Organic electroluminescent compound and application thereof

Abstract

The invention relates to the technical field of display, in particular to an organic electroluminescent compound and application thereof. The organic electroluminescent compound provided by the invention has a structure as shown in formula 1. The organic electroluminescent device containing the organic electroluminescent compound can have relatively low driving voltage, relatively high current efficiency and relatively long service life.

Description

Technical Field

[0001] This invention relates to the field of display technology, and more specifically to an organic electroluminescent compound and its applications. Background Technology

[0002] Electroluminescent devices (EL devices) are self-emissive devices that offer advantages such as a wider viewing angle, higher contrast ratio, and faster response time. Organic EL devices (OLEDs) convert electrical energy into light by applying electricity to organic electroluminescent materials and generally have a structure comprising an anode, a cathode, and an organic layer between the anode and cathode. The organic layer of an organic EL device can consist of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer (containing a host material and dopants), an electron buffer layer, a hole blocking layer, an electron transport layer, and an electron injection layer, etc. The materials used in the organic layer are classified according to their function as hole injection materials, hole transport materials, electron blocking materials, light-emitting materials, electron buffer materials, hole blocking materials, electron transport materials, and electron injection materials, etc. In the organic EL device, due to the application of voltage, holes are injected from the anode into the light-emitting layer, and electrons are injected from the cathode into the light-emitting layer, and high-energy excitons are formed through the recombination of holes and electrons. With this energy, the organic light-emitting compound reaches an excited state, and light is emitted by the energy generated by the return of the organic light-emitting compound from the excited state to the ground state.

[0003] The most important factor determining the luminescence efficiency of organic EL devices is the luminescent material. The luminescent material must possess high quantum efficiency and high electron and hole mobility, and the resulting luminescent material layer must be uniform and stable. Luminescent materials are classified according to the color of their emission into blue, green, and red luminescent materials, as well as yellow and orange luminescent materials. Furthermore, luminescent materials can also be classified according to their function into host materials and dopant materials.

[0004] Developing organic EL devices that offer high efficiency and long lifetime is a pressing issue. Specifically, considering the EL characteristic requirements of OLEDs for medium- or large-sized panels, it is necessary to develop materials that can exhibit better characteristics than conventional materials. However, the HOMO and LUMO energy levels of existing organic electroluminescent materials have poor matching with adjacent energy levels, leading to low stability and carrier mobility imbalance. This results in organic electroluminescent devices containing these materials having high driving voltages, low luminous efficiency, and short lifetimes, severely limiting their applications. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems in related technologies where the HOMO and LUMO energy levels of organic electroluminescent materials have poor matching with adjacent energy levels, resulting in low stability and unbalanced carrier mobility of the organic electroluminescent materials. This leads to problems such as high driving voltage, low luminous efficiency, and short lifetime of organic electroluminescent devices containing such materials. In this way, an organic electroluminescent compound and its application are provided.

[0006] In the definition of substituent terms in this invention:

[0007] As used in this invention, the term "substitution," when referring to a chemical group, means that one or more hydrogen atoms of the chemical group are removed and replaced by a substituent. Of course, those skilled in the art will understand that the position of substitution is not limited to a specific position, as long as the hydrogen at that position can be replaced by a substituent. When two or more substituents are present, the two or more substituents can be the same or different.

[0008] As used in this invention, the term "substituent" has the common meaning known in the art as referring to a chemical moiety covalently attached to or, where appropriate, fused to a parent nucleus group.

[0009] As used herein, the term "alkyl" refers, whether as part of other terms or used alone, to a saturated hydrocarbon group, which may be straight-chain or branched. The term "C1-C30 alkyl" is derived from a monovalent substituent of a straight-chain or branched saturated hydrocarbon having 1 to 30 carbon atoms. In some embodiments, the alkyl group contains 1 to 12, 1 to 8, 1 to 6, 1 to 4, 1 to 3, or 1 to 2 carbon atoms. Examples of such substituents include, but are not limited to, methyl, ethyl, propyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, and hexyl.

[0010] As used herein, the term "alkenyl" refers, whether as part of other terms or alone, to a saturated hydrocarbon group, which may be straight-chain or branched and has at least one carbon-carbon double bond. The term "C2-C30 alkenyl" refers to an alkenyl group having 2 to 30 carbon atoms. In some embodiments, the alkenyl group has 2 to 12, 2 to 10, 2 to 8, 2 to 6, 2 to 5, 2 to 4, or 2 to 3 carbon atoms. Of course, the alkenyl group includes, but is not limited to, vinyl, n-propenyl, isopropenyl, n-butenyl, sec-butenyl, etc.

[0011] As used herein, the term "C3-C30 cycloalkyl" refers to a cycloalkyl group consisting of at least three atoms, and more specifically, to a monocyclic or polycyclic hydrocarbon derived from a main ring chain having 3 to 30 carbon atoms. Obviously, the ring may also have one or more double bonds, but not a fully conjugated system. In some embodiments, the cycloalkyl group has 3 to 8, 3 to 6, or 4 to 6 ring-forming carbon atoms; of course, the cycloalkyl group includes, but is not limited to, cyclopropyl, cyclobutyl, adamantyl, etc.

[0012] As used in this invention, the terms "aryl" and "arylene" include monocyclic, polycyclic, or fused-ring aryl groups, wherein the rings may be interrupted by short non-aromatic units and may contain a spirostructure. Aryl groups include, but are not limited to, phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, anthracene, fluorene, and spirodifluorene, etc., and arylene groups include, but are not limited to, phenylene, biphenylene, terphenylene, naphthylene, phenanthrylene, anthraceneene, fluorene, and spirodifluorene, etc.

[0013] As used herein, the terms "heteroaryl" and "hybridoaryl" include monocyclic, polycyclic, or fused-ring heteroaryl groups, wherein the rings may be interrupted by short non-aromatic units, and the heteroatoms include nitrogen, oxygen, and sulfur. Heteroaryl groups include, but are not limited to, furanyl, phenylthio, pyrroloyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetraazinyl, triazolyl, tetraazolyl, furazolidyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, benzofuranyl, benzothiophene, isobenzofuranyl, dibenzofuranyl, dibenzothiophene, benzimidazolyl, and benzyl. Benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl, benzoxazolyl, isoindolyl, indolyl, indazoleyl, benzothiadiazolyl, quinolinyl, isoquinolinyl, cenolinyl, quinazolinyl, quinoxalinyl, carbazoleyl, phenoxazinyl, phenthiazinyl, phenanthidyl, benzo[m]dioxacyclopentenyl, dihydroacridyl, and their derivatives; heteroaryl groups include, but are not limited to, furanyl, phenylthio, and pyrroleyl. Imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazolyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, benzimidazolyl Azolyl, benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl, benzoxazolyl, isoindolyl, indolyl, ininazole, benzothiadiazolyl, quinolinyl, isoquinolinyl, cenolinyl, quinazolinyl, quinoxolinyl, carbazolyl, phenoxazinyl, phenthiazinyl, phenanthridyl, phenanthridyl, benzo[m]dioxacyclopentenyl, dihydroacridyl, and their derivatives, etc. As used herein, the term "substituted" means that a hydrogen atom in the compound is replaced by another substituent. This position is not limited to a specific position, as long as the hydrogen at that position can be replaced by a substituent. When two or more substituents are present, the two or more substituents can be the same or different.

[0014] As used in this invention, the term "halogen" refers to an atom selected from fluorine, chlorine, bromine, and iodine.

[0015] As used in this invention, unless otherwise stated, a hydrogen atom includes protium, deuterium, and tritium.

[0016] In this invention, the definition of a group specifies a range of carbon atoms, and the number of carbon atoms is any integer within the defined range, such as C6-C30 aryl. The number of carbon atoms representing an aryl group can be any integer within the range of 6-30, such as 6, 8, 10, 13, 15, 17, 20, 22, 25 or 30, etc.

[0017] In this invention, if the group is not specified as substituted or unsubstituted, it means that it has not been substituted.

[0018] In this invention, the term "organic electroluminescent material" refers to a material that can be used in organic electroluminescent devices and may contain at least one compound. If desired, the organic electroluminescent material may be contained in any layer constituting the organic electroluminescent device. For example, the organic electroluminescent material may be a hole injection material, a hole transport material, a hole assist material, a light-emitting assist material, an electron blocking material, a light-emitting material (containing a host material and a dopant material), an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc.

[0019] In this invention, Indicates the location of the connection key.

[0020] The solution adopted in this invention is as follows:

[0021] This invention provides an organic electroluminescent compound having the following structure:

[0022]

[0023] in, Selected from substituted or unsubstituted C6-C30 aromatic rings and substituted or unsubstituted C3-C30 heteroaromatic rings;

[0024] R1 and R2 are each independently selected from hydrogen, deuterium, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 ether, substituted or unsubstituted C2-C30 thioether, substituted or unsubstituted C2-C30 carbonyl, C3-C30 alkylsilyl, C6-C30 arylsilyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl.

[0025] Ar1 and Ar2 are each independently selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 ether, substituted or unsubstituted C2-C30 thioether, substituted or unsubstituted C2-C30 carbonyl, C3-C30 alkylsilyl, C6-C30 arylsilyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl.

[0026] a and b represent the quantities of the corresponding groups; a and b are each independent integers between 0 and 4.

[0027] Understandably, a and b can be independently selected from 0, 1, 2, 3, or 4.

[0028] The substituents in the substituted C6-C30 aromatic ring, substituted C3-C30 heteroaromatic ring, substituted C1-C30 alkyl, substituted C2-C30 alkenyl, substituted C2-C30 ether, substituted C2-C30 thioether, substituted C2-C30 carbonyl, C3-C30 alkylsilyl, C6-C30 arylsilyl, substituted C6-C30 aryl, and substituted C3-C30 heteroaromatic are each independently selected from one or a combination of at least two of the following: deuterium, halogen, cyano, C1-C12 alkyl, C3-C12 cycloalkyl, C6-C30 aryl, C3-C30 heteroaromatic, C6-C60 aromatic amino, and C3-C60 heteroaromatic amino.

[0029] Understandable. In Equation 1 Fusing connections are made at positions a and b, and positions c and d, respectively.

[0030] Preferred, Selected from substituted or unsubstituted C5-C20 aromatic rings and substituted or unsubstituted C3-C20 heteroaromatic rings;

[0031] The substituents in the substituted C5-C20 aromatic ring and the substituted C3-C20 heteroaromatic ring are each independently selected from one or a combination of at least two of the following: deuterium, halogen, cyano, C1-C12 alkyl, C3-C12 cycloalkyl, C6-C30 aryl, C3-C30 heteroaromatic, C6-C60 aromatic amino, and C3-C60 heteroaromatic amino.

[0032] Preferred, The ring B is selected from substituted or unsubstituted rings, wherein ring B is selected from: benzene ring, naphthalene ring, phenanthrene ring, pyridine ring, indole ring, benzofuran ring or benzothiophene ring;

[0033] The substituents in the substituted ring B are selected from one or a combination of at least two of the following: deuterium, halogen, cyano, C1-C12 alkyl, C3-C12 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C60 arylamine, and C3-C60 heteroarylamine.

[0034] Preferably, formula (1) is selected from the following structure:

[0035]

[0036] Preferably, Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6-C20 aryl groups and substituted or unsubstituted C3-C20 heteroaryl groups;

[0037] Wherein, the substituents in the substituted C6-C20 aryl and substituted C3-C20 heteroaryl are selected from one or a combination of at least two of the following: deuterium, halogen, cyano, C1-C12 alkyl, C3-C12 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C60 aromatic amino, and C3-C60 heteroaromatic amino.

[0038] Preferably, Ar1 and Ar2 are each independently selected from substituted or unsubstituted groups E, and group E is selected from phenyl, biphenyl, terphenyl, and triazine.

[0039] Wherein, the substituents in the substituted group E are selected from one or a combination of at least two of the following: deuterium, halogen, cyano, C1-C12 alkyl, C3-C12 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C60 aromatic amino, and C3-C60 heteroaryl.

[0040] Preferably, the substituents in the substituted group E are selected from deuterium and phenyl.

[0041] Optionally, Ar1 and Ar2 can each be independently selected from the following structures:

[0042]

[0043] In Equations A, B, and C, D represents deuterium, n is independent and does not affect each other, and the value of n is selected from 0, 3, 4, or 5 to satisfy either full deuterium or deuterium-free; where full deuterium means that all substituted positions on the benzene ring where (D)n is located are substituted by D, and deuterium-free means that all substituted positions on the benzene ring are not substituted by D.

[0044] Preferably, R1 and R2 are each independently selected from hydrogen, deuterium, substituted or unsubstituted C6-C20 aryl groups;

[0045] The substituents in the substituted C6-C20 aryl groups are selected from one or a combination of at least two of the following: deuterium, halogen, cyano, C1-C12 alkyl, C3-C12 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C60 aromatic amino, and C3-C60 heteroaryl.

[0046] Preferably, R1 and R2 are selected from deuterium;

[0047] Preferably, a is 1 and b is 4;

[0048] Preferably, a is 0 and b is 4.

[0049] Preferably, the structure of the organic electroluminescent compound is selected from any one of the following structures:

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065] This invention also provides a method for synthesizing the above-mentioned organic electroluminescent compound, the synthetic route of which is shown below:

[0066]

[0067] The specific steps are as follows:

[0068] Synthesis of intermediate 2: Intermediate 1 was taken and intermediate 2 was obtained through a substitution reaction;

[0069] Synthesis of intermediate 3: Intermediate 2 is converted into intermediate 3 via the Suzuki reaction;

[0070] Synthesis of intermediate 4: intermediate 3 is reduced to obtain intermediate 4;

[0071] Synthesis of the compound shown in formula (1): Intermediate 4 was used to generate the compound shown in formula (1) by the Buchwald reaction.

[0072] Specifically: The method for synthesizing the above-described organic electroluminescent compound provided by the present invention includes the synthesis method shown in general formula 1 or general formula 2;

[0073] Synthetic general formula (1)

[0074]

[0075] Synthetic general formula (2)

[0076]

[0077] The present invention also provides an organic electroluminescent material comprising the organic electroluminescent compound described above.

[0078] Preferably, the organic electroluminescent material includes a first compound and a second compound, wherein the first compound is the compound shown in formula (1), and Ar1 and Ar2 in formula (1) are not triazine groups; the second compound is the compound shown in formula (1), and one of Ar1 and Ar2 is selected from substituted or unsubstituted triazine groups, wherein the substituents in the substituted triazine groups are selected from deuterium and phenyl.

[0079] Optionally, the first compound and the second compound can be mixed according to a mass percentage. This application does not particularly limit the relative content of the two types of compounds in the organic electroluminescent material, and the selection can be made according to the specific application of the organic electroluminescent device. Typically, based on the total weight of the organic electroluminescent material, the mass percentage content of the first compound can be 1% to 99%, and the mass percentage content of the second compound can be 1% to 99%. For example, the mass ratio (%) of the first compound to the second compound can be 1:99, 20:80, 30:70, 40:60, 45:65, 50:50, 55:45, 60:40, 70:30, 80:20, 99:1, or any value within the above range.

[0080] The present invention also provides an organic electroluminescent device, the organic electroluminescent device comprising a cathode, an anode, and an organic layer between the cathode and the anode, the organic layer comprising the organic electroluminescent compound or the organic electroluminescent material described above.

[0081] Preferably, the organic layer includes a light-emitting layer, which contains an organic electroluminescent compound or an organic electroluminescent material as described above.

[0082] Optionally, the organic layer includes one or more of the following sequentially arranged layers: a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, wherein the light-emitting layer material includes the above-mentioned organic electroluminescent compound or the above-mentioned organic electroluminescent material.

[0083] Optionally, the hole injection layer is a layer that injects holes from the electrode, and the hole injection material is preferably a compound that has the ability to transport holes, has the effect of injecting holes into the anode, and has an excellent hole injection effect on the light-emitting layer or light-emitting material, preventing excitons generated in the light-emitting layer from moving to the electron injection layer or electron injection material, and is excellent in terms of thin film formation ability. Furthermore, it is preferred that the HOMO (highest occupied molecular orbital) of the hole injection material is between that of the work function of the anode material and the HOMO of the surrounding organic material layer. Specific examples of hole injection materials include, but are not limited to, metalloporphyrins, oligothiophenes, arylamine-based organic materials, hexanitrile hexaazabenzophenanthrene-based organic materials, quinacridone-based organic materials, perylene-based organic materials, anthraquinones, polyaniline, and polythiophene-based conductive polymers.

[0084] Optionally, the hole transport layer is a layer that receives holes from the hole injection layer and transports the holes to the light-emitting layer. Suitable hole transport materials are those with high hole mobility that can receive hole injections from the anode or hole injection layer and transfer the holes to the light-emitting layer. Specific examples of hole transport materials include, but are not limited to, arylamine-based organic materials, conductive polymers, and block copolymers containing both conjugated and non-conjugated portions.

[0085] Optionally, an electron blocking layer refers to a layer disposed between the light-emitting auxiliary layer and the light-emitting layer to prevent electrons injected from the cathode from transferring to the light-emitting auxiliary layer and recombinating in the light-emitting layer. It can also be called an electron blocking layer or an electron suppression layer. The electron blocking layer is preferably made of a material with a lower electron affinity than the electron transport layer.

[0086] Optionally, a hole blocking layer is disposed between the electron transport layer and the light-emitting layer to prevent holes injected from the anode from being transferred to the electron transport layer and recombinating in the light-emitting layer. This layer can also be referred to as a hole suppression layer or a hole blocking layer. The hole blocking layer is preferably made of a material with high ionization energy.

[0087] Optionally, the electron transport layer is a layer that receives electrons from the cathode or an electron injection layer formed on the cathode, transports electrons to the light-emitting layer, and suppresses hole transfer from the light-emitting layer. The electron transport material is suitably a material that can effectively receive electron injection from the cathode and transfer electrons to the light-emitting layer, and has a high electron mobility. Specific examples of electron transport materials include, but are not limited to, Al complexes of 8-hydroxyquinoline, complexes containing Alq3, organic radical compounds, hydroxyflavonoid-metal complexes, etc. The electron transport layer can be used with any desired cathode material, as used according to conventional techniques. In particular, suitable examples of cathode materials are typical materials with a small work function, followed by an aluminum or silver layer. Specific examples include cesium, barium, calcium, ytterbium, and samarium, each followed by an aluminum or silver layer.

[0088] Optionally, the electron injection layer is a layer that injects electrons from the electrode, and is preferably a compound that has the ability to transport electrons, the effect of injecting electrons from the cathode, and the effect of excellent electron injection into the light-emitting layer or light-emitting material, prevents excitons generated by the light-emitting layer from migrating to the hole injection layer, and is also excellent in its ability to form a thin film. Specific examples of electron injection layers include fluorenones, anthraquinone dimethane, biphenylquinone, thiamethane dioxide, azoles, diazoles, triazoles, imidazoles, perylenetetracarboxylic acid, fluorenemethane, anthrones, and their derivatives; metal complex compounds; nitrogen-containing 5-membered ring derivatives; and so on, but are not limited thereto.

[0089] The present invention also provides the application of the above-described organic electroluminescent device in optical fiber equipment, lighting equipment, electrophotographic photosensitive equipment, photoelectric converters, organic solar cells, switching element equipment, organic light-emitting field-effect transistors, image sensors, or dye lasers.

[0090] The beneficial effects of this invention are:

[0091] The organic electroluminescent compound provided by this invention, based on the core structure in Formula 1, can exhibit high electron transport or hole transport performance by combining different substituents. The HOMO and LUMO energy levels of the organic electroluminescent compound have a high degree of matching with adjacent energy levels, which makes the carrier mobility of the organic electroluminescent compound more balanced, thereby enabling the organic electroluminescent device containing the organic electroluminescent compound to have a lower driving voltage, higher luminous efficiency and longer lifetime.

[0092] Furthermore, the organic electroluminescent compound provided by the present invention, based on the structure of Formula 1, further defines the substitution positions and amounts of deuterium to improve the stability of the compound. Using it as a light-emitting layer material can enable organic electroluminescent devices of the organic electroluminescent compound to have higher luminous efficiency and longer lifespan. Attached Figure Description

[0093] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0094] Figure 1 This is a structural diagram of the organic electroluminescent device in the device embodiment of the present invention;

[0095] 1-Substrate; 2-Anode; 3-Hole injection layer; 4-Hole transport layer; 5-Electron blocking layer; 6-Light emitting layer; 7-Hole blocking layer; 8-Electron transport layer; 9-Electron injection layer; 10-Cathode. Detailed Implementation

[0096] The following embodiments are provided to better understand the present invention and are not intended to limit the scope of the preferred embodiments. They do not constitute a limitation on the content or scope of protection of the present invention. Any product identical or similar to the present invention derived by any person under the guidance of the present invention or by combining features of the present invention with other prior art falls within the scope of protection of the present invention. For example, the synthesis of those non-illustrative compounds according to this application can be successfully accomplished by those skilled in the art through modification methods, such as appropriately protecting interfering groups, utilizing other known reagents besides those described in this application, or making some conventional modifications to the reaction conditions, all of which fall within the scope of protection of the present invention.

[0097] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0098] The term "organic electroluminescent material" in this disclosure refers to a material that can be used in an organic electroluminescent device and may contain at least one compound. If desired, the organic electroluminescent material may be contained in any layer constituting the organic electroluminescent device. For example, the organic electroluminescent material may be a hole injection material, a hole transport material, a hole assist material, a light-emitting assist material, an electron blocking material, a light-emitting material (containing a host material and a dopant material), an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc.

[0099] The term "multiple organic electroluminescent materials" in this disclosure refers to one or more organic electroluminescent materials comprising a combination of at least two compounds, said materials being contained in any layer constituting an organic electroluminescent device. It can mean both materials contained before (e.g., before vapor deposition) and materials contained after (e.g., after vapor deposition) the organic electroluminescent device. For example, multiple organic electroluminescent materials can be a combination of at least two compounds, said materials being contained in at least one of: a hole injection layer, a hole transport layer, a hole assist layer, a light-emitting assist layer, an electron blocking layer, a light-emitting layer, an electron buffer layer, a hole blocking layer, an electron transport layer, and an electron injection layer. The at least two compounds can be contained in the same layer or different layers, and can be mixed-evaporated or co-evaporated, or can be evaporated individually.

[0100] Example 1

[0101] This embodiment provides an organic electroluminescent compound G-1. The preparation method of organic electroluminescent compound G-1 specifically includes the following steps:

[0102]

[0103] (1) Preparation of intermediate 1-2

[0104] In a dry stainless steel sealed container, a solution of compound 1-1 (20.2 g, 100 mmol), silver carbonate (5.5 g, 20 mmol), triphenylphosphine (15.7 g, 60 mmol), potassium carbonate (13.8 g, 100 mmol), and methyl tert-butyl ether (MTBE, 10 mL) in D2O (100 mL) was added. The container was purged with a stream of nitrogen and sealed with a polytetrafluoroethylene bushing with a fluororubber O-ring. The mixture was then heated and stirred at 120 °C for 24 hours, followed by quenching with a saturated NH4Cl solution. The product was extracted with ethyl acetate (3 × 50 mL), and the combined organic layers were washed with brine and dried over Na2SO4. After removing the solvent by vacuum distillation, the product was purified by column chromatography to give intermediate 1-2, 17.5 g, in 85% yield.

[0105] (2) Preparation of intermediates 1-4

[0106] Under nitrogen protection, compounds 1-2 (17.5 g, 85 mmol), 1-3 (24.4 g, 85 mmol), 200 ml of toluene, 23.5 g (170 mmol) of potassium carbonate, 982 mg (0.85 mmol) of tetraphenylphosphine palladium, and 40 ml of water were added to a 500 ml four-necked flask at room temperature. The mixture was stirred and heated under reflux for 2 hours. After cooling to room temperature, the aqueous phase was separated, and most of the solvent was removed by rotary evaporation. The precipitated solid was filtered and dried to obtain 25.7 g of solid intermediate 1-4 (yield: 82%).

[0107] (3) Preparation of intermediates 1-5

[0108] Add intermediate 1-4 (25.7 g, 70 mmol), triphenylphosphine (73 g), and o-dichlorobenzene (300 ml) to a dry reaction flask, heat to 200 °C and react overnight, cool to room temperature, remove solvent under reduced pressure, and purify by column chromatography to obtain intermediate 1-5, 20.2 g, yield 86%.

[0109] (4) Preparation of compound G-1

[0110] Under nitrogen protection, intermediate 1-5 (20 g, 60 mmol), compound 1-6 (14 g, 60 mmol), 200 ml of toluene, sodium tert-butoxide (11.5 g, 120 mmol), Pd2(dba)3 (500 mg, 0.6 mmol), and Sphos (570 mg, 120 mmol) were added to a 500 ml four-necked flask at room temperature. The mixture was stirred and heated under reflux for 2 hours until the reaction was complete. The mixture was then cooled to room temperature, 100 ml of water was added, and the mixture was stirred and separated. The organic phase was concentrated to dryness and purified by column chromatography to give 20.5 g of the target compound G-1 (yield: 70%).

[0111] Elemental analysis: (C36H20D4N2) Theoretical values: C, 88.49; H, 5.77; N, 5.73; Measured values: C, 88.45; H, 5.80; N, 5.74; m / z (M+): 689.2.

[0112] Example 2-11

[0113] Following the method of Example 1, the intermediates shown in Table 1 were used to replace the intermediates in the corresponding steps to obtain the compounds shown in Examples 2-12. The intermediates used in Examples 2-11 and the obtained products and elemental analyses are shown in Table 1 below.

[0114] Table 1

[0115]

[0116]

[0117]

[0118] Some of the intermediates are synthesized in the following way:

[0119] 1. The synthesis method of intermediates 1-3 used in Example 4 is shown in the following general formula, including the following steps:

[0120]

[0121] (1) Preparation of intermediate 1-3-2

[0122] Intermediate 1-3-1 (24 g, 100 mmol), o-nitrophenylboronic acid (16.7 g, 100 mmol), potassium carbonate (27.8 g, 200 mmol), tetra-triphenylphosphine palladium (1.15 g, 1 mmol), 250 mL toluene, and 90 mL water were added to a dry reaction flask. Under nitrogen protection, the mixture was heated to reflux for 2 h. After the reaction was complete, the mixture was cooled to room temperature, the aqueous phase was separated, and the mixture was concentrated to dryness and purified by column chromatography to obtain intermediate 1-3-2, 17 g, with a yield of 60%.

[0123] (2) Preparation of intermediate 1-3-3

[0124] Intermediate 1-3-2 (17 g, 60 mmol), triphenylphosphine (63 g, 240 mmol), and o-dichlorobenzene (200 ml) were added to a dry reaction flask. Under nitrogen protection, the mixture was stirred and heated to 200 °C for 4 h. After the reaction was complete, the solvent was evaporated and purified by column chromatography to obtain intermediate 1-3-3, 10.5 g, with a yield of 70%.

[0125] (3) Preparation of intermediate 1-3-4

[0126] Intermediate 1-3-3 (10.5 g, 42 mmol), 100 mL of toluene, sodium tert-butoxide (7.9 g, 82 mmol), Pd2(dba)3 (343 mg, 0.42 mmol), and Sphos (400 mg, 0.84 mmol) were added to a dry reaction flask. The mixture was stirred and heated under reflux for 2 hours until the reaction was complete. The mixture was then cooled to room temperature, 100 mL of water was added, and the mixture was stirred and separated. The organic phase was concentrated to dryness and purified by column chromatography to give intermediate 1-3-4, 14.7 g, with a yield of 85%.

[0127] (4) Preparation of intermediates 1-3

[0128] Intermediate 1-3-4 (14.7 g, 35.7 mmol), anhydrous dioxane, pinacol diboronate (11 g, 43 mmol), potassium acetate (7.1 g, 72 mmol), palladium acetate (80 mg, 0.36 mmol), and Xphos (350 mg, 0.72 mmol) were added to a dry reaction flask. The reaction was carried out under nitrogen protection for 6 h. After cooling, the inorganic salts were removed by filtration. The mixture was concentrated to dryness and purified by column chromatography to obtain intermediate 1-3, 14.4 g, with a yield of 80%.

[0129] 2. The synthesis methods of intermediates 1-3 used in Example 5 are as follows:

[0130]

[0131] (1) Preparation of intermediate 1-3-2

[0132] Add 20 g of 1-3-1 (100 mmol) and 200 ml of chloroform to a dry reaction flask, stir until dissolved, add NBS (17.8 g, 100 mmol), stir at room temperature for 6 h, add water after the reaction is complete, wash twice with water, dry with anhydrous sodium sulfate, filter, evaporate the filtrate to dryness, and purify by column chromatography to obtain intermediate 1-3-2, 18.2 g, yield 65%.

[0133] (2) Preparation of intermediate 1-3-3

[0134] Intermediate 1-3-2 (18.2 g, 65 mmol), cuprous iodide (2.5 g, 13 mmol), iodobenzene (13.3 g, 65 mmol), phenanthroline (2.3 g, 13 mmol), and 200 ml of DMF were added to a dry reaction flask. Under nitrogen protection, the mixture was stirred and heated to 100 °C for 4 h until the reaction was complete. Water was added, and the mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, filtered, concentrated, and purified by column chromatography to obtain intermediate 1-3-3, 16.5 g, with a yield of 72%.

[0135] (3) Preparation of intermediate 1-3-4

[0136] Intermediate 1-3-3 (16.5 g, 46 mmol) and anhydrous THF (170 ml) were added to a dry reaction flask. The mixture was cooled to -80 °C, and n-butyllithium solution (20 ml, 2.5 M) was added dropwise. After the addition was complete, the mixture was kept warm and stirred for 30 min. Then, heavy water (1 ml, 50 mmol) was added dropwise, and the mixture was kept warm and stirred for 30 min. The reaction was quenched with water after it was completely removed. The mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, filtered, evaporated to dryness, and purified by column chromatography to obtain intermediate 1-3-4, 11 g, with a yield of 86%.

[0137] (4) Preparation of intermediates 1-3

[0138] Intermediate 1-3-4 (11 g, 40 mmol), anhydrous dioxane, pinacol diboronate (12.2 g, 48 mmol), potassium acetate (7.8 g, 80 mmol), palladium acetate (90 mg, 0.4 mmol), and Xphos (380 mg, 0.8 mmol) were added to a dry reaction flask. The reaction was carried out under nitrogen protection for 5 h. After cooling, the inorganic salts were removed by filtration. The mixture was concentrated to dryness and purified by column chromatography to obtain intermediate 1-3 12.6 g, with a yield of 85%.

[0139] 3. The intermediates 1-3 used in Examples 6-8 were synthesized using the same method as intermediates 1-3 in Example 5, with the intermediates shown in Table 2 used to replace the compounds in the corresponding steps. The yields of the intermediates prepared are shown in Table 2.

[0140] Table 2. Intermediates and yields used in the preparation of intermediates 1-3 in Examples 6-11

[0141]

[0142]

[0143] The intermediates 1-3 used in Example 11 are specifically described below, and the synthetic route and process are shown below:

[0144]

[0145] (1) Preparation of intermediate 1-3-2

[0146] Add 1-3-1 (50 g, 200 mmol) and 500 ml of chloroform to a dry reaction flask, stir until dissolved, add NBS (35.6 g, 200 mmol), stir at -10 °C for 4 h, after the reaction is complete, add water, wash twice with water, dry with anhydrous sodium sulfate, filter, evaporate the filtrate to dryness, and purify by column chromatography to obtain intermediate 1-3-2, 23 g, yield 35%.

[0147] (2) Preparation of intermediate 1-3-3

[0148] Intermediate 1-3-2 (23 g, 70 mmol), cuprous iodide (2.7 g, 14 mmol), iodobenzene (14.6 g, 70 mmol), phenanthroline (2.5 g, 14 mmol), and 250 ml of DMF were added to a dry reaction flask. Under nitrogen protection, the mixture was stirred and heated to 100 °C for 4 h until the reaction was complete. Water was added, and the mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, filtered, concentrated, and purified by column chromatography to obtain intermediate 1-3-3, 21.3 g, with a yield of 75%.

[0149] (3) Preparation of intermediate 1-3-4

[0150] Intermediate 1-3-3 (21.3 g, 53 mmol) and anhydrous THF (200 ml) were added to a dry reaction flask. The mixture was cooled to -80 °C, and n-butyllithium solution (22 ml, 2.5 M) was added dropwise. After the addition was complete, the mixture was kept warm and stirred for 30 min. Then, heavy water (1.2 ml, 60 mmol) was added dropwise, and the mixture was kept warm and stirred for 30 min. The reaction was quenched with water after it was completely removed. The mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, filtered, and purified by column chromatography to obtain intermediate 1-3-4, 14.5 g, with a yield of 83%.

[0151] (4) Preparation of intermediates 1-3

[0152] Intermediate 1-3-4 (14.5 g, 44 mmol), anhydrous dioxane, pinacol diboronate (12.2 g, 48 mmol), potassium acetate (8.6 g, 88 mmol), palladium acetate (99 mg, 0.44 mmol), and Xphos (410 mg, 0.88 mmol) were added to a dry reaction flask. The reaction was carried out under nitrogen protection for 8 h. After cooling, the inorganic salts were removed by filtration. The mixture was concentrated to dryness and purified by column chromatography to obtain intermediate 1-3, 14.8 g, with a yield of 80%.

[0153] Device Example 1

[0154] This embodiment provides an organic electroluminescent device. Some of the materials used in the manufacturing embodiment 1 of the organic electroluminescent device are as follows:

[0155]

[0156] The organic electroluminescent devices in the device embodiments and comparative examples have similar structures (e.g., Figure 1 As shown, the device includes an anode 2, a hole injection layer 3, a hole transport layer 4, an electron blocking layer 5, a light-emitting layer 6, a hole blocking layer 7, an electron transport layer 8, an electron injection layer 9, and a cathode 10, which are sequentially stacked on a substrate 1. The device structure is: anode (indium tin oxide (ITO) coated glass substrate) / hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) / light-emitting layer (EML) / hole blocking layer (HBL) / electron transport layer (ETL) / electron injection layer (EIL) / cathode (Al).

[0157] The fabrication of the organic electroluminescent devices in the device embodiments and comparative examples includes the following steps:

[0158] 1) Substrate cleaning:

[0159] The glass substrate coated with transparent ITO was ultrasonically treated in an aqueous cleaning agent (the composition and concentration of the aqueous cleaning agent: ethylene glycol solvent ≤10wt%, triethanolamine ≤1wt%), then rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone and ethanol (volume ratio of acetone and ethanol 1:1), baked in a clean environment until all moisture was removed, and then cleaned with ultraviolet light and ozone.

[0160] 2) Preparation of organic layer:

[0161] The ITO transparent substrate was transferred to an evaporation equipment and vacuumed to 1×10⁻⁶. -6 Up to 2×10 -4 Pa, hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) / light emitting layer (EML) / hole blocking layer (HBL) / electron transport layer (ETL) / electron injection layer (EIL) / thick cathode (Al) are sequentially deposited on the anode film.

[0162] in:

[0163] The hole injection layer (HIL) is made of HI-1, has a thickness of 10 nm, and a total evaporation rate of 0.1 nm / s.

[0164] The hole transport layer (HTL) is made of HT-1 material, has a thickness of 100 nm, and a total evaporation rate of 0.1 nm / s.

[0165] The electron blocking layer (EBL) is made of EB-1, with a thickness of 30 nm and a total evaporation rate of 0.1 nm / s.

[0166] The light-emitting layer (EML) is vacuum-deposited by co-evaporation. The material of the light-emitting layer includes a host material and a guest material. The guest material is GD-1, and the host material includes compound G-1 and compound G-416. The specific ratio of the host material and the guest material is shown in Table 3 below. The thickness is 30 nm, and the total evaporation rate is 0.1 nm / s.

[0167] The hole blocking layer (HBL) is made of HB-1 with a thickness of 5 nm and a total evaporation rate of 0.1 nm / s.

[0168] The electron transport layer (ETL) is a binary mixture of ET-1 and LiQ in a mass ratio of 1:1, with a thickness of 30 nm and a total evaporation rate of 0.1 nm / s.

[0169] The electron injection layer (EIL) is made of LiF with a thickness of 1 nm and a total evaporation rate of 0.1 nm / s.

[0170] The cathode is made of aluminum with a thickness of 100 nm and a deposition rate of 1 nm / s.

[0171] Device Example 2

[0172] Similar to Device Example 1, the difference is that the host material of the light-emitting layer in Device Example 1 is replaced with a combination of compound G-37 and compound G-416. The specific ratio of the host material to the guest material is shown in Table 3 below.

[0173] Device Example 3

[0174] Similar to Device Example 1, the difference is that the host material of the light-emitting layer in Device Example 1 is replaced with a combination of compound G-207 and compound G-416. The specific ratio of the host material to the guest material is shown in Table 3 below.

[0175] Device Example 4

[0176] Similar to Device Example 1, the difference is that the host material of the light-emitting layer in Device Example 1 is replaced with a combination of compound G-401 and compound G-416. The specific ratio of the host material to the guest material is shown in Table 3 below.

[0177] Device Example 5

[0178] Similar to Device Example 1, the difference is that the host material of the light-emitting layer in Device Example 1 is replaced with a combination of compound G-12 and compound G-416. The specific ratio of the host material to the guest material is shown in Table 3 below.

[0179] Device Example 6

[0180] Similar to Device Example 1, the difference is that the host material of the light-emitting layer in Device Example 1 is replaced with a combination of compound G-114 and compound G-416. The specific ratio of the host material to the guest material is shown in Table 3 below.

[0181] Device Example 7

[0182] Similar to Device Example 1, the difference is that the host material of the light-emitting layer in Device Example 1 is replaced with a combination of compound G-404 and compound G-416. The specific ratio of the host material to the guest material is shown in Table 3 below.

[0183] Device Example 8

[0184] Similar to Device Example 1, the difference is that the host material of the light-emitting layer in Device Example 1 is replaced with a combination of compound G-217 and compound G-416. The specific ratio of the host material and the guest material is shown in Table 3 below.

[0185] Device Example 9

[0186] Similar to Device Example 1, the difference is that the host material of the light-emitting layer in Device Example 1 is replaced with a combination of compound G-66 and compound G-416. The specific ratio of the host material to the guest material is shown in Table 3 below.

[0187] Device Example 10

[0188] Similar to Device Example 1, the difference is that the host material of the light-emitting layer in Device Example 1 is replaced with a combination of compound G-313 and compound G-416. The specific ratio of the host material to the guest material is shown in Table 3 below.

[0189] Device Example 11

[0190] Similar to Device Example 1, the difference is that compound G-1 in the light-emitting layer of Device Example 1 is replaced with compound GH-1 with the following structure:

[0191]

[0192] Device Example 12

[0193] Similar to Device Example 1, the difference is that compound G-1 in the light-emitting layer of Device Example 1 is replaced with compound GH-2 with the following structure:

[0194]

[0195] Device Example 13

[0196] Similar to Device Example 1, the difference is that compound G-1 in the light-emitting layer of Device Example 1 is replaced with compound GH-3 with the following structure:

[0197]

[0198] Device Example 14

[0199] Similar to Device Example 1, the difference is that compound G-1 in the light-emitting layer of Device Example 1 is replaced with compound GH-4 with the following structure:

[0200]

[0201] Device Example 15

[0202] Similar to Device Example 1, the difference is that compound G-1 in the light-emitting layer of Device Example 1 is replaced with compound GH-5 with the following structure:

[0203]

[0204] Device Example 16

[0205] Similar to Device Example 1, the difference is that compound G-1 in the light-emitting layer of Device Example 1 is replaced with compound GH-6 with the following structure:

[0206]

[0207] Device Example 17

[0208] Similar to Device Example 1, the difference is that the compound G-416 in the light-emitting layer of Device Example 1 is replaced with the compound GH-7 with the following structure:

[0209]

[0210] Table 3

[0211] Serial Number EML material / thickness Device Example 1 G-1:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 2 G-37:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 3 G-207:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 4 G-401:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 5 G-12:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 6 G-114:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 7 G-404:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 8 G-217:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 9 G-66:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 10 G-313:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 11 GH-1:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 12 GH-2:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 13 GH-3:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 14 GH-4:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 15 GH-5:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 16 GH-6:G-416:GD-1 (mass ratio 45:45:10) / 30nm Device Example 17 G-1:GH-7:GD-1 (mass ratio 45:45:10) / 30nm

[0212] Device Test Examples

[0213] The organic electroluminescent devices obtained in Device Examples 1-17 of the Device Examples were tested.

[0214] Instruments: The current, voltage, brightness, emission spectrum and other characteristics of the device were tested simultaneously using a PR 650 spectral scanning luminance meter and a Keithley K 2400 digital source meter system;

[0215] Test conditions: Photoelectric property test conditions: current density 10 mA / cm² 2 .

[0216] Lifetime test: current density 10mA / cm 2 The recording time (in hours) is recorded when the device brightness drops to 95% of its original brightness.

[0217] The lifetime T95 of device comparative example 1 is set to 100, and the lifetimes of other devices are relative to the lifetimes of device comparative example 1.

[0218] The device performance test results are shown in Table 4:

[0219] Table 4

[0220]

[0221]

[0222] Based on the data from device examples 1-10 and 11-17, it was found that the current efficiency and lifetime were significantly improved. This is mainly due to the special asymmetric deuteration of the carbazole basic unit, which can further reduce molecular symmetry and increase molecular dipole, effectively improving the stability of molecular structure, thereby significantly improving the photoelectric stability and film-forming properties of the material. The asymmetric deuteration of the molecule makes the molecular vibration non-uniform, which is conducive to the release of energy from the excited state, thereby improving the current efficiency and lifetime of organic light-emitting devices.

[0223] Furthermore, the synthetic route shown in this application does not require the use of the pressure deuteration method in the prior art, such as patent KR1020210045244A and patent CN117683032A, and will not introduce uncontrollable and difficult-to-purify impurities, thereby improving the current efficiency and lifetime of organic light-emitting devices. In Device Examples 1-4, the basic compound unit carbazole was completely deuterated. In Device Examples 5-10, one carbazole in the basic compound unit was completely deuterated, while the other carbazole had only one deuteration. Overall, Device Examples 1-4 had better current efficiency and lifetime than Device Examples 5-10. This is mainly because the deuteration of the other basic compound unit carbazole led to excessive molecular vibration intensity and reduced molecular stability, thus reducing the current efficiency and lifetime of the organic light-emitting device. Under the special asymmetric deuteration conditions of the carbazole basic unit, as the number of deuterated carbazole units increased, such as in Device Examples 11-16, the molecular vibration intensity further increased, further reducing molecular stability and leading to a further reduction in the current efficiency and lifetime of the organic light-emitting device. Device Example 17 also illustrates that deuteration of both main compounds in a dual-substrate light-emitting material is beneficial to improving the current efficiency and lifetime of the organic light-emitting device.

[0224] 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. An organic electroluminescent compound, characterized in that, It has the following structure: in, Selected from substituted or unsubstituted C6-C30 aromatic rings and substituted or unsubstituted C3-C30 heteroaromatic rings; R1 and R2 are each independently selected from hydrogen, deuterium, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 ether, substituted or unsubstituted C2-C30 thioether, substituted or unsubstituted C2-C30 carbonyl, C3-C30 alkylsilyl, C6-C30 arylsilyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl. Ar1 and Ar2 are each independently selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 ether, substituted or unsubstituted C2-C30 thioether, substituted or unsubstituted C2-C30 carbonyl, C3-C30 alkylsilyl, C6-C30 arylsilyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl. a and b represent the quantities of the corresponding groups; a and b are each independent integers between 0 and 4. The substituents in the substituted C6-C30 aromatic ring, substituted C3-C30 heteroaromatic ring, substituted C1-C30 alkyl, substituted C2-C30 alkenyl, substituted C2-C30 ether, substituted C2-C30 thioether, substituted C2-C30 carbonyl, C3-C30 alkylsilyl, C6-C30 arylsilyl, substituted C6-C30 aryl, and substituted C3-C30 heteroaromatic are each independently selected from one or a combination of at least two of the following: deuterium, halogen, cyano, C1-C12 alkyl, C3-C12 cycloalkyl, C6-C30 aryl, C3-C30 heteroaromatic, C6-C60 aromatic amino, and C3-C60 heteroaromatic amino.

2. The organic electroluminescent compound according to claim 1, characterized in that, Selected from substituted or unsubstituted C5-C20 aromatic rings and substituted or unsubstituted C3-C20 heteroaromatic rings; The substituents in the substituted C5-C20 aromatic ring and the substituted C3-C20 heteroaromatic ring are each independently selected from one or a combination of at least two of the following: deuterium, halogen, cyano, C1-C12 alkyl, C3-C12 cycloalkyl, C6-C30 aryl, C3-C30 heteroaromatic, C6-C60 aromatic amino, and C3-C60 heteroaromatic amino. Preferred, The ring B is selected from substituted or unsubstituted rings, wherein ring B is selected from: benzene ring, naphthalene ring, phenanthrene ring, pyridine ring, indole ring, benzofuran ring or benzothiophene ring; The substituents in the substituted ring B are selected from one or a combination of at least two of the following: deuterium, halogen, cyano, C1-C12 alkyl, C3-C12 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C60 arylamine, and C3-C60 heteroarylamine.

3. The organic electroluminescent compound according to claim 1 or 2, characterized in that, Equation (1) is selected from the following structure:

4. The organic electroluminescent compound according to any one of claims 1-3, characterized in that, Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6-C20 aryl groups and substituted or unsubstituted C3-C20 heteroaryl groups; Wherein, the substituents in the substituted C6-C20 aryl and substituted C3-C20 heteroaryl are selected from one or a combination of at least two of the following: deuterium, halogen, cyano, C1-C12 alkyl, C3-C12 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C60 aromatic amino, and C3-C60 heteroaromatic amino. Preferably, Ar1 and Ar2 are each independently selected from substituted or unsubstituted groups E, and group E is selected from phenyl, biphenyl, terphenyl, and triazine. Wherein, the substituents in the substituted group E are selected from one or a combination of at least two of the following: deuterium, halogen, cyano, C1-C12 alkyl, C3-C12 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C60 aromatic amino, and C3-C60 heteroaryl. Preferably, the substituents in the substituted group E are selected from deuterium and phenyl; Preferably, R1 and R2 are each independently selected from hydrogen, deuterium, substituted or unsubstituted C6-C20 aryl groups; The substituents in the substituted C6-C20 aryl groups are selected from one or a combination of at least two of the following: deuterium, halogen, cyano, C1-C12 alkyl, C3-C12 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, C6-C60 aromatic amino, and C3-C60 heteroaryl. Preferably, R1 and R2 are selected from deuterium; Preferably, a is 1 and b is 4; Preferably, a is 0 and b is 4.

5. The organic electroluminescent compound according to any one of claims 1-4, characterized in that, The structure of the organic electroluminescent compound is selected from any of the following structures:

6. A method for synthesizing an organic electroluminescent compound as described in any one of claims 1-5, characterized in that, The synthesis route is shown below: The specific steps are as follows: Synthesis of intermediate 2: Intermediate 1 was taken and intermediate 2 was obtained through a substitution reaction; Synthesis of intermediate 3: Intermediate 2 is converted into intermediate 3 via the Suzuki reaction; Synthesis of intermediate 4: intermediate 3 is reduced to obtain intermediate 4; Synthesis of the compound shown in formula (1): Intermediate 4 was used to generate the compound shown in formula (1) by the Buchwald reaction.

7. An organic electroluminescent material, characterized in that, The organic electroluminescent material comprises the organic electroluminescent compound according to any one of claims 1-6.

8. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes a cathode, an anode, and an organic layer between the cathode and the anode, wherein the organic layer comprises an organic electroluminescent compound as described in any one of claims 1-6 or an organic electroluminescent material as described in claim 7.

9. The organic electroluminescent device according to claim 8, characterized in that, The organic layer includes a light-emitting layer, which comprises an organic electroluminescent compound as described in any one of claims 1-6 or an organic electroluminescent material as described in claim 7.

10. The application of an organic electroluminescent device as described in claim 8 or 9 in fiber optic devices, lighting devices, electrophotographic photosensitive devices, photoelectric converters, organic solar cells, switching element devices, organic light-emitting field-effect transistors, image sensors, or dye lasers.

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