenylphosphine)palladium under a nitrogen stream, and then add toluene (6 mL), methanol (2 mL), and deionized water (2 mL). After fully stirring for 10 minutes, the mixture was heated to 110 ° C under a nitrogen atmosphere and stirred to react overnight. The reaction mixture was cooled to room temperature. The organic phase was concentrated, concentrated by rotary evaporation, and purified by column chromatography (dichloromethane / petroleum ether=1 / 10, v / v) to obtain the target product, white solid intermediate 7d 0.047 g. Yield 20%. EI-MS (m / z): 938.2 (M + , 100%).

[0120] 5. Synthesis of free radical compound R7:

[0121] Add 7d (0.023 g, 0.025 mmol) and potassium tert-butoxide (0.005 g, 0.040 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, and add dry tetrahydrofuran solution (10 mL) in a nitrogen atmosphere. Heat the mixture to 80 ° C under a nitrogen atmosphere, stir overnight in a dark environment, and the solution color is purple. Cool to room temperature, add tetrachlorobenzoquinone (0.013 g, 0.054 mmol), and continue stirring for 2 hours in a dark environment at room temperature. After the reaction is completed, the organic solvent is removed in vacuo, and the target product is purified by column chromatography (dichloromethane / petroleum ether=1:10, v / v) to obtain the target product brown solid free radical compound R7 0.013 g, with a yield of about 55%. EI-MS (m / z): 937.3 (M +, 100%).

[0122] Synthesis route of boron-containing fused ring carbon radical compound R8:

[0123]

[0124] 1. Synthesis of intermediate 8a:

[0125] Place bis(4-tert-butylphenyl)amine (1.41 g, 5 mmol) and cesium carbonate (3.92 g, 12 mmol) in a dry two-necked bottle and evacuate for three cycles. Add dry DMF (15 mL) with a syringe under nitrogen flow, stir at room temperature for 30 min, add 2.5-dibromo-1.3-difluorobenzene (0.54 g, 2 mmol) under nitrogen flow, heat to 155 ° C for 12 hours, until the raw materials react completely. After the reaction, add a large amount of water to form a precipitate, filter, collect the precipitate and pass it through a column with dichloromethane: petroleum ether = 1:10. Obtain 1.14 g of white solid intermediate 8a with a yield of 60%. EI-MS (m / z): 794.7 (M + , 100%).

[0126] 2. Synthesis of intermediate 8b:

[0127] Intermediate 8a (2.32 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25.00 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and the temperature was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain 1.58 g of the target product, a white solid intermediate 8b, with a yield of 75%. EI-MS (m / z): 723.6 (M + , 100%).

[0128] 3. Synthesis of intermediate 8c:

[0129] The intermediate 8b (0.412 g, 0.570 mmol), biboric acid pinacol ester (0.230 g, 0.570 mmol), potassium acetate (0.600 g, 6.110 mmol) were placed in a 100 mL two-necked bottle, and the vacuum was evacuated and nitrogen was filled for three cycles. 1,4-dioxane (25 mL) was added under a nitrogen flow, and an appropriate amount of tetrakis(triphenylphosphine)palladium was added. The mixture was stirred at room temperature for 10 minutes, and the mixture was heated to 90°C under a nitrogen atmosphere and stirred overnight. The reaction mixture was cooled to room temperature. Concentrated and purified by column chromatography (petroleum ether / ethyl acetate = 5 / 1, v / v) to obtain the target product, yellow solid intermediate 8c 0.351 g. The yield was about 80%. EI-MS (m / z): 770.7 (M + , 100%).

[0130] 4. Synthesis of intermediate 8d:

[0131] Add 8c (0.193 g, 0.250 mmol), tris(2,4,6-trichlorophenyl)methane (0.180 g, 0.320 mmol), potassium carbonate (0.138 g, 1.000 mmol) to a Schlenck tube, evacuate and charge with nitrogen for three cycles, add an appropriate amount of tetrakis(triphenylphosphine)palladium under a nitrogen stream, and then add toluene (6 mL), methanol (2 mL), and deionized water (2 mL). After stirring for 10 minutes, the mixture was heated to 110 ° C under a nitrogen atmosphere and stirred to react overnight. The reaction mixture was cooled to room temperature. The organic phase was concentrated, concentrated by rotary evaporation, and purified by column chromatography (dichloromethane / petroleum ether=1 / 10, v / v) to obtain the target product, a white solid intermediate 8d 0.058 g. The yield was 20%. EI-MS (m / z): 1162.6 (M + , 100%).

[0132] 5. Synthesis of free radical compound R8:

[0133] Add 8d (0.029 g, 0.025 mmol) and potassium tert-butoxide (0.005 g, 0.040 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, and add dry tetrahydrofuran solution (10 mL) in a nitrogen atmosphere. Heat the mixture to 80 ° C under a nitrogen atmosphere, stir overnight in a dark environment, and the solution color is purple. Cool to room temperature, add tetrachlorobenzoquinone (0.013 g, 0.054 mmol), and continue stirring for 2 hours in a dark environment at room temperature. After the reaction is completed, the organic solvent is removed in vacuo, and the target product is purified by column chromatography (dichloromethane / petroleum ether=1:10, v / v) to obtain the target product brown solid free radical compound R8 0.016 g, with a yield of about 55%. EI-MS (m / z): 1161.3 (M + , 100%).

[0134] Example 9 Synthesis of Boron-Containing Condensed Ring Carbon Radical Compound R9

[0135] Synthesis route of boron-containing fused ring carbon radical compound R9:

[0136]

[0137] 1. Synthesis of intermediate 9a:

[0138] Take a dry 250mL two-necked reaction bottle, add phenoxazine (1.20g, 6.6mmol), potassium tert-butoxide (0.840g, 8.1mmol), evacuate and fill with nitrogen for three cycles, then add dry DMF (20mL) under nitrogen flow, stir at room temperature for 30 minutes, then add 2,5-dibromo-1,3-difluorobenzene (0.84g, 3mmol) DMF solution (10mL) dropwise under nitrogen, heat to 140℃ for 12 hours, cool to room temperature, concentrate, then extract with water and dichloromethane three times, concentrate the combined organic phase by rotary evaporation, and purify the target product by column chromatography (dichloromethane / petroleum ether = 1 / 5, v / v) to obtain yellow solid intermediate 9a 0.807g, yield 45%. EI-MS (m / z): 598.3 (M + , 100%).

[0139] 2. Synthesis of intermediate 9b:

[0140] Intermediate 9a (1.75 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25.00 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and the temperature was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain the target product, a white solid intermediate 9b, 1.08 g, with a yield of 70%. EI-MS (m / z): 527.2 (M + , 100%).

[0141] 3. Synthesis of intermediate 9c:

[0142] The intermediate 9b (0.301 g, 0.570 mmol), biboric acid pinacol ester (0.230 g, 0.570 mmol), potassium acetate (0.600 g, 6.110 mmol) were placed in a 100 mL two-necked bottle, and the vacuum was evacuated and nitrogen was filled for three cycles. 1,4-dioxane (25 mL) was added under a nitrogen flow, and an appropriate amount of tetrakis(triphenylphosphine)palladium was added. The mixture was stirred at room temperature for 10 minutes, and the mixture was heated to 90°C under a nitrogen atmosphere and stirred overnight. The reaction mixture was cooled to room temperature. Concentrated and purified by column chromatography (petroleum ether / ethyl acetate = 5 / 1, v / v) to obtain the target product, yellow solid intermediate 9c 0.246 g. The yield was about 75%. EI-MS (m / z): 574.3 (M + , 100%).

[0143] 4. Synthesis of intermediate 9d:

[0144] Add intermediate 9c (0.144 g, 0.250 mmol), tris(2,4,6-trichlorophenyl)methane (0.180 g, 0.320 mmol), potassium carbonate (0.138 g, 1.000 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, add an appropriate amount of tetrakis(triphenylphosphine)palladium under a nitrogen stream, and then add toluene (6 mL), methanol (2 mL), and deionized water (2 mL). After fully stirring for 10 minutes, the mixture was heated to 110 ° C under a nitrogen atmosphere and stirred to react overnight. The reaction mixture was cooled to room temperature. The organic phase was concentrated, concentrated by rotary evaporation, and purified by column chromatography (dichloromethane / petroleum ether=1 / 10, v / v) to obtain the target product, white solid intermediate 9d 0.046 g. Yield 19%. EI-MS (m / z): 966.1 (M + , 100%).

[0145] 5. Synthesis of free radical compound R9:

[0146] Add intermediate 9d (0.024 g, 0.025 mmol) and potassium tert-butoxide (0.005 g, 0.040 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, and add dry tetrahydrofuran solution (10 mL) in a nitrogen atmosphere. Heat the mixture to 80 ° C under a nitrogen atmosphere, stir overnight in a dark environment, and the solution color turns purple. Cool to room temperature, add tetrachlorobenzoquinone (0.013 g, 0.054 mmol), and continue stirring for 2 hours in a dark environment at room temperature. After the reaction is completed, the organic solvent is removed in vacuo, and the target product is purified by column chromatography (dichloromethane / petroleum ether=1:10, v / v) to obtain the target product brown solid free radical compound R9 0.014 g, with a yield of about 60%. EI-MS (m / z): 965.2 (M + , 100%).

[0147] Example 10 Synthesis of Boron-Containing Condensed Ring Carbon Radical Compound R10

[0148] Synthesis route of boron-containing fused ring carbon radical compound R10:

[0149]

[0150] 1. Synthesis of intermediate 10a:

[0151] Take a dry 250mL two-necked reaction bottle, add phenoxazine (1.31g, 6.6mmol), potassium tert-butoxide (0.840g, 8.1mmol), evacuate and fill with nitrogen for three cycles, then add dry DMF (20mL) under nitrogen flow, stir at room temperature for 30 minutes, then add 2,5-dibromo-1,3-difluorobenzene (0.84g, 3mmol) DMF solution (10mL) dropwise under nitrogen, heat to 140℃ for 12 hours, cool to room temperature, concentrate, and then extract with water and dichloromethane three times, the combined organic phase is concentrated by rotary evaporation, and the target product is purified by column chromatography (dichloromethane / petroleum ether = 1 / 5, v / v) to obtain yellow solid intermediate 10a 1.134g, with a yield of 60%. EI-MS (m / z): 630.4 (M + , 100%).

[0152] 2. Synthesis of intermediate 10b:

[0153] Intermediate 10a (1.84 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25.00 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and the temperature was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain the target product, a yellow solid intermediate 10b, 1.06 g, with a yield of 65%. EI-MS (m / z): 559.3 (M + , 100%).

[0154] 3. Synthesis of intermediate 10c:

[0155] The intermediate 10b (0.319 g, 0.570 mmol), biboric acid pinacol ester (0.230 g, 0.570 mmol), potassium acetate (0.600 g, 6.110 mmol) were placed in a 100 mL two-necked bottle, vacuumed and nitrogen filled for three cycles, 1,4-dioxane (25 mL) was added under nitrogen flow, and an appropriate amount of tetrakis(triphenylphosphine)palladium was added. The mixture was stirred at room temperature for 10 minutes, and the mixture was heated to 90°C under nitrogen atmosphere and stirred overnight. The reaction mixture was cooled to room temperature. Concentrated and purified by column chromatography (petroleum ether / ethyl acetate = 5 / 1, v / v) to obtain the target product, yellow solid intermediate 10c 0.280 g. The yield was about 81%. EI-MS (m / z): 606.4 (M + , 100%).

[0156] 4. Synthesis of intermediate 10d:

[0157] Add intermediate 10c (0.152 g, 0.250 mmol), tris(2,4,6-trichlorophenyl)methane (0.180 g, 0.320 mmol), potassium carbonate (0.138 g, 1.000 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, add an appropriate amount of tetrakis(triphenylphosphine)palladium under a nitrogen stream, and then add toluene (6 mL), methanol (2 mL), and deionized water (2 mL). After fully stirring for 10 minutes, the mixture was heated to 110°C under a nitrogen atmosphere and stirred to react overnight. The reaction mixture was cooled to room temperature. The organic phase was concentrated, concentrated by rotary evaporation, and purified by column chromatography (dichloromethane / petroleum ether=1 / 10, v / v) to obtain the target product, yellow solid intermediate 10d 0.055 g. Yield 22%. EI-MS (m / z): 998.3 (M + , 100%).

[0158] 5. Synthesis of free radical compound R10:

[0159] Add intermediate 10d (0.025 g, 0.025 mmol) and potassium tert-butoxide (0.005 g, 0.040 mmol) to a Schlenck tube, evacuate and fill with nitrogen for three cycles, and add dry tetrahydrofuran solution (10 mL) in a nitrogen atmosphere. Heat the mixture to 80 ° C under a nitrogen atmosphere, stir overnight in a dark environment, and the solution color is purple. Cool to room temperature, add tetrachlorobenzoquinone (0.013 g, 0.054 mmol), and continue stirring for 2 hours in a dark environment at room temperature. After the reaction is completed, the organic solvent is removed in vacuo, and the target product is purified by column chromatography (dichloromethane / petroleum ether=1:10, v / v) to obtain the target product brown solid free radical compound R100.015 g, with a yield of about 60%. EI-MS (m / z): 997.2 (M + , 100%).

[0160] Example 11 Preparation and Characterization of OLED Devices

[0161] The preparation steps of the OLED device with ITO / PEDOT:PSS (40nm) / EML (80nm) / TPBi (30nm) / LiF (1nm) / Al (120nm) / cathode are as follows:

[0162] (i) The ITO electrode was ultrasonically treated with an aqueous solution of 5% Decon90 cleaning solution for 30 minutes, then ultrasonically cleaned with deionized water for several times, then ultrasonically cleaned with isopropanol, and dried with nitrogen; treated with oxygen plasma for 5 minutes to clean the ITO surface and improve the work function of the ITO electrode;

[0163] (ii) Spin coating a PEDOT:PSS solution on an ITO glass substrate treated with oxygen plasma to obtain a 40 nm film, which was then annealed in air at 150°C for 20 minutes. PEDOT:PSS is an aqueous solution of a high molecular polymer, which is composed of two substances, PEDOT and PSS. PEDOT is a polymer of 3,4-ethylenedioxythiophene monomers, and PSS is polystyrene sulfonate.

[0164] (iii) PVK, PBD and free radical compounds (R1 to R10) were first dissolved in toluene at a mass ratio of 65:30:5, and the solution was spin-coated in a nitrogen glove box to obtain an 80 nm film, which was then annealed at 120° C. for 10 minutes. PVK is the abbreviation of polyvinyl carbazole, and PBD is the abbreviation of 2-(4-tert-butylphenyl)-5-biphenyloxadiazole.

[0165] (iv) Place the spin-coated device into a vacuum evaporation chamber, and sequentially evaporate 30nm TPBi, 1nm LiF and 100nm aluminum to obtain a light-emitting device. TPBi is the abbreviation of 1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene. The current-voltage-luminance (JVL) characteristics of the OLED device are characterized by a characterization device, and important parameters such as efficiency and external quantum efficiency are recorded at the same time. After testing, the maximum external quantum efficiency (EQE) of the OLED is 12%. The details are as follows:

[0166] Radical R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 EQE 7.5％ 8.5％ 5.5％ 6.5％ 10％ 11％ 9％ 10.5％ 12％ 9.5％

[0167] Further optimization, such as optimization of device structure, combination optimization of hole transport material (HTM), electron transport material (ETM) and host material, will further improve the performance of the device, especially efficiency, driving voltage and lifespan.

Claims

1. A boron-containing fused ring carbon radical compound, the general formula of which is shown in structure (I): in, It is a boron-containing fused ring organic unit, specifically selected from the following structures: Wherein, X is an O atom or an S atom, and R is a tert-butyl group or a H atom.

2. The boron-containing fused-ring carbon radical compound according to claim 1, characterized in that: The boron-containing fused ring carbon radical compound is selected from the following R1-R10:

3. The method for preparing the boron-containing fused-ring carbon radical compound according to claim 1 or 2, characterized in that: The following steps are involved: 1) First, 2,5-dibromo-1,3-difluorobenzene is used as a raw material to synthesize intermediates 1a-10a, and then monobrominated boron-containing fused ring compounds 1b-10b are synthesized through borylation reaction, and then the corresponding boron ester compounds 1c-10c are synthesized; 2) then subjecting the boron ester compounds 1c-10c prepared in step 1) to Suzuki coupling reaction with tris(2,4,6-trichlorophenyl)methane to form free radical precursor compounds 1d-10d; 3) Finally, under the action of potassium tert-butoxide and tetrachlorobenzoquinone, the free radical precursor prepared in step 2) is converted into free radical compounds R1-R10.

4. The method for preparing the boron-containing fused-ring carbon radical compound according to claim 3, characterized in that: The synthesis step of the intermediate 1a-10a compound in step 1) comprises: reacting 2,5-dibromo-1,3-difluorobenzene with a phenyl-containing compound under a nitrogen atmosphere at high temperature for 12 to 24 hours to obtain, preferably, the phenyl-containing compound comprises a phenolic compound, a carbazole compound or an aniline compound or phenoxazine; preferably, the phenolic compound comprises phenol, 4-tert-butylphenol, thiophenol or 4-tert-butylthiophenol; preferably, the carbazole compound comprises carbazole or di-tert-butylcarbazole; preferably, the aniline compound comprises diphenylamine or bis(4-tert-butylphenyl)amine.

5. The method for preparing the boron-containing fused-ring carbon radical compound according to claim 3, characterized in that: Step 1) The synthesis process of compound 1b-10b is as follows: dry m-xylene and n-butyl lithium are added to compound 1a-10a under a nitrogen atmosphere, stirred, then transferred to room temperature and continuously stirred, then boron tribromide is added and stirred, then the mixture is transferred to room temperature and stirred, then the mixture is heated and stirred, then cooled again, N,N-diisopropylethylamine is added, and finally the mixture is heated and stirred. After the reaction is completed, it is cooled to room temperature and the resulting solution is washed with a saturated sodium acetate solution, then water and dichloromethane are added for extraction several times, and the combined organic phase is concentrated by rotary evaporation and dried, and finally the target products, namely compound 1b-10b, are obtained.

6. The method for preparing the boron-containing fused-ring carbon radical compound according to claim 3, characterized in that: Step 1) The synthesis process of intermediates 1c to 10c is as follows: add pinacol diboron and potassium acetate to compounds 1b to 10b, respectively, evacuate and circulate with nitrogen, add 1,4-dioxane under a nitrogen flow, add tetrakis(triphenylphosphine)palladium, stir at room temperature, heat the mixture under a nitrogen atmosphere, and stir to react overnight, cool the reaction mixture to room temperature, concentrate, and purify by column chromatography to obtain the target product as a yellow solid intermediate, namely compounds 1c to 10c.

7. Use of the boron-containing fused-ring carbon radical compound according to claim 1 or 2 in the preparation of organic electronic devices.

8. The use according to claim 7, characterized in that: The organic electronic device includes one or more of an organic light emitting diode, an organic photovoltaic cell, an organic light emitting cell, an organic field effect transistor, an organic laser, an organic spin electronic device, an organic sensor or an organic plasmon emission diode.

9. An organic electronic device, characterized in that: The organic electronic device comprises the boron-containing fused-ring carbon radical compound according to claim 1 or 2.

10. The organic electronic device according to claim 9, characterized in that: The mass concentration of the boron-containing condensed-ring carbon radical compound is 3-10 wt %.

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