Organic light-emitting material and preparation method thereof, light-emitting layer, light-emitting device and display device

Abstract

The invention belongs to the technical field of organic light-emitting materials and devices, and particularly discloses an organic light-emitting material and a preparation method thereof, a light-emitting layer, a light-emitting device and a display device. The structure of the organic light-emitting material is shown as a formula I; specific raw materials are subjected to an aromatic nucleophilic substitution reaction, a lithiation cyclization reaction, a Buchwald-Hartwisting coupling reaction, a one-pot lithiation-boronation-cyclization reaction and the like to prepare the compound. The novel organic light-emitting material provided by the invention can be applied to the organic light-emitting device as a guest doping material, and the device has the characteristics of high external quantum efficiency, small device efficiency roll-off, high brightness, good stability and the like. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the technical field of organic light-emitting materials and devices, and specifically relates to an organic light-emitting material and a preparation method thereof, a light-emitting layer, a light-emitting device, and a display device. Background Art

[0002] Organic light-emitting diodes (OLEDs) are currently widely used in display fields such as high-end smartphones and high-resolution televisions, and the market size is constantly expanding. The key to the rapid improvement of OLED performance lies in the replacement of luminescent dyes. At present, the mainstream dyes of OLEDs are mainly phosphorescent dyes based on metal complexes. However, due to the presence of precious metals, the price of such dyes is relatively high, which increases the cost of devices. On the other hand, the emission spectrum of commercial organic luminescent materials is generally wide. In order to meet the market requirements of high color purity and wide color gamut for commercial display screens, in existing technologies, the luminescent color purity is mainly improved by adding filters and constructing optical microcavities. However, this undoubtedly increases the device process and cost, and more importantly, it will cause a significant reduction in the brightness and luminous efficiency of the display screen, resulting in energy loss. Therefore, seeking a new generation of pure organic light-emitting systems is the key to promoting the further development of OLED technology. In order to make organic light-emitting display technology meet the color gamut standard (BT 2020) set by the International Telecommunication Union for ultra-high-definition televisions, the research on high-color purity organic light-emitting materials and devices has become a current research hotspot in this field.

[0003] Multi-resonance thermally activated delayed fluorescence (MR-TADF) materials have gradually become an ideal system for developing high-efficiency, high-color purity luminescent materials. Compared with traditional donor-acceptor type TADF materials, MR-TADF materials are conducive to obtaining narrow-band luminescence with high color purity and extremely high quantum efficiency, making them ideal luminescent materials and widely used in organic light-emitting diodes (OL EDs). However, multi-resonance TADF materials are prone to severe exciton quenching effects at high doping concentrations and high brightness in device applications, resulting in spectral red shifts, large efficiency roll-offs and other problems, which is a huge challenge for the actual application of material production lines. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies of the prior art. Based on this, the first aspect of the present invention provides an organic light-emitting material, the structure of which is shown in Formula I:

[0005]

[0006] Wherein, X is O, S, Se or N-R5, and R5 is alkyl, phenyl or substituted phenyl;

[0007] R1 and R2 are independently selected from one of phenyl, substituted phenyl, alkyl, substituted alkyl, alkoxy and substituted alkoxy, and adjacent groups in R1 and R2 are fused to form a ring or are not fused to form a ring;

[0008] R3 and R4 are independently selected from one of hydrogen, deuterium, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C30 aryl, substituted C6-C30 aryl, 5-30 membered heteroaryl, substituted 5-30 membered heteroaryl, diphenylamino and substituted diphenylamino.

[0009] The present invention proposes a novel multi-resonance organic light-emitting material by introducing a substituent group of a specific structure. When used in an organic electroluminescent device, the material can reduce the aggregation quenching of excitons while maintaining narrow-band emission, alleviate the device efficiency roll-off under high brightness and high doping concentration, and has a high fluorescence quantum yield.

[0010] In some preferred implementations, the structure of the organic light-emitting material is one of compounds 1-70:

[0011]

[0012]

[0013] More preferably, the structure of the organic light-emitting material is as shown in compound 21. When the structure is as shown in compound 21, the maximum external quantum efficiency of the electroluminescent device composed of the organic light-emitting material can reach 32.5%, 1000 cd / m 2 The electroluminescence external quantum efficiency can reach 29.4% under high brightness, and the device life (T95) can reach 134.8h.

[0014] The second aspect of the present invention provides a method for preparing the above-mentioned organic light-emitting material, comprising the following synthesis route:

[0015]

[0016] The raw material A is subjected to the first step of aromatic nucleophilic substitution reaction to obtain intermediate-1, intermediate-1 and raw material B are subjected to the second step of lithiation cyclization reaction to obtain intermediate-2, intermediate-2 and raw material C are subjected to the third step of Buchwald-Hartwig coupling reaction to obtain intermediate-3, and intermediate-3 is subjected to a one-pot lithiation-boration-cyclization reaction to finally obtain the above-mentioned organic light-emitting material.

[0017] Wherein, the raw material A is raw material A1 or raw material A2; the raw material B is raw material B1, raw material B2, raw material B3, raw material B4, raw material B5, raw material B6 or raw material B7; the raw material C is raw material C1, raw material C2, raw material C3, raw material C4 or raw material C5; the structures are as follows:

[0018]

[0019] The third aspect of the present invention provides a light-emitting layer, comprising a host material and a light-emitting guest material, wherein the light-emitting guest material is the organic light-emitting material. In some preferred implementations, the light-emitting layer further comprises a sensitizer.

[0020] The fourth aspect of the present invention provides an organic electroluminescent device, comprising an anode and a cathode, and further comprising the above-mentioned light-emitting layer comprising the organic light-emitting material of the present invention between the above-mentioned anode and the above-mentioned cathode. More specifically, the above-mentioned organic electroluminescent device comprises, in sequence: the above-mentioned anode, a hole transport layer (which may include a first hole transport layer and a second hole transport layer in sequence), the above-mentioned light-emitting layer, an electron transport layer, an electron injection layer, and the above-mentioned cathode.

[0021] A fifth aspect of the present invention provides a display device comprising the above-mentioned organic electroluminescent device.

[0022] The beneficial effects of the present invention are as follows: the novel organic light-emitting material proposed in the present invention can be used as a guest doping material in an organic electroluminescent device, and enables the device to have the characteristics of high external quantum efficiency, small device efficiency roll-off, high brightness, good stability, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure shows the structure of an organic electroluminescent device, wherein 1 is an ITO anode, 2 is a first hole transport layer, 3 is a second hole transport layer, 4 is a light-emitting layer, 5 is an electron transport layer, 6 is an electron injection layer, and 7 is a metal cathode. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present invention, so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0025] The structures of compounds 1-70 involved in the following contents are shown below:

[0026]

[0027]

[0028] The synthetic route of the above compound 1-70 is as follows:

[0029] .

[0031] Among them, raw material A is raw material A1 or raw material A2; raw material B is raw material B1, raw material B2, raw material B3, raw material B4, raw material B5, raw material B6 or raw material B7; raw material C is raw material C1, raw material C2, raw material C3, raw material C4 or raw material C5; the structures are as follows:

[0032]

[0033] The structures of H1-48, TRZ-8, TAPC, TCTA, IrPPy3 and compound D1 involved in the following contents are as follows:

[0034]

[0035] In addition, in the following content, the sources of the raw materials used are not particularly limited, and they can be commercially available products or prepared by a preparation method known to those skilled in the art. Room temperature refers to about 25°C.

[0036] The mass spectra (MS) of molecules with a relative molecular weight below 1000 were measured by ITQ1100 ion trap gas chromatography-mass spectrometry from Thermo Fisher, and the mass spectra of molecules with a relative molecular weight above 1000 were measured by Autoflex Speed ​​matrix-assisted laser desorption / time-of-flight mass spectrometry from Bruker. The elemental analysis of the final product was performed by Flash EA1112 from Elemental Analysis.

[0037] Example 1

[0038] An organic light-emitting material, whose structure is shown in Compound 1; and its preparation method comprises the following synthetic route:

[0039]

[0040] ; Specifically include the following steps:

[0041] (1) Under nitrogen atmosphere, raw material A1 (11 mmol), 1-bromo-2-chloro-3-fluoro-4-iodobenzene (10 mmol), and cesium carbonate (20 mmol) were dissolved in 80 mL of DMF solution. Under N2 protection, the reaction was stopped by heating at reflux for 8 h. The cooled reaction solution was poured into water and stirred for 2 h, then extracted with dichloromethane, concentrated, and separated by column chromatography (silica gel, dichloromethane / hexane) to obtain powdery intermediate-1 (7.5 mmol, yield 75%).

[0042] (2) Under nitrogen, the obtained intermediate-1 (7 mmol) was dissolved in 100 mL of tetrahydrofuran solvent. At -78°C, n-butyl lithium (14 mmol) was slowly added dropwise to the reaction solution. After the addition was completed, the reaction was allowed to react at -78°C for 1 h. Then, the raw material B1 (15 mmol) was added to the reaction solution. The temperature was raised to room temperature for 12 h to stop the reaction. The reaction was quenched with water, extracted with dichloromethane, concentrated and separated by column chromatography (silica gel, petroleum ether). The obtained product was added to 60 mL of acetic acid, dissolved and then 2 mL of hydrochloric acid was added. The reaction solution was heated at 110°C for 6 h to stop the reaction. The cooled reaction mixture was poured into ice water to precipitate and filter the crude product. Then, it was purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-2 (4.4 mmol, yield 63%).

[0043] (3) Under nitrogen conditions, the obtained intermediate-2 (4 mmol), raw material C1 (4.8 mmol), tri(dibenzylideneacetone)dipalladium (0.12 mmol), sodium tert-butoxide (8 mmol), and tri-tert-butylphosphine tetrafluoroborate (1.2 mmol) were dissolved in 60 mL of toluene. Under N2 protection, the reaction was stopped by heating at reflux for 12 h. The cooled reaction solution was poured into water and stirred for 10 min. The crude product was precipitated and filtered, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-3 (3.04 mmol, yield 76%).

[0044] (4) Under nitrogen atmosphere, the obtained intermediate-3 (3 mmol) was dissolved in 90 mL of tert-butylbenzene solution. At 0°C, 4.6 mL of tert-butyllithium pentane solution (1.30 M, 6 mmol) was slowly dripped into the above solution. After dripping, the temperature was raised to 60°C for reaction for 2 h. Then the temperature was cooled to -40°C, boron tribromide (6 mmol) was slowly added, and then the temperature was raised to room temperature and stirring was continued for 0.5 h. Then the temperature was cooled to 0°C, N,N-diisopropylethylamine (12 mmol) was added, and the reaction was continued at 140°C for 6 h before stopping. After the reaction system was cooled to room temperature, the reaction was quenched with 7.5 mL of methanol and 7.5 mL of water, and the reaction mixture was extracted with dichloromethane and water. The organic phase was heated to dryness under vacuum, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain the final product compound 1 (1.65 mmol, yield 55%).

[0045] Example 2

[0046] An organic light-emitting material, whose structure is shown in Compound 2; and its preparation method includes the following synthetic route:

[0047]

[0048] ; Specifically include the following steps:

[0049] (1) Under nitrogen atmosphere, raw material A1 (11 mmol), 1-bromo-2-chloro-3-fluoro-4-iodobenzene (10 mmol), and cesium carbonate (20 mmol) were dissolved in 80 mL of DMF solution. Under N2 protection, the reaction was stopped by heating at reflux for 8 h. The cooled reaction solution was poured into water and stirred for 2 h, then extracted with dichloromethane, concentrated, and separated by column chromatography (silica gel, dichloromethane / hexane) to obtain powdery intermediate-1 (7.5 mmol, yield 75%).

[0050] (2) Under nitrogen, the obtained intermediate-1 (7 mmol) was dissolved in 100 mL of tetrahydrofuran solvent. At -78°C, n-butyl lithium (14 mmol) was slowly added dropwise to the reaction solution. After the addition was completed, the reaction was allowed to react at -78°C for 1 h. Then, the raw material B2 (15 mmol) was added to the reaction solution. The temperature was raised to room temperature for 12 h to stop the reaction. The reaction was quenched with water, extracted with dichloromethane, concentrated and separated by column chromatography (silica gel, petroleum ether). The obtained product was added to 60 mL of acetic acid, dissolved and then 2 mL of hydrochloric acid was added. The reaction solution was heated at 110°C for 6 h to stop the reaction. The cooled reaction mixture was poured into ice water to precipitate and filter the crude product. Then, it was purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-2 (4.27 mmol, yield 61%).

[0051] (3) Under nitrogen conditions, the obtained intermediate-2 (4 mmol), raw material C1 (4.8 mmol), tri(dibenzylideneacetone)dipalladium (0.12 mmol), sodium tert-butoxide (8 mmol), and tri-tert-butylphosphine tetrafluoroborate (1.2 mmol) were dissolved in 60 mL of toluene. Under N2 protection, the reaction was stopped by heating at reflux for 12 h. The cooled reaction solution was poured into water and stirred for 10 min. The crude product was precipitated and filtered, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-3 (2.92 mmol, yield 73%).

[0052] (4) Under nitrogen atmosphere, the obtained intermediate-3 (2.5 mmol) was dissolved in 90 mL of tert-butylbenzene solution. At 0°C, 3.8 mL of tert-butyllithium pentane solution (1.30 M, 5 mmol) was slowly dripped into the above solution. After dripping, the temperature was raised to 60°C for reaction for 2 h. Then the temperature was cooled to -40°C, boron tribromide (5 mmol) was slowly added, and then the temperature was raised to room temperature and stirring was continued for 0.5 h. Then the temperature was cooled to 0°C, N,N-diisopropylethylamine (10 mmol) was added, and the reaction was continued at 140°C for 6 h before stopping. After the reaction system was cooled to room temperature, the reaction was quenched with 6.3 mL of methanol and 6.3 mL of water, and the reaction mixture was extracted with dichloromethane and water. The organic phase was heated to dryness under vacuum, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain the final product compound 2 (1.3 mmol, yield 52%).

[0053] Example 3

[0054] An organic light-emitting material, whose structure is shown in compound 3; and its preparation method includes the following synthetic route:

[0055]

[0056] ; Specifically include the following steps:

[0057] (1) Under nitrogen atmosphere, raw material A1 (11 mmol), 1-bromo-2-chloro-3-fluoro-4-iodobenzene (10 mmol), and cesium carbonate (20 mmol) were dissolved in 80 mL of DMF solution. Under N2 protection, the reaction was stopped by heating at reflux for 8 h. The cooled reaction solution was poured into water and stirred for 2 h, then extracted with dichloromethane, concentrated, and separated by column chromatography (silica gel, dichloromethane / hexane) to obtain powdery intermediate-1 (7.5 mmol, yield 75%).

[0058] (2) Under nitrogen, the obtained intermediate-1 (7 mmol) was dissolved in 100 mL of tetrahydrofuran solvent. At -78°C, n-butyl lithium (14 mmol) was slowly added dropwise to the reaction solution. After the addition was completed, the reaction was allowed to react at -78°C for 1 h. Then, the raw material B3 (15 mmol) was added to the reaction solution. The temperature was raised to room temperature for 12 h to stop the reaction. The reaction was quenched with water, extracted with dichloromethane, concentrated and separated by column chromatography (silica gel, petroleum ether). The obtained product was added to 60 mL of acetic acid, dissolved and then 2 mL of hydrochloric acid was added. The reaction solution was heated at 110°C for 6 h to stop the reaction. The cooled reaction mixture was poured into ice water to precipitate and filter the crude product. Then, it was purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-2 (4.2 mmol, yield 60%).

[0059] (3) Under nitrogen conditions, the obtained intermediate-2 (4 mmol), raw material C1 (4.8 mmol), tri(dibenzylideneacetone)dipalladium (0.12 mmol), sodium tert-butoxide (8 mmol), and tri-tert-butylphosphine tetrafluoroborate (1.2 mmol) were dissolved in 60 mL of toluene. Under N2 protection, the reaction was stopped by heating at reflux for 12 h. The cooled reaction solution was poured into water and stirred for 10 min. The crude product was precipitated and filtered, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-3 (2.88 mmol, yield 72%).

[0060] (4) Under nitrogen atmosphere, the obtained intermediate-3 (2.5 mmol) was dissolved in 90 mL of tert-butylbenzene solution. At 0°C, 3.8 mL of tert-butyllithium pentane solution (1.30 M, 5 mmol) was slowly dripped into the above solution. After dripping, the temperature was raised to 60°C for reaction for 2 h. Then the temperature was cooled to -40°C, boron tribromide (5 mmol) was slowly added, and then the temperature was raised to room temperature and stirring was continued for 0.5 h. Then the temperature was cooled to 0°C, N,N-diisopropylethylamine (10 mmol) was added, and the reaction was continued at 140°C for 6 h before stopping. After the reaction system was cooled to room temperature, the reaction was quenched with 6.3 mL of methanol and 6.3 mL of water, and the reaction mixture was extracted with dichloromethane and water. The organic phase was heated to dryness under vacuum, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain the final product compound 3 (1.3 mmol, yield 51%).

[0061] Example 4

[0062] An organic light-emitting material, whose structure is shown in compound 4; and its preparation method includes the following synthetic route:

[0063]

[0064] ; Specifically include the following steps:

[0065] (1) Under nitrogen atmosphere, raw material A1 (11 mmol), 1-bromo-2-chloro-3-fluoro-4-iodobenzene (10 mmol), and cesium carbonate (20 mmol) were dissolved in 80 mL of DMF solution. Under N2 protection, the reaction was stopped by heating at reflux for 8 h. The cooled reaction solution was poured into water and stirred for 2 h, then extracted with dichloromethane, concentrated, and separated by column chromatography (silica gel, dichloromethane / hexane) to obtain powdery intermediate-1 (7.5 mmol, yield 75%).

[0066] (2) Under nitrogen, the obtained intermediate-1 (7 mmol) was dissolved in 100 mL of tetrahydrofuran solvent. At -78°C, n-butyl lithium (14 mmol) was slowly added dropwise to the reaction solution. After the addition was completed, the reaction was allowed to react at -78°C for 1 h. Then, the raw material B4 (15 mmol) was added to the reaction solution. The temperature was raised to room temperature for 12 h to stop the reaction. The reaction was quenched with water, extracted with dichloromethane, concentrated and separated by column chromatography (silica gel, petroleum ether). The obtained product was added to 60 mL of acetic acid, dissolved and then 2 mL of hydrochloric acid was added. The reaction solution was heated at 110°C for 6 h to stop the reaction. The cooled reaction mixture was poured into ice water to precipitate and filter the crude product. Then, it was purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-2 (4.5 mmol, yield 64%).

[0067] (3) Under nitrogen conditions, the obtained intermediate-2 (4 mmol), raw material C1 (4.8 mmol), tri(dibenzylideneacetone)dipalladium (0.12 mmol), sodium tert-butoxide (8 mmol), and tri-tert-butylphosphine tetrafluoroborate (1.2 mmol) were dissolved in 60 mL of toluene. Under N2 protection, the reaction was stopped by heating at reflux for 12 h. The cooled reaction solution was poured into water and stirred for 10 min. The crude product was precipitated and filtered, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-3 (3.12 mmol, yield 78%).

[0068] (4) Under nitrogen atmosphere, the obtained intermediate-3 (3 mmol) was dissolved in 90 mL of tert-butylbenzene solution. At 0°C, 4.6 mL of tert-butyllithium pentane solution (1.30 M, 6 mmol) was slowly dripped into the above solution. After dripping, the temperature was raised to 60°C for reaction for 2 h. Then the temperature was cooled to -40°C, boron tribromide (6 mmol) was slowly added, and then the temperature was raised to room temperature and stirring was continued for 0.5 h. Then the temperature was cooled to 0°C, N,N-diisopropylethylamine (12 mmol) was added, and the reaction was continued at 140°C for 6 h before stopping. After the reaction system was cooled to room temperature, the reaction was quenched with 7.5 mL of methanol and 7.5 mL of water, and the reaction mixture was extracted with dichloromethane and water. The organic phase was heated to dryness under vacuum, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain the final product compound 4 (1.62 mmol, yield 54%).

[0069] Example 5

[0070] An organic light-emitting material, whose structure is shown in Compound 5; and its preparation method comprises the following synthetic route:

[0071]

[0072] ; Specifically include the following steps:

[0073] (1) Under nitrogen atmosphere, raw material A1 (11 mmol), 1-bromo-2-chloro-3-fluoro-4-iodobenzene (10 mmol), and cesium carbonate (20 mmol) were dissolved in 80 mL of DMF solution. Under N2 protection, the reaction was stopped by heating at reflux for 8 h. The cooled reaction solution was poured into water and stirred for 2 h, then extracted with dichloromethane, concentrated, and separated by column chromatography (silica gel, dichloromethane / hexane) to obtain powdery intermediate-1 (7.5 mmol, yield 75%).

[0074] (2) Under nitrogen, the obtained intermediate-1 (7 mmol) was dissolved in 100 mL of tetrahydrofuran solvent. At -78°C, n-butyl lithium (14 mmol) was slowly added dropwise to the reaction solution. After the addition was completed, the reaction was allowed to react at -78°C for 1 h. Then, the raw material B5 (15 mmol) was added to the reaction solution. The temperature was raised to room temperature for 12 h to stop the reaction. The reaction was quenched with water, extracted with dichloromethane, concentrated and separated by column chromatography (silica gel, petroleum ether). The obtained product was added to 60 mL of acetic acid, dissolved and then 2 mL of hydrochloric acid was added. The reaction solution was heated at 110°C for 6 h to stop the reaction. The cooled reaction mixture was poured into ice water to precipitate and filter the crude product. Then, it was purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-2 (4.6 mmol, yield 66%).

[0075] (3) Under nitrogen conditions, the obtained intermediate-2 (4 mmol), raw material C1 (4.8 mmol), tri(dibenzylideneacetone)dipalladium (0.12 mmol), sodium tert-butoxide (8 mmol), and tri-tert-butylphosphine tetrafluoroborate (1.2 mmol) were dissolved in 60 mL of toluene. Under N2 protection, the reaction was stopped by heating at reflux for 12 h. The cooled reaction solution was poured into water and stirred for 10 min. The crude product was precipitated and filtered, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-3 (3.1 mmol, yield 77%).

[0076] (4) Under nitrogen atmosphere, the obtained intermediate-3 (3 mmol) was dissolved in 90 mL of tert-butylbenzene solution. At 0°C, 4.6 mL of tert-butyllithium pentane solution (1.30 M, 6 mmol) was slowly dripped into the above solution. After dripping, the temperature was raised to 60°C for reaction for 2 h. Then the temperature was cooled to -40°C, boron tribromide (6 mmol) was slowly added, and then the temperature was raised to room temperature and stirring was continued for 0.5 h. Then the temperature was cooled to 0°C, N,N-diisopropylethylamine (12 mmol) was added, and the reaction was continued at 140°C for 6 h before stopping. After the reaction system was cooled to room temperature, the reaction was quenched with 7.5 mL of methanol and 7.5 mL of water, and the reaction mixture was extracted with dichloromethane and water. The organic phase was heated to dryness under vacuum, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain the final product compound 5 (1.47 mmol, yield 49%).

[0077] Example 6

[0078] An organic light-emitting material, whose structure is shown in Compound 6; and its preparation method includes the following synthetic route:

[0079]

[0080] ; Specifically include the following steps:

[0081] (1) Under nitrogen atmosphere, raw material A1 (11 mmol), 1-bromo-2-chloro-3-fluoro-4-iodobenzene (10 mmol), and cesium carbonate (20 mmol) were dissolved in 80 mL of DMF solution. Under N2 protection, the reaction was stopped by heating at reflux for 8 h. The cooled reaction solution was poured into water and stirred for 2 h, then extracted with dichloromethane, concentrated, and separated by column chromatography (silica gel, dichloromethane / hexane) to obtain powdery intermediate-1 (7.5 mmol, yield 75%).

[0082] (2) Under nitrogen, the obtained intermediate-1 (7 mmol) was dissolved in 100 mL of tetrahydrofuran solvent. At -78°C, n-butyl lithium (14 mmol) was slowly added dropwise to the reaction solution. After the addition was completed, the reaction was allowed to react at -78°C for 1 h. Then, the raw material B6 (15 mmol) was added to the reaction solution. The temperature was raised to room temperature for 12 h to stop the reaction. The reaction was quenched with water, extracted with dichloromethane, concentrated and separated by column chromatography (silica gel, petroleum ether). The obtained product was added to 60 mL of acetic acid, dissolved and then 2 mL of hydrochloric acid was added. The reaction solution was heated at 110°C for 6 h to stop the reaction. The cooled reaction mixture was poured into ice water to precipitate and filter the crude product. Then, it was purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-2 (4.55 mmol, yield 65%).

[0083] (3) Under nitrogen conditions, the obtained intermediate-2 (4 mmol), raw material C1 (4.8 mmol), tri(dibenzylideneacetone)dipalladium (0.12 mmol), sodium tert-butoxide (8 mmol), and tri-tert-butylphosphine tetrafluoroborate (1.2 mmol) were dissolved in 60 mL of toluene. Under N2 protection, the reaction was stopped by heating at reflux for 12 h. The cooled reaction solution was poured into water and stirred for 10 min. The crude product was precipitated and filtered, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-3 (3.04 mmol, yield 76%).

[0084] (4) Under nitrogen atmosphere, the obtained intermediate-3 (3 mmol) was dissolved in 90 mL of tert-butylbenzene solution. At 0°C, 4.6 mL of tert-butyllithium pentane solution (1.30 M, 6 mmol) was slowly dripped into the above solution. After dripping, the temperature was raised to 60°C for reaction for 2 h. Then the temperature was cooled to -40°C, boron tribromide (6 mmol) was slowly added, and then the temperature was raised to room temperature and stirring was continued for 0.5 h. Then the temperature was cooled to 0°C, N,N-diisopropylethylamine (12 mmol) was added, and the reaction was continued at 140°C for 6 h before stopping. After the reaction system was cooled to room temperature, the reaction was quenched with 7.5 mL of methanol and 7.5 mL of water, and the reaction mixture was extracted with dichloromethane and water. The organic phase was heated to dryness under vacuum, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain the final product compound 6 (1.5 mmol, yield 50%).

[0085] Example 7

[0086] An organic light-emitting material, whose structure is shown in Compound 7; and its preparation method comprises the following synthetic route:

[0087]

[0088] ; Specifically include the following steps:

[0089] (1) Under nitrogen atmosphere, raw material A1 (11 mmol), 1-bromo-2-chloro-3-fluoro-4-iodobenzene (10 mmol), and cesium carbonate (20 mmol) were dissolved in 80 mL of DMF solution. Under N2 protection, the reaction was stopped by heating at reflux for 8 h. The cooled reaction solution was poured into water and stirred for 2 h, then extracted with dichloromethane, concentrated, and separated by column chromatography (silica gel, dichloromethane / hexane) to obtain powdery intermediate-1 (7.5 mmol, yield 75%).

[0090] (2) Under nitrogen, the obtained intermediate-1 (7 mmol) was dissolved in 100 mL of tetrahydrofuran solvent. At -78°C, n-butyl lithium (14 mmol) was slowly added dropwise to the reaction solution. After the addition was completed, the reaction was allowed to react at -78°C for 1 h. Then, the raw material B7 (15 mmol) was added to the reaction solution. The temperature was raised to room temperature for 12 h to stop the reaction. The reaction was quenched with water, extracted with dichloromethane, concentrated and separated by column chromatography (silica gel, petroleum ether). The obtained product was added to 60 mL of acetic acid, dissolved and then 2 mL of hydrochloric acid was added. The reaction solution was heated at 110°C for 6 h to stop the reaction. The cooled reaction mixture was poured into ice water to precipitate and filter the crude product. Then, it was purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-2 (4.69 mmol, yield 67%).

[0091] (3) Under nitrogen conditions, the obtained intermediate-2 (4 mmol), raw material C1 (4.8 mmol), tri(dibenzylideneacetone)dipalladium (0.12 mmol), sodium tert-butoxide (8 mmol), and tri-tert-butylphosphine tetrafluoroborate (1.2 mmol) were dissolved in 60 mL of toluene. Under N2 protection, the reaction was stopped by heating at reflux for 12 h. The cooled reaction solution was poured into water and stirred for 10 min. The crude product was precipitated and filtered, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain intermediate-3 (3.12 mmol, yield 78%).

[0092] (4) Under nitrogen atmosphere, the obtained intermediate-3 (3 mmol) was dissolved in 90 mL of tert-butylbenzene solution. At 0°C, 4.6 mL of tert-butyllithium pentane solution (1.30 M, 6 mmol) was slowly dripped into the above solution. After dripping, the temperature was raised to 60°C for reaction for 2 h. Then the temperature was cooled to -40°C, boron tribromide (6 mmol) was slowly added, and then the temperature was raised to room temperature and stirring was continued for 0.5 h. Then the temperature was cooled to 0°C, N,N-diisopropylethylamine (12 mmol) was added, and the reaction was continued at 140°C for 6 h before stopping. After the reaction system was cooled to room temperature, the reaction was quenched with 7.5 mL of methanol and 7.5 mL of water, and the reaction mixture was extracted with dichloromethane and water. The organic phase was heated to dryness under vacuum, and then purified by column chromatography (silica gel, dichloromethane / petroleum ether) to obtain the final product compound 7 (1.59 mmol, yield 53%).

[0093] Example 8

[0094] Compounds 8-70 were prepared by a similar preparation method to that of Examples 1-7. The elemental analysis of the raw materials and products (the percentage of C, H and N in the compounds), the molecular weight data of mass spectrometry test, and the comprehensive yield are shown in Table 1.

[0095] Table 1

[0096]

[0097]

[0098]

[0099] Example 9

[0100] An organic electroluminescent device (OLED device) having a structure as follows Figure 1 As shown, it includes in sequence: an ITO anode 1, a first hole transport layer 2, a second hole transport layer 3, a light-emitting layer 4, an electron transport layer 5, an electron injection layer 6, and a metal cathode 7.

[0101] The method for preparing the OLED device comprises the following steps:

[0102] (1) Substrate treatment: Transparent ITO glass was used as the substrate material for the device preparation. It was first ultrasonically treated with 5% ITO washing solution for 30 min, then ultrasonically washed with distilled water (2 times), acetone (2 times), and isopropanol (2 times) in sequence, and finally the ITO glass was stored in isopropanol. Before each use, the surface of the ITO glass was carefully wiped with acetone cotton balls and isopropanol cotton balls, and then dried after rinsing with isopropanol, and then treated with plasma for 5 min for use. The subsequent preparation of the device was completed by combining spin coating and vacuum evaporation process.

[0103] (2) Preparation of hole injection layer or hole transport layer: The hole transport layer or hole injection layer is prepared by evaporation process. When the vacuum degree of vacuum evaporation system reaches 5×10 -4 Pa, the deposition rate was monitored by a Sense film thickness meter. The hole transport layer or hole injection layer was deposited on the surface of the ITO electrode in sequence using a vacuum evaporation process. The deposition rate of the hole transport layer material or the hole injection layer material was

[0104] (3) Preparation of the luminescent layer: The luminescent layer was prepared by evaporation process. When the vacuum degree of the vacuum evaporation system reached 5×10 - 4 Pa, the deposition rate was monitored by a Sense film thickness meter. The light-emitting layer was deposited on the hole transport layer using a vacuum evaporation process. The deposition rate of the light-emitting layer material was

[0105] (4) Preparation of electron transport layer, electron injection layer and metal electrode: The electron transport layer, electron injection layer and metal electrode are prepared by evaporation process. When the vacuum degree of vacuum evaporation system reaches 5×10 -4 When the temperature is below Pa, the deposition begins, and the deposition rate is monitored by a Sense film thickness meter. The electron transport layer, electron injection layer, and metal electrode are deposited on the light-emitting layer in sequence using a vacuum evaporation process. The deposition rate of the electron transport layer material is The deposition rate of the electron injection layer is The deposition rate of the metal electrode is

[0106] Among them, TAPC is used as the material of the first hole transport layer 2, TCTA is used as the material of the second hole transport layer 3, H1 is used as the main material in the light-emitting layer 4 (content is 82wt%), IrPPy3 is used as a sensitizer (content is 15wt%), Compound 1, Compound 21, Compound 25, and Compound 46 prepared in Examples 1-8 are used as doped light-emitting materials (content is 3wt%), E1 is used as the material of the electron transport layer 5, LiF is used as the electron injection layer 6, and Al is used as the metal cathode 7. The structure of the organic electroluminescent device is [ITO / NPB (335nm) / TCTA (5nm) EML (25nm) / TPBI (40nm) / LiF (1nm) / Al (100nm)], and EML represents the light-emitting layer. Thus, devices 1-device 4 are prepared.

[0107] Compound D1 was used as the doped light-emitting material, and other materials remained the same to prepare device D.

[0108] Performance test of organic electroluminescent devices (OLED devices)

[0109] The organic electroluminescent devices 1-4 and device D prepared in Example 9 were tested. The current, voltage, brightness, luminescence spectrum and other characteristics of the device were tested synchronously using a Photo Research PR 655 spectrum scanning luminance meter and a Keithley K2400 digital source meter system. The performance test of the device was carried out at room temperature and ambient atmosphere. The test results are shown in Table 2. The device life (T95, hours) in Table 2 refers to the initial brightness of the device at 1000 cd / m 2 When the device brightness drops to 95% of the initial brightness (i.e. the device brightness drops to 950cd / m 2 time) required.

[0110] Table 2

[0111]

[0112] As can be seen from Table 2, the organic electroluminescent device prepared using the compound provided by the present application shows high efficiency at high brightness, and the device stability is also very good, indicating that the organic electroluminescent device of the present application has the advantages of high external quantum efficiency, small device efficiency roll-off (i.e., the efficiency decreases slowly as the device brightness increases) and high brightness.

[0113] The above is only a preferred embodiment of the present invention. The present invention is not limited to the above implementation. As long as the technical effect of the present invention is achieved by the same means, it should belong to the protection scope of the present invention. Within the protection scope of the present invention, its technical scheme and / or implementation method can have various modifications and changes.

Claims

1. An organic light-emitting material, characterized in that: Its structure is shown in Formula I: Wherein, X is O, S, Se or N-R5, and R5 is alkyl, phenyl or substituted phenyl; R1 and R2 are independently selected from one of phenyl, substituted phenyl, alkyl, substituted alkyl, alkoxy and substituted alkoxy, and adjacent groups in R1 and R2 are fused to form a ring or are not fused to form a ring; R3 and R4 are independently selected from one of hydrogen, deuterium, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C30 aryl, substituted C6-C30 aryl, 5-30 membered heteroaryl, substituted 5-30 membered heteroaryl, diphenylamino and substituted diphenylamino.

2. The organic light-emitting material according to claim 1, characterized in that: Its structure is one of compounds 1-70:

3. The organic light-emitting material according to claim 2, characterized in that: Its structure is shown in Compound 21.

4. A method for preparing an organic light-emitting material according to any one of claims 1 to 3, characterized in that: The following synthetic routes are included:

5. The preparation method according to claim 4, characterized in that: The raw material A is raw material A1 or raw material A2; the raw material B is raw material B1, raw material B2, raw material B3, raw material B4, raw material B5, raw material B6 or raw material B7; the raw material C is raw material C1, raw material C2, raw material C3, raw material C4 or raw material C5; the structures are as follows:

6. A light-emitting layer, characterized in that: It comprises a host material and a luminescent guest material, wherein the luminescent guest material is the organic luminescent material according to any one of claims 1 to 3.

7. The light-emitting layer according to claim 6, characterized in that Also included are sensitizers.

8. An organic electroluminescent device, characterized in that: The method comprises an anode and a cathode, and further comprises the light-emitting layer according to claim 6 or 7 between the anode and the cathode.

9. The organic electroluminescent device according to claim 8, characterized in that: Including in order: The anode, the hole transport layer, the light emitting layer, the electron transport layer, the electron injection layer, and the cathode.

10. A display device, characterized in that: The organic electroluminescent device comprises the organic electroluminescent device according to claim 8 or 9.

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