Compound for organic electroluminescent material and organic electroluminescent device

Abstract

This invention relates to a novel organic compound having the structure of the following formula (1): L 1 ~L 3 Each C6 to C6 bond is independently selected from single bonds, substituted or unsubstituted bonds. 30 aryl, substituted or unsubstituted C3-C 30 One of the heteroaryl groups; Ar 1 C3-C, whether substituted or unsubstituted 30 heteroaryl; X 1 ~X 7 CR independently 2 Or N, and at least two of them are N; Y 1 ~Y 5 CR are independent of each other. 3 Or N, and at least one of them is N; R 1 ~R 3 Each is independently selected from hydrogen, C1 to C2. 12 Alkyl, C1-C 12 Alkoxy, halogen, cyano, nitro, hydroxyl, silyl, amino, substituted or unsubstituted C6-C 30 arylamino, substituted or unsubstituted C3-C 30 heteroarylamino, substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C3-C 30 One of the heteroaryl groups. When used as a light-emitting material in OLED devices or as an electron transport material, the compounds of this invention exhibit excellent device performance and stability. This invention also protects organic electroluminescent devices employing the above-described general formula compounds.

Description

[0001] This application is a divisional application of patent application number 201811630718.3, the parent application being filed on December 29, 2018, and the parent invention being entitled "Organic Electroluminescent Material and Device". Technical Field

[0002] This invention relates to an organic compound that can be used as a light-emitting layer material in organic electroluminescent devices; this invention also relates to the application of this compound in organic electroluminescent devices. Background Technology

[0003] With the continuous advancement of OLED technology in both display and lighting fields, research on its core materials has become increasingly focused. Common functionalized organic materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, as well as luminescent host materials and luminescent guest materials (dyes).

[0004] Previous articles and patents have reported various types of electron transport materials with strong transport capabilities and high stability. Generally, electron transport materials are compounds with electron-deficient nitrogen-containing heterocyclic groups. They mostly have high electron affinity and therefore strong electron accepting capabilities. However, compared to hole transport materials, common electron transport materials such as AlQ3 (aluminum octahydroxyquinoline) have much lower electron mobility than hole transport materials. Therefore, in OLED devices, this leads to two problems: firstly, it reduces the probability of hole-electron recombination caused by the imbalance between carrier injection and transport, thus reducing the device's luminous efficiency; secondly, electron transport materials with lower electron mobility lead to higher device operating voltage, thus affecting power efficiency and hindering energy conservation.

[0005] Currently, OLED screen manufacturers widely use Liq (lithium octahydroxyquinoline) doping technology in the ET material layer to achieve low voltage and high efficiency in devices, while also improving device lifespan. The main function of Liq is to reduce trace amounts of metallic lithium under the influence of electrons injected from the cathode, effectively n-doping the electron transport material and significantly improving electron injection efficiency. Furthermore, lithium ions coordinate with nitrogen atoms in the electron transport material, increasing the electron mobility of the ET material. This results in Liq-doped ET devices exhibiting low operating voltage and high luminous efficiency.

[0006] However, in order to further meet the ever-increasing demand for the photoelectric performance of OLED devices and the energy-saving requirements of mobile electronic devices, it is necessary to continuously develop new and efficient OLED materials. Among them, the development of new electron transport materials with high electron injection capability and high mobility is of great significance. Summary of the Invention

[0007] In view of the problems of the prior art, the object of the present invention is to provide a new class of compounds for organic electroluminescent devices to meet the ever-increasing demand for the photoelectric performance of OLED devices.

[0008] This invention provides an organic compound that, when introduced as an electron transport material into organic electroluminescent devices, can achieve excellent electron injection and transport performance.

[0009] Specifically, as one aspect of the present invention, a compound represented by the following general formula (1) is provided: in: a is an integer from 1 to 3.

[0010] L 1 ~L 3 Whether identical or different, they are independently selected from single-bonded, substituted or unsubstituted C6 to C6 bonds. 30 aryl, substituted or unsubstituted C3-C 30 One of the heteroaryl groups.

[0011] Ar 1 C3-C, whether substituted or unsubstituted 30 Mixed aromatics; Furthermore, Ar 1 The following groups, substituted or unsubstituted, are: pyridine, dibenzofuran, dibenzothiophene, and quinoline.

[0012] X 1 ~X 7 Whether they are the same or different, they are independently designated as CR. 2 Or N, and at least two of them are N; Y 1 ~Y 5 Whether they are the same or different, they are CRs independently. 3 Or N, and at least one of them is N; R 1 ~R 3 Each is independently selected from hydrogen, C1 to C2. 12 Alkyl, C1-C 12 Alkoxy, halogen, cyano, nitro, hydroxyl, silyl, amino, substituted or unsubstituted C6-C 30arylamino, substituted or unsubstituted C3-C 30 heteroarylamino, substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C3-C 30 One of the heteroaryl groups; When the above groups contain substituents, the substituents are independently selected from halogens, C1-C... 10 Alkyl or cycloalkyl, C2-C 10 Alkenyl, C1-C6 alkoxy or thioalkoxy groups, C6-C 30 Monocyclic aromatic hydrocarbons or fused-ring aromatic hydrocarbon groups, C3-C 30 One of the monocyclic heteroaromatic hydrocarbons or fused-ring heteroaromatic hydrocarbon groups.

[0013] Furthermore, the A mentioned above is selected from the following A1-A20 structures, either substituted or unsubstituted: .

[0014] Furthermore, the above B is selected from the following groups, either substituted or unsubstituted: pyridine, pyrazine, pyrimidine, pyridazine, and triazine.

[0015] Furthermore, A is preferably a substituted or unsubstituted quinazoline group; B is preferably a substituted or unsubstituted triazine group.

[0016] Furthermore, the above general formula (1) is preferably the structure of the following general formula (2): .

[0017] In equation (2), R 1 a, Ar 1 L 1 ~L 3 X 1 ~X 7 and Y 1 ~Y 5 The definitions are the same as those in general formula (1).

[0018] Furthermore, Ar 1 The following groups, substituted or unsubstituted, are: pyridine, dibenzofuran, dibenzothiophene, and quinoline.

[0019] .

[0020] Furthermore, B is selected from substituted or unsubstituted groups of the following: pyridine, pyrazine, pyrimidine, pyridazine, and triazine. Furthermore, A is preferably a substituted or unsubstituted quinazoline group; B is preferably a substituted or unsubstituted triazine group.

[0021] Furthermore, R 1Preferably derived from H, F, Cl, Br, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthryl, indene, fluorenyl, fluoranyl, triphenylene, pyrene, peryl, thioyl, furanyl, thiophene, pyrrole, pyridyl, benzofuranyl, benzothiophene, isobenzofuranyl, indolyl, dibenzofuranyl, dibenzothiophene, or carbazole.

[0022] Furthermore, as preferred structures of the compounds involved in this invention, examples include compounds with structures shown in C1 to C80, but are not limited to these compounds.

[0023] .

[0024] As another aspect of the present invention, the present invention also provides the application of the compound described above in an organic electroluminescent device. The compound can be used, but is not limited to, as an electron transport layer material.

[0025] Furthermore, the compounds of the present invention can be applied to organic electronic devices, such as organic electroluminescent devices, lighting elements, organic thin-film transistors, organic field-effect transistors, organic thin-film solar cells, information tags, electronic artificial skin sheets, sheet-type scanners and other large-area sensors, electronic paper and organic EL panels, etc.

[0026] As another technical solution of the present invention, the present invention provides an organic electroluminescent device, comprising a first electrode, a second electrode, and one or more organic layers inserted between the first electrode and the second electrode, characterized in that the organic layer contains the compound described above.

[0027] Furthermore, the organic layer between the first electrode and the second electrode typically includes an electron injection layer, an electron transport layer, a light-emitting layer, a hole transport layer, a hole injection layer, etc., wherein the organic layer containing the compound of the present invention can be used as, but is not limited to, an electron transport layer.

[0028] This invention provides a novel compound, and it has been found that introducing it as an electron transport material into organic electroluminescent devices can significantly improve the performance of the devices.

[0029] The specific reasons for the excellent performance of the compounds of the present invention as electron transport materials are not yet clear, but it is speculated that the reasons may be as follows: Compared with the commonly used single oxazole, thiazole, imidazole, triazole, or triazine structures in the prior art, the compounds of this invention introduce an electron-deficient group at the intermediate position, giving them relatively stronger electron-deficient properties, thus facilitating electron injection. Simultaneously, the introduction of a third conjugated aromatic heterocyclic compound containing nitrogen, oxygen, and sulfur atoms further enhances the conjugation of the overall molecular structure, improving electron mobility on one hand; and on the other hand, the intermolecular hydrogen bonding interactions improve the molecular thermal stability, thereby indirectly increasing the device lifetime.

[0030] The advantages of the compounds of the present invention are: the synthesis method of the compounds of the present invention is simple, and the devices using the compounds of the present invention can obtain better photoelectric performance and longer lifespan. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments.

[0032] All the chemical reagents used in this invention, such as petroleum ether, ethyl acetate, sodium sulfate, toluene, tetrahydrofuran, dichloromethane, acetic acid, potassium phosphate, and sodium tert-butoxide, were purchased from common chemical product suppliers, including but not limited to Shanghai Titan Technology Co., Ltd. and Xilong Chemical Co., Ltd. The mass spectrometer used to determine the following compounds was a ZAB-HS type mass spectrometer (manufactured by Micromass, UK). In this invention, nuclear magnetic resonance (NMR) was performed using a BRUKER 500MHz NMR spectrometer (manufactured by BRUKER, Germany).

[0033] Representative synthetic pathways: The first step involves using 2-(3-bromo-5-chlorophenyl)-4,6-diphenyl-1,3,5-triazine as a starting material and reacting it with a first electron-deficient arylboronic acid via a Suzuki coupling reaction to generate intermediate M1. The second step involves converting the chlorinated derivative of intermediate M1 into the corresponding borate ester intermediate M2. The third step involves using intermediate M2 as a starting material and reacting it with another electron-deficient aryl halide via a Suzuki coupling reaction to obtain the product.

[0034] More specifically, the following provides methods for synthesizing representative compounds of the present invention.

[0035] Synthesis Example 1: Synthesis of Compound C3 Preparation of compounds 1-2 Compound 1-1 (42.1 g, 0.1 mol), 2-phenyl-5-pyridineboronic acid (21.9 g, 0.11 mol), and potassium carbonate (41 g, 0.3 mol) were dissolved in a flask containing toluene / ethanol / water (150 mL / 50 mL / 50 mL). After purging with nitrogen at room temperature, Pd(PPh3)4 (1.16 g, 0.001 mol) was added. The mixture was stirred and refluxed for 4 hours, with the reaction endpoint monitored by TLC. The solid was filtered after cooling to room temperature, washed with water and ethanol, dried, and purified by column chromatography (eluent: dichloromethane) to give compound 1-2 (43.6 g, 88% yield).

[0036] Preparation of compounds 1-3 Compound 1-1 (39.7 g, 0.08 mol), pinacol borate (30.5 g, 0.12 mol), and potassium acetate (24 g, 0.24 mol) were added to a flask containing 1,4-dioxane (300 mL). After purging with nitrogen at room temperature, Pd2(dba)3 (733 mg, 0.8 mmol) and sphos (1 g, 1.6 mmol) were added. The mixture was stirred and refluxed for 4 hours, and the reaction endpoint was monitored by TLC. The precipitated solid was filtered, washed with water, and dried to give compound 1-3 (38.1 g, 81% yield).

[0037] Preparation of compound C3 Compounds 1-3 (10.6 g, 18 mmol), 2-chloro-4-phenylquinazoline (4.3 g, 18 mmol), and potassium carbonate (7.45 g, 54 mmol) were added to a flask containing tetrahydrofuran:water (150 mL:50 mL). After purging with nitrogen under stirring at room temperature, Pd(PPh3)4 (208 mg, 0.18 mmol) was added. The mixture was then heated under reflux for 12 hours with stirring under nitrogen atmosphere, and TLC showed complete reaction. The precipitated white solid was filtered off. It was dissolved in dichloromethane, dried over anhydrous sodium sulfate, and subjected to column chromatography (eluent: dichloromethane:ethyl acetate 4:1) to give a white solid, compound C3 (8.5 g, 71% yield). Calculated molecular weight: 666.25, measured C / Z: 666.2.

[0038] Synthesis Example 2: Synthesis of Compound C11 Preparation of compound 2-1 Compound 1-1 (42.1 g, 0.1 mol), 3-pyridineboronic acid (13.5 g, 0.11 mol), and potassium carbonate (41.4 g, 0.3 mol) were dissolved in a flask containing toluene / ethanol / water (300 mL / 50 mL / 50 mL). After purging with nitrogen at room temperature, Pd(PPh3)4 (1.15 g, 0.001 mol) was added. The mixture was stirred and refluxed for 4 hours, with the reaction endpoint monitored by TLC. After cooling to room temperature, the mixture was filtered, and the solid was washed successively with toluene, water, and ethanol, and then dried. The solid was purified by column chromatography (eluent: dichloromethane:ethyl acetate = 5:1 to 1:1) to give compound 2-1 (37.8 g, 90% yield).

[0039] Preparation of compound 2-2 Compound 2-1 (33.6 g, 0.08 mol), pinacol borate (30.5 g, 0.12 mol), and potassium acetate (24 g, 0.24 mol) were added to a flask containing 1,4-dioxane (300 mL). After purging with nitrogen at room temperature, Pd2(dba)3 (733 mg, 0.8 mmol) and sphos (1 g, 1.6 mmol) were added. The mixture was stirred and refluxed for 24 hours, with the reaction endpoint monitored by TLC. The precipitated solid was filtered, washed with water, and dried to give compound 2-2 (32.4 g, 79% yield).

[0040] Preparation of compounds 2-3 Compound 2,4-dichloroquinazoline (19.8 g, 0.1 mol), 9-phenanthroline (24.4 g, 0.11 mol), and potassium carbonate (41.4 g, 0.3 mol) were dissolved in a flask containing toluene / ethanol / water (300 mL / 50 mL / 50 mL). After purging with nitrogen at room temperature, Pd(PPh3)4 (1.15 g, 0.001 mol) was added. The mixture was stirred and refluxed for 4 hours, with the reaction endpoint monitored by TLC. After cooling to room temperature, the mixture was filtered, and the solid was washed successively with toluene, water, and ethanol, and then dried. The solid was purified by column chromatography (eluent: dichloromethane) to give compound 2-3 (30.9 g, 91% yield).

[0041] Preparation of compound C11 Compound 2-2 (9.2 g, 18 mmol), compound 2-3 (6.1 g, 18 mmol), and potassium carbonate (7.45 g, 54 mmol) were added to a flask containing tetrahydrofuran:water (150 mL: 50 mL). After purging with nitrogen under stirring at room temperature, Pd(PPh3)4 (208 mg, 0.18 mmol) was added. The mixture was then heated under reflux for 12 hours with stirring under nitrogen atmosphere, and TLC showed complete reaction. The precipitated white solid was filtered off. It was dissolved in dichloromethane, dried over anhydrous sodium sulfate, and subjected to column chromatography (eluent: dichloromethane:ethyl acetate 4:1) to give a white solid, compound C11 (9.3 g, 75% yield). Calculated molecular weight: 690.25, measured C / Z: 690.2.

[0042] Synthesis Example 3: Synthesis of Compound C24 Preparation of compound 3-1 Compound 1-1 (42.1 g, 0.1 mol), 3-quinolineboric acid (19 g, 0.11 mol), and potassium carbonate (41.4 g, 0.3 mol) were dissolved in a flask containing toluene / ethanol / water (300 mL / 50 mL / 50 mL). After purging with nitrogen at room temperature, Pd(PPh3)4 (1.15 g, 0.001 mol) was added. The mixture was stirred and refluxed for 4 hours, with the reaction endpoint monitored by TLC. After cooling to room temperature, the mixture was filtered, and the solid was washed successively with toluene, water, and ethanol, and then dried. The solid was purified by column chromatography (eluent: dichloromethane:ethyl acetate = 5:1–2:1) to give compound 3-1 (40 g, 85% yield).

[0043] Preparation of compound 3-2 Compound 3-1 (37.6 g, 0.08 mol), pinacol borate (30.5 g, 0.12 mol), and potassium acetate (24 g, 0.24 mol) were added to a flask containing 1,4-dioxane (300 mL). After purging with nitrogen at room temperature, Pd₂(dba)₃ (733 mg, 0.8 mmol) and sphos (1 g, 1.6 mmol) were added. The mixture was stirred and refluxed for 24 hours, and the reaction endpoint was monitored by TLC. The precipitated solid was filtered, washed with water, and dried to give compound 3-2 (32.3 g, 72% yield).

[0044] Preparation of compound 3-3 Compound 2,4-dichloroquinazoline (19.8 g, 0.1 mol), 9,9-dimethyl-2-fluorenboronic acid (26.2 g, 0.11 mol), and potassium carbonate (41.4 g, 0.3 mol) were dissolved in a flask containing toluene / ethanol / water (300 mL / 50 mL / 50 mL). After purging with nitrogen at room temperature, Pd(PPh3)4 (1.15 g, 0.001 mol) was added. The mixture was stirred and refluxed for 4 hours, with the reaction endpoint monitored by TLC. After cooling to room temperature, the mixture was filtered, and the solid was washed successively with toluene, water, and ethanol, and then dried. The solid was purified by column chromatography (eluent: dichloromethane) to give compound 3-3 (30.6 g, 86% yield).

[0045] Preparation of compound C24 Compound 3-2 (10.1 g, 18 mmol), compound 3-3 (6.4 g, 18 mmol), and potassium carbonate (7.45 g, 54 mmol) were added to a flask containing tetrahydrofuran:water (150 mL: 50 mL). After purging with nitrogen under stirring at room temperature, Pd(PPh3)4 (208 mg, 0.18 mmol) was added. The mixture was then heated under reflux for 12 hours with stirring under nitrogen atmosphere, and TLC showed complete reaction. The precipitated white solid was filtered off. It was dissolved in dichloromethane, dried over anhydrous sodium sulfate, and subjected to column chromatography (eluent: dichloromethane:ethyl acetate 4:1) to give a white solid, compound C24 (9.6 g, 71% yield). Calculated molecular weight: 756.30, measured C / Z: 756.3.

[0046] Synthesis Example 4: Synthesis of Compound C55 Preparation of compound 4-1 Compound 1-1 (42.1 g, 0.1 mol), 4-dibenzofuranboronic acid (23.3 g, 0.11 mol), and potassium carbonate (41.4 g, 0.3 mol) were dissolved in a flask containing toluene / ethanol / water (300 mL / 50 mL / 50 mL). After purging with nitrogen at room temperature, Pd(PPh3)4 (1.15 g, 0.001 mol) was added. The mixture was stirred and refluxed for 4 hours, with the reaction endpoint monitored by TLC. After cooling to room temperature, the mixture was filtered, and the solid was washed successively with toluene, water, and ethanol, and then dried. The solid was purified by column chromatography (eluent: dichloromethane:ethyl acetate = 5:1 to 1:1) to give compound 4-1 (47.3 g, 93% yield).

[0047] Preparation of compound 4-2 Compound 4-1 (40.7 g, 0.08 mol), pinacol borate (30.5 g, 0.12 mol), and potassium acetate (24 g, 0.24 mol) were added to a flask containing 1,4-dioxane (300 mL). After purging with nitrogen at room temperature, Pd₂(dba)₃ (733 mg, 0.8 mmol) and sphos (1 g, 1.6 mmol) were added. The mixture was stirred and refluxed for 24 hours, and the reaction endpoint was monitored by TLC. The precipitated solid was filtered, washed with water, and dried to give compound 4-2 (36 g, 75% yield).

[0048] Preparation of compound 4-3 Compound 2,4-dichloroquinazoline (19.8 g, 0.1 mol), 3-pyridineboronic acid (13.5 g, 0.11 mol), and potassium carbonate (41.4 g, 0.3 mol) were dissolved in a flask containing toluene / ethanol / water (300 mL / 50 mL / 50 mL). After purging with nitrogen at room temperature, Pd(PPh3)4 (1.15 g, 0.001 mol) was added. The mixture was stirred and refluxed for 4 hours, with the reaction endpoint monitored by TLC. After cooling to room temperature, the mixture was filtered, and the solid was washed successively with toluene, water, and ethanol, and then dried. The solid was purified by column chromatography (eluent: dichloromethane) to give compound 4-3 (17.8 g, 74% yield).

[0049] Preparation of compound C55 Compound 4-2 (10.8 g, 18 mmol), compound 4-3 (4.3 g, 18 mmol), and potassium carbonate (7.45 g, 54 mmol) were added to a flask containing tetrahydrofuran:water (150 mL:50 mL). After purging with nitrogen under stirring at room temperature, Pd(PPh3)4 (208 mg, 0.18 mmol) was added. The mixture was then heated under reflux for 12 hours with stirring under nitrogen atmosphere, and TLC showed complete reaction. The precipitated white solid was filtered off. It was dissolved in dichloromethane, dried over anhydrous sodium sulfate, and subjected to column chromatography (eluent: dichloromethane:ethyl acetate 4:1) to give a white solid, compound C55 (8.6 g, 70% yield). Calculated molecular weight: 680.23, measured C / Z: 680.2.

[0050] Device Examples Implementation method: An OLED includes a first electrode and a second electrode, and an organic material layer located between the electrodes. This organic material layer can be further divided into multiple regions. For example, the organic material layer may include a hole transport region, a light-emitting layer, and an electron transport region.

[0051] In specific embodiments, a substrate can be used below the first electrode or above the second electrode. The substrate is typically made of glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. Furthermore, thin-film transistors (TFTs) can also be incorporated into the substrate used for displays.

[0052] The first electrode can be formed by sputtering or depositing the material used as the first electrode on a substrate. When the first electrode is used as the anode, it can be a transparent conductive oxide material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), or any combination thereof. When the first electrode is used as the cathode, it can be a metal or alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), or any combination thereof. Organic material layers can be formed on electrodes using methods such as vacuum thermal evaporation, spin coating, and printing. The compounds used as organic material layers can be small organic molecules, large organic molecules, polymers, and combinations thereof.

[0053] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a single-layer hole transport layer (HTL), including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport region can also be a multilayer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0054] The material for the hole transport region may be selected from, but is not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives as shown in HT-1 to HT-34 below; or any combination thereof.

[0055] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can be one or more compounds of HT-1 to HT-34 mentioned above, or one or more compounds of HI1 to HI3 mentioned below; it can also be one or more compounds of HT-1 to HT-34 doped with one or more compounds of HI1 to HI3 mentioned below.

[0056] The emissive layer includes luminescent dyes (i.e., dopants) that can emit different wavelengths of light, and may also include a host material. The emissive layer can be a monochromatic emissive layer emitting a single color such as red, green, or blue. Multiple monochromatic emissive layers of different colors can be arranged in a planar pattern according to pixel design, or they can be stacked together to form a colored emissive layer. When different colored emissive layers are stacked together, they can be separated from each other or connected to each other. The emissive layer can also be a single colored emissive layer that can simultaneously emit different colors such as red, green, and blue.

[0057] Depending on the technology used, the light-emitting layer material can be various, including fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescence materials. An OLED device can employ a single light-emitting technology or a combination of different technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0058] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent host material of the light-emitting layer may be selected from, but is not limited to, one or more combinations of BFH-1 to BFH-17 listed below.

[0059] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of BFD-1 to BFD-12 listed below.

[0060] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The main material of the light-emitting layer is selected from, but not limited to, one or more combinations of GPH-1 to GPH-80.

[0061] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0062] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The main material of the light-emitting layer is selected from, but not limited to, one or more combinations of RH-1 to RH-31.

[0063] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0064] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of YPD-1-YPD-11 listed below.

[0065] In one aspect of the invention, the light-emitting layer employs thermally activated delayed fluorescence emission technology. The fluorescent dopant in the light-emitting layer may be selected from, but is not limited to, one or more combinations of TDE-1 to TDE-39 listed below.

[0066] In one aspect of the invention, the light-emitting layer employs thermally activated delayed fluorescence emission technology. The main material of the light-emitting layer is selected from, but not limited to, one or more combinations of TDH1-TDH24.

[0067] The OLED organic material layer may further include an electron transport region between the light-emitting layer and the cathode. The electron transport region can be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. The electron transport region may also be a multilayer structure including at least one layer of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL). In one aspect of the invention, the electron transport layer material may be selected from, but is not limited to, one or more combinations of ET-1 to ET-57 listed below.

[0068] Organic electroluminescent devices may also include an electron injection layer located between the electron transport layer and the cathode, and the electron injection layer material includes, but is not limited to, one or more combinations of the following.

[0069] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca.

[0070] To facilitate comparison of the device application performance of the luminescent materials of the present invention, compounds ET-46, ET-58 and ET-59, as shown below, were used as comparative materials.

[0071] The technical effects and advantages of the present invention are demonstrated and verified by specifically applying the compounds of the present invention to an organic electroluminescent device and testing their actual performance. The preparation process of the organic electroluminescent device in this embodiment is as follows: The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a acetone:ethanol mixed solvent, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam. The glass substrate with the anode was placed in a vacuum chamber and evacuated until the pressure was less than 10. -5 Pa, on the above-mentioned anode film, the evaporation rate of hole transport material HT-33 was adjusted to 0.1 nm / s and the evaporation rate of hole injection material HT-32 was set to 7% on the anode film, and the total evaporation film thickness was 10 nm. HT-33 was vacuum-deposited on top of the hole injection layer as the first hole transport layer of the device at a deposition rate of 0.1 nm / s and a total film thickness of 40 nm. HT-34 was vacuum-deposited on top of the first hole transport layer as the second hole transport layer of the device at a deposition rate of 0.1 nm / s and a total film thickness of 10 nm. The light-emitting layer of the device is vacuum-deposited on the second hole transport layer. The light-emitting layer includes a host material and a dye material. Using a multi-source co-evaporation method, the evaporation rate of the host material BFH-4 is adjusted to 0.1 nm / s, the evaporation rate of the dye BFD-4 is set to 5%, and the total evaporation film thickness is 20 nm. ET-17 was vacuum-deposited on the first light-emitting layer as a hole-blocking layer for the device at a deposition rate of 0.1 nm / s and a total film thickness of 5 nm. On top of the hole blocking layer, using a multi-source co-evaporation method, the evaporation rate of the electron transport material C1~C95 or the comparative materials ET-46, ET-58 and ET-58 of the present invention is adjusted to 0.1 nm / s, and the evaporation rate of ET-57 is set to 100% of that of ET-57, with a total evaporation film thickness of 23 nm. A 1 nm thick LiF layer was vacuum-deposited on the electron transport layer (ETL) as an electron injection layer, and an 80 nm thick Al layer was used as the cathode of the device.

[0072] Test methods for organic electroluminescent devices The organic electroluminescent devices prepared by the above process were subjected to the following performance measurements: Under the same brightness, the driving voltage and current efficiency of the organic electroluminescent devices prepared in Examples 1-4 and Comparative Examples 1-3 were measured using a Photo Research PR750 radiometer and ST-86LA luminance meter (Beijing Normal University Optoelectronic Instrument Factory) and a Keithley 4200 testing system. Specifically, the voltage was increased at a rate of 0.1V per second, and the driving voltage and current efficiency were measured when the brightness of the organic electroluminescent device reached 1000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is measured simultaneously; the ratio of brightness to current density is the current efficiency; the life test of LT95 is as follows: using a luminance meter at 3000 cd / m² 2 At a constant current, the brightness of the organic electroluminescent device decreased to 2850 cd / m² under the specified brightness. 2 The time is in hours.

[0073] Example 1

[0074] Using compound C3 of the present invention as an electron transport material, an organic electroluminescent device was prepared according to the above-described preparation process for an organic electroluminescent device, and the device performance was tested according to the above-described testing method for organic electroluminescent devices.

[0075] Example 2

[0076] Organic electroluminescent devices were prepared using the same method as in Example 1, except that compound C3 was replaced with C11.

[0077] Example 3

[0078] Organic electroluminescent devices were prepared using the same method as in Example 1, except that compound C3 was replaced with C24.

[0079] Example 4

[0080] Organic electroluminescent devices were prepared using the same method as in Example 1, except that compound C3 was replaced with C55.

[0081] Comparative Example 1: Organic electroluminescent devices were prepared using the same method as in Example 1, except that compound C3 was replaced with ET-46.

[0082] Comparative Example 2: Organic electroluminescent devices were prepared using the same method as in Example 1, except that compound C3 was replaced with ET-58.

[0083] Comparative Example 3: Organic electroluminescent devices were prepared using the same method as in Example 1, except that compound C3 was replaced with ET-59.

[0084] Table 1 shows the performance of organic electroluminescent devices: Compared to Comparative Examples 1-3, in Examples 1-4, with other materials remaining the same in the organic electroluminescent device structure, the compounds of the present invention exhibited lower voltage and significantly higher efficiency compared to the electron transport materials ET-46 in Comparative Example 1 and ET-58 in Comparative Example 2. This is presumably because, compared to ET-46 and ET-58, the compounds of the present invention introduce electron-deficient groups at the intermediate position of their structure, giving them relatively stronger electron-deficient properties, thus facilitating electron injection. Compared to the compounds in Comparative Example 3, the compound of the present invention showed slightly better photoelectric performance but a significantly improved lifetime. This is presumably because the introduction of a third conjugated aromatic heterocyclic compound containing nitrogen, oxygen, and sulfur atoms further enhanced the conjugation of the overall molecular structure, improving electron mobility on one hand; and on the other hand, the intermolecular hydrogen bond interactions improved the molecular thermal stability, thereby indirectly improving the device lifetime. The above experimental data indicate that the novel organic materials of the present invention are high-performance organic light-emitting functional materials as electron transport materials for organic electroluminescent devices, and are expected to be widely used in commercial applications.

[0085] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0086] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0087] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

[0088] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A compound of the general formula (1) as follows: in: A is a substituted or unsubstituted quinazoline group; B is a substituted or unsubstituted triazine group; L 1 ~L 3 Selected from single bonds; Ar 1 C3-C, whether substituted or unsubstituted 30 Mixed aromatics; a is an integer from 1 to 3; R 1 Selected from hydrogen, C1 to C 12 Alkyl, C1-C 12 Alkoxy, halogen, cyano, nitro, hydroxyl, silyl, amino, substituted or unsubstituted C6-C 30 arylamino, substituted or unsubstituted C3-C 30 heteroarylamino, substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C3-C 30 One of the heteroaryl groups; When the above groups contain substituents, the substituents are independently selected from halogens, C1-C... 10 Alkyl or cycloalkyl, C2-C 10 Alkenyl, C1-C6 alkoxy or thioalkoxy groups, C6-C 30 Monocyclic aromatic hydrocarbons or fused-ring aromatic hydrocarbon groups, C3-C 30 One of the monocyclic heteroaromatic hydrocarbons or fused-ring heteroaromatic hydrocarbon groups.

2. The compound of the general formula according to claim 1, wherein, Ar 1 Selected from the following groups, whether substituted or unsubstituted: pyridine, dibenzofuran, dibenzothiophene, and quinoline.

3. The compound of general formula according to any one of claims 1 to 2, having the structure shown in the following general formula (2): 。 4. The compound of the general formula according to claim 1 or 3, wherein: R 1 It is selected from one of H, F, Cl, Br, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthryl, indene, fluorenyl, fluoranyl, triphenylene, pyrene, peryl, thioyl, furanyl, thiophene, pyrrole, pyridyl, benzofuranyl, benzothiophene, isobenzofuranyl, indolyl, dibenzofuranyl, dibenzothiophene, and carbazole.

5. The compound of the general formula according to claim 1, wherein the compound is selected from the following specific structural compounds: 。 6. The application of the compound of the general formula according to claim 1, wherein the application is as an electron transport material in an organic electroluminescent device.

7. An organic electroluminescent device, comprising a first electrode, a second electrode, and one or more organic layers inserted between the first electrode and the second electrode, characterized in that, The organic layer includes at least one compound as described in claim 1 or 5.

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