Compounds for organic electroluminescence devices and organic electroluminescence devices comprising the same

Abstract

This invention provides a compound and its application, the compound having the structure shown in Formula I: In Formula I, L 1 and L 2 Each is independently selected from one of the single-bonded, substituted or unsubstituted C6-C30 arylene, or substituted or unsubstituted C3-C30 heteroarylene; Ar 1 and Ar 2 Each is independently selected from one of substituted or unsubstituted C6-C30 aryl groups or substituted or unsubstituted C3-C30 heteroaryl groups; X 1 ~X 3 Each independently selected from CR 1 Or N; Y 1 ~Y 8 Each independently selected from CR 2 Or N; A has the structure shown in Formula II: In Formula II, X is selected from S, O; Z 1 or Z 4 The connection point between Equation II and Equation I is Z, which serves as the connection point. 1 or Z 4 For C; Z 1 ~Z 8 Except for the connecting sites, each is independently selected from CR 3 Or N. The present invention also provides an organic electroluminescent device, comprising a substrate, a first electrode, a second electrode, and at least one organic layer located between the first electrode and the second electrode, wherein the organic layer contains at least one of the above-described compounds.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescence technology, and particularly to a compound and its applications, and organic electroluminescent devices comprising the same. Background Technology

[0002] OLED (organic light-emitting diode) refers to the phenomenon where organic functional materials emit light when excited by an electric field, directly converting electrical energy into light energy. In 1979, Dr. Ching W. Tang, the "father of OLED," accidentally discovered the electroluminescent properties of organic thin-film devices in his laboratory, thus initiating research into OLED devices and making significant contributions to the practical application of OLED technology. OLED devices are all-solid-state self-emissive devices, characterized by fast response speed, wide viewing angle, and a wide operating temperature range. Organic light-emitting materials can be structurally designed and improved according to application requirements, theoretically enabling full-color output. Compared to liquid crystal display technology, OLED devices have a simpler structure, allowing for ultra-thin, large-area flat panel displays. They are also more lightweight, flexible, and foldable, giving them a wider range of applications.

[0003] With the advent of the 5G ultra-high-speed network communication era, human demand for information will explode, and the requirements for the randomness and timeliness of information acquisition will become increasingly stringent. Portable, large-size display technology is essential to meeting this demand. Currently, organic light-emitting diodes (OLEDs), which use organic semiconductors as functional materials, are the most promising technology. This is due to OLED technology's advantages, including wide viewing angles, fast response times, low driving voltages, a wide adaptable display temperature range, and the ability to achieve full-color display across the blue to red light spectrum. Furthermore, by using flexible substrates, large-area display devices with excellent portability can be fabricated through bending and flexing.

[0004] However, OLED display technology still faces some challenges, such as high driving voltage, low luminous efficiency, and short display lifespan, which severely hinder its further development in practical applications. Therefore, continuous efforts are needed to develop high-performance materials that can improve device efficiency, lifespan, and reduce driving voltage.

[0005] In organic light-emitting devices (OLEDs), materials used as the organic layer can be broadly categorized by function into luminescent materials, hole injection materials, hole transport materials, and electron transport materials. Based on the light-emitting mechanism, they can be classified into fluorescent materials that emit light through singlet excited states and phosphorescent materials that emit light through triplet excited states. To effectively mitigate the aggregation of triplet excitons in luminescent materials and avoid concentration quenching, a host-guest doping system is typically employed, where the host material is doped with the luminescent material. Excitons generated by the host are transported to the dopant, thereby emitting highly efficient light.

[0006] Organic hole materials play a crucial role in transporting holes injected from the anode to the emissive layer. Transport materials with good hole injection capability and hole mobility are beneficial for balancing carrier injection within the device, thereby reducing the device's driving voltage, improving efficiency, and extending lifetime. On the other hand, to prevent excitons generated in the emissive layer from diffusing into the hole transport layer, which could lead to color distortion and reduced luminous efficiency, an electron blocking layer is needed to prevent exciton diffusion into the hole transport layer, thus preventing device efficiency roll-off and improving device stability.

[0007] Therefore, there is an urgent need in this field to develop higher-performance OLED hole transport materials to improve device performance. Summary of the Invention

[0008] The problem the invention aims to solve

[0009] The purpose of this invention is to provide a compound that has excellent hole migration and electron blocking capabilities, and exhibits good hole injection and migration performance in devices.

[0010] Another object of the present invention is to provide an organic electroluminescent device that uses the compounds of the present invention as hole transport materials or electron blocking materials, and has a low start-up voltage and high efficiency.

[0011] Solution to the problem

[0012] Through dedicated research, the inventors discovered that by introducing a naphthalene ring structure at the para position of a specific aromatic amine and simultaneously introducing a specific fused-ring aryl group at the ortho position of the aromatic amine, compounds with excellent hole migration and electron blocking capabilities can be obtained.

[0013] Specifically, one objective of this invention is to provide a compound having the structure shown in Formula I:

[0014]

[0015] In formula I, L 1 and L 2Each is independently selected from one of the single-bonded, substituted or unsubstituted C6-C30 arylene, or substituted or unsubstituted C3-C30 heteroarylene;

[0016] Ar 1 and Ar 2 Each is independently selected from one of substituted or unsubstituted C6-C30 aryl groups or substituted or unsubstituted C3-C30 heteroaryl groups;

[0017] X 1 ~X 3 Each independently selected from CR 1 Or N, the R 1 Independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, aldehyde, amino, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, wherein R 1 Each can independently choose to connect with the connected aromatic ring or heteroaromatic ring to form a ring;

[0018] Y 1 ~Y 8 Each independently selected from CR 2 Or N, the R 2 Independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, aldehyde, amino, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, wherein R 2 Each can independently choose to connect with the connected aromatic ring or heteroaromatic ring to form a ring;

[0019] A has the structure shown in Equation II:

[0020]

[0021] In Formula II, X is selected from S and O;

[0022] Z 1 or Z 4 The connection point between Equation II and Equation I is Z, which serves as the connection point. 1 or Z 4 The answer is C;

[0023] Z 1 ~Z 8 Except for the connecting sites, each is independently selected from CR 3 Or N, the R 3 Independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, aldehyde, amino, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, wherein R 3 Each can independently choose to connect with the connected aromatic ring or heteroaromatic ring to form a ring;

[0024] When the above groups contain substituents, the substituents are selected from one or a combination of at least two of the following: halogen, cyano, nitro, hydroxyl, aldehyde, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C3-C60 heteroarylamino, C6-C60 aryl, and C3-C60 heteroaryl.

[0025] The specific reasons why the above-mentioned composition of the present invention performs excellently as a hole transport material or an electron blocking material are not yet clear, but it is speculated that the reasons may be as follows: naphthalene has good planarity and excellent photoelectric properties; by introducing a naphthalene ring structure at the para position of the aromatic amine, the molecular conjugation system can be improved, which is beneficial to enhancing the charge transport capability; at the same time, the introduction of a fused-ring aryl group with a specific structure at the ortho position of the aromatic amine... This can further increase the conjugation level of the entire molecule, enhancing its transport capability. On the other hand, the fused ring, located adjacent to the amine group, can increase the steric hindrance of the molecule, causing a certain degree of structural distortion and preventing crystallization. Through the above-mentioned rational molecular design, the molecule exhibits more suitable HOMO and triplet energy levels, demonstrating excellent hole injection and migration performance in devices.

[0026] In this specification, the expression Ca to Cb represents that the group has a to b carbon atoms. Unless otherwise specified, the number of carbon atoms generally does not include the number of carbon atoms of the substituents.

[0027] In this specification, the way a ring structure is represented by "—" indicates that the connection point is located at any position on the ring structure where bonding can occur.

[0028] In this specification, "each independently" means that when there are multiple subjects, they may be the same or different from each other.

[0029] In this invention, unless otherwise specified, the description of chemical elements generally includes the concept of their isotopes. For example, the description of "hydrogen (H)" includes its isotopes. 1 H (protium or H), 2 The concept of H (deuterium or D); carbon (C) includes... 12 C 13 C, etc., will not be elaborated further.

[0030] In this invention, heteroatoms generally refer to atoms or groups of atoms selected from N, O, S, P, Si and Se, preferably selected from N, O and S.

[0031] Examples of halogens in this specification include fluorine, chlorine, bromine, and iodine.

[0032] In this invention, a monocyclic aryl group refers to a molecule containing one or at least two phenyl groups. When the molecule contains at least two phenyl groups, the phenyl groups are independent of each other and connected by single bonds, such as phenyl, diphenyl, terphenyl, etc. Fused-ring aryl groups refer to a molecule containing at least two benzene rings, but the benzene rings are not independent of each other, but are fused together by sharing ring edges, such as naphthyl, anthracene, etc. A monocyclic heteroaryl group refers to a molecule containing at least one heteroaryl group. When the molecule contains one heteroaryl group and other groups (such as aryl, heteroaryl, alkyl, etc.), the heteroaryl group and other groups are independent of each other and connected by single bonds, such as pyridine, furan, thiophene, etc. Fused-ring heteroaryl groups refer to a molecule formed by the fusion of at least one phenyl group and at least one heteroaryl group, or a molecule formed by the fusion of at least two heteroaryl rings, such as quinoline, isoquinoline, benzofuran, dibenzofuran, benzothiophene, dibenzothiophene, etc.

[0033] In this invention, unless otherwise specified, aryl and heteroaryl groups include both monocyclic and fused-ring types.

[0034] In this invention, unless otherwise specified, the substituents do not fuse with the group to which they belong.

[0035] The C3-C60 heteroaryl groups mentioned in this invention include monocyclic heteroaryl groups and fused-ring heteroaryl groups, preferably C3-C30 heteroaryl groups, more preferably C4-C20 heteroaryl groups, and even more preferably C5-C12 heteroaryl groups. A monocyclic heteroaryl group refers to a molecule containing at least one heteroaryl group. When a molecule contains one heteroaryl group and other groups (such as aryl, heteroaryl, alkyl, etc.), the heteroaryl group and the other groups are independent of each other and connected by a single bond. Examples of monocyclic heteroaryl groups include furanyl, thiophene, pyrrole, and pyridinyl. A fused-ring heteroaryl group refers to a molecule containing at least one aromatic heterocycle and an aromatic ring (aromatic heterocycle or aromatic ring), and the two are not independent of each other but share a group consisting of two adjacent atoms fused together. Examples of fused-ring heteroaryl groups include: benzofuranyl, benzothiophenyl, isobenzofuranyl, indolyl, dibenzofuranyl, dibenzothiophenyl, carbazoyl, acridineyl, isobenzofuranyl, isobenzothiophenyl, benzocarbazoyl, azircarbazoyl, phenothiazinyl, phenothiazinyl, 9-phenylcarbazoyl, 9-naphthylcarbazoyl, dibenzocarbazoyl, indolocarbazoyl, etc.

[0036] Specific examples of aryl groups in this invention can be exemplified by removing one hydrogen atom from the aforementioned aryl examples to obtain a divalent group. Specific examples of heteroaryl groups in this invention can be exemplified by removing one hydrogen atom from the aforementioned heteroaryl examples to obtain a divalent group.

[0037] The aryl group in this invention can be exemplified by the monovalent group composed of the above-mentioned aryl and heteroaryl groups and oxygen.

[0038] Examples of C6-C30 arylamino groups mentioned in this invention include phenylamino, methylphenylamino, naphthylamino, anthraceneylamino, phenanthreneamino, and biphenylamino.

[0039] Examples of C3-C30 heteroaryl amino groups mentioned in this invention include pyridinyl amino, pyrimidinyl amino, and dibenzofuranyl amino.

[0040] Unless otherwise specified, the chain alkyl groups mentioned in this invention include straight-chain alkyl groups and branched-chain alkyl groups. Specifically, the substituted or unsubstituted C1-C20 chain alkyl groups are preferably substituted or unsubstituted C1-C10 chain alkyl groups. Examples of substituted or unsubstituted C1-C10 chain alkyl groups include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, neopentyl, n-hexyl, neohexyl, n-heptyl, n-octyl, 2-ethylhexyl, etc.

[0041] In this invention, the cycloalkyl group includes monocycloalkyl and polycycloalkyl; the monocycloalkyl group contains only one cyclic structure; the polycycloalkyl group refers to a structure formed by two or more cycloalkyl groups sharing one or more carbon atoms; the C3-C20 cycloalkyl group is preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, etc.

[0042] In this specification, the substituted or unsubstituted C1-C20 alkoxy group is preferably a substituted or unsubstituted C1-C10 alkoxy group. Examples of C1-C10 alkoxy groups include: methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy, pentooxy, isopentoxy, hexoxy, heptoxy, octoxy, nonoxy, decoxy, undecoxy, dodecoxy, etc., among which methoxy, ethoxy, n-propoxy, isopropoxy, tert-butoxy, sec-butoxy, isobutoxy, isopentoxy, and isopentoxy are preferred, and methoxy is more preferred.

[0043] In this specification, the substituted or unsubstituted C1-C20 silanes and the substituted or unsubstituted C1-C10 silanes are examples of silanes substituted with groups listed in the above C1-C10 silanes, specifically including: methylsilane, dimethylsilane, trimethylsilane, ethylsilane, diethylsilane, triethylsilane, tert-butyldimethylsilane, tert-butyldiphenylsilane, etc.

[0044] Specifically, the compound has the structure shown in formula (2-1) or formula (2-2):

[0045]

[0046] Specifically, the compound has the structure shown in formula (3-1) or formula (3-2):

[0047]

[0048] More specifically, the compound has the structure shown in formula (4-1), formula (4-2), formula (4-3), or formula (4-4):

[0049]

[0050] In equations 2-1 to 4-4 above, X and L 1 L 2 Ar 1 Ar 2 X 1 X 2 X 3 Y 1 Y 2 Y3 Y 4 Y 5 Y 6 Y 7 Y 8 Z 1 Z 2 Z 3 Z 4 Z 5 Z 6 Z 7 Z 8 All of them have the same meaning as in Equation I.

[0051] The compounds of the present invention preferably satisfy one or more of the following:

[0052] 1.X 1 ~X 3 Each independently selected from CR 1 The R 1 Independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, aldehyde, amino, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, wherein R 1 Each can independently choose to connect with the connected aromatic ring or heteroaromatic ring to form a ring;

[0053] 2.Y 1 ~Y 8 Each independently selected from CR 2 The R 2 Independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, aldehyde, amino, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, wherein R 1 Each can independently choose to connect with the connected aromatic ring or heteroaromatic ring to form a ring;

[0054] 3.Z 1 ~Z 8 Each independently selected from CR 3 The R 2Independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, aldehyde, amino, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, wherein R 1 Each can be independently selected and linked to form a ring with an aromatic ring or heteroaromatic ring.

[0055] When the above groups contain substituents, the substituents are selected from one or a combination of at least two of the following: halogen, cyano, nitro, hydroxyl, aldehyde, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C3-C60 heteroarylamino, C6-C60 aryl, and C3-C60 heteroaryl.

[0056] The compounds of the present invention are more preferably satisfied with all three of the above conditions.

[0057] The compound of the present invention is further preferably R. 1 R 2 and R 3 At least one of them is hydrogen, and R is even more preferred. 1 R 2 and R 3 All are hydrogen. To avoid molecular fragmentation caused by excessively high sublimation temperatures, it is necessary to control the molecular weight, R. 1 R 2 and R 3 All compounds in this application, which are all hydrogen-based, exhibit good thermal stability.

[0058] That is, the compounds of the present invention are more preferably having the structures shown in formula (5-1), formula (5-2), formula (5-3) or (formula 5-4):

[0059]

[0060] The X, L 1 L 2 Ar 1 and Ar 2 All of them have the same meaning as in Equation I.

[0061] The compound of the present invention is preferably the L 1 and L 2Each arylene group is independently selected from single-bonded or substituted or unsubstituted C6-C30 aryl groups, with single-bonded or substituted or unsubstituted phenylene groups being more preferred, and single-bonded or substituted phenylene groups being even more preferred.

[0062] When the above groups contain substituents, the substituents are selected from one or a combination of at least two of the following: halogen, cyano, nitro, hydroxyl, aldehyde, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C3-C60 heteroarylamino, C6-C60 aryl, and C3-C60 heteroaryl.

[0063] The compound of the present invention is preferably Ar. 1 and Ar 2 Each is independently selected from one of substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C3-C30 heteroaryl groups; more preferably one of the following A) and B):

[0064] A): The Ar 1 and Ar 2 Each group is independently selected from one of the following substituted or unsubstituted groups: phenyl, naphthyl, anthracene, benzo[a]anthrayl, phenanthrene, benzo[a]phenanthrene, pyrene, fluoranyl, tetraphenyl, pentaphenyl, benzo[a]pyrene, biphenyl, terphenyl, tetraphenyl, fluorenyl, benzo[a]fluorenyl, indol[a]fluorenyl, spirodifluorenyl, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis-indeno[a]fluorenyl, trans-indeno[a]fluorenyl, trimerinyl, isotrimericindenoyl, spirotrimericindenoyl. Spiroisotrimeric indenyl, thiaanthrayl, phenoxathiyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, benzodibenzofuranyl, fluorenylbenzofuranyl, thiophenyl, benzothiophenyl, isobenzothiophenyl, dibenzothiophenyl, benzodibenzothiophenyl, fluorenylbenzothiophenyl, acridineyl, pyrroleyl, indoleyl, isoindoleyl, carbazoyl, benzocarbazoyl, carbazoindoleyl, phenothiazinyl or phenotoxazinyl; preferably Ar 1 and Ar 2 Each is independently selected from one of phenyl, naphthyl, biphenyl, terphenyl, fluorenyl, spirofluorenyl, dibenzofuranyl, dibenzothiopheneyl, phenanthryl, fluoranyl or carbazoleyl.

[0065] B): The Ar 1 and Ar 2Each group is independently selected from one of the following substituted or unsubstituted groups: phenyl, naphthyl, anthracene, benzo[a]anthrayl, phenanthrene, benzo[a]phenanthrene, pyrene, fluoranyl, tetraphenyl, pentaphenyl, benzo[a]pyrene, biphenyl, terphenyl, tetraphenyl, fluorenyl, benzo[a]fluorenyl, indol[a]fluorenyl, spirodifluorenyl, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis-indeno[a]fluorenyl, trans-indeno[a]fluorenyl, trimerinyl, isotrimericindenoyl, spirotrimericindenoyl Spiroisotrimeric indene, thiaanthrayl, phenoxathiyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, benzodibenzofuranyl, fluorenylbenzofuranyl, thiophenyl, benzothiophenyl, isobenzothiophenyl, dibenzothiophenyl, benzodibenzothiophenyl, fluorenylbenzothiophenyl, acridineyl, pyrroleyl, indoleyl, isoindoleyl, carbazoyl, benzocarbazoyl, carbazoindoleyl, phenothiazinyl or phenotoxazinyl, wherein up to One of the following is selected from substituted or unsubstituted C6-C30 fused-ring aryl groups and substituted or unsubstituted C3-C30 fused-ring heteroaryl groups, preferably selected from naphthyl, anthracene, benzo[a]anthrayl, phenanthryl, benzo[a]phenanthryl, pyrene, fluoranyl, tetraphenyl, pentaphenyl, benzo[a]pyrene, fluorenyl, benzo[a]fluorenyl, indol[a]fluorenyl, spirodifluorenyl, dihydrophenanthryl, dihydropyrene, tetrahydropyrene, cis-indeno[a]fluorenyl, trans-indeno[a]fluorenyl, trimer[a]indeno[a], etc. One of the following: isotrimeric indene, spirotrimeric indene, spiroisotrimeric indene, thiaanthrayl, phenoxathiyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, benzodibenzofuranyl, fluorenobenzofuranyl, benzothiophenyl, isobenzothiophenyl, dibenzothiophenyl, benzodibenzothiophenyl, fluorenobenzothiophenyl, acridineyl, indolyl, isoindolyl, carbazoyl, benzocarbazoyl, carbazoindolyl, phenthiazinyl, or phenoxathiyl;

[0066] More preferably Ar 1 and Ar 2 Each of the following is independently selected from one of phenyl, naphthyl, biphenyl, terphenyl, fluorenyl, spirofluorenyl, dibenzofuranyl, dibenzothiopheneyl, phenanthryl, fluoranyl, or carbazoleyl, more preferably at least one of the following is selected from one of naphthyl, fluorenyl, spirofluorenyl, dibenzofuranyl, dibenzothiopheneyl, phenanthryl, fluoranyl, or carbazoleyl.

[0067] When the above groups contain substituents, the substituents are selected from one or a combination of at least two of the following: halogen, cyano, nitro, hydroxyl, aldehyde, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C3-C60 heteroarylamino, C6-C60 aryl, and C3-C60 heteroaryl.

[0068] Preferably, the compound has any one of the following structures:

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079] A second objective of this invention is to provide an application of the compound described in one objective, wherein the compound is used in an organic electroluminescent device.

[0080] Preferably, the compound is used as a hole transport material or an electron blocking material in an organic electroluminescent device.

[0081] A third objective of this invention is to provide an organic electroluminescent device, the organic electroluminescent device comprising a substrate, a first electrode, a second electrode, and at least one organic layer located between the first electrode and the second electrode, the organic layer comprising at least one of the compounds described in one of the objectives.

[0082] Preferably, the organic layer includes a hole transport layer, the hole transport layer containing at least one of the compounds described in one of the objectives.

[0083] Preferably, the organic layer comprises an electron blocking layer, the electron blocking layer containing at least one of the compounds described in one of the objectives.

[0084] Invention Effects

[0085] Compared with the prior art, the present invention has the following beneficial effects:

[0086] The compounds provided by this invention employ a naphthalene ring structure introduced at the para position of an aromatic amine. Naphthalene exhibits good planarity and excellent photoelectric properties, increasing the conjugation level of the molecule and thus enhancing charge transport and improving charge mobility. Furthermore, dibenzofuran or dibenzothiophene is introduced at the ortho position of the aromatic amine, with the binding sites defined at positions 1 and 4. The 1 or 4 positions of dibenzofuran and dibenzothiophene have higher electron cloud densities than other substitution sites. These two positions, as binding sites, allow for greater superposition of the electron clouds of dibenzofuran or dibenzothiophene with the electron clouds of the linked aniline group, thereby significantly increasing the overall conjugation level of the molecule and enhancing hole injection and transport capabilities. Secondly, the ortho substitution provides steric hindrance, improving the molecule's resistance to crystallization. These structural characteristics enable the molecule to exhibit excellent hole injection and migration properties as a whole. Therefore, when the compounds of the present invention are used as hole transport materials or electron blocking materials in organic electroluminescent devices, the efficiency roll-off of the device can be suppressed, the hole injection and migration efficiency in the device can be effectively improved, thereby ensuring that the device achieves excellent low start-up voltage and extending the device's lifespan.

[0087] In addition, the preparation process of the compounds of the present invention is simple and easy to implement, the raw materials are readily available, and it is suitable for mass production scale-up. Detailed Implementation

[0088] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0089] In one specific embodiment of the present invention, the OLED includes a first electrode and a second electrode, and an organic material layer located between the electrodes. The organic material layer can be further divided into multiple regions. For example, the organic material layer may include a hole transport region, a light-emitting layer, and an electron transport region.

[0090] In specific embodiments, a substrate can be used below the first electrode or above the second electrode. The substrate is typically made of glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. Furthermore, thin-film transistors (TFTs) can also be incorporated into the substrate used for displays.

[0091] The first electrode can be formed by sputtering or depositing the material to be used as the first electrode on a substrate. When the first electrode is used as the anode, transparent conductive oxide materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), and zinc oxide (ZnO) and any combination thereof can be used. When the first electrode is used as the cathode, metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), and magnesium-silver (Mg-Ag) and any combination thereof can be used.

[0092] Organic material layers can be formed on electrodes using methods such as vacuum thermal evaporation, spin coating, and printing. The compounds used as organic material layers can be small organic molecules, large organic molecules, polymers, and combinations thereof.

[0093] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a single-layer hole transport layer (HTL), including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport region can also be a multilayer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0094] In one aspect of the invention, the material of the hole transport region may be selected from one or more compounds represented by Formula I of the invention. The electron blocking layer of the hole transport region may be absent or may be present and selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives as shown in HT-1 to HT-51 below; or any combination thereof.

[0095]

[0096]

[0097]

[0098] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can be one or more compounds of HT-1 to HT-51 described above, or one or more compounds of HI-1 to HI-3 described below; it can also be one or more compounds of HT-1 to HT-51 doped with one or more compounds of HI-1 to HI-3 described below.

[0099]

[0100] The emissive layer includes luminescent dyes (i.e., dopants) that can emit different wavelengths of light, and may also include a host material. The emissive layer can be a monochromatic emissive layer emitting a single color such as red, green, or blue. Multiple monochromatic emissive layers of different colors can be arranged in a planar pattern according to pixel design, or they can be stacked together to form a colored emissive layer. When different colored emissive layers are stacked together, they can be separated from each other or connected to each other. The emissive layer can also be a single colored emissive layer that can simultaneously emit different colors such as red, green, and blue.

[0101] Depending on the technology used, the light-emitting layer material can be various, including fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescence materials. An OLED device can employ a single light-emitting technology or a combination of different technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0102] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent host material of the light-emitting layer may be selected from, but is not limited to, one or more combinations of BFH-1 to BFH-17 listed below.

[0103]

[0104] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent dopant of the light-emitting layer may be selected from, but is not limited to, one or more combinations of BFD-1 to BFD-24 listed below.

[0105]

[0106]

[0107] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The main material of the light-emitting layer is selected from, but not limited to, one or more combinations of pH-1 to pH-85.

[0108]

[0109]

[0110]

[0111]

[0112] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0113]

[0114]

[0115] Where D represents deuterium.

[0116] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0117]

[0118] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but is not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0119]

[0120]

[0121] In one aspect of the invention, the light-emitting layer employs thermally activated delayed fluorescence emission technology. The main material of the light-emitting layer is selected from, but not limited to, one or more combinations of PH-1 to PH-85 described above.

[0122] In one aspect of the invention, the light-emitting layer employs thermally activated delayed fluorescence emission technology. The fluorescent dopant in the light-emitting layer may be selected from, but not limited to, one or more combinations of TDE1-TDE37 listed below.

[0123]

[0124]

[0125] In one aspect of the present invention, an electron blocking layer (EBL) is located between the hole transport layer and the light-emitting layer. The electron blocking layer may employ, but is not limited to, one or more compounds of HT-1 to HT-51 described above, or one or more compounds of PH-47 to PH-77 described above; or a mixture of one or more compounds of HT-1 to HT-51 and one or more compounds of PH-47 to PH-77 may be employed.

[0126] The OLED organic material layer may also include an electron transport region between the light-emitting layer and the cathode. The electron transport region can be a single-layer electron transport layer (ETL), including single-layer electron transport layers containing only one compound and single-layer electron transport layers containing multiple compounds. Alternatively, the electron transport region can be a multilayer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0127] In one aspect of the present invention, the electron transport layer material may be selected from, but not limited to, one or more combinations of ET-1 to ET-73 listed below.

[0128]

[0129]

[0130]

[0131] In one aspect of the present invention, a hole blocking layer (HBL) is located between the electron transport layer and the light-emitting layer. The hole blocking layer may employ, but is not limited to, one or more compounds of ET-1 to ET-73, or one or more compounds of PH-1 to PH-46; or a mixture of one or more compounds of ET-1 to ET-73 and one or more compounds of PH-1 to PH-46 may be employed.

[0132] The device may also include an electron injection layer located between the electron transport layer and the cathode, and the electron injection layer material includes, but is not limited to, one or more combinations of the following.

[0133] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Mg, Yb.

[0134] The compounds of general formula I of this invention can be synthesized according to the following synthetic route:

[0135]

[0136] The specific preparation methods of the above-mentioned new compounds of the present invention will be described in detail below using several synthetic examples, but the preparation methods of the present invention are not limited to these synthetic examples.

[0137] All the chemical reagents used in this invention, such as petroleum ether, ethyl acetate, sodium sulfate, toluene, tetrahydrofuran, dichloromethane, acetic acid, and potassium carbonate, were purchased from Shanghai Titan Technology Co., Ltd. and Xilong Chemical Co., Ltd. The mass spectrometer used to determine the following compounds was a ZAB-HS type mass spectrometer (manufactured by Micromass, UK).

[0138] The synthesis method of the intermediate is as follows:

[0139] Synthesis of intermediate M1:

[0140]

[0141] Synthetic compound M1-1

[0142] The starting materials 2-bromo-4-iodoaniline (50.0 g, 168 mmol), 1-naphthoboric acid (31.8 g, 185 mmol), and potassium carbonate (17.8 g, 201 mmol) were placed in a three-necked flask containing 500 mL toluene, 200 mL ethanol, and 200 mL water. The mixture was stirred thoroughly, and the air in the flask was purged three times with nitrogen. Tetraphenylphosphine palladium (1.94 g, 1.68 mmol) was added to the reaction solution under nitrogen protection. The mixture was then heated to 100 °C and reacted for 18 h. After cooling, the reaction solution was poured into a saturated aqueous solution of ammonium chloride and extracted with ethyl acetate (500 mL, three times). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a dark brown oily substance. This crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate, 10 / 1) to give 45 g of a yellow solid, namely compound M1-1.

[0143] Synthetic intermediate M1

[0144] The synthesized compound M1-1 (45.0 g, 151 mmol), dibenzofuran-4-boronic acid (41.6 g, 196 mol), and potassium carbonate (25.0 g, 181 mmol) were placed in a three-necked flask containing 500 mL toluene, 200 mL ethanol, and 200 mL water. The mixture was stirred thoroughly, and the air in the flask was purged three times with nitrogen. Tetraphenylphosphine palladium (1.74 g, 1.51 mmol) was added to the reaction mixture under nitrogen protection. The mixture was then heated to 100 °C and reacted for 18 h. After cooling, the reaction mixture was poured into a saturated aqueous solution of ammonium chloride and extracted with ethyl acetate (500 mL, three times). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brownish-red oily substance. This crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate, 10 / 1) to give 41 g of a pale yellow solid, which is intermediate M1.

[0145] Similarly, intermediates M2, M3, M4, M5, M6, M7, and M8 can be obtained.

[0146]

[0147] The synthesis method of intermediate M2 differs from that of M1 in that it involves... Replace with equal amounts of substance The intermediate M2 is obtained.

[0148] The synthesis method of intermediate M3 differs from that of M1 in that it involves... Replace with equal amounts of substance The intermediate M3 is obtained.

[0149] The synthesis method of intermediate M4 differs from that of M1 in that it involves... Replace with equal amounts of substance Will Replace with equal amounts of substance Intermediate M4 was obtained. The synthesis method of intermediate M5 differs from that of M1 in that... Replace with equal amounts of substance The intermediate M5 is obtained.

[0150] The synthesis method of intermediate M6 differs from that of M1 in that it involves... Replace with equal amounts of substance Will Replace with equal amounts of substance Intermediate M6 was obtained. The synthesis method of intermediate M7 differs from that of M1 in that... Replace with equal amounts of substance The intermediate M7 was obtained.

[0151] The synthesis method of intermediate M8 differs from that of M1 in that it involves... Replace with equal amounts of substance Will Replace with equal amounts of substance The intermediate M8 is obtained.

[0152] Synthesis Example 1: Synthesis of Compound 7

[0153]

[0154] Synthetic compound 7-1

[0155] Intermediate M1 (15 g, 39.0 mmol), 4-bromobiphenyl (9.9 g, 42.8 mmol), and sodium tert-butoxide (4.9 g, 50.7 mmol) were placed in a 250 mL three-necked flask. Toluene (150 mL) was then added, and the mixture was stirred thoroughly. The air in the flask was purged with nitrogen. Next, the catalyst tris(dibenzylacetone)dipalladium (350 mg, 0.39 mmol) and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (160 mg, 0.39 mmol) were added, and the mixture was heated to 80 °C and reacted for 4 h. After cooling to room temperature, the reaction mixture was passed through a silica gel column and washed with toluene until no product was obtained. The toluene filtrate was concentrated to obtain a brown oily substance. The crude product was refluxed in ethanol with stirring, and a solid precipitated. The solid was recrystallized from toluene and petroleum ether to give 16.6 g of a pale yellow solid, namely compound 7-1.

[0156] Synthetic compound 7

[0157] Compound 7-1 (16.6 g, 30.9 mmol), 2,4-diphenylbromobenzene (13.0 g, 40.2 mmol), and sodium tert-butoxide (4.5 g, 46.4 mmol) were dissolved in a 500 mL three-necked flask containing 200 mL of toluene by stirring thoroughly. The air in the flask was then completely purged with nitrogen. Next, the catalyst tris(dibenzylacetone)dipalladium (284 mg, 0.31 mmol) and a solution of tri-tert-butylphosphine in xylene (0.3 mL) were added to the reaction mixture, and the mixture was heated to reflux for 5 h. After cooling, the reaction mixture was passed through a silica gel column and eluted with toluene until no product was filtered out. The toluene solution was concentrated to obtain a yellow oily substance. The crude product was refluxed in ethanol for 2 h, precipitating a solid. The solid was recrystallized twice in toluene and petroleum ether, and then further purified by sublimation, yielding 15.0 g of a pale yellow solid, which is compound 7.

[0158] The synthesis methods of Synthetic Examples 2-25 and Comparative Synthetic Example 1 are the same as those of Synthetic Example 1, and the corresponding raw materials used are summarized in Table 1.

[0159] Table 1

[0160]

[0161]

[0162]

[0163]

[0164] Synthesis Example 27

[0165] Synthesis of compound HT214

[0166]

[0167] Compounds M1-1 (15.0 g, 50.5 mmol), IM-1 (23.0 g, 60.6 mol), and potassium carbonate (15.2 g, 110.2 mmol) synthesized in the previous step were placed in a three-necked flask containing 300 mL toluene, 40 mL ethanol, and 20 mL water. The mixture was stirred thoroughly, and the air in the flask was purged three times with nitrogen. Under nitrogen protection, tetra(triphenylphosphine)palladium (0.590 g, 0.51 mmol) was added to the reaction solution, and the mixture was heated to 100 °C and reacted for 18 h. After cooling, the reaction solution was poured into a saturated aqueous solution of ammonium chloride and extracted with ethyl acetate (500 mL, three times). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brownish-red oily substance. This crude product precipitated 23 g of solid, compound 214-2, in petroleum ether with stirring.

[0168] Compound 214-2 (10.0 g, 18.1 mmol), bromobenzene (6.5 g, 41.7 mmol), and sodium tert-butoxide (4.4 g, 45.3 mmol) were dissolved in a 250 mL three-necked flask containing 150 mL of toluene by stirring thoroughly. The air in the flask was then completely purged with nitrogen. Next, the catalyst tris(dibenzylacetone)dipalladium (0.17 g, 0.18 mmol) and a solution of tri-tert-butylphosphine in xylene (0.3 mL) were added to the reaction mixture, and the mixture was heated to reflux for 6 h. After cooling, the reaction mixture was passed through a silica gel column and eluted with toluene until no product was filtered out. The toluene solution was concentrated to obtain a yellow oily substance. The crude product was refluxed in ethanol for 2 h, precipitating a solid. The solid was recrystallized twice in toluene and petroleum ether, and then further purified by sublimation. 8.0 g of the pale yellow solid, compound 214, MS (M+H): 705.3, was obtained.

[0169] Synthesis of compound HT216

[0170]

[0171] The starting materials 2-bromo-4-iodoaniline (10.0 g, 33.7 mmol), 3-hydroxy-1-naphthoic acid (7.6 g, 40.4 mmol), and potassium carbonate (7.0 g, 50.6 mmol) were placed in a three-necked flask containing 120 mL toluene, 30 mL ethanol, and 20 mL water. The mixture was stirred thoroughly, and the air in the flask was purged three times with nitrogen. Tetraphenylphosphine palladium (0.40 g, 0.34 mmol) was added to the reaction mixture under nitrogen protection. The mixture was then heated to 100 °C and reacted for 18 h. After cooling, the reaction mixture was poured into a saturated aqueous solution of ammonium chloride and extracted with ethyl acetate (500 mL, three times). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a dark brown oily substance. This crude product was stirred for a long time in petroleum ether to yield 7.0 g of a brown solid, compound 216-1.

[0172] Compound 216-1 (7.0 g, 22.4 mmol), 4-boronic acid dibenzofuran (5.7 g, 26.9 mol), and potassium carbonate (6.2 g, 44.8 mmol) synthesized in the previous step were placed in a three-necked flask containing 100 mL toluene, 10 mL ethanol, and 10 mL water. The mixture was stirred thoroughly, and the air in the flask was purged three times with nitrogen. Under nitrogen protection, tetra(triphenylphosphine) palladium (0.350 g, 0.30 mmol) was added to the reaction solution, and the mixture was heated to 100 °C and reacted for 18 h. After cooling, the reaction solution was poured into a saturated aqueous solution of ammonium chloride and extracted with ethyl acetate (500 mL, three times). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brownish-red oily substance. This crude product precipitated 6.5 g of solid, compound 216-2, in petroleum ether upon stirring.

[0173] Compound 216-2 (6.5 g, 16.2 mmol), 4-bromobiphenyl (8.6 g, 37.3 mmol), and sodium tert-butoxide (4.7 g, 48.6 mmol) were dissolved in a 250 mL three-necked flask containing 150 mL of toluene by stirring thoroughly. The air in the flask was then completely purged with nitrogen. Next, the catalyst tris(dibenzylacetone)dipalladium (0.45 g, 0.5 mmol) and a solution of tri-tert-butylphosphine in xylene (0.5 mL) were added to the reaction mixture, and the mixture was heated to reflux for 8 hours. After cooling, the reaction mixture was passed through a short silica gel column and eluted with toluene until no product was filtered out. The toluene solution was concentrated to obtain a yellow oily substance. The crude product was stirred in ethanol for 16 hours, resulting in the precipitation of a solid. The solid was recrystallized twice in toluene and petroleum ether, and then further purified by sublimation. 4.0 g of the pale yellow solid was obtained, namely compound 216, MS (M+H): 706.3. The synthesis of compounds R-1 and R-2 was compared with the synthesis method in patent document KR1020200061302A, and its description is omitted here.

[0174]

[0175] The structures of compounds R-3 and R-4 are shown below for comparison:

[0176]

[0177] The synthesis steps of compound R-3 are as follows:

[0178] All intermediates used in the synthesis were purchased from the custom company.

[0179]

[0180] Intermediate A1 (12.2 g, 29.6 mmol), 2-bromo-9,9-dimethylfluorene (17.8 g, 65.3 mmol), and sodium tert-butoxide (7.1 g, 74.0 mmol) were placed in a 500 mL three-necked flask containing 250 mL of toluene and stirred thoroughly to dissolve. The air in the flask was then completely purged with nitrogen. Next, the catalyst tris(dibenzylacetone)dipalladium (570 mg, 0.62 mmol) and a solution of tri-tert-butylphosphine in xylene (0.5 mL) were added to the reaction mixture, and the mixture was heated to reflux for 6 h. After cooling, the reaction mixture was passed through a short silica gel column and washed with toluene until no product was filtered out. The toluene solution was concentrated to obtain a yellow oily substance. The crude product was refluxed in ethanol for 2 h, precipitating a solid. The solid was recrystallized twice in toluene and petroleum ether to obtain a pale yellow solid. Further purification was achieved by sublimation, yielding 18.5 g of the pale yellow solid, which is the comparative compound R-3. MZ(M+H):796.4

[0181] The synthesis steps of compound R-4 are as follows:

[0182]

[0183] Intermediate B1 (10.0 g, 24.3 mmol), 4-bromobiphenyl (12.4 g, 53.5 mmol), and sodium tert-butoxide (5.8 g, 60.8 mmol) were placed in a 500 mL three-necked flask containing 200 mL of toluene and stirred thoroughly to dissolve. The air in the flask was then completely purged with nitrogen. Next, the catalyst tris(dibenzylacetone)dipalladium (450 mg, 0.49 mmol) and a solution of tri-tert-butylphosphine in xylene (0.3 mL) were added to the reaction mixture, and the mixture was heated to reflux for 8 hours. After cooling, the reaction mixture was passed through a silica gel column and washed with toluene until no product was filtered out. The toluene solution was concentrated to obtain a brown solid. The crude product was refluxed in petroleum ether for 3 hours, precipitating a solid. The solid was recrystallized twice in toluene and petroleum ether to obtain a white solid. Further purification was achieved by sublimation, yielding 13.0 g of the white solid, which is the comparative compound R-4. MZ(M+H): 715.3

[0184] Synthesis of compound R-5: The specific method is based on the synthesis method in patent document WO2015130069A, and its description is omitted here.

[0185]

[0186] The structure of the comparative compound R-6 is shown below:

[0187]

[0188] The synthetic steps for compound R-6 are as follows:

[0189]

[0190] The intermediates used in the synthesis were purchased from the custom company.

[0191] Intermediate C1 (20.0 g, 59.7 mmol), bromobenzene (21.4 g, 137.3 mmol), and sodium tert-butoxide (14.3 g, 149.3 mmol) were placed in a 500 mL three-necked flask containing 300 mL of toluene and stirred thoroughly to dissolve. The air in the flask was then completely purged with nitrogen. Next, the catalyst tris(dibenzylacetone)dipalladium (550 mg, 0.60 mmol) and a solution of tri-tert-butylphosphine in xylene (0.3 mL) were added to the reaction mixture, and the mixture was heated to reflux for 8 hours. After cooling, the reaction mixture was passed through a short silica gel column and washed with toluene until no product was filtered out. The toluene solution was concentrated to obtain a brownish-red oily substance. The crude product was refluxed in petroleum ether for 3 hours, precipitating a solid. The solid was recrystallized twice in toluene and petroleum ether to obtain a white solid. Further purification was achieved by sublimation, yielding 21.0 g of the white solid, which is the comparative compound R-6. MZ(M+H):538.2

[0192] Example 1

[0193] This embodiment provides an organic electroluminescent device, and the specific fabrication method is as follows:

[0194] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a acetone:ethanol mixed solvent, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0195] The glass substrate with the anode was placed in a vacuum chamber and evacuated to a vacuum level of less than 1 × 10⁻⁶. -5 Pa, HI-3 is vacuum-deposited on the above-mentioned anodic layer as a hole injection layer at a deposition rate of 0.1 nm / s and a film thickness of 10 nm.

[0196] A hole transport layer of the device is vacuum-deposited on top of the hole injection layer at a deposition rate of 0.1 nm / s and a total film thickness of 80 nm. Compound 1 of the present invention is selected as the hole transport layer material.

[0197] An electron blocking layer for the device was further vacuum-deposited on top of the hole transport layer at a deposition rate of 0.1 nm / s and a total film thickness of 60 nm. Compound HT-48 was used as the electron blocking layer material.

[0198] The light-emitting layer of the device is vacuum-deposited on top of the electron blocking layer. The light-emitting layer includes a host material and a dye material. The compound PH-34:RPD-10 (100:100:3, w / w) mixture is used as the light-emitting layer by using a multi-source co-evaporation method with an evaporation rate of 0.1 nm / s and a film thickness of 30 nm.

[0199] The electron transport layer materials ET-69 and ET-57 were vacuum-deposited on the light-emitting layer at a ratio of 50% and a deposition rate of 0.1 nm / s, with a total film thickness of 3 nm.

[0200] A 0.5 nm thick LiF layer was vacuum-deposited on the electron transport layer (ETL) as the electron injection layer, and a 150 nm thick Al layer was used as the cathode of the device.

[0201] The difference between Examples 2-19 and Comparative Examples 1-6 and Example 1 is that the hole transport material (compound 1) is replaced with other compounds, as detailed in Table 2.

[0202] Device testing methods (including equipment and testing conditions):

[0203] The organic electroluminescent devices prepared by the above process were subjected to the following performance measurements:

[0204] At the same brightness, the driving voltage and current efficiency of the organic electroluminescent devices prepared in Examples 1-19 and Comparative Examples 1-6 were measured using a digital source meter (Keithley 2400) and a luminance meter (ST-86LA type luminance meter, Beijing Normal University Optoelectronic Instrument Factory). Specifically, the voltage was increased at a rate of 0.1V per second, and the driving voltage and current efficiency were measured when the brightness of the organic electroluminescent device reached 3000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is measured simultaneously; the ratio of brightness to current density is the current efficiency.

[0205] The performance of organic electroluminescent devices is shown in Table 2 below:

[0206] Table 2

[0207]

[0208] As can be seen from the results in Table 2, using the novel organic material of the present invention as the hole transport material in organic electroluminescent devices can effectively reduce the device's start-up voltage and improve the device's efficiency compared to devices prepared using comparative compounds R-1, R-2, R-3, R-4, and R-5 as hole transport materials.

[0209] The only difference between R-3 in Comparative Example 3 and compound 203 in Example 15 is that compound 203 has a 1-substituted dibenzothiophene at the ortho position, while R-3 has a 2-substituted 9,9-dimethylfluorene at the ortho position. The device performance of Comparative Example 3 is significantly lower than that of Example 15.

[0210] The only difference between R-1 in Comparative Example 1 and compound 2 in Example 2 is that compound 2 has a 4-substituted dibenzofuran at the ortho position, while R-1 has a 3-substituted dibenzofuran at the ortho position. The device performance of Comparative Example 1 is significantly lower than that of Example 2.

[0211] The only difference between R-2 in Comparative Example 2 and compound 205 in Example 16 is that compound 205 has a 4-substituted dibenzothiophene at the ortho position, while R-2 has a 3-substituted dibenzothiophene at the ortho position. The device performance of Comparative Example 2 is significantly lower than that of Example 16.

[0212] The only difference between R-5 in Comparative Example 5 and Compound 1 in Example 1 is that Compound 1 has a 4-substituted dibenzofuran at the ortho position, while R-5 has a 3-substituted phenylcarbazole at the ortho position. The device performance of Comparative Example 5 is significantly lower than that of Example 1.

[0213] The only difference between R-6 in Comparative Example 6 and Compound 1 in Example 1 is that the amino substituent in Compound 1 is 4-naphthyl-2-(4-dibenzofuran), while the amino substituent in R-6 is 4-phenyl-2-(4-dibenzofuran). Naphthyl has better transport ability than phenyl, and the device performance of Example 1 is significantly improved compared with Comparative Example 6.

[0214] The above experimental results demonstrate that by introducing a naphthalene ring structure at the para position of an aromatic amine and simultaneously introducing a fused aromatic ring with a specific substitution structure at the ortho position, the substituents work synergistically with each other, which enables the reduction of driving voltage and improvement of device efficiency when used as a hole transport material.

[0215] Example 19

[0216] The difference from Example 1 is that the hole transport material compound 1 is replaced with compound HT-21, and the electron blocking material HT-14 is replaced with compound 4.

[0217] The only difference between Examples 20-26, Comparative Examples 7-9 and Example 19 is that the electron blocking material (compound 4) is replaced with other compounds. For details and the performance of the organic electroluminescent devices, please refer to Table 3.

[0218] Table 3

[0219]

[0220] As can be seen from the results in Table 3, using the novel organic material of the present invention as the electron blocking layer material for organic electroluminescent devices can effectively reduce the device's start-up voltage and improve the device's efficiency, compared to devices prepared using comparative compounds R-2, R-3, and R-4 as the electron blocking layer material.

[0221] Among them, when used as an electron blocking layer material, compound R-4 (Comparative Example 7) is still less effective than compound 4 (Example 17); compound R-3 (Comparative Example 9) is less effective than compound 203 (Example 24); and compound R-2 (Comparative Example 8) is less effective than compound 205 (Example 21).

[0222] The above experimental results demonstrate that the present invention, by introducing a naphthalene ring structure at the para position of an aromatic amine and simultaneously introducing a fused aromatic ring with a specific substitution structure at the ortho position, achieves the technical effect of reducing driving voltage and increasing service life when used as an electron barrier, thanks to the synergistic effect of the substituents.

[0223] The present invention has been illustrated with the above embodiments to explain the detailed method of the present invention. However, the present invention is not limited to the detailed method described above, that is, it does not mean that the present invention must rely on the detailed method described above to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A compound, characterized in that, The compound has the structure shown in formula (4-1), formula (4-2), formula (4-3), or formula (4-4): (Equation 4-1) (Equation 4-2) (Equation 4-3) (Equation 4-4); In the formula, L 1 and L 2 Each is independently selected from single-bonded or substituted or unsubstituted phenylene compounds; Ar 1 and Ar 2 Each group is independently selected from one of the following groups, whether substituted or unsubstituted: phenyl, naphthyl, biphenyl, terphenyl, fluorenyl, dibenzofuranyl, dibenzothiophene, phenanthryl, fluoranyl or carbazole; X 1 ~X 3 Each independently selected from CR 1 The R 1 It is independently selected from one of hydrogen, halogen, and C6-C30 aryl groups; Y 1 ~Y 8 Each independently selected from CR 2 The R 2 Independently selected from one of hydrogen, hydroxyl, C1-C10 alkoxy, and C6-C30 aryl. X is selected from S, O; Z 1 ~Z 8 Each independently selected from CR 3 The R 3 It is independently selected from one of hydrogen, cyano, aldehyde, C6~C30 arylamino, and C6~C30 aryl; When the above groups contain substituents, the substituents are selected from halogens, C1-C20 chain alkyl groups, C3-C20 cycloalkyl groups, and C6-C60 aryl groups.

2. The compound according to claim 1, characterized in that, Ar 1 and Ar 2 At least one of naphthyl and fluorenyl is selected.

3. The compound according to claim 1, characterized in that, R 2 and R 3 Both are hydrogen.

4. Compounds having the structures shown below: 。 5. An organic electroluminescent device, characterized in that, It includes a substrate, a first electrode, a second electrode, and at least one organic layer located between the first electrode and the second electrode, wherein the organic layer contains at least one compound according to any one of claims 1 to 4.

6. The organic electroluminescent device according to claim 5, characterized in that, The organic layer includes a hole transport layer, wherein the hole transport layer contains at least one compound according to any one of claims 1 to 4.

7. The organic electroluminescent device according to claim 5, characterized in that, The organic layer includes an electron blocking layer, wherein the electron blocking layer contains at least one compound according to any one of claims 1 to 4.

8. The use of the compound according to any one of claims 1 to 4 in an organic electroluminescent device, wherein the compound is used as a hole transport material or an electron blocking material in the organic electroluminescent device.

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