A fully deuterated pyridoborane heterocyclic compound and its application

Abstract

The present invention relates to the technical field of organic electroluminescent materials, and specifically to a fully deuterated pyridine and boron oxygen heterocyclic compound and its application. The fully deuterated pyridine and boron oxygen heterocyclic compound has the structural formula:; The fully deuterated pyridine and boron oxygen heterocyclic compound can be applied to the field of organic electroluminescent materials, and can achieve ultra-high green light base color purity. The parent structure of the fully deuterated pyridine and boron oxygen heterocyclic compound is a high-rigidity condensed ring structure with six six-membered heterocyclic rings arranged in parallel, which has a large steric hindrance, significantly increases the spin-orbit coupling effect between different excited states, and greatly limits the molecular relaxation process. Finally, the device achieves ultra-pure green light emission, and the full deuteration can significantly improve the device life and luminous efficiency.

Description

Technical Field

[0001] The invention relates to a fully deuterated pyridoborane-oxygen heterocyclic compound and application thereof, belonging to the technical field of organic electroluminescent materials. Background Art

[0002] OLED is an organic electroluminescent display. Its operating principle is that under the drive of an electric field, organic semiconductor light-emitting materials emit light through carrier injection and recombination. OLED is the third generation of display technology after the CRT era and LCD era.

[0003] The main body of OLED materials includes: luminescent materials and basic general materials, each accounting for about 30% in OLED devices. Among them, luminescent materials are divided into three types: red, green and blue. At present, the mainstream luminescent materials in the market are basically phosphorescent materials with precious metals such as iridium and platinum as the core, and the cost required is high.

[0004] Organic light-emitting materials have large structural relaxation, which causes their luminescence spectrum to be significantly broadened. This results in that although organic light-emitting materials are cheaper, their color purity is difficult to match that of precious metal phosphorescent materials. After weighing the pros and cons in commercial applications, organic light-emitting materials also have a broad space, but in the high-value market of ultra-high-definition display, organic light-emitting materials have few application scenarios.

[0005] The International Telecommunication Union has proposed the Rec.2020 standard for ultra-high-definition display technology, which has updated higher indicators for the luminous color purity of the three primary colors of RGB, especially green. The CIE color coordinates of green light in the old indicator Rec.709 are (0.30, 0.60), and the new indicator CIE color coordinates are updated to (0.170, 0.797).

[0006] Different from the long wavelength of red light and the short wavelength of blue light, green light is emitted right in the middle of the visible spectrum and is extremely sensitive to spectrum broadening or shoulder peaks. A slight fluctuation will significantly reduce its CIE y coordinate, affecting the color purity of green light. Therefore, ultra-high color purity green light OLED materials are a bottleneck that needs to be broken through. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a fully deuterated pyridoborane oxygen heterocyclic compound and its application. The fully deuterated pyridoborane oxygen heterocyclic compound is applied to OLED devices to significantly improve the green light primary color purity and service life of the device.

[0008] The technical solution of the present invention to solve the above technical problem is as follows: a fully deuterated pyridoborane oxygen heterocyclic compound, the structural formula of the fully deuterated pyridoborane oxygen heterocyclic compound is as follows:

[0009] ;

[0010] The R is selected from any one of the following structural formulas:

[0011] ;

[0012] n represents the number of deuterium replacing hydrogen in the formula, that is, the number of deuterium in the chemical formula.

[0013] Furthermore, the fully deuterated pyridoboroxime heterocyclic compound is selected from any one of the following structural formulas:

[0014] .

[0015] Furthermore, the fully deuterated pyridoboroxime heterocyclic compound is selected from any one of the following structural formulas:

[0016] ;

[0017] ;

[0018] .

[0019] The invention also discloses an application of a fully deuterated pyrido-borane-oxygen heterocyclic compound. The fully deuterated pyrido-borane-oxygen heterocyclic compound is applied to an organic electroluminescent device.

[0020] Furthermore, the organic layer of the organic electroluminescent device comprises at least one of the fully deuterated pyridoboroxime heterocyclic compounds.

[0021] Furthermore, the organic layer includes a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer and an electron injection layer.

[0022] Furthermore, the fully deuterated pyridoboroxime heterocyclic compound is used as a light-emitting layer material of an organic electroluminescent device.

[0023] The beneficial effects of the present invention are:

[0024] The fully deuterated pyridoborane heterocyclic compound of the present invention has a parent structure of a high-rigidity condensed ring structure of six six-membered heterocyclic rings arranged in parallel, and has a large steric hindrance, which significantly increases the spin-orbit coupling between different excited states, so that the molecular relaxation process is greatly restricted, and ultimately the device can achieve ultra-pure green light emission. At the same time, full deuteration can significantly improve the device life and luminous efficiency.

[0025] The OLED organic light-emitting device prepared from the fully deuterated pyridoborane heterocyclic compound provided by the present invention has significantly improved luminous efficiency and working life characteristics and has good stability.

[0026] The organic light-emitting device made of the fully deuterated pyridoborane heterocyclic compound of the present invention can be applied to the highly practical OLED industry, surface-emitting OLED luminescent bodies for lighting, flexible luminescent bodies, etc., and has a good application prospect. DETAILED DESCRIPTION

[0027] The specific implementation of the present invention is described in detail below. The present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.

[0029] Example 1

[0030] [3-1] The synthetic route is as follows:

[0031] ;

[0032] (1) Synthesis of compound 1: 500 mmol of 1,3-dibromo-2-chloro-5-iodobenzene (CAS: 2387266-13-7), 525 mmol of phenylboric acid, 1000 mmol of sodium carbonate, 322 g of purified water, and 1500 g of tetrahydrofuran were added to the reaction flask, stirred, and protected by nitrogen. Then, 2.5 mmol of Pd (pph) catalyst was added. 3 ) 4 , heat to 60℃ and keep warm for 15 hours. After TLC tracking detection shows that there is no 1,3-dibromo-2-chloro-5-iodobenzene remaining, cool to room temperature, hydrolyze, extract and wash with 2000g toluene, wash the organic phase with hot purified water until neutral, add anhydrous sodium sulfate to dry the organic phase, and pass through a silica gel column at normal pressure. After the column is passed, rinse the column with 50g toluene each time, for a total of 3 times. After the elution is completed, combine the eluent and the column liquid and remove the solvent under negative pressure. After the stripping is completed (a yellow oil is obtained), use ethyl acetate mixed with n-hexane as the eluent, and purify by column chromatography to obtain 400mmol of compound 1 (dark yellow solid), with a yield of 80%. Mass spectrum: 346.44. Hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 7.72 (s, 2H), 7.69 –7.62 (m, 2H), 7.43 – 7.35 (m, 2H), 7.35 – 7.30 (m, 1H).

[0033] (2) Synthesis of Compound 2: Add 400mmol of Compound 1 and 1000g of tetrahydrofuran into the reaction bottle, stir, protect with nitrogen, cool to -85℃, add 400mmol of n-butyllithium n-hexane solution (2.5mol / L) dropwise, and keep at -85℃ for 1 hour. After TLC tracking detection shows that no compound 1 is left, continue to control the temperature at -85℃ and add 400mmol of 5-methoxy-3-pyridinecarboxaldehyde tetrahydrofuran solution (110g), keep at -85℃ for 2 hours. After TLC tracking detection shows that no 5-methoxy-3-pyridinecarboxaldehyde is left, hydrolyze, extract with 1000g of toluene and wash with water, wash the organic phase with hot purified water until neutral, add anhydrous sodium sulfate to dry the organic phase, and pass through a silica gel column at normal pressure. After the column was washed, 50 g of toluene was used to elute the column for 3 times. After the washing, the eluent and the column liquid were combined and the solvent was removed under negative pressure. After the removal (a yellow oily substance was obtained), ethyl acetate mixed with n-hexane was used as the eluent and purified by column chromatography to obtain 320 mmol of compound 2 (yellow solid) with a yield of 80%. Mass spectrum: 404.68. Hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.61 (d, J = 1.2 Hz, 1H), 8.13 (d, J = 1.2 Hz, 1H),7.84 (dd, J = 1.9, 1.0 Hz, 1H), 7.70 – 7.62 (m, 3H), 7.49 – 7.42 (m, 2H), 7.42 – 7.35 (m, 1H), 7.23 (t, J = 1.2 Hz, 1H), 6.29 (dd, J = 5.0, 1.0 Hz,1H), 5.67 (d, J = 4.9 Hz, 1H), 3.80 (s, 3H).

[0034] (3) Synthesis of compound 3: Add 600g of glacial acetic acid and 160mmol of iodine pellets to the reaction flask, stir, protect with nitrogen, drop 480mmol of hypophosphorous acid (50%wt.), heat to 90-100℃ and keep warm for 1 hour, cool to 50℃, add 320mmol of compound 2, heat to 90-100℃ and keep warm for 6h. After TLC tracking and detection of no residue of compound 2, cool to room temperature, hydrolyze, and a large amount of crude product 3 is precipitated, filter, and rinse the filter cake with purified water until the eluent is neutral, extract the filter cake with 800g of toluene and add alkaline solution containing 40g of sodium hydroxide, heat to 80℃ and keep warm for 2 hours, wash the organic phase with water until it is neutral, add anhydrous sodium sulfate to dry the organic phase, and pass through a silica gel column at normal pressure. After the column was washed, 50 g of toluene was used to elute the column for 3 times. After the washing, the eluent and the column liquid were combined and the solvent was removed under negative pressure. After the removal, 240 mmol of compound 3 (light yellow solid) was recrystallized from toluene to obtain a yield of 75%. Mass spectrum: 388.69. Hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.50 (d, J = 1.3 Hz,1H), 8.18 (d, J = 1.3 Hz, 1H), 7.68 – 7.62 (m, 2H), 7.58 (d, J = 2.0 Hz, 1H),7.51 – 7.44 (m, 3H), 7.40 – 7.33 (m, 1H), 7.14 (t, J = 1.2 Hz, 1H), 4.10 (d, J = 1.1 Hz, 2H), 3.83 (s, 3H).

[0035] (4) Synthesis of compound 4: Add 240mmol of compound 3 and 1000g of tetrahydrofuran into the reaction bottle, stir, protect with nitrogen, cool to -85℃, add 252mmol of n-butyl lithium n-hexane solution (2.5mol / L) dropwise, and keep at -85℃ for 1 hour. After TLC tracking detection shows that there is no residual compound 3, continue to control the temperature at -85℃ and add 240mmol of 5-fluoro-3-pyridinecarboxaldehyde tetrahydrofuran solution (60g), keep at -85℃ for 2 hours. After TLC tracking detection shows that there is basically no residual 5-fluoro-3-pyridinecarboxaldehyde, hydrolyze, extract with 1000g of toluene and wash with water, wash the organic phase with hot purified water until neutral, add anhydrous sodium sulfate to dry the organic phase, and pass it through a silica gel column at normal pressure. After the column was washed, 50 g of toluene was used to elute the column for 3 times. After the washing, the eluent and the column liquid were combined and the solvent was removed under negative pressure. After the removal (brown oily substance was obtained), ethyl acetate mixed with n-hexane was used as the eluent and purified by column chromatography to obtain 200 mmol of compound 4 (off-white solid) with a yield of 83%. Mass spectrum: 434.89. Hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.60 (d, J = 1.1 Hz, 1H), 8.50 (dd, J = 11.0, 1.2Hz, 2H), 8.11 (d, J = 1.3 Hz, 1H), 7.94 (dd, J = 2.0, 0.9 Hz, 1H), 7.65 –7.59 (m, 2H), 7.54 (dt, J = 2.0, 0.9 Hz, 1H), 7.47 – 7.40 (m, 2H), 7.43 –7.34 (m, 2H), 7.19 (t, J = 1.2 Hz, 1H), 6.63 (dd, J = 4.9, 1.1 Hz, 1H), 5.64(d, J = 5.1 Hz, 1H), 4.18 (dd, J = 12.5, 0.9 Hz, 1H), 4.14 (dd, J = 12.4, 1.0Hz, 1H), 3.83 (s, 2H).

[0036] (5) Synthesis of compound 5: Add 500g of glacial acetic acid and 100mmol of iodine pellets to the reaction flask, stir, protect with nitrogen, drop 300mmol of hypophosphorous acid (50%wt.), heat to 90-100℃ and keep warm for 1 hour, cool to 50℃, add 200mmol of compound 4, heat to 90-100℃ and keep warm for 6h. After TLC tracking and detection of no residue of compound 4, cool to room temperature, hydrolyze, and a large amount of crude product 5 is precipitated, filter, and rinse the filter cake with purified water until the eluent is neutral, extract the filter cake with 800g of toluene and add alkaline solution containing 60g of sodium hydroxide, heat to 80℃ and keep warm for 2 hours, wash the organic phase with water until it is neutral, add anhydrous sodium sulfate to dry the organic phase, and pass through a silica gel column at normal pressure. After the column was washed, 50 g of toluene was used to elute the column for 3 times. After the washing, the eluent and the column liquid were combined and the solvent was removed under negative pressure. After the removal, 140 mmol of compound 5 (yellow solid) was recrystallized from toluene to obtain a yield of 70%. Mass spectrum: 418.89. Hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.52 (dd, J = 3.1, 1.3Hz, 2H), 8.48 (d, J = 1.2 Hz, 1H), 8.11 (d, J = 1.3 Hz, 1H), 7.57 – 7.52 (m,2H), 7.52 – 7.48 (m, 2H), 7.45 – 7.38 (m, 2H), 7.38 – 7.33 (m, 1H), 7.12 (dt, J = 7.5, 1.2 Hz, 2H), 4.21 – 4.14 (m, 3H), 4.12 (dd, J = 12.3, 1.0 Hz, 1H), 3.84 (s, 3H).

[0037] (6) Synthesis of compound 6: 140 mmol of compound 5 and 2000 g of dichloroethane were added to the reaction flask, stirred and protected with nitrogen. The temperature was cooled to -5 to 5°C and boron tribromide (CAS: 10294-33-4) was added dropwise. The temperature was kept at -5 to 5°C for 3 hours. After TLC tracking and detection of no residue of compound 5, hydrolysis was performed. The hydrolysis aqueous phase was separated. Alkali solution was added to the organic phase to adjust the pH to ≥ 10. Alkali solution containing 50 g of sodium hydroxide was added again. The temperature was raised to 80°C and kept for 2 hours. The organic phase was washed with purified water until neutral. After washing, anhydrous sodium sulfate was added to dry the organic phase and passed through a silica gel column at normal pressure. After the column was washed, 150 g of dichloroethane was used to elute the column for 3 times. After the washing, the eluent and the column liquid were combined and the solvent was removed under negative pressure. After the removal (brown oil was obtained), ethyl acetate mixed with n-hexane was used as the eluent, and 100 mmol of compound 6 (off-white solid) was purified by column chromatography with a yield of 71%. Mass spectrum: 404.86. Hydrogen spectrum: 1 H NMR (500 MHz, DMSO- d 6 ) δ 9.94 (s, 1H), 8.62 (d, J = 1.3 Hz,1H), 8.52 (d, J = 1.3 Hz, 1H), 8.46 (d, J = 1.3 Hz, 1H), 8.18 (d, J = 1.2 Hz,1H), 7.63 (dt, J = 2.0, 0.9 Hz, 1H), 7.61 – 7.54 (m, 3H), 7.47 – 7.43 (m,1H), 7.43 – 7.34 (m, 2H), 7.22 (t, J = 1.3 Hz, 1H), 7.11 (t, J = 1.3 Hz, 1H),4.17 (d, J = 0.9 Hz, 4H).

[0038] (7) Synthesis of compound 7: 100 mmol of compound 6, 250 mmol of potassium carbonate and 350 g of N,N-dimethylformyl were added to the reaction flask, stirred, protected by nitrogen, heated to 135-140°C and kept for 36 hours. After TLC tracking detected that there was no residual compound 6, the temperature was cooled to room temperature and filtered. The filtrate was retained and the solvent was removed under negative pressure to obtain a black oily substance. 600 g of toluene was added for hot dissolution, and then the organic phase was washed with hot purified water until neutral. After washing, anhydrous sodium sulfate was added to dry the organic phase and passed through a silica gel column at normal pressure. After passing through the column, the column was rinsed with 50 g of toluene each time, for a total of 3 times. After elution, the eluent and the column liquid were combined and the solvent was removed under negative pressure. After removal (brown-black oily substance was obtained), ethyl acetate mixed with n-hexane was used as the eluent, and 45 mmol of compound 7 (brown-yellow solid) was purified by column chromatography with a yield of 45%. Mass spectrum: 384.86. Hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.23 ​​(d, J = 1.3 Hz, 2H), 8.09 (d, J = 1.2 Hz, 2H), 7.65 –7.58 (m, 2H), 7.58 (d, J = 0.7 Hz, 2H), 7.52 (t, J = 1.2 Hz, 2H), 7.47 – 7.40(m, 2H), 7.40 – 7.33 (m, 1H), 4.08 (d, J = 0.6 Hz, 4H).

[0039] (8) [3-1] Synthesis of deuterated pre-compound: Add 45mmol of compound 7 and 300g of toluene to the reaction flask, stir, protect with nitrogen, control the temperature to 10-15℃, add 67mmol of isopropyl magnesium chloride solution (1.3mol / L), and keep the temperature at 10-15℃ for 2 hours. After TLC tracking detection shows that there is no compound 7 remaining, continue to control the temperature at 10-15℃ and add 67mmol of triisopropyl borate, keep the temperature at 10-15℃ for 2 hours, hydrolyze, extract and wash with 1000g of toluene, wash the organic phase with hot purified water until neutral, reflux and separate until no water is left, add 45mmol of 1,8-diazabicycloundec-7-ene (CAS: 6674-22-2) to prepare a solution, and wait for dropwise addition. 270mmol aluminum chloride and 100g toluene were added to the reaction flask, stirred, protected by nitrogen, and heated to 80-85°C. The above-mentioned solution containing compound 7 was added dropwise. After the addition was completed, the temperature was controlled at 80-85°C and kept for 3h, hydrolyzed, and the hydrolysis aqueous phase was separated. Alkali solution was added to the organic phase to adjust the pH to ≥10, and then 50g of sodium hydroxide was added again. The temperature was raised to 80°C and kept for 2 hours. The organic phase was washed with hot high-purity distilled water until neutral. After washing, the organic phase was refluxed and separated until there was no water. Activated carbon was added and the temperature was controlled at 60°C and kept for 1h, and then passed through a silica gel column at normal pressure (to eliminate metal ions in the compound to a content of less than or equal to 100ppb). After the column was washed, 50 g of toluene was used to elute the column for 3 times. After the washing, the eluent and the column liquid were combined and the solvent was removed under negative pressure. After the removal, 23 mmol [3-1] deuterated pre-compound (light pink to off-white solid) was purified by column chromatography, with a yield of 51%. Mass spectrum: 358.20. Hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.31 (s, 2H), 7.72 (s,2H), 7.66 – 7.60 (m, 2H), 7.46 – 7.39 (m, 2H), 7.39 – 7.31 (m, 3H), 3.28 (d, J = 0.8 Hz, 4H).

[0040] (9) Synthesis of compound [3-1]: 41.0 mmol of the pre-deuterated compound [3-1] and 200 g of mesitylene were added to a reaction flask, stirred, and protected by nitrogen. Then, 98 g of heavy water, 98 g of deuterated sulfuric acid, and 86 g of tetrabutylammonium bromide were added, and the mixture was stirred and heated to 140°C for a hydrogen-deuterium replacement reaction for 10 h. After the reaction was completed, the aqueous phase was separated. The hydrogen-deuterium replacement reaction was repeated twice in the same manner. Each time, 98 g of heavy water, 98 g of deuterated sulfuric acid, and 86 g of tetrabutylammonium bromide were added to the system, stirred and heated to 140°C for a hydrogen-deuterium replacement reaction for 10 h. After the reaction was completed, the aqueous phase was separated and the next hydrogen-deuterium replacement reaction was performed. The molar ratio of the pre-deuterated compound [3-1], heavy water, deuterated sulfuric acid, and tetrabutylammonium bromide was 1:120:24:10. After the three hydrogen-deuterium exchange reactions were completed, saturated ammonium chloride aqueous solution was added to quench the reaction, and then 400 g of toluene was added for extraction. The organic phase was washed with hot high-purity distilled water until it was neutral. After washing, the organic phase was refluxed and separated until there was no water. Activated carbon was added to control the temperature at 60°C and kept warm for 1 hour. Then, the mixture was passed through a silica gel column at normal pressure (to eliminate metal ions in the compound until the content was less than or equal to 100 ppb), and the solvent was removed. Ethyl acetate mixed with n-hexane was used as the eluent, and 32.8 mmol of compound [3-1] was obtained by column chromatography purification, with a yield of 80%, a mass spectrum of 373.3, and a deuteration rate of 74.2%.

[0041] Example 2

[0042] The synthetic route of [3-3] is as follows:

[0043] ;

[0044] (1) Synthesis of compound 8: 500 mmol of 1,3-dibromo-2-chloro-5-iodobenzene (CAS: 2387266-13-7), 525 mmol of phenylboric acid, 1000 mmol of sodium carbonate, 322 g of purified water, and 1500 g of tetrahydrofuran were added to the reaction flask, stirred, and protected by nitrogen. Then, 2.5 mmol of Pd (pph) catalyst was added. 3 ) 4 , heat to 60℃ and keep warm for 15 hours. After TLC tracking detection shows that there is no 1,3-dibromo-2-chloro-5-iodobenzene remaining, cool to room temperature, hydrolyze, extract and wash with 2000g toluene, wash the organic phase with hot purified water until neutral, add anhydrous sodium sulfate to dry the organic phase, and pass through a silica gel column at normal pressure. After passing through the column, rinse the column with 50g toluene each time, for a total of 3 times. After elution, combine the eluent and the column liquid and remove the solvent under negative pressure. After stripping (obtaining a yellow oil), use ethyl acetate mixed with n-hexane as the eluent, and purify by column chromatography to obtain 375mmol of compound 8 (dark yellow solid), with a yield of 75%. Mass spectrum: 422.54. Hydrogen spectrum: 1H NMR (500 MHz, DMSO- d 6 ) δ 7.68 – 7.60 (m, 6H), 7.44 –7.36 (m, 2H), 7.36 – 7.31 (m, 3H).

[0045] (2) The synthesis method and steps of compound 9 are similar to those of step b of synthesis [3-1], and the intermediate compound 9 is obtained with a yield of 82%, mass spectrum: 480.78, hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.58 (d, J = 1.3Hz, 1H), 8.10 (d, J = 1.1 Hz, 1H), 7.87 (dd, J = 2.0, 1.1 Hz, 1H), 7.71 –7.68 (m, 1H), 7.68 – 7.65 (m, 1H), 7.65 – 7.58 (m, 3H), 7.44 – 7.27 (m, 5H),7.23 (t, J = 1.2 Hz, 1H), 6.12 (dd, J = 4.9, 0.9 Hz, 1H), 5.67 (d, J = 4.9 Hz, 1H), 3.82 (s, 3H).

[0046] (3) The synthesis method and steps of compound 10 are similar to those of step c of synthesis [3-1], and the intermediate compound 10 is obtained with a yield of 75%, mass spectrum: 464.78, hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.54 (d, J = 1.3Hz, 1H), 8.11 (d, J = 1.3 Hz, 1H), 7.68 – 7.55 (m, 5H), 7.50 (dt, J = 2.0,1.0 Hz, 1H), 7.45 – 7.27 (m, 5H), 7.13 (t, J = 1.3 Hz, 1H), 4.14 (d, J = 0.9 Hz, 2H), 3.84 (s, 3H).

[0047] (4) The synthesis method and steps of compound 11 are similar to those of step d of synthesis in [3-1], and the intermediate compound 11 is obtained with a yield of 80%. The mass spectrum is 510.99, and the hydrogen spectrum is 1H NMR (500 MHz, Chloroform- d ) δ 8.60 (d, J = 1.2Hz, 1H), 8.54 (d, J = 1.3 Hz, 1H), 8.48 (d, J = 1.2 Hz, 1H), 8.11 (d, J = 1.3Hz, 1H), 7.94 (dd, J = 2.0, 0.9 Hz, 1H), 7.68 – 7.62 (m, 2H), 7.61 – 7.51 (m,3H), 7.42 – 7.26 (m, 6H), 7.08 (t, J = 1.3 Hz, 1H), 6.41 (dd, J = 4.9, 0.9Hz, 1H), 5.63 (d, J = 5.1 Hz, 1H), 4.16 (dd, J = 12.5, 1.1 Hz, 1H), 4.11 (dd, J = 12.3, 1.0 Hz, 1H), 3.83 (s, 3H).

[0048] (5) The synthesis method and steps of compound 12 are similar to those of step e of synthesis in [3-1], and the intermediate compound 12 is obtained with a yield of 75%, mass spectrum: 494.99, hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.55 (dd, J =12.5, 1.3 Hz, 2H), 8.48 (d, J = 1.2 Hz, 1H), 8.11 (d, J = 1.3 Hz, 1H), 7.65(dd, J = 3.7, 2.0 Hz, 2H), 7.65 – 7.56 (m, 3H), 7.50 (dt, J = 2.0, 1.0 Hz,1H), 7.45 – 7.37 (m, 2H), 7.34 (d, J= 4.0 Hz, 1H), 7.33 – 7.26 (m, 2H), 7.15(t, J = 1.2 Hz, 1H), 7.06 (t, J = 1.3 Hz, 1H), 4.14 (dd, J = 5.9, 1.0 Hz, 4H), 3.83 (s, 3H).

[0049] (6) The synthesis method and steps of compound 13 are similar to step f of synthesis [3-1], and the intermediate compound 13 is obtained with a yield of 70%, mass spectrum: 480.96, hydrogen spectrum: 1 H NMR (500 MHz, DMSO- d 6 ) δ 9.94 (s, 1H), 8.53 (dd, J = 13.0, 1.3 Hz, 2H), 8.46 (d, J = 1.3 Hz, 1H), 8.21 (d, J = 1.3 Hz,1H), 7.73 – 7.61 (m, 5H), 7.58 (dt, J = 1.9, 0.9 Hz, 1H), 7.45 – 7.37 (m,2H), 7.36 – 7.27 (m, 3H), 7.25 – 7.20 (m, 1H), 7.17 (t, J = 1.3 Hz, 1H), 4.17(t, J = 1.1 Hz, 4H).

[0050] (7) The synthesis method and steps of compound 14 are similar to those of step g of synthesis [3-1], and the intermediate compound 14 is obtained with a yield of 40%, mass spectrum: 460.95, hydrogen spectrum: 1 H NMR (500 MHz, DMSO- d 6 ) δ 8.21 (d, J = 1.3 Hz,2H), 8.16 (d, J = 1.2 Hz, 2H), 7.74 – 7.67 (m, 2H), 7.66 – 7.61 (m, 2H), 7.52(t, J = 1.2 Hz, 4H), 7.46 – 7.40 (m, 2H), 7.37 – 7.28 (m, 3H), 4.11 (d,J =0.7 Hz, 4H).

[0051] (8) The synthesis method and steps of the deuterated precursor compound [3-3] are similar to those of step h of the synthesis of [3-1], and the intermediate compound [3-3] deuterated precursor compound is obtained with a yield of 50%, mass spectrum: 434.30, hydrogen spectrum: 1 H NMR (500 MHz, DMSO- d 6 ) δ8.21 (s, 2H), 7.76 (s, 2H), 7.69 – 7.60 (m, 4H), 7.45 – 7.39 (m, 2H), 7.39 –7.29 (m, 5H), 3.67 (d, J = 0.7 Hz, 2H), 3.38 (d, J = 0.6 Hz, 2H).

[0052] (9) Synthesis of compound [3-3]: 40.0 mmol of the pre-deuterated compound [3-3] and 200 g of mesitylene were added to a reaction flask, stirred and protected by nitrogen, and then 96 g of heavy water, 96 g of deuterated sulfuric acid, and 84 g of tetrabutylammonium bromide were added. The mixture was stirred and heated to 140°C for 10 h of hydrogen-deuterium replacement reaction. After the reaction was completed, the aqueous phase was separated. The hydrogen-deuterium replacement reaction was repeated twice in the same manner. Each time, 96 g of heavy water, 96 g of deuterated sulfuric acid, and 84 g of tetrabutylammonium bromide were added to the system. The mixture was stirred and heated to 140°C for 10 h of hydrogen-deuterium replacement reaction. After the reaction was completed, the aqueous phase was separated and the next hydrogen-deuterium replacement reaction was carried out. The molar ratio of the pre-deuterated compound [3-3], heavy water, deuterated sulfuric acid, and tetrabutylammonium bromide was 1:120:24:10. After the three hydrogen-deuterium replacement reactions were completed, saturated ammonium chloride aqueous solution was added to quench, and then 400 g of toluene was added for extraction. The organic phase was washed with hot high-purity distilled water until neutral. After washing, the organic phase was refluxed and separated until there was no water. After adding activated carbon and keeping the temperature at 60°C for 1 hour, it was passed through a silica gel column at normal pressure (eliminating the metal ions in the compound to a content of less than or equal to 100 ppb), and the solvent was removed. Ethyl acetate mixed with n-hexane was used as the eluent, and 32.0 mmol of compound [3-3] was obtained by column chromatography purification, with a yield of 80% and a mass spectrum of 453.4. The deuterium substitution rate was 71.5%.

[0053] Example 3

[0054] The synthetic route of [3-20] is as follows:

[0055] ;

[0056] (1) Synthesis of compound 15: 500 mmol of 1,3-dibromo-2-chloro-5-iodobenzene (CAS: 2387266-13-7), 525 mmol of 4-dibenzothiophene boronic acid, 1000 mmol of sodium carbonate, 322 g of purified water and 1500 g of tetrahydrofuran were added to a reaction flask and stirred under nitrogen protection. Then, 2.5 mmol of Pd(pph3)4 catalyst was added and the temperature was raised to 60°C and kept for 15 hours. After TLC tracking detected that no 1,3-dibromo-2-chloro-5-iodobenzene remained, the temperature was lowered to room temperature and hydrolyzed. The mixture was extracted and washed with 2000 g of toluene. The organic phase was washed with hot purified water until it was neutral. After washing, anhydrous sodium sulfate was added to dry the organic phase and the mixture was passed through a silica gel column at normal pressure. After the column was washed, 50 g of toluene was used to elute the column for 3 times. After the washing, the eluent and the column liquid were combined and the solvent was removed under negative pressure. After the removal (yellow oily substance was obtained), ethyl acetate mixed with n-hexane was used as the eluent and purified by column chromatography to obtain 390 mmol of compound 15 (dark yellow solid) with a yield of 78%. Mass spectrum: 452.59. Hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.06 (s,1H), 7.96 (s, 1H), 7.73 (s, 1H), 7.57 (d, J = 13.0 Hz, 3H), 7.48 (d, J = 3.8Hz, 2H), 7.36 (s, 1H).

[0057] (2) The synthesis method and steps of compound 16 are similar to those of step b of synthesis [3-1], and the intermediate compound 16 is obtained with a yield of 80%, mass spectrum: 510.83, hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.54 (d, J = 1.2Hz, 1H), 8.14 – 8.08 (m, 2H), 8.06 (s, 1H), 7.87 (dd, J = 2.0, 1.1 Hz, 1H),7.74 (s, 1H), 7.60 – 7.53 (m, 3H), 7.43 (s, 1H), 7.36 (s, 1H), 7.21 (t, J =1.3 Hz, 1H), 6.13 (dd, J = 5.0, 1.0 Hz, 1H), 5.67 (d, J = 4.9 Hz, 1H), 3.81(s, 3H).

[0058] (3) The synthesis method and steps of compound 17 are similar to those of step c of synthesis [3-1], and the intermediate compound 17 is obtained with a yield of 70%, mass spectrum: 494.83, hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.59 (d, J = 1.3Hz, 1H), 8.11 (d, J = 4.4 Hz, 3H), 7.74 (s, 1H), 7.60 (d, J = 2.2 Hz, 2H),7.57 – 7.53 (m, 2H), 7.44 (s, 1H), 7.36 (s, 1H), 7.08 (t, J = 1.3 Hz, 1H),4.14 (d, J = 1.1 Hz, 2H), 3.83 (s, 3H).

[0059] (4) The synthesis method and steps of compound 18 are similar to those of step d of synthesis in [3-1], and the intermediate compound 18 is obtained with a yield of 70%, mass spectrum: 541.03, hydrogen spectrum: 1H NMR (500 MHz, Chloroform-d) δ 8.60 (d, J = 1.1Hz, 1H), 8.54 (d, J = 1.3 Hz, 1H), 8.48 (d, J = 1.2 Hz, 1H), 8.11 (d, J = 1.3Hz, 1H), 7.99 – 7.92 (m, 3H), 7.65 (s, 1H), 7.63 – 7.55 (m, 2H), 7.50 (s,1H), 7.39 (d, J = 2.6 Hz, 2H), 7.35 (t, J = 1.3 Hz, 1H), 7.06 (t, J = 1.3 Hz, 1H), 6.35 (dd, J = 4.9, 1.1 Hz, 1H), 5.63 (d, J = 5.1 Hz, 1H), 4.12 (t, J =0.8 Hz, 2H), 3.82 (s, 3H).

[0060] (5) The synthesis method and steps of compound 19 are similar to those of step e of synthesis in [3-1], and the intermediate compound 19 is obtained with a yield of 80%. The mass spectrum is 525.04, and the hydrogen spectrum is: 1 H NMR (500 MHz, Chloroform- d ) δ 8.55 (dd, J =12.5, 1.2 Hz, 2H), 8.48 (d, J = 1.2 Hz, 1H), 8.11 (d, J = 1.3 Hz, 1H), 7.97(d, J = 2.9 Hz, 2H), 7.70 (s, 1H), 7.61 (s, 1H), 7.52 (d, J = 17.6 Hz, 3H),7.46 (s, 1H), 7.39 (s, 1H), 7.18 – 7.14 (m, 1H), 7.05 (t, J = 1.3 Hz, 1H), 4.16 – 4.12 (m, 4H), 3.82 (s, 3H).

[0061] (6) The synthesis method and steps of compound 20 are similar to those of step f of synthesis [3-1], and the intermediate compound 20 is obtained with a yield of 75%, mass spectrum: 511.01, hydrogen spectrum: 1 H NMR (500 MHz, DMSO- d 6 ) δ 10.06 (s, 1H), 8.53 (dd, J = 13.0, 1.3 Hz, 2H), 8.46 (d, J = 1.4 Hz, 1H), 8.24 – 8.19 (m, 2H), 8.12 (s, 1H), 7.77 (s, 1H), 7.64 (s, 1H), 7.60 (d, J = 1.0 Hz, 2H), 7.54 (s,1H), 7.40 (d, J = 6.3 Hz, 2H), 7.19 (dt, J = 2.7, 1.2 Hz, 2H), 4.15 (d, J =2.4 Hz, 4H).

[0062] (7) The synthesis method and steps of compound 21 are similar to step g of synthesis [3-1], and the intermediate compound 21 is obtained with a yield of 35%, mass spectrum: 491.00, hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.20 – 8.14 (m,3H), 8.14 – 8.07 (m, 3H), 7.72 (s, 1H), 7.61 (s, 1H), 7.54 (s, 1H), 7.50 (d, J = 0.7 Hz, 2H), 7.48 – 7.41 (m, 3H), 7.36 (s, 1H), 4.08 (d, J = 0.9 Hz, 4H).

[0063] (8) The synthesis method and steps of the deuterated precursor compound [3-20] are similar to those of step h of the synthesis of [3-1], and the intermediate compound [3-3] deuterated precursor compound is obtained with a yield of 55%, mass spectrum: 464.34, hydrogen spectrum: 1 H NMR (500 MHz, Chloroform- d ) δ 8.22 (s, 2H), 8.12 (s, 2H), 7.76 (s, 2H), 7.69 (s, 1H), 7.57(s, 1H), 7.52 – 7.44 (m, 4H), 7.37 (s, 1H), 3.53 (d, J = 0.8 Hz, 2H), 3.38(d, J = 0.6 Hz, 2H).

[0064] (9) Synthesis of compound [3-20]: 33.5mmol of the pre-deuterated compound [3-20] and 200g of mesitylene were added to a reaction flask, stirred and protected by nitrogen, and then 80g of heavy water, 80g of deuterated sulfuric acid and 70g of tetrabutylammonium bromide were added, stirred and heated to 140°C for a hydrogen-deuterium replacement reaction for 10h. After the reaction was completed, the aqueous phase was separated. The hydrogen-deuterium replacement reaction was carried out twice in the same reaction mode. Each time, 80g of heavy water, 80g of deuterated sulfuric acid and 70g of tetrabutylammonium bromide were added to the system, stirred and heated to 140°C for a hydrogen-deuterium replacement reaction for 10h. After the reaction was completed, the aqueous phase was separated and the next hydrogen-deuterium replacement reaction was carried out. The molar ratio of the pre-deuterated compound [3-20], heavy water, deuterated sulfuric acid and tetrabutylammonium bromide was 1:120:24:10. After the three hydrogen-deuterium replacement reactions were completed, saturated ammonium chloride aqueous solution was added to quench, and then 400g toluene was added for extraction. The organic phase was washed with hot high-purity distilled water until neutral. After washing, the organic phase was refluxed and separated until there was no water. After adding activated carbon and keeping the temperature at 60°C for 1h, it was passed through a silica gel column at normal pressure (eliminating the metal ions in the compound to a content of less than or equal to 100ppb), desolventized, and ethyl acetate mixed with n-hexane was used as an eluent. 23.7mmol of compound [3-20] was obtained by column chromatography purification, with a yield of 71% and a mass spectrum of 481.5. The deuterium substitution rate was 65.9%.

[0065] The same method as in the above example was used to prepare fully deuterated pyridoborane heterocyclic compounds of other structures. The specific reaction substances, generated substances and yields involved are summarized in Table 1 below.

[0066] Table 1 Summary of reaction substances, generated substances and yields

[0067]

[0068]

[0069]

[0070]

[0071] The application effects of the compounds of the present invention on OLED devices are described in detail below through application examples and comparative examples.

[0072] Organic light-emitting device preparation method:

[0073] (1) Preparation of ITO (indium tin oxide) glass substrate: Place an ITO glass substrate with a film thickness of 150 nm in distilled water for ultrasonic cleaning for 20 minutes, then ultrasonically clean it with isopropyl alcohol, acetone, and methanol for 10 minutes each, dry it, and transfer it to a plasma cleaning machine. Wash the above substrate for 5 minutes, perform UV-Ozone treatment (ultraviolet light ozone treatment), and finally send it to a vacuum evaporator.

[0074] (2) Hole injection layer: 2-TNATA was evaporated on the ITO glass substrate using a vacuum evaporator at a evaporation rate of 1 Å / s, and the coating thickness was 10 nm.

[0075] (3) Hole transport layer: a-NPD was evaporated on the hole injection layer using a vacuum evaporator at a deposition rate of 1.5 Å / s, and the coating thickness was 60 nm.

[0076] (4) Light-emitting layer: The main material and the dopant material are evaporated on the hole transport layer using a vacuum evaporator at a evaporation rate of 1Å / s. The coating thickness is 25nm. The evaporation rate ratio of the main material to the dopant material is 95:5. The composition of the main material and the dopant material is shown in Table 2 below:

[0077] Table 2 Composition of main materials and doping materials of the light-emitting layer

[0078]

[0079] (5) Electron transport layer: Liq was evaporated on the light-emitting layer using a vacuum evaporator at a evaporation rate of 1 Å / s, and the coating thickness was 30 nm.

[0080] (6) Electron injection layer and cathode: Lithium fluoride (LiF) was evaporated on the electron transport layer using a vacuum evaporator at a deposition rate of 0.5 Å / s to a film thickness of 1 nm. Then, an aluminum layer with a thickness of 80 nm was evaporated at a deposition rate of 1 Å / s as the cathode.

[0081] (7) Packaging: The evaporated substrate and cover are pressed together and packaged using ultraviolet curing resin (or UV glue light curing) in a nitrogen glove box.

[0082] The structures of the compounds involved in the application examples and comparative examples are shown below:

[0083] .

[0084] The current voltage and luminescence characteristics of the obtained organic light-emitting device were characterized by characterization equipment, and the driving voltage, color coordinates, efficiency and life of each device were recorded. The characterization results are shown in Table 3, where the following comparative examples and application example devices were tested under the same external environment and the same brightness (1000nit).

[0085] Table 3 Test results of OLED light-emitting characteristics

[0086]

[0087] From the data in Table 3, it can be seen from Application Examples 1-12 and Comparative Example 1 that the compounds of the present invention have better green light base color purity. Because the parent structure of the present invention is a high-rigidity condensed ring π-conjugated structure with six six-membered heterocyclic rings arranged in parallel, the vibration relaxation process of the structure in the excited state is effectively suppressed. At the same time, the steric hindrance of the condensed ring molecular structure itself makes it present a highly distorted geometric configuration, which in turn leads to changes in the orbital transition components of the molecular excited state, which can significantly increase the spin-orbit coupling between different excited states, so that the device achieves ultra-pure green light emission.

[0088] From the data in Table 3, it can be seen that the compounds of the present invention have better green light color purity from Application Example 1 and Comparative Examples 3 and 4. Because the parent structure of the present invention has two pyridine rings, which induces the lowest two triplet states (T1 and T2) to produce charge resonance excitation characteristics, which allows the triplet excitons of the material to be converted into singlet excitons with the help of the high-energy T2 state, thereby enabling the device to achieve ultra-pure green light emission.

[0089] From the data in Table 3, it can be seen from Application Example 1 and Comparative Example 2 that the luminous efficiency and lifespan of the compounds of the present invention are improved. This is because after the structure of the compound of the present invention is fully deuterated, due to the heavy atom effect, after the deuterium atom is introduced, the spin-orbit coupling effect in the molecule will be enhanced, thereby facilitating the generation of light, increasing the quantum efficiency, and at the same time increasing the half-life and prolonging the lifespan.

[0090] The organic light-emitting device prepared from the fully deuterated pyridoborane heterocyclic compound of the present invention can obtain ultra-high green light base color purity, good luminous efficiency and life span, and can therefore be applied to the highly practical OLED industry. The organic light-emitting device of the present invention can be applied to flat panel displays, flat luminous bodies, surface-emitting OLED luminous bodies for lighting, copiers, printers, LCD backlights or metering machine-type light sources, display panels, signs, etc.

[0091] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, all of which belong to the protection scope of the present invention. The protection scope of the present invention shall be based on the attached claims.

Claims

1. A fully deuterated pyridoboroxime heterocyclic compound, characterized in that: The structural formula of the fully deuterated pyridoboroxo heterocyclic compound is as follows: ； The R is selected from any one of the following structural formulas: ； n represents the number of deuterium replacing hydrogen in the formula, that is, the number of deuterium in the chemical formula.

2. A fully deuterated pyridoboroxime heterocyclic compound according to claim 1, characterized in that: The fully deuterated pyridoboroxime heterocyclic compound is selected from any one of the following structural formulas: 。 3. A fully deuterated pyridoboroxime heterocyclic compound according to claim 1, characterized in that: The fully deuterated pyridoboroxime heterocyclic compound is selected from any one of the following structural formulas: ； ； ； 。 4. A fully deuterated pyridoboroxime heterocyclic compound, characterized in that: The fully deuterated pyridoboroxo heterocyclic compound is selected from the following structural compounds: 。 5. A use of a fully deuterated pyridoboroxine heterocyclic compound according to any one of claims 1 to 4, characterized in that: The fully deuterated pyridoborane heterocyclic compound is applied to an organic electroluminescent device.

6. The use of a fully deuterated pyridoboroxine heterocyclic compound according to claim 5, characterized in that: The organic layer of the organic electroluminescent device comprises at least one of the fully deuterated pyridoborane heterocyclic compounds.

7. The use of a fully deuterated pyridoboroxime heterocyclic compound according to claim 6, characterized in that: The organic layer includes a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer and an electron injection layer.

8. The use of a fully deuterated pyridoboroxime heterocyclic compound according to claim 7, characterized in that: The fully deuterated pyridoborane heterocyclic compound is used as a light-emitting layer material of an organic electroluminescent device.

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