An organic electroluminescent compound and an organic electroluminescent device thereof

Abstract

The application provides an organic electroluminescent compound and an organic electroluminescent device thereof, and relates to the technical field of organic electroluminescent materials.The compound has the advantages of high electron mobility and hole blocking capacity, a suitable HOMO energy level, high glass transition temperature and molecular thermal stability, and is a luminescent material with excellent performance.When the compound is used in an electron transport region, a luminescent layer and a light extraction layer of an organic electroluminescent device, the luminescent efficiency, driving voltage and service life of the device are all improved.

Description

Technical Field

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

[0002] With the development of science and technology, displays have become indispensable tools in people's daily lives, playing a crucial role in the interaction between humans and machines. Simultaneously, with the emergence of new display technologies, the display market is developing at an astonishing pace. Among the newly emerging flat panel display technologies, OLED (Organic Light Emitting Diode) is the most promising new technology. OLED is commonly referred to as Organic Electroluminescence (OEL). Using this component and technology, displays can be made that are thin, flexible, and have low power consumption. Compared to traditional displays, these displays have wider viewing angles, shorter response times, and overcome the image retention issues of traditional displays, making them the future trend of flat panel displays.

[0003] The basic structure of an OLED consists of an electron transport layer (ETL), an emissive layer (EML), a hole transport layer (HTL), and a hole injection layer (HIL) placed between the anode and cathode. The light-emitting principle of an OLED is very similar to that of an LED. Both devices first inject electrons and holes into the two electrodes, respectively, and then, through the carrier transport layer, emit light through carrier recombination in the emissive region. The difference is that in OLEDs, carrier recombination occurs in the emissive layer, while in LEDs it occurs at the pn junction.

[0004] To obtain excellent OLED devices, in addition to a reasonable device structure and strict experimental conditions, high-performance OLED materials are essential. Organic electroluminescent materials are generally divided into organic electroluminescent materials and organic electroluminescent auxiliary materials according to their different functions. Organic electroluminescent materials include electrode materials and luminescent materials, with luminescent materials further divided into host materials and guest materials. Organic electroluminescent auxiliary materials include carrier injection, transport, and light extraction materials, specifically including electron injection materials, hole injection materials, electron transport materials, hole transport materials, hole blocking materials, electron blocking materials, and light extraction materials.

[0005] As research on OLED devices continues to deepen, the types of OLED materials are becoming increasingly diverse. However, the poor performance of most OLED materials currently prevents organic electroluminescent devices from meeting industry requirements. Among these materials, electron transport materials also suffer from poor performance. Therefore, it is essential to research and develop new high-performance electron transport materials. Summary of the Invention

[0006] To address the problems existing in the prior art, the present invention provides a novel type of organic electroluminescent compound that can effectively improve electron mobility and luminous efficiency, thereby improving the performance of organic electroluminescent devices. This organic electroluminescent compound is represented by the following chemical formula (1) or chemical formula (2).

[0007]

[0008] In chemical formula (1) and chemical formula (2),

[0009] The ring A is a substituted or unsubstituted N-heterobenzene ring, and the number of N atoms is 1, 2 or 3;

[0010] X is selected from N or CR1;

[0011] The Y is selected from O, S, CR2R3 or NR4;

[0012] Z is selected from CR5;

[0013] The V is selected from N or CR6;

[0014] R1, R2, R3, R4, R5, and R6 are independently selected from one of the following: hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylthio, substituted or unsubstituted C1-C15 alkyl, substituted or unsubstituted C3-C15 cycloalkyl, substituted or unsubstituted C6-C30 aryl, fused cycloalcoholic group of substituted or unsubstituted C3-C15 alicyclic and C6-C30 aromatic ring, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C3-C15 alicyclic and C2-C30 heteroaryl, or adjacent substituents can combine with each other to form a substituted or unsubstituted cyclic structure.

[0015] Ar1 and Ar2 are independently selected from one of the following: hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted silyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylthio, substituted or unsubstituted C1-C15 alkyl, substituted or unsubstituted C3-C15 cycloalkyl, substituted or unsubstituted C6-C30 aryl, fused cycloalcoholic group of substituted or unsubstituted C3-C15 alicyclic and C6-C30 aromatic ring, substituted or unsubstituted C2-C30 heteroaryl, fused cycloalcoholic group of substituted or unsubstituted C3-C15 alicyclic and C2-C30 heteroaryl, or Ar1 and Ar2 can be combined with each other to form a substituted or unsubstituted cyclic structure.

[0016] The L1, L2, and L3 are independently selected from one of the following: single bond, substituted or unsubstituted C6-C30 arylene, fused cycloalcoholic group of substituted or unsubstituted divalent C3-C15 alicyclic and C2-C30 aromatic ring, substituted or unsubstituted C2-C30 heteroarylene, and fused cycloalcoholic group of substituted or unsubstituted divalent C3-C15 alicyclic and C2-C30 heteroaromatic ring.

[0017] The present invention also provides an organic electroluminescent device, comprising a substrate, an anode, a cathode, and an organic layer, wherein the organic layer contains one of the organic electroluminescent compounds of the present invention.

[0018] Beneficial effects:

[0019] The organic electroluminescent compound of this invention possesses high electron mobility and hole blocking ability, enabling effective electron transport and promoting a balance between electron and hole transport. It effectively confines electrons and holes within the emissive layer for recombination and luminescence, significantly improving the device's luminous efficiency and driving voltage. Furthermore, this organic electroluminescent material exhibits suitable HOMO energy levels, allowing for good matching with adjacent organic layers, reducing energy consumption. It can be used as the host material in the emissive layer to improve the device's luminous efficiency.

[0020] The organic electroluminescent compounds of this invention have high glass transition temperatures and high molecular thermal stability. Therefore, when the compounds of this invention are applied to organic electroluminescent devices, they can maintain the stability of the film layer after the material is formed, thereby improving the service life of the device.

[0021] In addition, when the organic electroluminescent compound of the present invention is applied to the light extraction layer of the device, the total internal reflection of light inside the device can be effectively avoided, thereby improving the light extraction efficiency of the device and thus improving the luminous efficiency of the device. Detailed Implementation

[0022] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope of protection claimed in this application.

[0023] In the compounds of the present invention, any atom not specified as a particular isotope is included as any stable isotope of that atom, and includes atoms at both their natural and non-natural isotopic abundances.

[0024] The halogens described in this invention include fluorine, chlorine, bromine, and iodine.

[0025] In this invention, when the position of the substituent on the ring is not fixed, it means that it can be attached to any of the corresponding optional sites on the ring.

[0026] For example, Can represent Can represent Can represent And so on.

[0027] The “substituted or unsubstituted silyl group” as described in this invention refers to the -Si(R)3 group, wherein each R is the same or different and is selected from the following groups: hydrogen, deuterium, tritium, cyano, halogen, nitro, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 alkenyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C2-C60 heteroaryl, fused cycloalcoholic group of substituted or unsubstituted C3-C30 alicyclic and C6-C60 aromatic rings, and fused cycloalcoholic group of substituted or unsubstituted C3-C30 alicyclic and C2-C60 heteroaryl rings. Preferably, each R, whether identical or different, is selected from the following groups: hydrogen, deuterium, tritium, cyano, halogen, nitro, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15, even more preferably 1 to 10, and most preferably 1 to 8. The cycloalkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15, even more preferably 3 to 10, and most preferably 3 to 7. Preferably, each R, whether identical or different, is selected from the following groups: hydrogen, deuterium, tritium, cyano, halogen, nitro, or substituted or unsubstituted of the following groups: methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, cyclopropyl, cyclobutyl, cyclohexyl, cycloheptyl, adamantyl, norbornyl, camphenyl, phenyl, biphenyl, naphthyl. More preferably, “substituted or unsubstituted silyl” includes, but is not limited to, trimethylsilyl, triethylsilyl, triisopropylsilyl, tri-tert-butylsilyl, tert-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, etc.

[0028] The alkoxy group described in this invention refers to a monovalent group consisting of an alkyl group and an oxygen atom. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15, even more preferably 1 to 10, and most preferably 1 to 6. Specific examples include, but are not limited to, methoxy, ethoxy, and propoxy groups.

[0029] The alkylthio group described in this invention refers to a monovalent group consisting of an alkyl group and a sulfur atom. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15, even more preferably 1 to 10, and most preferably 1 to 6. Specific examples include, but are not limited to, methylthio, ethylthio, and propylthio.

[0030] The alkyl group described in this invention, i.e., a saturated hydrocarbon group, is a hydrocarbon group formed by removing one hydrogen atom from an alkane molecule. The alkyl group is a straight-chain alkyl group or a branched alkyl group, preferably with 1 to 15 carbon atoms, more preferably with 1 to 10 carbon atoms, and even more preferably with 1 to 6 carbon atoms. When the number of carbon atoms is greater than 3, it includes its isomers. Specific examples include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, 2-methylpentyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, heptyl, 2,2-dimethylpentane, 2,3-dimethylpentane, 3-methylhexane, 2,4-dimethylpentane, 2,2,3-trimethylbutane, 2-methylhexane, 3-ethylpentane, octyl, 2-methylheptane, 2,2-dimethylhexane, 2,2,4-trimethylpentane, 2,2,3,3-tetramethylbutane, etc.

[0031] The cycloalkyl group described in this invention refers to a hydrocarbon group formed by removing one hydrogen atom from a cycloalkane molecule. The cycloalkyl group is a monocyclic cycloalkyl group, a polycyclic cycloalkyl group, or a bridged cycloalkyl group, preferably with 3 to 15 carbon atoms, more preferably 3 to 10, and even more preferably 3 to 6. Specific examples include, but are not limited to: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, norbornel, camphenyl, fentanyl, isocamphenyl, etc.

[0032] The aryl group referred to in this invention refers to the general term for a monovalent group remaining after removing one hydrogen atom from the aromatic carbon atom of an aromatic hydrocarbon molecule. The aryl group is a monocyclic aryl, polycyclic aryl, fused-ring aryl, or a combination thereof, preferably with 6 to 30 carbon atoms, more preferably 6 to 25, more preferably 6 to 20, and most preferably 6 to 12. Specific examples include, but are not limited to: phenyl, biphenyl, terphenyl, tetraphenyl, naphthyl, phenanthryl, anthracene, phenylenetriene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, spirodifluorenyl, benzospirodifluorenyl, pyrene, fluoranyl, etc. Base, famaryl, etc.

[0033] The fused alicyclic and aromatic ring groups described in this invention refer to the general term for monovalent groups formed by fusion of an alicyclic and an aromatic ring and the removal of one hydrogen atom. The alicyclic ring preferably has 3 to 15 carbon atoms, more preferably 3 to 10, and even more preferably 3 to 6. The aromatic ring preferably has 6 to 30 carbon atoms, more preferably 6 to 25, even more preferably 6 to 20, and most preferably 6 to 12. Specific examples include, but are not limited to: benzocyclopropane, benzocyclobutane, dihydroindenyl, tetrahydronaphthyl, benzocycloheptyl, benzocyclobutenyl, indenyl, dihydronaphthyl, benzocycloheptenyl, etc.

[0034] The heteroaryl group described in this invention refers to a monovalent group in which at least one carbon atom of an aryl group is replaced by a heteroatom. The heteroatom includes, but is not limited to, O, S, N, Si, B, P, etc. The heteroaryl group is a monocyclic heteroaryl, a polycyclic heteroaryl, a fused-ring heteroaryl, or a combination thereof, and the number of carbon atoms is preferably 2 to 30, more preferably 2 to 25, more preferably 2 to 20, and most preferably 2 to 12. Specific examples include, but are not limited to: pyrrole, pyrazolyl, imidazolyl, triazolyl, pyridyl, pyrazinyl, pyridazinyl, triazinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, naphthidyl, pteridyl, phenanthrolinel, benzo[a]quinolinyl, benzo[a]isoquinolinyl, indole, isoindole, benzo[a]indole, naphtho[a]indole, phenanthro[a]indole, anthraquinone, tri-benzimidoyl, benzimidazolyl, naphtho[a]imidazolyl, phenanthro[a]imidazolyl, anthraquinone, tri-benzimidazolyl, pyridinyl Azolyl, pyrimidinimidazole, triazinimidazole, quinolineimidazole, isoquinolineimidazole, quinoxalolineimidazole, quinoxalolineimidazole, furanyl, benzofuranyl, naphthofuranyl, phenanthrofuranyl, anthraquinofuranyl, tri-benzofuranyl, dibenzofuranyl, thiophene, benzothiophene, naphthothiophene, phenanthiophene, anthraquinothiophene, tri-benzothiophene, dibenzothiophene, oxazolyl, benzooxazolyl, naphthooxazolyl, thiazolyl, benzothiazolyl, naphthothiazolyl, carbazole, etc.

[0035] The fused cyclic group of alicyclic and heteroaromatic rings described in this invention refers to the general term for a monovalent group remaining after alicyclic and heteroaromatic rings are fused together and one hydrogen atom is removed. The alicyclic ring preferably has 3 to 15 carbon atoms, more preferably 3 to 10, and even more preferably 3 to 6. The heteroaromatic ring preferably has 2 to 30 carbon atoms, more preferably 2 to 25, even more preferably 2 to 20, and most preferably 2 to 12. Specific examples include, but are not limited to: pyridocyclobutane, pyridocyclopentane, pyridocyclohexane, pyridocyclopentenyl, pyridocyclohexenyl, pyrimidinocyclopentane, and pyrimidinocyclohexane, etc.

[0036] The term "arylene" as used in this invention refers to the general term for divalent groups remaining after removing one hydrogen atom from an aryl molecule, and the above description of aryl groups can be applied to it.

[0037] The divalent alicyclic and aromatic fused cyclic group described in this invention refers to the general term for the group remaining after removing one hydrogen atom from the fused cyclic group molecule of alicyclic and aromatic rings. The above description of fused cyclic groups of alicyclic and aromatic rings can be applied to it.

[0038] The term "hybrid aryl" as used in this invention refers to the general term for a divalent group remaining after removing one hydrogen atom from a heteroaryl molecule. The above description of heteroaryl groups can be applied to this.

[0039] The fused cyclic group of alicyclic and heterocyclic rings described in this invention refers to the general term for the group remaining after removing one hydrogen atom from the fused cyclic group molecule of alicyclic and heterocyclic rings. The above description of fused cyclic groups of alicyclic and heterocyclic rings can be applied to it.

[0040] In the context of this invention, "unsubstituted" in "substituted or unsubstituted" means that the hydrogen atom on the group is not replaced by a substituent.

[0041] In this invention, "substituted or unsubstituted" means that at least one hydrogen atom on a group is replaced by a substituent, and the position of substitution is not limited, as long as the position is where a hydrogen atom is substituted. Furthermore, when two or more substituents are substituted, the two or more substituents can be the same as or different from each other. The substituents include, but are not limited to: hydrogen, deuterium, halogen, cyano, nitro, silyl, alkoxy, alkylthio, alkyl, cycloalkyl, aryl, fused alicyclic and aromatic rings, heteroaryl, fused alicyclic and heteroaromatic rings, etc. The preferred substituents are: hydrogen, deuterium, halogen, cyano, nitro, methylsilyl, dimethylsilyl, trimethylsilyl, ethylsilyl, diethylsilyl, triethylsilyl, triethylsilyl, tripropylsilyl, triisopropylsilyl, tributylsilyl, tritert-butylsilyl, triphenylsilyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, pentyl, isopentyl, neopentyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, norbornel, camphenyl, isopentyl, fronyl, benzocyclopropane, benzocyclobutane, dihydroindyl, tetrahydronaphthyl, benzocyclobutenyl, indyl, dihydronaphthyl, phenyl, biphenyl, terphenyl, naphthyl, phenanthrene, triphenylene, anthracene, pyrene. Substituents include fluorenyl, spirodifluorenyl, pyridyl, pyrazinyl, pyridazinyl, triazinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxolinyl, phenanthrolineyl, oxazolyl, benzoxazolyl, thiazolyl, benzothiazolyl, imidazolyl, benzoimidazolyl, benzofuranyl, dibenzofuranyl, benzothiopheneyl, dibenzothiopheneyl, indoleyl, carbazoleyl, etc. Furthermore, each of the above substituents can be substituted or unsubstituted, and two adjacent substituents can be linked together to form a substituted or unsubstituted ring.

[0042] In this invention, "two adjacent groups connecting to form a substituted or unsubstituted ring" means that two adjacent groups are connected to each other by chemical bonds and optionally aromatized to form a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle. The hydrocarbon ring can be an aliphatic hydrocarbon ring or an aromatic hydrocarbon ring. The heterocycle can include an aliphatic heterocycle or an aromatic heterocycle. The aliphatic hydrocarbon ring can be a saturated aliphatic hydrocarbon ring or an unsaturated aliphatic hydrocarbon ring, and the aliphatic heterocycle can be a saturated aliphatic heterocycle or an unsaturated aliphatic heterocycle. The hydrocarbon ring and heterocycle can be monocyclic or polycyclic groups. Furthermore, the ring formed by the combination of adjacent groups can be connected to another ring to form a spirostructure. An example is shown below:

[0043]

[0044] In this invention, the ring formed by the connection can be an aromatic ring system, an aliphatic ring system, or a ring system formed by the fusion of the two. The ring formed by the connection can be a three-membered ring, a four-membered ring, a five-membered ring, a six-membered ring, a seven-membered ring, a fused ring, etc. Specific examples include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclopentene, cyclohexene, benzene, naphthalene, phenanthrene, triphenylene, pyridine, pyrimidine, quinoline, fluorene, furan, thiophene, carbazole, etc., but are not limited thereto.

[0045] This invention provides an organic electroluminescent compound represented by chemical formula (1) or chemical formula (2):

[0046]

[0047] In chemical formula (1) and chemical formula (2),

[0048] The ring A is a substituted or unsubstituted N-heterobenzene ring, and the number of N atoms is 1, 2 or 3;

[0049] X is selected from N or CR1;

[0050] The Y is selected from O, S, CR2R3 or NR4;

[0051] Z is selected from CR5;

[0052] The V is selected from N or CR6;

[0053] R1, R2, R3, R4, R5, and R6 are independently selected from one of the following: hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylthio, substituted or unsubstituted C1-C15 alkyl, substituted or unsubstituted C3-C15 cycloalkyl, substituted or unsubstituted C6-C30 aryl, fused cycloalcoholic group of substituted or unsubstituted C3-C15 alicyclic and C6-C30 aromatic ring, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C3-C15 alicyclic and C2-C30 heteroaryl, or adjacent substituents can combine with each other to form a substituted or unsubstituted cyclic structure.

[0054] Ar1 and Ar2 are independently selected from one of the following: hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted silyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylthio, substituted or unsubstituted C1-C15 alkyl, substituted or unsubstituted C3-C15 cycloalkyl, substituted or unsubstituted C6-C30 aryl, fused cycloalcoholic group of substituted or unsubstituted C3-C15 alicyclic and C6-C30 aromatic ring, substituted or unsubstituted C2-C30 heteroaryl, fused cycloalcoholic group of substituted or unsubstituted C3-C15 alicyclic and C2-C30 heteroaryl, or Ar1 and Ar2 can be combined with each other to form a substituted or unsubstituted cyclic structure.

[0055] The L1, L2, and L3 are independently selected from one of the following: single bond, substituted or unsubstituted C6-C30 arylene, fused cycloalcoholic group of substituted or unsubstituted divalent C3-C15 alicyclic and C2-C30 aromatic ring, substituted or unsubstituted C2-C30 heteroarylene, and fused cycloalcoholic group of substituted or unsubstituted divalent C3-C15 alicyclic and C2-C30 heteroaromatic ring.

[0056] Preferably, ring A is selected from one of the following groups:

[0057]

[0058] The R7 is independently selected from one of the following: hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted silyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylthio, substituted or unsubstituted C1-C15 alkyl, substituted or unsubstituted C3-C15 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C15 alicyclic and C6-C30 aromatic ring fused cycloyl, substituted or unsubstituted C2-C30 heteroaryl, substituted or unsubstituted C3-C15 alicyclic and C2-C30 heteroaryl;

[0059] a1 is selected from 0, 1 or 2; a2 is selected from 0 or 1.

[0060] Preferably, R7 is independently selected from hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted groups as follows: methyl, trifluoromethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, norbornel, phenyl, biphenyl, naphthyl, pyridyl.

[0061] Preferably, ring A is selected from one of the following groups:

[0062]

[0063] Preferably, Ar1 and Ar2 can combine with each other to form one of the following substituted or unsubstituted ring structures:

[0064]

[0065] The substituents are independently selected from deuterium, halogen, cyano, nitro, substituted or unsubstituted groups as shown below: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, norbornel, phenyl, biphenyl, naphthyl, pyridyl, or two adjacent substituents may be linked together to form a substituted or unsubstituted ring.

[0066] Preferably, the Choose from one of the structures shown below.

[0067]

[0068]

[0069] The above structure can be further substituted or unsubstituted by one or more substituents selected from deuterium, cyano, halogen, methyl, deuterated methyl, trifluoromethyl, ethyl, isopropyl, deuterated isopropyl, tert-butyl, deuterated tert-butyl, cyclopropyl, cyclobutyl, cyclohexyl, adamantyl, norbornel, phenyl, deuterated phenyl, biphenyl, deuterated biphenyl, naphthyl, deuterated naphthyl, pyridyl, pyrimidinyl, quinolinyl, and isoquinolinyl. In the case of substitution by multiple substituents, the multiple substituents may be the same as or different from each other.

[0070] Preferably, the Choose one of the following structures,

[0071]

[0072] The R8 is independently selected from hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted groups as shown below: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, norbornel, phenyl, biphenyl, naphthyl, phenanthrene, pyridine, pyrimidinyl, quinolinyl, isoquinolinyl, quinoxalinyl, quinazolinyl, or two adjacent R8s can be linked together to form a substituted or unsubstituted ring;

[0073] b1 is selected from 0, 1, 2, 3, 4 or 5; b2 is selected from 0, 1, 2, 3 or 4; b3 is selected from 0, 1, 2 or 3; b4 is selected from 0, 1 or 2; b5 is selected from 0 or 1.

[0074] Preferably, the Choose one of the following structures,

[0075]

[0076]

[0077] The above structure can be further substituted or unsubstituted by one or more substituents selected from deuterium, cyano, halogen, methyl, deuterated methyl, trifluoromethyl, ethyl, isopropyl, deuterated isopropyl, tert-butyl, deuterated tert-butyl, cyclopropyl, cyclobutyl, cyclohexyl, adamantyl, norbornel, phenyl, deuterated phenyl, biphenyl, deuterated biphenyl, naphthyl, deuterated naphthyl, pyridyl, pyrimidinyl, quinolinyl, and isoquinolinyl. In the case of substitution by multiple substituents, the multiple substituents may be the same as or different from each other.

[0078] Preferably, L, L1, and L2 are independently selected from one of the following groups: single-bonded, substituted, or unsubstituted.

[0079]

[0080]

[0081] The substituents are independently selected from deuterium, halogen, cyano, nitro, substituted or unsubstituted groups as shown below: methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, norbornel, phenyl, biphenyl, naphthyl, pyridyl, or two adjacent substituents may be linked together to form a substituted or unsubstituted ring.

[0082] Most preferably, the chemical formula (1) or chemical formula (2) is selected from one of the structures shown below.

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106] The above lists some specific chemical structures of the organic electroluminescent compounds described in chemical formulas (1) and (2) of this invention. However, this invention is not limited to these listed chemical structures. Any structure based on the structure shown in chemical formulas (1) and (2) with substituents as defined above should be included.

[0107] This invention also provides an organic electroluminescent device, comprising a substrate, an anode, a cathode, and an organic layer, wherein the organic layer contains the organic electroluminescent compound described in this invention.

[0108] Preferably, the organic layer includes at least one of the light-emitting layer between the anode and the cathode and the electron transport region, wherein the light-emitting layer and the at least one of the electron transport region contain the organic electroluminescent compound of the present invention.

[0109] Preferably, the organic layer includes an electron transport region containing the organic electroluminescent compound of the present invention.

[0110] Preferably, the electron transport region includes at least one of an electron transport layer and a hole blocking layer, wherein the at least one of the electron transport layer and the hole blocking layer contains the organic electroluminescent compound described in this invention.

[0111] Preferably, the organic layer includes a light-emitting layer containing the organic electroluminescent compound of the present invention.

[0112] Preferably, the light-emitting layer contains a host material and a dopant material, wherein the host material contains the organic electroluminescent compound described in this invention.

[0113] Preferably, the organic layer includes a light extraction layer on the side of the cathode opposite to the anode, and the light extraction layer contains the organic electroluminescent compound of the present invention.

[0114] The organic layer in the organic electroluminescent device of the present invention may include one or more of the following functional layers: hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole blocking layer, electron transport layer, electron injection layer, light extraction layer, etc. Each functional layer may be composed of a single thin film or multiple thin films, and each thin film may contain one material or multiple materials.

[0115] The materials in each organic layer of the organic electroluminescent device mentioned above, as well as the electrode materials on both sides of the device, will be described below:

[0116] The substrate, as the connection point between external circuits and devices, is a crucial factor in whether charge can be injected smoothly, light can be transmitted smoothly, and whether the device can become a flexible device. Substrate materials can include silicon wafers, quartz, glass plates, metal plates, plastic films or sheets, but are not limited to these.

[0117] Anode materials should possess characteristics such as high conductivity, high transmittance, and high work function. Indium tin oxide (ITO) not only has a high work function (4.5eV~5.3eV), but also has relatively stable performance and good transmittance, making it the best choice for anode materials and still in use today. In addition, anode materials can also include indium zinc oxide (IZO), aluminum (Al), titanium (Ti), gold (Au), platinum (Pt), copper (Cu), silver (Ag), and indium tin oxide / silver / indium tin oxide (ITO / Ag / ITO), but are not limited to these.

[0118] Hole injection materials are typically used to reduce the interfacial barrier between organic materials, change their interfacial properties, and make it easier to inject holes, thus introducing a class of electrode materials. Hole injection materials can include, but are not limited to, N,N'-bis[4-di(m-tolyl)aminophenyl]-N,N'-diphenylbenzidine (DNTPD), 4,4',4"-tris(N-(1-naphthyl)-N-phenylamino)triphenylamine (1-TNATA), 4,4',4"-tris(N,N-2-naphthylphenylamino)triphenylamine (2-TNATA), molybdenum trioxide (MoO3), vanadium pentoxide (V2O5), copper phthalocyanine (CuPC), titanium phthalocyanine (TiOPC), 1,4,5,8,9,11-hexaazabenzonitrile (HAT-CN), 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone (F4-TCNQ), poly(4-vinyltriphenylamine) (PVTPA), etc.

[0119] Hole transport materials possess high hole mobility. These compounds not only require high thermal stability but also readily form amorphous thin films. Hole transport materials that can be made include N,N'-diphenyl-N,N'-di(2-naphthyl)-1,1'-biphenyl-4,4'-diamine (β-NPB), N,N,N',N'-tetra-1-naphthyl[1,1'-biphenyl]-4,4'-diamine (α-TNB), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB), and N,N'... The following are examples of amino acids and compounds, but not limited to: bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] (TAPC), 1,3,5-tris(9-carbazolyl)benzene (TCB), 4,4',4”-tris(carbazol-9-yl)triphenylamine (TCTA), polyvinylcarbazole (PVC), etc.

[0120] An electron blocking layer is positioned between the hole transport layer and the light-emitting layer. As an electron blocking material, it needs to possess both good hole transport capability and electron blocking capability to effectively transport holes and restrict electrons. Hole transport materials can include N,N-bis([1,1'-biphenyl]-4-yl)-(9H-carbazole-9-yl)-[1,1'-biphenyl]-4-amine, N-(4'-(9H-carbazole-9-yl)-[1,1'-biphenyl]-4-N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-9H-fluorene-2-amine, N,N'-bis(naphthyl-1-yl)-N,N'-diphenyl-benzidine (NPD), etc., but are not limited to these.

[0121] Luminescent materials should possess good carrier transport properties and semiconductor characteristics, as well as good thermal stability and film-forming properties. Luminescent materials consist of host materials and guest materials. The luminescent host material can be 9,9'-diphenyl-9H,9'H-3,3'-bicarbazole, 9,9'-biphenyl-9H,9'H-3,3'-bicarbazole-6-onitrile (BCzSCN), 9-(5-(3-(9H-carbazole-9-yl)phenyl)pyridin-3-yl)-9H-carbazole (CPPyC), 4,4'-bis(carbazole-9-yl)-2,2'-dimethylbiphenyl (CDBP), 1,3-bis(N-carbazole)benzene (MCP), 9,9-dimethyl-N,N-diphenyl-7-(4-(1-phenyl-1Hbenzimidazol-2-yl)phenyl)-9H-fluorene-2-amine (EFIN), or 10-(4'-(diphenylamino)biphenyl-4-yl)acridin-9(10H). ☐-ketone (ADBP), tris[4-(pyrene)-phenyl]amine (TPyPA), 9,10-di(2-naphthyl)anthracene (ADN), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (TBADN), 1-(7-[9,9'-bianthra]-10-yl-9,9-dioctyl-9H-fluorene-2-yl)pyrene (BAnF8Pye), 9,9,9',9'-tetratetra(4-methylphenyl)-2,2'-bi-9H-fluorene (BDAF), tris(6-fluoro-8-hydroxyquinoline)aluminum (6FAlq3), tris(8-hydroxyquinoline)aluminum (Alq3), bis(10-hydroxybenzo[H]quinoline)beryllium (BeBq2), bis(8-hydroxyquinoline)zinc (Znq2), etc., but not limited to these;Luminescent guest materials can be bis(2-(2-hydroxyphenyl)-pyridine)beryllium (Bepp2), bis(3,4,5-trifluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium (Ir(tfpd)2pic), bis(2-(naphth-2-yl)pyridine)(acetylacetone)iridium (Ir(npy)2acac), tris[2-phenyl-4-methylquinoline)]iridium (Ir(Mphq)3), bis(2-phenylpyridine)iridium acetylacetone (Ir(ppy)2(acac)), tris[2-(3-methyl-2-pyridyl)phenyl]iridium (Ir(3mppy)3), bis(2-benzoquinoline-C2,N')(acetylacetone)iridium (Ir(bzq)2(acac)), tris(2-(3,5-dimethylphenyl)quinoline- C2,N') iridium (Ir(dmpq)3), bis(1-phenyl-isoquinoline)(acetylacetone) iridium (Ir(piq)2(acac)), tris[5-hexyl-2-(1-isoquinoline)phenyl]iridium (Hex-Ir(piq)3), octaethylporphyrin platinum (PtOEP), 2,5,8,11-tetratert-butylperylene (TBPe), rubrene, 9-(9-phenylcarbazole-3-yl)-10-(naphthyl-1-yl) (PCAN), 1,4-bis(4-(9H-carbazole-9-yl)styryl)benzene (BCzSB), 1,1'-(4,4'-(4-phenyl-4H-1,2,4-triazol-3,5-diyl)bis(4,1-phenylene))bis(1H-phenoxazine) (2PXZ-TAZ), etc., but not limited to these.

[0122] Hole-blocking materials possess low HOMO energy levels, wide band gaps, and high oxidation potentials. Furthermore, for better applications, they must exhibit good stability, film-forming properties, and mobility. Suitable hole-blocking materials include, but are not limited to, 1,3,5-tris(N-phenyl-2-benzimidazole)benzene (TPBi), 4,7-diphenyl-1,10-phenanthroline (Bphen), di(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP).

[0123] Electron transport materials should possess high electron mobility to facilitate electron transport and good thermodynamic stability to prevent crystallization during device fabrication, thereby improving device efficiency and lifespan. Suitable electron transport materials include 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBphen), 1,3,5-tris(4-pyridin-3-ylphenyl)benzene (TpPyPB), 3-(biphenyl-4-yl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (TAZ), aluminum 8-hydroxyquinoline (Alq3), aluminum tri(4-methyl-8-hydroxyquinoline) (Al(4-Mq)3), beryllium bis(10-hydroxybenzoquinoline) (Bepq2), beryllium bis(10-hydroxybenzoquinoline) (BeBq2), and zinc bis(8-hydroxyquinoline) (II) (Znq), but are not limited to these.

[0124] Electron-injected materials possess the ability to transport electrons, exhibit an electron-injected effect from the cathode, and demonstrate excellent thin-film formation capabilities. Electron-injected materials can include, but are not limited to, lithium (Li), lithium fluoride (LiF), sodium fluoride (NaF), lithium 8-hydroxyquinoline (Liq), cesium carbonate (Cs₂CO₃), rubidium acetate (CH₃COORb), and lithium oxide (Li₂O).

[0125] The cathode of this invention needs to have a low work function to improve electron injection efficiency. Cathode materials can include aluminum (Al), silver (Ag), calcium (Ca), indium (In), magnesium:silver (Mg:Ag), etc., but are not limited to these.

[0126] The light extraction material should have a high refractive index to couple out light trapped within the device. Suitable light extraction materials include, but are not limited to, tris(8-hydroxyquinoline)aluminum(III) (Alq3), N,N'-di(naphthyl-1-yl)-N,N'-di(phenyl)-2,2'-dimethylbenzidine (α-NPD), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB), and 4,4'-di(9-carbazole)biphenyl (CBP).

[0127] The present invention does not impose any special restrictions on the thickness of each organic layer of the organic electroluminescent device; thicknesses commonly used in the field can be adopted.

[0128] The organic electroluminescent device of the present invention can be made using any one of the following methods: vacuum evaporation, spin coating, vapor deposition, blade coating, laser thermal transfer, electrospray coating, slot coating, and dip coating. In the present invention, vacuum evaporation is preferred.

[0129] The organic electroluminescent device described in this invention can be widely used in panel displays, lighting sources, flexible OLEDs, electronic paper, organic solar cells, organic photosensitive materials or organic thin-film transistors, signs, signal lights and other fields.

[0130] The invention is explained in more detail through the following examples, but is not intended to limit the invention. Based on this description, those skilled in the art will be able to practice the invention and prepare other compounds and devices according to the invention within the entire scope disclosed without inventive effort.

[0131] Synthesis Examples

[0132] There are no particular limitations on the preparation methods of the organic electroluminescent compounds shown in chemical formulas (1) and (2) of this invention, and conventional methods well known to those skilled in the art can be used. For example, carbon-carbon coupling reactions, etc. The following lists the synthetic route of the organic electroluminescent compound shown in chemical formula (1) of this invention, but this invention is not limited by this route, and the organic electroluminescent compound shown in chemical formula (2) can also be prepared by referring to this method.

[0133] ①. When and When they are the same:

[0134]

[0135] ②. When and Not at the same time:

[0136]

[0137] The Xn is independently selected from F, Cl, Br or I.

[0138] Similarly, compounds of chemical formula (2) can be synthesized using a similar method.

[0139] Raw materials and reagents: All raw materials and reagents used in this invention are of reagent purity. This invention does not impose any particular limitations on the raw materials or reagents used in the following synthesis examples; they can be commercially available products or prepared using methods well-known to those skilled in the art.

[0140] Instruments: (1) G2-Si quadrupole tandem time-of-flight high-resolution mass spectrometer (Waters Corporation, UK); (2) Vario EL cube organic elemental analyzer (Elementar Corporation, Germany); (3) Bruker-510 nuclear magnetic resonance spectrometer (Bruker Corporation, Germany).

[0141] Synthesis Example 1: Preparation of Compound 27

[0142]

[0143] Preparation of intermediate A-27:

[0144] Under nitrogen protection, a-27 (41.00 g, 150.00 mmol), B2Pin2 (76.94 g, 303.00 mmol), KOAc (49.00 g, 500.00 mmol), Pd(dppf)Cl2 (2.20 g, 3.00 mmol), and THF (1000 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 7 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled water was added, and the mixture was filtered to obtain a filter cake. The cake was then dried in a vacuum oven and purified by silica gel column chromatography (n-hexane:ethyl acetate = 1:1) to obtain intermediate A-27 (44.09 g, yield 80%); HPLC purity ≥98.75%.

[0145] Preparation of intermediate B-27:

[0146] Under nitrogen protection, A-27 (41.52 g, 113.00 mmol), b-27 (54.36 g, 220.00 mmol), Na₂CO₃ (42.40 g, 400.00 mmol), Pd(PPh₃)₄ (2.54 g, 2.20 mmol), and 1,4-dioxane (700 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 7 hours. After the reaction was completed, the mixture was cooled to room temperature, extracted with dichloromethane, dried over anhydrous MgSO₄, and the solvent was removed under reduced pressure. The mixture was recrystallized from toluene / petroleum ether at a ratio of 4:1 to give intermediate B-27 (37.44 g, yield 76%); HPLC purity ≥99.66%.

[0147] Preparation of intermediate C-27:

[0148] Under nitrogen protection, B-27 (35.83 g, 80.00 mmol), B2Pin2 (21.08 g, 83.00 mmol), Na2CO3 (16.96 g, 160.00 mmol), Pd(dppf)Cl2 (0.73 g, 1.00 mmol), and THF (400 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 6 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled water was added, and the mixture was filtered to obtain a filter cake. The cake was recrystallized from toluene / n-hexane at a ratio of 5:1 to give intermediate C-27 (33.23 g, yield 77%); HPLC purity ≥99.89%.

[0149] Preparation of compound 27:

[0150] Under nitrogen protection, C-27 (17.26 g, 32.00 mmol), c-27 (8.20 g, 30.00 mmol), Na₂CO₃ (6.36 g, 60.00 mmol), Pd(OAc)₂ (0.08 g, 0.35 mmol), P(t-Bu)₃ (0.08 g, 0.40 mmol), and THF (120 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 8 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled water was added, and the mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous MgSO₄, the solvent was removed under reduced pressure, and the mixture was recrystallized from toluene to give compound 27 (13.45 g, yield 74%). The purity of the solid was ≥99.95% as determined by HPLC. Mass spectrometry m / z: 605.2115 (theoretical value: 605.2103). Theoretical elemental content (%) C 42 H 27 N3O2: C, 83.29; H, 4.49; N, 6.94. Measured elemental content (%): C, 83.26; H, 4.47; N, 6.96.

[0151] Synthesis Example 2: Preparation of Compound 29

[0152]

[0153] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-29 and c-29, respectively, to obtain compound 29 (13.09 g). HPLC analysis showed a solid purity ≥99.96%. Mass spectrometry m / z: 581.2112 (theoretical value: 581.2103). Theoretical elemental content (%) C 40 H 27 N3O2: C, 82.60; H, 4.68; N, 7.22. Measured elemental content (%): C, 82.63; H, 4.65; N, 7.24.

[0154] Synthesis Example 3: Preparation of Compound 37

[0155]

[0156] Following the preparation method of Synthesis Example 1, a-27, b-27, and c-27 were replaced with equimolar amounts of a-37, b-29, and c-29, respectively, to obtain compound 37 (12.78 g). HPLC analysis showed a solid purity ≥99.93%. Mass spectrometry m / z: 583.2020 (theoretical value: 583.2008). Theoretical elemental content (%) C 38 H 25N5O2: C, 78.20; H, 4.32; N, 12.00. Measured elemental content (%): C, 78.23; H, 4.30; N, 12.05.

[0157] Synthesis Example 4: Preparation of Compound 38

[0158]

[0159] Preparation of intermediate A-27:

[0160] Under nitrogen protection, a-27 (41.00 g, 150.00 mmol), B2Pin2 (76.94 g, 303.00 mmol), KOAc (49.00 g, 500.00 mmol), Pd(dppf)Cl2 (2.20 g, 3.00 mmol), and THF (1000 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 7 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled water was added, and the mixture was filtered to obtain a filter cake. The cake was then dried in a vacuum oven and purified by silica gel column chromatography (n-hexane:ethyl acetate = 1:1) to obtain intermediate A-27 (44.09 g, yield 80%); HPLC purity ≥98.75%.

[0161] Preparation of intermediate B-38:

[0162] Under nitrogen protection, A-27 (41.52 g, 113.00 mmol), b-38 (61.52 g, 220.00 mmol), Na₂CO₃ (42.40 g, 400.00 mmol), Pd(PPh₃)₄ (2.54 g, 2.20 mmol), and 1,4-dioxane (700 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 7 hours. After the reaction was completed, the mixture was cooled to room temperature, extracted with dichloromethane, dried over anhydrous MgSO₄, and the solvent was removed under reduced pressure. The mixture was recrystallized from toluene / petroleum ether at a ratio of 4:1 to give intermediate B-38 (41.25 g, 75% yield); HPLC purity ≥99.68%.

[0163] Preparation of intermediate C-38:

[0164] Under nitrogen protection, B-38 (40.00 g, 80.00 mmol), B2Pin2 (21.08 g, 83.00 mmol), Na2CO3 (16.96 g, 160.00 mmol), Pd(dppf)Cl2 (0.73 g, 1.00 mmol), and THF (400 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 6 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled water was added, and the mixture was filtered to obtain a filter cake. The cake was recrystallized from toluene / n-hexane at a ratio of 5:1 to give intermediate C-38 (36.91 g, yield 78%); HPLC purity ≥99.89%.

[0165] Preparation of intermediate D-38:

[0166] C-38 (36.67 g, 62.00 mmol), d-38 (15.57 g, 60.00 mmol), K₂CO₃ (16.59 g, 120.00 mmol), Pd(PPh₃)₄ (0.81 g, 0.70 mmol), and a toluene / ethanol / water (2:1:1) mixed solvent (300 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 5 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered to obtain a filter cake, and finally recrystallized from toluene / methanol at a ratio of 7:1 to obtain intermediate D-38 (29.76 g, yield 77%); HPLC purity ≥99.87%.

[0167] Preparation of intermediate E-38:

[0168] Under nitrogen protection, D-38 (28.98 g, 45.00 mmol), B2Pin2 (11.94 g, 47.00 mmol), K2CO3 (12.44 g, 90.00 mmol), Pd(dppf)Cl2 (0.37 g, 0.50 mmol), and THF (200 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 8 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled water was added, and the mixture was filtered to obtain a filter cake. The cake was recrystallized from toluene / ethanol at a ratio of 10:1 to obtain intermediate E-38 (24.49 g, yield 74%); HPLC purity ≥99.89%.

[0169] Preparation of compound 38:

[0170] Under nitrogen protection, E-38 (23.54 g, 32.00 mmol), c-38 (8.20 g, 30.00 mmol), Na₂CO₃ (6.36 g, 60.00 mmol), Pd(OAc)₂ (0.08 g, 0.35 mmol), P(t-Bu)₃ (0.08 g, 0.40 mmol), and THF (120 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 8 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled water was added, and the mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous MgSO₄, the solvent was removed under reduced pressure, and the mixture was recrystallized from toluene to give compound 38 (17.08 g, yield 71%). The purity of the solid was ≥99.92% as determined by HPLC. Mass spectrometry m / z: 801.2615 (theoretical value: 801.2603). Theoretical elemental content (%) C 53 H 34 F3N3O2: C, 79.39; H, 4.27; N, 5.24. Measured elemental content (%): C, 79.36; H, 4.28; N, 5.21.

[0171] Synthesis Example 5: Preparation of Compound 42

[0172]

[0173] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-42 and c-38, respectively, to obtain compound 42 (14.60 g). HPLC analysis showed a solid purity ≥99.96%. Mass spectrometry m / z: 657.2428 (theoretical value: 657.2416). Theoretical elemental content (%) C 46 H 31 N3O2: C, 84.00; H, 4.75; N, 6.39. Measured elemental content (%): C, 84.04; H, 4.73; N, 6.36.

[0174] Synthesis Example 6: Preparation of Compound 44

[0175]

[0176] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-44 and c-44, respectively, to obtain compound 44 (16.07 g). HPLC analysis showed a solid purity ≥99.94%. Mass spectrometry m / z: 733.2740 (theoretical value: 733.2729). Theoretical elemental content (%) C 52 H 35 N3O2: C, 85.11; H, 4.81; N, 5.73. Measured elemental content (%): C, 85.13; H, 4.85; N, 5.70.

[0177] Synthesis Example 7: Preparation of Compound 49

[0178]

[0179] Following the preparation method of Synthesis Example 4, b-38, d-38, and c-38 were replaced with equimolar amounts of b-29, d-49, and c-27, respectively, to obtain compound 49 (14.29 g). HPLC analysis showed a solid purity ≥99.95%. Mass spectrometry m / z: 661.2678 (theoretical value: 661.2667). Theoretical elemental content (%) C 46 H 27 D4N3O2: C, 83.49; H, 5.33; N, 6.35. Measured elemental content (%): C, 83.46; H, 5.37; N, 6.33.

[0180] Synthesis Example 8: Preparation of Compound 57

[0181]

[0182] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-57 and c-57, respectively, to obtain compound 57 (12.98 g). HPLC analysis showed a solid purity ≥99.97%. Mass spectrometry m / z: 584.1974 (theoretical value: 584.1961). Theoretical elemental content (%) C 37 H 24 N6O2: C, 76.01; H, 4.14; N, 14.38. Measured elemental content (%): C, 76.03; H, 4.16; N, 14.34.

[0183] Synthesis Example 9: Preparation of Compound 70

[0184]

[0185] Following the preparation method of Synthesis Example 1, a-27 and b-27 were replaced with equimolar amounts of a-70 and b-70, respectively, to obtain compound 70 (16.62 g). HPLC analysis showed a solid purity ≥99.96%. Mass spectrometry m / z: 758.2668 (theoretical value: 758.2682). Theoretical elemental content (%) C 53 H 34 N4O2: C, 83.88; H, 4.52; N, 7.38. Measured elemental content (%): C, 83.86; H, 4.57; N, 7.34.

[0186] Synthesis Example 10: Preparation of Compound 77

[0187]

[0188] Following the preparation method of Synthesis Example 4, b-38, d-38, and c-38 were replaced with equimolar amounts of b-29, d-77, and c-77, respectively, to obtain compound 77 (14.21 g). HPLC analysis showed a solid purity ≥99.97%. Mass spectrometry m / z: 631.2274 (theoretical value: 631.2260). Theoretical elemental content (%) C 44 H 29 N3O2: C, 83.66; H, 4.63; N, 6.65. Measured elemental content (%): C, 83.63; H, 4.65; N, 6.62.

[0189] Synthesis Example 11: Preparation of Compound 124

[0190]

[0191] Following the preparation method of Synthesis Example 1, a-27, b-27, and c-27 were replaced with equimolar amounts of a-124, b-124, and c-124, respectively, to obtain compound 124 (17.12 g). HPLC analysis showed a solid purity ≥99.94%. Mass spectrometry m / z: 781.2739 (theoretical value: 781.2729). Theoretical elemental content (%) C 56 H 35 N3O2: C, 86.02; H, 4.51; N, 5.37. Measured elemental content (%): C, 86.05; H, 4.54; N, 5.32.

[0192] Synthesis Example 12: Preparation of Compound 155

[0193]

[0194] Following the preparation method of Synthesis Example 4, b-38, d-38, and c-38 were replaced with equimolar amounts of b-29, d-155, and c-155, respectively, to obtain compound 155 (15.29 g). HPLC analysis showed a solid purity ≥99.95%. Mass spectrometry m / z: 707.2523 (theoretical value: 707.2511). Theoretical elemental content (%) C 50 H 25 N3O2: C, 84.84; H, 4.70; N, 5.94. Measured elemental content (%): C, 84.82; H, 4.74; N, 5.91.

[0195] Synthesis Example 13: Preparation of Compound 185

[0196]

[0197] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-29 and c-185, respectively, to obtain compound 185 (14.29 g). HPLC analysis showed a solid purity ≥99.93%. Mass spectrometry m / z: 643.1884 (theoretical value: 643.1896). Theoretical elemental content (%) C 44 H 25 N3O3: C, 82.10; H, 3.91; N, 6.53. Measured elemental content (%): C, 82.14; H, 3.95; N, 6.50.

[0198] Synthesis Example 14: Preparation of Compound 218

[0199]

[0200] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of c-44 and c-218, respectively, to obtain compound 218 (13.11 g). HPLC analysis showed a solid purity ≥99.94%. Mass spectrometry m / z: 582.2542 (theoretical value: 582.2531). Theoretical elemental content (%) C 41 H 30 DN3O: C, 84.51; H, 5.54; N, 7.21. Measured elemental content (%): C, 84.55; H, 5.52; N, 7.23.

[0201] Synthesis Example 15: Preparation of Compound 220

[0202]

[0203] Following the preparation method of Synthesis Example 4, b-38, d-38, and c-38 were replaced with equimolar amounts of c-38, d-220, and b-29, respectively, to obtain compound 220 (14.69 g). HPLC analysis showed a solid purity ≥99.92%. Mass spectrometry m / z: 660.3045 (theoretical value: 661.3031). Theoretical elemental content (%) C 47 H 31 D4N3O: C, 85.29; H, 5.94; N, 6.35. Measured elemental content (%): C, 85.25; H, 5.97; N, 6.33.

[0204] Synthesis Example 16: Preparation of Compound 285

[0205]

[0206] Following the preparation method of Example 1, b-27 and c-27 were replaced with equimolar amounts of b-285 and c-285, respectively, to obtain compound 285 (19.84 g). HPLC analysis showed a solid purity ≥99.95%. Mass spectrometry m / z: 905.3418 (theoretical value: 905.3406). Theoretical elemental content (%) C 67 H 43 N3O: C, 88.81; H, 4.78; N, 4.64. Measured elemental content (%): C, 88.84; H, 4.76; N, 4.62.

[0207] Synthesis Example 17: Preparation of Compound 331

[0208]

[0209] Following the preparation method of Synthesis Example 4, b-38, d-38, and c-38 were replaced with equimolar amounts of b-331, d-331, and c-331, respectively, to obtain compound 331 (16.56 g). HPLC analysis showed a solid purity ≥99.96%. Mass spectrometry m / z: 755.2441 (theoretical value: 755.2429). Theoretical elemental content (%) C 51 H 37 N3S2: C, 81.03; H, 4.93; N, 5.56. Measured elemental content (%): C, 81.05; H, 4.91; N, 5.59.

[0210] Synthetic Example 18: Preparation of Compound 334

[0211]

[0212] Following the preparation method of Synthesis Example 1, a-27, b-27, and c-27 were replaced with equimolar amounts of a-37, b-331, and c-334, respectively, to obtain compound 334 (12.62 g). HPLC analysis showed a solid purity ≥99.95%. Mass spectrometry m / z: 560.1396 (theoretical value: 560.1381). Theoretical elemental content (%) C 37 H 24 N2S2: C, 79.25; H, 4.31; N, 5.00. Measured elemental content (%): C, 79.27; H, 4.35; N, 5.02.

[0213] Synthesis Example 19: Preparation of Compound 339

[0214]

[0215] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-331 and c-44, respectively, to obtain compound 339 (13.81 g). HPLC analysis showed a solid purity ≥99.93%. Mass spectrometry m / z: 613.1679 (theoretical value: 613.1646). Theoretical elemental content (%) C 40 H 27 N3S2: C, 78.27; H, 4.43; N, 6.85. Measured elemental content (%): C, 78.24; H, 4.48; N, 6.83.

[0216] Synthesis Example 20: Preparation of Compound 342

[0217]

[0218] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-342 and c-342, respectively, to obtain compound 342 (14.43 g). HPLC analysis showed a solid purity ≥99.94%. Mass spectrometry m / z: 649.1474 (theoretical value: 649.1458). Theoretical elemental content (%) C 40 H 25 F2N3S2: C, 73.94; H, 3.88; N, 6.47. Measured elemental content (%): C, 73.96; H, 3.84; N, 6.44.

[0219] Synthesis Example 21: Preparation of Compound 343

[0220]

[0221] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-343 and c-29, respectively, to obtain compound 343 (13.67 g). HPLC analysis showed a solid purity ≥99.96%. Mass spectrometry m / z: 615.1558 (theoretical value: 615.1551). Theoretical elemental content (%) C 38 H 25 N5S2: C, 74.12; H, 4.09; N, 11.37. Measured elemental content (%): C, 74.15; H, 4.04; N, 11.35.

[0222] Synthesis Example 22: Preparation of Compound 345

[0223]

[0224] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-345 and c-44, respectively, to obtain compound 345 (15.52 g). HPLC analysis showed a solid purity ≥99.97%. Mass spectrometry m / z: 689.1951 (theoretical value: 689.1959). Theoretical elemental content (%) C 46 H 31 N3S2: C, 80.09; H, 4.53; N, 6.09. Measured elemental content (%): C, 80.05; H, 4.58; N, 6.06.

[0225] Synthesis Example 23: Preparation of Compound 352

[0226]

[0227] Following the preparation method of Example 1, b-27 and c-27 were replaced with equimolar amounts of b-331 and c-352, respectively, to obtain compound 352 (15.32 g). HPLC analysis showed a solid purity ≥99.94%. Mass spectrometry m / z: 689.1974 (theoretical value: 689.1959). Theoretical elemental content (%) C 46 H 31 N3S2: C, 80.09; H, 4.53; N, 6.09. Measured elemental content (%): C, 80.04; H, 4.56; N, 6.06.

[0228] Synthesis Example 24: Preparation of Compound 358

[0229]

[0230] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-358 and c-358, respectively, to obtain compound 358 (15.63 g). HPLC analysis showed a solid purity ≥99.96%. Mass spectrometry m / z: 713.1975 (theoretical value: 713.1959). Theoretical elemental content (%) C 48 H 31 N3S2: C, 80.76; H, 4.38; N, 5.89. Measured elemental content (%): C, 80.73; H, 4.39; N, 5.87.

[0231] Synthesis Example 25: Preparation of Compound 368

[0232]

[0233] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-368 and c-368, respectively, to obtain compound 368 (16.82 g). HPLC analysis showed a solid purity ≥99.94%. Mass spectrometry m / z: 767.2188 (theoretical value: 767.2177). Theoretical elemental content (%) C 50 H 33 N5O2: C, 78.20; H, 4.33; N, 9.12. Measured elemental content (%): C, 78.25; H, 4.31; N, 9.14.

[0234] Synthesis Example 26: Preparation of Compound 370

[0235]

[0236] Preparation of intermediate A-370:

[0237] Under nitrogen protection, a-370 (71.57 g, 150.00 mmol), B2Pin2 (38.85 g, 153.00 mmol), KOAc (29.44 g, 300.00 mmol), Pd(dppf)Cl2 (1.17 g, 1.60 mmol), and THF (700 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 5 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled water was added, and the mixture was filtered to obtain a filter cake. The cake was then dried in a vacuum oven and purified by silica gel column chromatography (n-hexane:ethyl acetate = 1:1) to obtain intermediate A-27 (58.70 g, yield 82%); HPLC purity ≥98.78%.

[0238] Preparation of intermediate B-370:

[0239] Under nitrogen protection, A-370 (53.92 g, 113.00 mmol), b-331 (23.44 g, 110.00 mmol), Na₂CO₃ (2120 g, 200.00 mmol), Pd(PPh₃)₄ (1.27 g, 1.10 mmol), and 1,4-dioxane (500 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 7 hours. After the reaction was completed, the mixture was cooled to room temperature, extracted with dichloromethane, dried over anhydrous MgSO₄, and the solvent was removed under reduced pressure. The mixture was recrystallized from toluene / petroleum ether at a ratio of 4:1 to give intermediate B-370 (41.48 g, yield 78%); HPLC purity ≥99.67%.

[0240] Preparation of intermediate C-370:

[0241] Under nitrogen protection, B-370 (38.67 g, 80.00 mmol), B2Pin2 (21.08 g, 83.00 mmol), Na2CO3 (16.96 g, 160.00 mmol), Pd(dppf)Cl2 (0.73 g, 1.00 mmol), and THF (400 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 6 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled water was added, and the mixture was filtered to obtain a filter cake. The cake was recrystallized from toluene / n-hexane at a ratio of 5:1 to obtain intermediate C-370 (32.68 g, yield 77%); HPLC purity ≥99.87%.

[0242] Preparation of compound 370:

[0243] Under nitrogen protection, C-370 (16.98 g, 32.00 mmol), b-44 (8.19 g, 30.00 mmol), Na₂CO₃ (6.36 g, 60.00 mmol), Pd(OAc)₂ (0.08 g, 0.35 mmol), P(t-Bu)₃ (0.08 g, 0.40 mmol), and THF (120 mL) were added to a reaction flask. The mixture of the above reactants was heated under reflux for 8 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled water was added, and the mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous MgSO₄, the solvent was removed under reduced pressure, and the mixture was recrystallized from toluene to give compound 370 (13.43 g, yield 75%). The purity of the solid was ≥99.95% as determined by HPLC. Mass spectrometry m / z: 596.1936 (theoretical value: 596.1922). Theoretical elemental content (%) C 41 H 28 N₂OS: C, 82.52; H, 4.73; N, 4.69. Measured elemental content (%): C, 82.55; H, 4.71; N, 4.66.

[0244] Synthesis Example 27: Preparation of Compound 394

[0245]

[0246] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-394 and c-394, respectively, to obtain compound 394 (16.25 g). HPLC analysis showed a solid purity ≥99.93%. Mass spectrometry m / z: 741.1781 (theoretical value: 741.1769). Theoretical elemental content (%) C 46 H 27 N7S2: C, 74.47; H, 3.67; N, 13.22. Measured elemental content (%): C, 74.45; H, 3.69; N, 13.25.

[0247] Synthesis Example 28: Preparation of Compound 419

[0248]

[0249] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-419 and c-419, respectively, to obtain compound 419 (16.16 g). HPLC analysis showed a solid purity ≥99.92%. Mass spectrometry m / z: 737.1722 (theoretical value: 737.1708). Theoretical elemental content (%) C 48 H 27 N5S2: C, 78.13; H, 3.69; N, 9.49. Measured elemental content (%): C, 78.16; H, 3.65; N, 9.48.

[0250] Synthesis Example 29: Preparation of Compound 436

[0251]

[0252] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-331 and c-436, respectively, to obtain compound 436 (17.05 g). HPLC analysis showed a solid purity ≥99.94%. Mass spectrometry m / z: 767.1533 (theoretical value: 767.1524). Theoretical elemental content (%) C 50 H 29 N3S3: C, 78.20; H, 3.81; N, 5.47. Measured elemental content (%): C, 78.24; H, 3.82; N, 5.44.

[0253] Synthesis Example 30: Preparation of Compound 448

[0254]

[0255] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-448 and b-345, respectively, to obtain compound 448 (17.60 g). HPLC analysis showed a solid purity ≥99.97%. Mass spectrometry m / z: 825.3189 (theoretical value: 825.3178). Theoretical elemental content (%) C 59 H 43 N3S: C, 85.79; H, 5.25; N, 5.09. Measured elemental content (%): C, 85.76; H, 5.27; N, 5.07.

[0256] Synthesis Example 31: Preparation of Compound 472

[0257]

[0258] Following the preparation method of Synthesis Example 1, a-27, b-27, and c-27 were replaced with equimolar amounts of a-37, b-472, and c-472, respectively, to obtain compound 472 (14.96 g). HPLC analysis showed a solid purity ≥99.96%. Mass spectrometry m / z: 673.2566 (theoretical value: 673.2552). Theoretical elemental content (%) C 47 H 35 N3S: C, 83.77; H, 5.24; N, 6.24. Measured elemental content (%): C, 83.78; H, 5.21; N, 6.26.

[0259] Synthesis Example 32: Preparation of Compound 494

[0260]

[0261] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of c-155 and b-331, respectively, to obtain compound 494 (18.44 g). HPLC analysis showed a solid purity ≥99.95%. Mass spectrometry m / z: 841.2566 (theoretical value: 841.2552). Theoretical elemental content (%) C 61 H 35 N3S: C, 87.01; H, 4.19; N, 4.99. Measured elemental content (%): C, 87.04; H, 4.15; N, 4.97.

[0262] Synthesis Example 33: Preparation of Compound 520

[0263]

[0264] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of b-520 and c-520, respectively, to obtain compound 520 (18.92 g). HPLC analysis showed a solid purity ≥99.94%. Mass spectrometry m / z: 689.1951 (theoretical value: 863.3996). Theoretical elemental content (%) C 62 H 49 N5: C, 86.18; H, 5.72; N, 8.10. Measured elemental content (%): C, 86.16; H, 5.76; N, 8.15.

[0265] Synthesis Example 34: Preparation of Compound 530

[0266]

[0267] Following the preparation method of Synthesis Example 1, a-27, b-27, and c-27 were replaced with equimolar amounts of a-37, b-530, and c-530, respectively, to obtain compound 530 (17.41 g). HPLC analysis showed a solid purity ≥99.96%. Mass spectrometry m / z: 805.3469 (theoretical value: 805.3457). Theoretical elemental content (%) C 60 H 43 N3: C, 89.41; H, 5.38; N, 5.21. Measured elemental content (%): C, 89.43; H, 5.34; N, 5.26.

[0268] Synthesis Example 35: Preparation of Compound 575

[0269]

[0270] Following the preparation method of Synthesis Example 1, b-27 and c-27 were replaced with equimolar amounts of c-38 and c-575, respectively, to obtain compound 575 (16.27 g). HPLC analysis showed a solid purity ≥99.93%. Mass spectrometry m / z: 732.3266 (theoretical value: 732.3253). Theoretical elemental content (%) C 53 H 40 N4: C, 86.85; H, 5.50; N, 7.64. Measured elemental content (%): C, 86.86; H, 5.54; N, 7.61.

[0271] Synthesis Example 36: Preparation of Compound 612

[0272]

[0273] Following the preparation method of Synthesis Example 4, b-38 and d-38 were replaced with equimolar amounts of c-612 and d-612, respectively, to obtain compound 612 (13.78 g). HPLC analysis showed a solid purity ≥99.95%. Mass spectrometry m / z: 637.3378 (theoretical value: 637.3395). Theoretical elemental content (%) C 46 H 35 D4N3: C, 86.62; H, 6.79; N, 6.59. Measured elemental content (%): C, 86.64; H, 6.76; N, 6.58.

[0274] Synthesis Example 37: Preparation of Compound 645

[0275]

[0276] Following the preparation method in Synthesis Example 4, b-38, d-38, and c-38 were replaced with equimolar amounts of b-645, d-77, and c-645, respectively, to obtain compound 645 (18.74 g). HPLC analysis showed a solid purity ≥99.97%. Mass spectrometry m / z: 891.4564 (theoretical value: 891.4552). Theoretical elemental content (%) C 66 H 57 N3: C, 88.85; H, 6.44; N, 4.71. Measured elemental content (%): C, 88.81; H, 6.48; N, 4.72.

[0277] Synthesis Example 38: Preparation of Compound 672

[0278]

[0279] Following the preparation method in Synthesis Example 4, b-38, d-38, and c-38 were replaced with equimolar amounts of b-672, d-672, and b-612, respectively, to obtain compound 672 (15.93 g). HPLC analysis showed a solid purity ≥99.94%. Mass spectrometry m / z: 747.4348 (theoretical value: 747.4336). Theoretical elemental content (%) C 54 H 29 D 14 N3: C, 86.71; H, 7.68; N, 5.62. Measured element content (%): C, 86.74; H, 7.65; N, 5.63.

[0280] Device Examples

[0281] Comparative Example 1: ITO glass was used as the substrate material for fabricating the device. It was first ultrasonically treated with 5% ITO cleaning solution for 30 minutes, and then ultrasonically cleaned twice with distilled water, twice with acetone, and twice with isopropanol. It was then dried on a hot plate heated to 120°C. The dried substrate was then transferred to a plasma cleaner and washed for 5 minutes before being transferred to an evaporation machine. An organic electroluminescent device was fabricated by vacuum evaporating an 8 nm thick HAT-CN layer on a substrate as a hole injection layer, a 70 nm thick NPB layer on the hole injection layer as a hole transport layer, a 30 nm thick CBzCBI:Ir(ppy)2(acac)=93:7 (mass ratio) layer on the hole transport layer as a light-emitting layer, a 35 nm thick R-1 layer on the light-emitting layer as an electron transport layer, a 1 nm thick LiF layer on the electron transport layer as an electron injection layer, and a 150 nm thick Al layer on the electron injection layer as a cathode.

[0282] Comparative Example 2: Following the preparation method of Comparative Example 1, R-1 was replaced with R-2 as the electron transport layer.

[0283] Device Examples 1-38: Following the preparation method of Comparative Example 1, R-1 was replaced with the compounds shown in the table below as electron transport layers.

[0284] The molecular formulas of the relevant materials are shown below:

[0285]

[0286] Test Method: A combined IVL test system was constructed using test software, a computer, a Keithley K2400 digital source meter, and a Photo Research PR788 spectral scanning luminance meter to test the driving voltage and luminous efficiency of organic light-emitting diodes (OLEDs). Lifetime testing employed a McScience M6000 OLED lifetime testing system to measure the time it took for the OLED's brightness to decay to 97%. The test environment was atmospheric, at room temperature. The test results are shown in Table 1.

[0287] Table 1. Test data on the luminescence characteristics of organic electroluminescent devices.

[0288]

[0289]

[0290] As shown in Table 1, compared with the comparative devices, devices 1-38 of the present invention exhibit superior performance, specifically lower driving voltage, higher luminous efficiency, and longer lifespan. This indicates that the organic electroluminescent compound structure of the present invention is more stable and has higher electron mobility.

[0291] Comparative Example 3: ITO glass was used as the substrate material for fabricating the device. It was first ultrasonically treated with 5% ITO cleaning solution for 30 minutes, and then ultrasonically cleaned twice with distilled water, twice with acetone, and twice with isopropanol. It was then dried on a hot plate heated to 120°C. The dried substrate was then transferred to a plasma cleaner and washed for 5 minutes before being transferred to an evaporation machine. An organic electroluminescent device was fabricated by vacuum evaporating an 8 nm thick HAT-CN layer on a substrate as a hole injection layer, a 70 nm thick NPB layer on the hole injection layer as a hole transport layer, a 30 nm thick CBzCBI:Ir(ppy)2(acac)=93:7 (mass ratio) layer on the hole transport layer as a light-emitting layer, a 30 nm thick R-1 layer on the light-emitting layer as a hole blocking layer, a 25 nm thick Alq3 layer on the hole blocking layer as an electron transport layer, a 1 nm thick LiF layer on the electron transport layer as an electron injection layer, and a 130 nm thick Al layer on the electron injection layer as a cathode.

[0292] Comparative Example 4: Following the preparation method of Comparative Example 3, R-1 was replaced with R-2 as a hole blocking layer.

[0293] Device Examples 39-68: Following the preparation method of Comparative Example 3, R-1 was replaced with the compounds shown in the table below as hole blocking layers.

[0294] The molecular formulas of the relevant materials are shown below:

[0295]

[0296] The test results are shown in Table 2:

[0297] Table 2. Test data on the luminescence characteristics of organic electroluminescent devices.

[0298]

[0299]

[0300] As can be seen from Table 2, compared with the other devices, devices 39-68 have lower driving voltage, higher luminous efficiency, and longer lifespan. This indicates that the organic electroluminescent compound of the present invention has better hole blocking ability, which can effectively block holes in the light-emitting layer and increase the recombination probability of holes and electrons.

[0301] Comparative Example 5: ITO glass was used as the substrate material for fabricating the device. It was first ultrasonically treated with 5% ITO cleaning solution for 30 minutes, and then ultrasonically cleaned twice with distilled water, twice with acetone, and twice with isopropanol. It was then dried on a hot plate heated to 120°C. The dried substrate was then transferred to a plasma cleaner and washed for 5 minutes before being transferred to an evaporation machine. An organic electroluminescent device was fabricated by vacuum evaporating a 60 nm thick NTNPB layer on a substrate as a hole injection layer, a 25 nm thick HT1 layer on the hole injection layer as a hole transport layer, a 35 nm thick RH1:R-1:Ir(piq)3 = 47:47:6 (mass ratio) layer on the hole transport layer as a light-emitting layer, a 30 nm thick NBphen layer on the light-emitting layer as an electron transport layer, a 1 nm thick LiF layer on the electron transport layer as an electron injection layer, and a 120 nm thick Al layer on the electron injection layer as a cathode.

[0302] Comparative Example 6: Following the preparation method of Comparative Example 5, R-1 was replaced with R-2 as the luminescent host material.

[0303] Device Examples 69-90: Following the preparation method of Comparative Example 5, R-1 was replaced with the compounds shown in the table below as the luminescent host material.

[0304] The molecular formulas of the relevant materials are shown below:

[0305]

[0306] The test results are shown in Table 3:

[0307] Table 3. Test data on the luminescence characteristics of organic electroluminescent devices.

[0308]

[0309]

[0310] As can be seen from Table 3, compared with comparative devices 5-6, the organic electroluminescent device of the present invention has a lower driving voltage, higher luminous efficiency, and longer service life.

[0311] Comparative Example 7: ITO-Ag-ITO glass was used as the substrate material for fabricating the device. It was first ultrasonically treated with 5% ITO cleaning solution for 30 minutes, and then ultrasonically cleaned twice with distilled water, twice with acetone, and twice with isopropanol. It was then dried on a hot plate heated to 120°C. The dried substrate was then transferred to a plasma cleaner and washed for 5 minutes before being transferred to an evaporation machine. An organic electroluminescent device was fabricated by vacuum evaporating a 10 nm thick HAT-CN layer on a substrate as a hole injection layer, a 90 nm thick NPB layer on the hole injection layer as a hole transport layer, a 30 nm thick CBzCBI:Ir(ppy)2(acac)=93:7 (mass ratio) layer on the hole transport layer as a light-emitting layer, a 35 nm thick Alq3 layer on the light-emitting layer as an electron transport layer, a 0.5 nm thick LiF layer on the electron transport layer as an electron injection layer, a 15 nm thick Mg-Ag layer (mass ratio 9:1) on the electron injection layer as a cathode, and an 80 nm thick R-3 layer on the cathode as a light extraction layer.

[0312] Device Examples 91-100: Following the preparation method of Comparative Example 7, R-3 was replaced with the compounds shown in the table below as the light extraction layer.

[0313] The molecular formulas of the relevant materials are shown below:

[0314]

[0315] The test results are shown in Table 4:

[0316] Table 4. Test data on the luminescence characteristics of organic electroluminescent devices.

[0317]

[0318]

[0319] As can be seen from Table 4, the device of the present invention has superior performance compared with the comparative device, indicating that the organic electroluminescent compound of the present invention can effectively couple out the light trapped in the device and has good chemical stability.

[0320] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organic electroluminescent compound, characterized in that, The organic electroluminescent compound is represented by the following chemical formula (1): In chemical formula (1), The ring A is selected from one of the following groups. The R7 is independently selected from one of hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1 to C6 alkyl groups; a1 is selected from 0, 1, or 2; a2 is selected from 0 or 1; The Choose from one of the structures shown below. The R8 is independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted groups as shown below: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, phenyl, or two adjacent R8s can be linked together to form a substituted or unsubstituted benzene ring. b1 is selected from 0, 1, 2, 3, 4 or 5; b2 is selected from 0, 1, 2, 3 or 4; b3 is selected from 0, 1, 2 or 3; The Y is selected from O, S, CR2R3 or NR4; The V is selected from N or CR6; R2 and R3 are independently selected from one of hydrogen, deuterium, substituted or unsubstituted C1 to C6 alkyl, substituted or unsubstituted phenyl; The R4 is selected from one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, or substituted or unsubstituted naphthyl. The R6 is independently selected from one of hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted phenyl, or adjacent substituents can combine with each other to form a substituted or unsubstituted benzene ring; The Ar1 and Ar2 are independently selected from one of hydrogen, deuterium, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, and substituted or unsubstituted naphthyl, or the Ar1 and Ar2 can be combined with each other to form one of the substituted or unsubstituted cyclic structures shown below. The substituents referred to as "substituted or unsubstituted" in Ar1 and Ar2 are independently selected from deuterium, halogen, cyano, and deuterium-substituted or unsubstituted groups as shown below: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl; The L1 and L2 are independently selected from one of the following groups: single-bonded, substituted, or unsubstituted. The substituents referred to as "substituted or unsubstituted" in L1 and L2 are independently selected from deuterium, halogen, cyano, and deuterium-substituted or unsubstituted groups as shown below: methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl; The L3 is independently selected from one of the following: single bond, substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted terphenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted pyridylene, and substituted or unsubstituted pyrimidinylene. The "substituted or unsubstituted" in R7, R8, R2, R3, R4, R6, and L3 means that at least one hydrogen atom on the group is replaced by a substituent, which is: deuterium, halogen, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl.

2. The organic electroluminescent compound according to claim 1, characterized in that, The ring A is selected from one of the following groups.

3. The organic electroluminescent compound according to claim 1, characterized in that, Ar1 and Ar2 can combine with each other to form one of the following substituted or unsubstituted ring structures. The substituent is independently selected from deuterium, deuterated or unsubstituted groups as shown below: methyl, ethyl, isopropyl, tert-butyl.

4. The organic electroluminescent compound according to claim 1, characterized in that, The Choose from one of the structures shown below.

5. The organic electroluminescent compound according to claim 1, characterized in that, The Choose from one of the structures shown below. The R8 is independently selected from hydrogen, deuterium, deuterated or unsubstituted groups as shown below: methyl, ethyl, isopropyl, tert-butyl, phenyl.

6. The organic electroluminescent compound according to claim 1, characterized in that, The Choose from one of the structures shown below.

7. The organic electroluminescent compound according to claim 1, characterized in that, The L1 and L2 are independently selected from one of the following groups: single-bonded, substituted, or unsubstituted.

8. An organic electroluminescent compound, characterized in that, The compound is selected from one of the structures shown below.

9. An organic electroluminescent device, comprising a substrate, an anode, a cathode, and an organic layer, characterized in that, The organic layer contains one of the organic electroluminescent compounds according to claims 1 to 8.

10. The organic electroluminescent device according to claim 9, wherein the organic layer comprises at least one of a hole transport region between the anode and the cathode, a light-emitting layer, an electron transport region, and a light extraction layer on the side of the cathode opposite to the anode, characterized in that, At least one of the light-emitting layer, the electron transport region, and the light extraction layer contains one of the organic electroluminescent compounds according to claims 1 to 8.

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