An aromatic amine derivative and its organic electroluminescent device

Abstract

This invention provides an aromatic amine derivative and its organic electroluminescent device, relating to the field of organic optoelectronic materials technology. The aromatic amine derivative provided by this invention has a specially linked fluorene ring structure, with a methyl fluorene structure linked at position 1 or 4, and aryl substitution within the benzene ring. This special linkage imparts a unique spatial configuration to the compound, improving hole transport efficiency. Organic electroluminescent devices prepared using the materials of this invention exhibit higher device efficiency and luminescence lifetime. Furthermore, fluorene compounds possess high molecular rigidity, exhibiting good thermal stability in industrial applications, and are simple to prepare with readily available raw materials, making them an ideal choice for organic electroluminescent device materials.

Description

Technical Field

[0001] This invention relates to the field of organic optoelectronic materials technology, and in particular to an aromatic amine derivative and its organic electroluminescent device. Background Technology

[0002] Organic light-emitting devices (OLEDs) are a new type of light-emitting device that uses an electric current to drive an organic semiconductor thin film to achieve light emission and display. With its superior properties such as thinness, flexibility, low power consumption, and surface light source, OLEDs have become a leader in next-generation full-color displays and solid-state lighting.

[0003] OLEDs typically consist of a "sandwich" structure with an anode and cathode sandwiching organic functional layers such as a hole transport layer, an emissive layer, and an electron transport layer. The principle involves using an ITO transparent electrode and a metal electrode as the anode and cathode, respectively. Under a certain voltage, electrons and holes are injected from the cathode and anode into the electron and hole transport layers, respectively. The electrons and holes then migrate through the electron and hole transport layers to the emissive layer, where they meet, forming excitons and exciting the light-emitting molecules. These molecules then emit visible light through radiative relaxation.

[0004] The hole transport layer (HTL) is a crucial component of organic functional layers. Its hole transport performance directly determines the transport and injection process of holes into the light-emitting layer, thus affecting the equilibrium recombination of charge carriers and ultimately influencing device performance. However, organic hole transport materials themselves suffer from several drawbacks, including low hole mobility, poor conductivity, and high injection barriers due to poor contact with metal electrodes, limiting improvements in device performance. Therefore, developing materials with high hole transport efficiency is essential for obtaining high-performance organic electroluminescent devices. Summary of the Invention

[0005] Technical issues

[0006] The present invention aims to first provide an aromatic amine derivative that can be used to prepare organic electroluminescent devices with low driving voltage and / or high luminous efficiency, and secondly, to provide an organic electroluminescent device containing the aromatic amine derivative, thereby solving the problems of low luminous efficiency and short lifespan of existing organic electroluminescent devices.

[0007] Technical solution

[0008] As a result of in-depth research to solve the above technical problems, the inventors of this invention have discovered that the aforementioned objective can be achieved by an aromatic amine derivative represented by the following formula (1), thus completing this invention.

[0009]

[0010] Wherein, Ar1 is selected from any group represented by formula (2) or formula (3) below:

[0011]

[0012] R5, R6, and R7 are independently selected from hydrogen, cyano, halogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted aliphatic rings having 3 to 30 carbon atoms, and fused cyclic groups of aromatic rings having 6 to 30 carbon atoms, or -SiRR'R”; R, R', and R” are independently selected from hydrogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 30 carbon atoms.

[0013] The R a R b It is independently selected from substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 30 carbon atoms;

[0014] The 'e' is selected from 0, 1, 2, 3, 4, or 5; the 'f' is selected from 0, 1, or 2; the 'g' is selected from 0, 1, 2, 3, or 4.

[0015] The n is selected from 1, 2, or 3;

[0016] The asterisk (*) indicates a binding site with an adjacent atom.

[0017] The Ar2 is selected from substituted or unsubstituted aryl groups having 6 to 60 carbon atoms, or substituted or unsubstituted aliphatic rings having 3 to 30 carbon atoms and aromatic rings having 6 to 30 carbon atoms in a fused ring group; wherein the substituents in "substituted or unsubstituted aryl groups" and "substituted or unsubstituted aliphatic rings having 3 to 30 carbon atoms and aromatic rings having 6 to 30 carbon atoms" are selected from cyano, halogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted aliphatic rings having 3 to 30 carbon atoms and aromatic rings having 6 to 30 carbon atoms in a fused ring group, or -SiR r R s R t One or more of the following, wherein, when substituted by multiple substituents, the multiple substituents may be the same or different from each other; the R r R s R t It is independently selected from hydrogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 30 carbon atoms;

[0018] L1 and L2 are independently selected from arylene groups with 6 to 30 carbon atoms that are either single-bonded or substituted or unsubstituted, or fused cyclic groups of aliphatic rings with 3 to 30 carbon atoms and aromatic rings with 6 to 30 carbon atoms.

[0019] R1, R2, R3, and R4 are independently selected from hydrogen, cyano, halogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted aliphatic rings having 3 to 30 carbon atoms, and fused ring groups of aromatic rings having 6 to 30 carbon atoms, -SiR m R n R p One of them; or two adjacent groups bonded to each other to form a substituted or unsubstituted ring; said R m R n R p It is independently selected from hydrogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 30 carbon atoms;

[0020] a, b, and c are independently selected from 0, 1, 2, 3, or 4; d is selected from 0, 1, 2, or 3.

[0021] The present invention also provides an organic electroluminescent device, comprising an anode, an organic layer, and a cathode, wherein the organic layer is located between the anode and the cathode or outside one or more electrodes of the anode and the cathode, and the organic layer contains the aromatic amine derivatives of the present invention described above.

[0022] Beneficial effects:

[0023] The aromatic amine derivatives of formula (1) provided by this invention have a spirofluorene structure and simultaneously connect fluorene structures with aryl substitutions at positions 1 or 4. This enhances molecular rigidity while effectively altering the intramolecular conjugated structure, increasing its energy level width, and achieving higher glass transition temperature and thermal stability. Furthermore, the aryl substitution at specific positions on the fluorene group allows for better spatial morphology and molecular stacking, while maintaining deep HOMO energy levels and high hole mobility. When the compounds of this invention are used as hole transport materials in organic electroluminescent devices, they effectively improve the driving voltage, luminous efficiency, and lifespan of the devices, especially significantly improving the device lifespan. Detailed Implementation

[0024] 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.

[0025] 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.

[0026] In this invention, "substituted or unsubstituted alkyl group having 1 to 30 carbon atoms" refers to the number of carbon atoms in the unsubstituted alkyl group, excluding the number of carbon atoms in the substituent. Similarly, "substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms" refers to the number of carbon atoms in the unsubstituted cycloalkyl group, excluding the number of carbon atoms in the substituent. And so on.

[0027] The alkyl group described in this invention refers to a monovalent group formed by removing one hydrogen atom from an alkane molecule. The alkyl group has 1 to 30 carbon atoms, preferably 1 to 20, more preferably 1 to 15, and even more preferably 1 to 10. Examples of alkyl groups include, but are not limited to, the following groups: methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, heptadecyl, etc.

[0028] The cycloalkyl group described in this invention refers to a monovalent group formed by removing one hydrogen atom from a cycloalkane molecule. The cycloalkyl group has 3 to 30 carbon atoms, preferably 3 to 20, more preferably 3 to 15, and even more preferably 3 to 10. Examples of the cycloalkyl group include, but are not limited to, the following groups: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, adamantyl, camphenyl, norbornyl, ferruginyl, isocamphenyl, etc.

[0029] The aryl group described in this invention refers to a monovalent group formed by removing one hydrogen atom from the aromatic carbon atom of an aromatic hydrocarbon molecule. The aryl group includes monocyclic aryl, polycyclic aryl, and fused-ring aryl groups. The number of carbon atoms in the aryl group is 6 to 60, preferably 6 to 20, more preferably 6 to 15, and even more preferably 6 to 12. Examples of the aryl group include, but are not limited to, the following groups: phenyl, biphenyl, terphenyl, tetraphenyl, pentaphenyl, naphthyl, indene, dihydroindene, dihydronaphthyl, tetrahydronaphthyl, phenanthrene, triphenylene, anthracene, pyrene, fluorenyl, spirodifluorenyl, spiroanthracenefluorenyl, benzo[a]fluorenyl, benzo[a]spirodifluorenyl, etc.

[0030] The fused ring groups of aliphatic and aromatic rings described in this invention refer to rings containing one or more aromatic rings and one or more aliphatic rings fused together by sharing two adjacent carbon atoms. The aromatic rings preferably have 6 to 30 carbon atoms, more preferably 6 to 18 carbon atoms, and most preferably 6 to 12 carbon atoms. The aliphatic rings preferably have 3 to 30 carbon atoms, more preferably 3 to 18 carbon atoms, more preferably 3 to 12 carbon atoms, and most preferably 3 to 7 carbon atoms. Examples include benzocyclopropane, benzocyclobutane, benzocyclopentane, benzocyclohexane, benzocycloheptane, benzocyclobutenyl, benzocyclopentenyl, benzocyclohexenyl, naphthocyclopropane, naphthocyclobutane, naphthocyclopentane, naphthocyclohexane, naphthocyclopentenyl, naphthocyclohexenyl, etc., but are not limited thereto.

[0031] In this invention, silyl group is a substituent including Si, having Si atoms directly linked as free radicals, and consisting of -SiRR'R" and -SiR". r R s R t or -SiR m R n R p Indicates: R, R', R”, R r R s R t R m R n R p They may be identical or different from each other, and are independently selected from hydrogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 30 carbon atoms. Specific examples of silyl groups may include, but are not limited to, trimethylsilyl, triethylsilyl, tripropylsilyl, tri-tert-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, etc.

[0032] The arylene group referred to in this invention refers to the general term for the divalent group remaining after removing two hydrogen atoms from the aromatic carbon atom of an aromatic compound molecule. It can be a monocyclic arylene, a polycyclic arylene, or a fused-ring arylene, preferably having 6 to 25 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 14 carbon atoms, and most preferably 6 to 12 carbon atoms. The monocyclic arylene includes, but is not limited to, phenylene; the polycyclic arylene includes, but is not limited to, biphenylene, terphenylene; and the fused-ring arylene includes, but is not limited to, naphthylene, anthracene, phenanthrene, fluorene, pyrene, trimethyleneene, fluorene, and phenylfluorene. The aforementioned arylene groups are preferably phenylene, biphenylene, terphenylene, naphthyl, fluorene, or phenylfluorene.

[0033] The fused aliphatic and aromatic ring groups described in this invention refer to the general term for divalent groups remaining after removing two hydrogen atoms from an aliphatic ring and an aromatic ring fused together. Preferably, they have 7 to 30 carbon atoms, more preferably 7 to 18 carbon atoms, and most preferably 7 to 12 carbon atoms. Examples may include, but are not limited to, benzo[a]cyclopropyl, benzo[a]cyclobutyl, benzo[a]cyclopentyl, benzo[a]cyclohexyl, benzo[a]cycloheptyl, benzo[a]cyclopentenyl, benzo[a]cyclohexenyl, benzo[a]cycloheptenyl, naphtho[a]cyclopropyl, naphtho[a]cyclobutyl, naphtho[a]cyclopentyl, and naphtho[a]cyclohexyl, etc.

[0034] In this invention, "substituted or unsubstituted" means unsubstituted or substituted by one or more substituents selected from the group consisting of: halogen atom, amino, cyano, nitro, substituted or unsubstituted alkyl with 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl with 3 to 30 carbon atoms, substituted or unsubstituted cycloalkenyl with 3 to 30 carbon atoms, substituted or unsubstituted heterocyclic with 3 to 30 carbon atoms, substituted or unsubstituted alkoxy with 3 to 30 carbon atoms, substituted or unsubstituted aryl with 6 to 60 carbon atoms, substituted or unsubstituted aryloxy with 6 to 60 carbon atoms, substituted or unsubstituted heteroaryl with 2 to 60 carbon atoms, silyl, preferably halogen atom, cyano, alkyl with 1 to 12 carbon atoms, cycloalkyl with 3 to 12 carbon atoms, aryl with 6 to 30 carbon atoms, silyl. In the case of substitution by multiple substituents, the multiple substituents may be the same or different from each other, or the multiple substituents may be linked together to form a ring.

[0035] Preferably, the term "substituted or unsubstituted" in this invention means either unsubstituted or substituted by one or more substituents selected from the group consisting of: fluorine, chlorine, bromine, iodine, cyano, nitro, methyl, trifluoromethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropane, methyl-substituted cyclopropane, ethyl-substituted cyclopropane, cyclobutane, methyl-substituted cyclobutane, ethyl-substituted cyclobutane, cyclopentane, methyl-substituted cyclopentane, ethyl-substituted cyclopentane, cyclohexane, methyl-substituted cyclohexane, ethyl-substituted cyclohexane, n-propyl-substituted cyclohexane, n-butyl-substituted cyclohexane, cyclohexane-substituted cyclohexane, cycloheptane, cyclopentenyl, methyl-substituted cyclopentenyl, ethyl-substituted cyclopentenyl, cyclohexenyl, cycloheptenyl, adamantyl, methyl-substituted adamantyl, ethyl-substituted adamantyl Argonyl, norbornyl, methyl-substituted norbornyl, ethyl-substituted norbornyl, tetrahydropyrrolyl, piperidinyl, morpholinyl, thiomorpholinyl, methyl-substituted piperazine, ethyl-substituted piperazine, phenyl-substituted piperazine, naphthyl-substituted piperazine, methoxy, ethoxy, phenyl, naphthyl, anthracene, phenanthrene, triphenylene, pyrene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, spirodifluorenyl, spiro-cyclopentyl-fluorenyl, Spiro-cyclohexyl-fluorenyl, spiro-adamantyl-fluorenyl, spiro-cyclopentenyl-fluorenyl, spiro-cyclohexenyl-fluorenyl, pyridyl, pyrimidinyl, triazinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, N-phenylcarbazoyl, dibenzofuranyl, dibenzothiophenyl, trimethylsilyl, triphenylsilyl, wherein when substituted with multiple substituents, the multiple substituents may be the same or different from each other, or the multiple substituents may be linked together to form a ring.

[0036] In this specification, 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.

[0037] For example, Can represent Can represent Can represent And so on.

[0038] In this specification, "adjacent" groups mean substituents that replace atoms directly bonded to the atoms substituted by the corresponding substituents, substituents that are spatially closest to the corresponding substituents, or other substituents that replace the atoms substituted by the corresponding substituents. For example, two substituents that replace the adjacent positions of a benzene ring and two substituents that replace the same carbon atom in an aliphatic ring can be interpreted as groups that are "adjacent" to each other.

[0039] The phrase "two adjacent groups bonded together to form a substituted or unsubstituted ring" as used in this invention refers to two groups being connected to each other by chemical bonds and optionally aromatized. The resulting ring can be an aliphatic ring or an aromatic hydrocarbon ring. Except for those not being monovalent groups, the structures exemplified above as cycloalkyl and aryl groups can be used. Preferably, in this invention, the resulting ring can be a three-membered ring, four-membered ring, five-membered ring, six-membered ring, seven-membered ring, eight-membered ring, fused ring, spirocyclic ring, etc., such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclopentene, cyclohexene, benzene, naphthalene, phenanthrene, triphenylene, pyridine, pyrimidine, quinoline, isoquinoline, quinazoline, quinoxaline, fluorene, dibenzofuran, dibenzothiophene, carbazole, etc., but is not limited thereto.

[0040] In the following text, an aromatic amine derivative according to one embodiment will be described.

[0041] According to one embodiment, the aromatic amine derivative is represented by the following formula (1).

[0042]

[0043] Wherein, Ar1 is selected from any group represented by formula (2) or formula (3) below:

[0044]

[0045] R5, R6, and R7 are independently selected from hydrogen, cyano, halogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted aliphatic rings having 3 to 30 carbon atoms, and fused rings of aromatic rings having 6 to 30 carbon atoms, or -SiRR'R”; R, R', and R” are independently selected from hydrogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 30 carbon atoms.

[0046] The R a R b It is independently selected from substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 30 carbon atoms;

[0047] The 'e' is selected from 0, 1, 2, 3, 4, or 5; the 'f' is selected from 0, 1, or 2; the 'g' is selected from 0, 1, 2, 3, or 4.

[0048] The n is selected from 1, 2, or 3;

[0049] The asterisk (*) indicates a binding site with an adjacent atom.

[0050] The Ar2 is selected from substituted or unsubstituted aryl groups having 6 to 60 carbon atoms, or substituted or unsubstituted aliphatic rings having 3 to 30 carbon atoms and aromatic rings having 6 to 30 carbon atoms in a fused ring group; wherein the substituents in "substituted or unsubstituted aryl groups" and "substituted or unsubstituted aliphatic rings having 3 to 30 carbon atoms and aromatic rings having 6 to 30 carbon atoms" are selected from cyano, halogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted aliphatic rings having 3 to 30 carbon atoms and aromatic rings having 6 to 30 carbon atoms in a fused ring group, or -SiR r R s R t One or more of the following, wherein, when substituted by multiple substituents, the multiple substituents may be the same or different from each other; the R r R s R t It is independently selected from hydrogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 30 carbon atoms;

[0051] L1 and L2 are independently selected from arylene groups with 6 to 30 carbon atoms that are either single-bonded or substituted or unsubstituted, or fused cyclic groups of aliphatic rings with 3 to 30 carbon atoms and aromatic rings with 6 to 30 carbon atoms.

[0052] R1, R2, R3, and R4 are independently selected from hydrogen, cyano, halogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted aliphatic rings having 3 to 30 carbon atoms, and fused ring groups of aromatic rings having 6 to 30 carbon atoms, -SiR m R n R p One of them; or two adjacent groups bonded to each other to form a substituted or unsubstituted ring; said R m R n R p It is independently selected from hydrogen, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 30 carbon atoms;

[0053] a, b, and c are independently selected from 0, 1, 2, 3, or 4; d is selected from 0, 1, 2, or 3.

[0054] Preferably, equation (1) can be represented by any one of equations (4) or (5):

[0055]

[0056] In equations (4) and (5), L1, L2, Ar2, R1, R2, R3, R4, R5, R6, R7, a, b, c, d, e, f, and g are as defined in equation (1) above.

[0057] Preferably, equation (1) can be represented by any one of the following equations (6), (7), (8) or (9):

[0058]

[0059] In formulas (6), (7), (8), or (9), L1, L2, Ar1, Ar2, R1, R2, R3, R4, a, b, c, and d are as defined in formula (1) above. Preferably, the Ar2 is selected from one of the following groups:

[0060]

[0061] Wherein, R8 is selected from hydrogen, cyano, halogen, substituted or unsubstituted groups of the following: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, trimethylsilyl, triphenylsilyl, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, adamantane, norbornel, phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, phenylenetriene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, 9-methyl-9phenylfluorenyl, spiro-difluorenyl, benzocyclopropane, benzocyclobutane, benzocyclopentane, benzocyclohexane, benzocycloheptane, any one or more of these groups, or two adjacent groups bonded to each other to form a substituted or unsubstituted ring; in the case of being substituted by multiple substituents, the multiple substituents may be the same or different from each other;

[0062] h1 is selected from 0, 1, 2, 3, 4, or 5; h2 is selected from 0, 1, 2, 3, or 4; h3 is selected from 0, 1, 2, or 3; h4 is selected from 0, 1, 2, 3, 4, 5, 6, or 7; h5 is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9; h6 is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11; h7 is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13; h8 is selected from 0, 1, or 2; h9 is selected from 0, 1, 2, 3, 4, 5, or 6; h 10 Selected from 0, 1, 2, 3, 4, 5, 6, 7, or 8; the h 11 Choose from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0063] Preferably, R1, R2, R3, and R4 are independently selected from hydrogen, cyano, halogen, substituted or unsubstituted groups of any one or more of the following: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, trimethylsilyl, triphenylsilyl, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, adamantane, norbornene, phenyl, biphenyl, terphenyl, and naphthyl. Alternatively, any two adjacent substituents of R1, R2, R3, and R4 may form a substituted or unsubstituted ring. In the case of substitution by multiple substituents, the multiple substituents may be the same as or different from each other.

[0064] Preferably, L1 and L2 are independently selected from single bonds or one of the following groups:

[0065]

[0066] R9 is selected from hydrogen, cyano, halogen, substituted or unsubstituted groups of the following: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, adamantane, norbornane, phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, benzocyclopropane, benzocyclobutane, benzocyclopentane, benzocyclohexane, benzocycloheptane, trimethylsilyl, triphenylsilyl, or any one or more of these groups, or any two adjacent substituents form a substituted or unsubstituted ring, wherein in the case of being substituted by multiple substituents, the multiple substituents are the same or different from each other;

[0067] The i1 is selected from 0, 1, 2, 3 or 4; the i2 is selected from 0, 1, 2 or 3; the i3 is selected from 0, 1, 2, 3, 4 or 5; the i4 is selected from 0, 1 or 2; the i5 is selected from 0, 1, 2, 3, 4, 5 or 6; and the i6 is selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8.

[0068] Preferably, the aromatic amine derivative represented by formula (1) is selected from one of the following structures:

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082] The above lists some specific chemical structures of the aromatic amine derivatives of the present invention with structural formula (1). However, the present invention is not limited to these listed chemical structures. Any aromatic amine derivative based on structural formula (1) with substituents as defined above should be included.

[0083] Furthermore, the present invention also provides an organic electroluminescent device, comprising an anode, an organic layer, and a cathode, wherein the organic layer is located between the anode and the cathode or outside one or more electrodes of the anode and the cathode, and the organic layer contains the amine compound described in the present invention.

[0084] Preferably, the organic layer includes a hole transport region containing the aromatic amine derivative of the present invention described above.

[0085] Preferably, the hole transport region includes at least one of a hole injection layer and a hole transport layer, the hole transport layer being located between the hole injection layer and the cathode, and at least one of the hole injection layer and the hole transport layer containing the aromatic amine derivative of the present invention described above.

[0086] Preferably, the hole transport region includes a hole transport layer, and the hole transport layer contains the aromatic amine derivative of the present invention described above.

[0087] The light-emitting device of the present invention is typically formed on a substrate. The substrate need not change during the formation of electrodes and organic layers; for example, a plate made of glass, quartz, or plastic can be used. Alternatively, a flexible substrate can be used. Examples of flexible substrates include plastic substrates formed of polycarbonate, polyarylate, polyethersulfone, polypropylene, polyester, polyvinyl fluoride, and polyvinyl chloride. Inorganic vapor-deposited films can also be used. When the substrate is opaque, the electrodes opposite it are preferably transparent or translucent.

[0088] anode

[0089] The anode formed on the substrate is preferably a metal, alloy, conductive compound, or mixture thereof with a high work function (specifically 4.0 eV or higher). Examples of suitable materials include indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide, indium oxide containing tungsten oxide and zinc oxide, and graphene. Other suitable materials include gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium (Ti), or nitrides of these metals (e.g., titanium nitride), but are not limited to these. The anode can be formed into a multilayer structure of two or more layers, such as ITO / Ag / ITO. Preferably, the anode of the present invention uses a transparent ITO substrate.

[0090] Hole injection layer

[0091] A hole injection layer is a layer containing a material with high hole injection properties (hole injection material), formed between the anode and the light-emitting layer, or between the hole transport layer and the anode in the presence of a hole transport layer. Hole injection materials can include, but are not limited to, molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide, and manganese oxide.

[0092] Hole transport layer

[0093] The hole transport layer is a layer containing a material with high hole transportability (hole transport material), formed between the anode and the light-emitting layer, or between the hole injection layer and the light-emitting layer in the presence of a hole injection layer. The hole transport layer can be a single-layer structure or a multi-layer structure containing two or more layers. For example, the hole transport layer can be a two-layer structure containing a first hole transport layer (anode side) and a second hole transport layer (cathode side). In one embodiment of the invention, the hole transport layer of the aforementioned single-layer structure is preferably adjacent to the light-emitting layer, or is the hole transport layer closest to the anode in the aforementioned multi-layer structure.

[0094] The hole transport layer is preferably composed of a material with high hole mobility, such as aromatic amine compounds, carbazole derivatives, anthracene derivatives, polymeric compounds, etc., but is not limited to these. Preferably, the hole transport layer is selected from any one or a combination of at least two of the aromatic amine derivatives described in this invention.

[0095] dopant material of the light-emitting layer

[0096] The dopant for the luminescent layer can be made of various materials. For example, fluorescent luminescent materials and phosphorescent luminescent materials can be used as dopant materials. Fluorescent luminescent materials are compounds that emit light using a singlet excited state, and phosphorescent luminescent materials are compounds that emit light using a triplet excited state, etc., but are not limited to these.

[0097] The main material of the light-emitting layer

[0098] The light-emitting layer can be configured by dispersing the aforementioned dopant material within other materials (the host material). Preferably, a material with a lower least occupied orbital (LUMO) energy level higher than the dopant material and a higher highest occupied orbital (HOMO) energy level lower than the dopant material is used. As the host material, examples include metal complexes, heterocyclic compounds, fused aromatic compounds, and aromatic amine compounds, but are not limited to these.

[0099] Electron transport layer

[0100] The electron transport layer is a layer containing a material with high electron transport properties (electron transport material), formed between the light-emitting layer and the cathode, or between the electron injection layer and the light-emitting layer in the presence of an electron injection layer. Examples of suitable materials include, but not limited to, metal complexes such as aluminum complexes, beryllium complexes, and zinc complexes, imidazole derivatives, benzimidazole derivatives, azazine derivatives, carbazole derivatives, phenanthroline derivatives, and other heteroaromatic compounds and polymers.

[0101] Electron injection layer

[0102] An electron injection layer is a layer containing a material with high electron injection properties (electron injection material), formed between the cathode and the light-emitting layer, or between the electron transport layer and the cathode in the presence of an electron transport layer. Alkali metals such as lithium (Li) and cesium (Cs), alkaline earth metals such as magnesium (Mg), calcium (Ca), and strontium (Sr), rare earth metals such as europium (Eu) and ytterbium (Yb), and compounds containing these metals can be used. Examples of such compounds include, but are not limited to, alkali metal oxides, alkali metal halides, alkali metal-containing organic complexes, alkaline earth metal oxides, alkaline earth metal halides, alkaline earth metal-containing organic complexes, rare earth metal oxides, rare earth metal halides, and rare earth metal-containing organic complexes.

[0103] cathode

[0104] The cathode preferably uses metals, alloys, conductive compounds, and mixtures thereof with low work functions (specifically, below 3.8 eV). Specific examples of such cathode materials include elements belonging to Group 1 or Group 2 of the periodic table, namely alkali metals such as lithium (Li) and cesium (Cs), alkaline earth metals such as magnesium (Mg), calcium (Ca), and strontium (Sr), as well as alloys containing them (e.g., MgAg, AlLi), rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing them, but are not limited to these.

[0105] The layers of the aforementioned organic electroluminescent device can be formed using conventionally known methods such as vapor deposition and coating. For example, any one of vacuum vapor deposition, spin coating, vapor deposition, blade coating, laser thermal transfer, electrospray coating, slot coating, and dip coating can be used. In this invention, vacuum vapor deposition is preferred.

[0106] There are no particular restrictions on the thickness of each layer. Generally speaking, if the film thickness is too thin, defects such as pinholes are likely to occur. Conversely, if the film thickness is too thick, a high driving voltage is required and the efficiency will be reduced. Therefore, the thickness is usually 5nm to 10μm, and more preferably 10nm to 0.2μm.

[0107] The organic electroluminescent device described in this invention can be widely used in information display technology, lighting sources, flexible OLEDs, electronic paper, organic solar cells, organic photosensitive materials or organic thin-film transistors, signs, traffic lights, and other fields. In information display, it is widely used in various information displays, such as mobile phones, tablets, televisions, wearable devices, VR, smartwatches, digital cameras, vehicle displays, and taillights.

[0108] The present invention will be further described in detail below using examples, but the present invention is not limited to the following examples.

[0109] Synthesis Examples

[0110] Raw materials and reagents: 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. All raw materials and reagents used in this invention are of reagent purity.

[0111] Instruments: G2-Si quadrupole tandem time-of-flight high-resolution mass spectrometer (Waters Corporation, UK); Vario ELcube organic elemental analyzer (Elementar Corporation, Germany).

[0112] There are no particular limitations on the preparation method of the aromatic amine derivative of structural formula (1) of the present invention, and conventional methods well known to those skilled in the art can be used. For example, carbon-nitrogen coupling reaction, carbon-carbon coupling reaction, etc. For example, the aromatic amine derivative of structural formula (1) of the present invention can be prepared by the following synthetic route.

[0113]

[0114] X1 and X2 are halogen atoms, which may be the same or different and selected from I, Br, and Cl.

[0115] Synthesis Example 1: Preparation of Compound 1

[0116]

[0117] Preparation of intermediate C-1:

[0118] Under nitrogen protection, e-1 (10.77 g, 35.00 mmol), f-1 (4.27 g, 35.00 mmol), Pd(PPh3)4 (0.49 g, 0.42 mmol), potassium carbonate (7.74 g, 56.00 mmol), and 250 mL of a toluene / ethanol / water (2:1:1) mixture were added sequentially to a reaction flask. The mixture was stirred and refluxed for 3 hours. After the reaction was complete, the mixture was cooled to room temperature, filtered, and the filter cake was obtained. The filter cake was washed with ethanol, and finally recrystallized from the filter cake with ethyl acetate to obtain intermediate C-1 (8.85 g, yield 83%) with an HPLC purity ≥99.71%. Mass spectrometry m / z: 304.1011 (theoretical value: 304.1019).

[0119] Preparation of intermediate I-1:

[0120] Under nitrogen protection, a-1 (13.84 g, 35.00 mmol), b-1 (3.26 g, 35.00 mmol), sodium tert-butoxide (5.05 g, 52.50 mmol), Pd(OAc)2 (0.08 g, 0.35 mmol), P(t-Bu)3 (1.40 mL, 0.70 mmol, 0.5 M toluene solution), and 250 mL of toluene were added sequentially to the reaction flask. The mixture was stirred and refluxed for 4.5 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled water was added, and the mixture was extracted with dichloromethane. The mixture was allowed to stand and separated, and the organic layer was collected, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated by vacuum distillation. The mixture was cooled to crystallize, filtered, and the resulting solid was recrystallized from toluene / ethanol (6:1, v / v) to give intermediate I-1 (11.55 g, yield 81%) with an HPLC purity ≥ 99.88%. Mass spectrometry m / z: 407.1687 (theoretical value: 407.1674).

[0121] Preparation of compound 1:

[0122] Under nitrogen protection, intermediates I-1 (10.19 g, 25 mmol), C-1 (7.62 g, 25 mmol), sodium tert-butoxide (4.81 g, 50 mmol), Pd2(dba)3 (0.23 g, 0.25 mmol), X-Phos (0.24 g, 0.50 mmol), and 150 ml of toluene were added sequentially to a reaction flask. The mixture was stirred and refluxed for 5.5 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled water was added, and the mixture was extracted with dichloromethane. The layers were allowed to stand and separated, and the organic layer was collected, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated by vacuum distillation. Crystals were precipitated by cooling and filtered. The resulting solid was recrystallized from toluene to give compound 1 (13.35 g, 79%) with an HPLC purity ≥ 99.96%. Mass spectrometry m / z: 675.2945 (theoretical value: 675.2926). Theoretical elemental content (%) C 52 H 37 N: C, 92.41; H, 5.52; N, 2.07. Measured elemental content (%): C, 92.43; H, 5.53; N, 2.04.

[0123] Synthesis Example 2: Preparation of Compound 27

[0124]

[0125] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-6 and b-1 were replaced with equimolar amounts of e-27 and b-27, respectively, to obtain Compound 27 (15.17 g), with an HPLC purity ≥ 99.92%. Mass spectrometry m / z: 787.4189 (theoretical value: 787.4178). Theoretical elemental content (%) C 60 H 53 N: C, 91.44; H, 6.78; N, 1.78. Measured elemental content (%): C, 91.42; H, 6.77; N, 1.79.

[0126] Synthesis Example 3: Preparation of Compound 38

[0127]

[0128] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-6 and b-1 were replaced with equimolar amounts of e-38 and b-38, respectively, to obtain Compound 38 (14.38 g), with an HPLC purity ≥ 99.94%. Mass spectrometry m / z: 747.3333 (theoretical value: 747.3321). Theoretical elemental content (%) C 55 H 45NSi: C, 88.31; H, 6.06; N, 1.87. Measured elemental content (%): C, 88.33; H, 6.07; N, 1.85.

[0129] Synthesis Example 4: Preparation of Compound 65

[0130]

[0131] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-6 and b-1 were replaced with equimolar amounts of e-27 and b-65, respectively, to obtain Compound 65 (14.59 g), with an HPLC purity ≥ 99.93%. Mass spectrometry m / z: 809.4010 (theoretical value: 809.4022). Theoretical elemental content (%) C 62 H 51 N: C, 91.93; H, 6.35; N, 1.73. Measured element content (%): C, 91.94; H, 6.37; N, 1.74.

[0132] Synthesis Example 5: Preparation of Compound 72

[0133]

[0134] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of a-1 and b-1 were replaced with equimolar amounts of a-72 and b-72, respectively, to obtain Compound 72 (15.98 g), with an HPLC purity ≥ 99.95%. Mass spectrometry m / z: 769.3719 (theoretical value: 769.3709). Theoretical elemental content (%) C 59 H 47 N: C, 92.03; H, 6.15; N, 1.82. Measured element content (%): C, 92.02; H, 6.17; N, 1.83.

[0135] Synthesis Example 6: Preparation of Compound 86

[0136]

[0137] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1, f-1, a-1, and b-1 were replaced with equimolar amounts of e-38, f-86, a-86, and b-72, respectively, to obtain Compound 86 (16.75 g), with an HPLC purity ≥ 99.93%. Mass spectrometry m / z: 869.4037 (theoretical value: 869.4022). Theoretical elemental content (%) C 67 H 51N: C, 92.48; H, 5.91; N, 1.61. Measured elemental content (%): C, 92.46; H, 5.92; N, 1.62.

[0138] Synthesis Example 7: Preparation of Compound 88

[0139]

[0140] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of b-1 were replaced with equimolar amounts of b-88 to obtain Compound 88 (15.04 g), with an HPLC purity ≥ 99.97%. Mass spectrometry m / z: 751.3242 (theoretical value: 751.3229). Theoretical elemental content (%) C 58 H 41 N: C, 92.64; H, 5.50; N, 1.86. Measured element content (%): C, 92.62; H, 5.49; N, 1.88.

[0141] Synthesis Example 8: Preparation of Compound 105

[0142]

[0143] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1 and b-1 were replaced with equimolar amounts of e-27 and b-105, respectively, to obtain Compound 105 (14.94 g), with an HPLC purity ≥ 99.96%. Mass spectrometry m / z: 765.3379 (theoretical value: 765.3396). Theoretical elemental content (%) C 59 H 43 N: C, 92.51; H, 5.66; N, 1.83. Measured element content (%): C, 92.53; H, 5.65; N, 1.82.

[0144] Synthesis Example 9: Preparation of Compound 133

[0145]

[0146] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1, a-1, and b-1 were replaced with equimolar amounts of e-38, a-133, and b-88, respectively, to obtain Compound 133 (16.85 g), with an HPLC purity ≥ 99.95%. Mass spectrometry m / z: 863.4491 (theoretical value: 863.4491). Theoretical elemental content (%) C 66 H 57 N: C, 91.73; H, 6.65; N, 1.62. Measured element content (%): C, 91.74; H, 6.63; N, 1.63.

[0147] Synthetic Example 10: Preparation of Compound 140

[0148]

[0149] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1, a-1, and b-1 were replaced with equimolar amounts of e-38, a-140, and b-140, respectively, to obtain Compound 140 (15.72 g), with an HPLC purity ≥ 99.93%. Mass spectrometry m / z: 805.3725 (theoretical value: 805.3709). Theoretical elemental content (%) C 62 H 47 N: C, 92.38; H, 5.88; N, 1.74. Measured element content (%): C, 92.39; H, 5.86; N, 1.73.

[0150] Synthetic Example 11: Preparation of Compound 165

[0151]

[0152] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1, a-1, and b-1 were replaced with equimolar amounts of e-165, a-165, and b-165, respectively, to obtain Compound 165 (17.41 g), with an HPLC purity ≥ 99.94%. Mass spectrometry m / z: 903.3875 (theoretical value: 903.3865). Theoretical elemental content (%) C 70 H 49 N: C, 92.99; H, 5.46; N, 1.55. Measured elemental content (%): C, 92.97; H, 5.47; N, 1.56.

[0153] Synthesis Example 12: Preparation of Compound 174

[0154]

[0155] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1 and b-1 were replaced with equimolar amounts of e-174 and b-174, respectively, to obtain Compound 174 (16.15 g), with an HPLC purity ≥ 99.96%. Mass spectrometry m / z: 827.3544 (theoretical value: 827.3552). Theoretical elemental content (%) C 64 H 45 N: C, 92.83; H, 5.48; N, 1.69. Measured elemental content (%): C, 92.81; H, 5.49; N, 1.70.

[0156] Synthetic Example 13: Preparation of Compound 187

[0157]

[0158] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1 and b-1 were replaced with equimolar amounts of e-27 and b-187, respectively, to obtain Compound 187 (16.35 g), with an HPLC purity ≥ 99.93%. Mass spectrometry m / z: 827.3543 (theoretical value: 827.3552). Theoretical elemental content (%) C 64 H 45 N: C, 92.83; H, 5.48; N, 1.69. Measured elemental content (%): C, 92.84; H, 5.50; N, 1.68.

[0159] Synthesis Example 14: Preparation of Compound 217

[0160]

[0161] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1, a-1, and b-1 were replaced with equimolar amounts of e-27, a-217, and b-217, respectively, to obtain Compound 217 (14.16 g), with an HPLC purity ≥ 99.93%. Mass spectrometry m / z: 725.3072 (theoretical value: 725.3083). Theoretical elemental content (%) C 56 H 39 N: C, 92.66; H, 5.42; N, 1.93. Measured element content (%): C, 92.68; H, 5.41; N, 1.92.

[0162] Synthesis Example 15: Preparation of Compound 222

[0163]

[0164] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of b-1 were replaced with equimolar amounts of b-222 to obtain Compound 222 (15.05 g), with an HPLC purity ≥ 99.95%. Mass spectrometry m / z: 781.3728 (theoretical value: 781.3709). Theoretical elemental content (%) C 60 H 47 N: C, 92.15; H, 6.06; N, 1.79. Measured element content (%): C, 92.14; H, 6.05; N, 1.81.

[0165] Synthesis Example 16: Preparation of Compound 228

[0166]

[0167] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1 and b-1 were replaced with equimolar amounts of e-165 and b-228, respectively, to obtain Compound 228 (15.44 g), with an HPLC purity ≥ 99.96%. Mass spectrometry m / z: 801.3382 (theoretical value: 801.3396). Theoretical elemental content (%) C 62 H 43 N: C, 92.85; H, 5.40; N, 1.75. Measured element content (%): C, 92.86; H, 5.38; N, 1.76.

[0168] Synthetic Example 17: Preparation of Compound 255

[0169]

[0170] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of a-1 and b-1 were replaced with equimolar amounts of a-133 and b-255, respectively, to obtain Compound 255 (17.37 g), with an HPLC purity ≥ 99.92%. Mass spectrometry m / z: 913.4660 (theoretical value: 913.4648). Theoretical elemental content (%) C 70 H 59 N: C, 91.96; H, 6.51; N, 1.53. Measured element content (%): C, 91.93; H, 6.52; N, 1.54.

[0171] Synthesis Example 18: Preparation of Compound 266

[0172]

[0173] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of b-1 were replaced with equimolar amounts of b-266 to obtain Compound 266 (15.25 g), with an HPLC purity ≥ 99.93%. Mass spectrometry m / z: 791.3565 (theoretical value: 791.3552). Theoretical elemental content (%) C 61 H 45 N: C, 92.50; H, 5.73; N, 1.77. Measured elemental content (%): C, 92.48; H, 5.74; N, 1.78.

[0174] Synthetic Example 19: Preparation of Compound 295

[0175]

[0176] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1 and b-1 were replaced with equimolar amounts of e-38 and b-295, respectively, to obtain Compound 295 (16.62 g), with an HPLC purity ≥ 99.95%. Mass spectrometry m / z: 851.3534 (theoretical value: 851.3552). Theoretical elemental content (%) C 66 H 45 N: C, 93.03; H, 5.32; N, 1.64. Measured element content (%): C, 93.05; H, 5.31; N, 1.63.

[0177] Synthesis Example 20: Preparation of Compound 301

[0178]

[0179] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of a-1 and b-1 were replaced with equimolar amounts of a-217 and b-301, respectively, to obtain Compound 301 (16.62 g), with an HPLC purity ≥ 99.93%. Mass spectrometry m / z: 851.3545 (theoretical value: 851.3552). Theoretical elemental content (%) C 66 H 45 N: C, 93.03; H, 5.32; N, 1.64. Measured elemental content (%): C, 93.04; H, 5.33; N, 1.62.

[0180] Synthesis Example 21: Preparation of Compound 307

[0181]

[0182] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1, a-1, and b-1 were replaced with equimolar amounts of e-38, a-307, and b-307, respectively, to obtain Compound 307 (18.25 g) with an HPLC purity ≥ 99.91%. Mass spectrometry m / z: 959.4499 (theoretical value: 959.4491). Theoretical elemental content (%) C 74 H 57 N: C, 92.56; H, 5.98; N, 1.46. Measured element content (%): C, 92.54; H, 5.97; N, 1.45.

[0183] Synthesis Example 22: Preparation of Compound 311

[0184]

[0185] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of b-1 were replaced with equimolar amounts of b-311 to obtain Compound 311 (15.64 g), with an HPLC purity ≥ 99.96%. Mass spectrometry m / z: 791.3566 (theoretical value: 791.3552). Theoretical elemental content (%) C 61 H 45 N: C, 92.50; H, 5.73; N, 1.77. Measured elemental content (%): C, 92.52; H, 5.72; N, 1.76.

[0186] Synthesis Example 23: Preparation of Compound 337

[0187]

[0188] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1 and b-1 were replaced with equimolar amounts of e-38 and b-337, respectively, to obtain Compound 337 (16.71 g), with an HPLC purity ≥ 99.95%. Mass spectrometry m / z: 867.3877 (theoretical value: 867.3865). Theoretical elemental content (%) C 67 H 49 N: C, 92.70; H, 5.69; N, 1.61. Measured elemental content (%): C, 92.68; H, 5.70; N, 1.62.

[0189] Synthesis Example 24: Preparation of Compound 345

[0190]

[0191] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1 and b-1 were replaced with equimolar amounts of e-165 and b-345, respectively, to obtain Compound 345 (18.70 g), with an HPLC purity ≥ 99.93%. Mass spectrometry m / z: 983.4473 (theoretical value: 983.4491). Theoretical elemental content (%) C 76 H 57 N: C, 92.74; H, 5.84; N, 1.42. Measured element content (%): C, 92.76; H, 5.85; N, 1.39.

[0192] Synthesis Example 25: Preparation of Compound 359

[0193]

[0194] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of a-1, e-1, and b-1 were replaced with equimolar amounts of a-359, e-165, and b-359, respectively, to obtain Compound 359 (18.70 g), with an HPLC purity ≥ 99.94%. Mass spectrometry m / z: 917.4038 (theoretical value: 917.4022). Theoretical elemental content (%) C 71 H 51 N: C, 92.88; H, 5.60; N, 1.53. Measured element content (%): C, 92.86; H, 5.61; N, 1.54.

[0195] Synthesis Example 26: Preparation of Compound 362

[0196]

[0197] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of b-1 were replaced with equimolar amounts of b-362 to obtain Compound 362 (15.54 g), with an HPLC purity ≥ 99.93%. Mass spectrometry m / z: 817.3721 (theoretical value: 817.3709). Theoretical elemental content (%) C 63 H 47 N: C, 92.50; H, 5.79; N, 1.71. Measured element content (%): C, 92.48; H, 5.80; N, 1.72.

[0198] Synthesis Example 27: Preparation of Compound 366

[0199]

[0200] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1 and b-1 were replaced with equimolar amounts of e-38 and b-337, respectively, to obtain Compound 366 (16.80 g), with an HPLC purity ≥ 99.93%. Mass spectrometry m / z: 883.4166 (theoretical value: 883.4178). Theoretical elemental content (%) C 68 H 53 N: C, 92.37; H, 6.04; N, 1.58. Measured elemental content (%): C, 92.35; H, 6.05; N, 1.60.

[0201] Synthesis Example 28: Preparation of Compound 385

[0202]

[0203] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of b-1 were replaced with equimolar amounts of b-385 to obtain Compound 385 (17.18 g), with an HPLC purity ≥ 99.94%. Mass spectrometry m / z: 915.3877 (theoretical value: 915.3865). Theoretical elemental content (%) C 71 H 49 N: C, 93.08; H, 5.39; N, 1.53. Measured element content (%): C, 93.09; H, 5.40; N, 1.51.

[0204] Synthesis Example 29: Preparation of Compound 392

[0205]

[0206] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1 and b-1 were replaced with equimolar amounts of e-165 and b-392, respectively, to obtain Compound 392 (17.70 g), with an HPLC purity ≥ 99.94%. Mass spectrometry m / z: 943.4195 (theoretical value: 943.4178). Theoretical elemental content (%) C 73 H 53 N: C, 92.86; H, 5.66; N, 1.48. Measured elemental content (%): C, 92.87; H, 5.68; N, 1.47.

[0207] Synthesis Example 30: Preparation of Compound 411

[0208]

[0209] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1 and b-1 were replaced with equimolar amounts of e-38 and b-411, respectively, to obtain Compound 411 (17.37 g), with an HPLC purity ≥ 99.94%. Mass spectrometry m / z: 913.3702 (theoretical value: 913.3709). Theoretical elemental content (%) C 71 H 47 N: C, 93.29; H, 5.18; N, 1.53. Measured element content (%): C, 93.30; H, 5.19; N, 1.51.

[0210] Synthesis Example 31: Preparation of Compound 425

[0211]

[0212] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of e-1 and b-1 were replaced with equimolar amounts of e-38 and b-425, respectively, to obtain Compound 425 (17.69 g), with an HPLC purity ≥ 99.92%. Mass spectrometry m / z: 955.4159 (theoretical value: 955.4178). Theoretical elemental content (%) C 74 H 53 N: C, 92.95; H, 5.59; N, 1.46. Measured element content (%): C, 92.94; H, 5.60; N, 1.47.

[0213] Synthesis Example 32: Preparation of Compound 436

[0214]

[0215] Following the same preparation method as Compound 1 in Synthesis Example 1, equimolar amounts of a-1 and b-1 were replaced with equimolar amounts of a-436 and b-436, respectively, to obtain Compound 436 (14.84 g), with an HPLC purity ≥ 99.92%. Mass spectrometry m / z: 801.3379 (theoretical value: 801.3396). Theoretical elemental content (%) C 62 H 43 N: C, 92.85; H, 5.40; N, 1.75. Measured element content (%): C, 92.86; H, 5.39; N, 1.74.

[0216] Device Examples

[0217] In this invention, the ITO glass substrate is ultrasonically cleaned twice with a 5% glass cleaning solution for 20 minutes each time, followed by ultrasonic cleaning twice with deionized water for 10 minutes each time. It is then ultrasonically cleaned sequentially with acetone and isoacetone for 20 minutes each time, and dried at 120°C. All organic materials are sublimated and have a purity of over 99.99%.

[0218] A combined IVL testing system was constructed, consisting of testing software, a computer, a Keithley K2400 digital source meter, and a PhotoResearch PR788 spectrophotometer, to test the driving voltage, luminous efficiency, and CIE color coordinates of organic electroluminescent devices. Lifetime testing was performed using a McScience M6000 OLED lifetime testing system. The testing environment was ambient air at room temperature.

[0219] The device was fabricated using a vacuum evaporation system, with continuous evaporation under uninterrupted vacuum conditions. The materials used were housed in separate quartz crucibles containing different evaporation sources, the temperatures of which could be individually controlled. The thermal evaporation rate of organic materials was typically set at 0.1 nm / s, while the evaporation rate of electrode metals ranged from 0.4 to 0.6 nm / s. The prepared glass substrate was then placed in an OLED vacuum coating machine. During the thin film fabrication process, the system vacuum level should be maintained at 5 × 10⁻⁶. -5 Below Pa, organic layers and metal electrodes were deposited by changing the mask. The deposition rate was measured using an Inficon SQM160 quartz crystal film thickness gauge, and the film thickness was measured using a quartz crystal oscillator.

[0220] Example 1: Fabrication of Organic Electroluminescent Device 1

[0221] ITO is used as the anode on a glass substrate; a hole injection layer of 60 nm HAT-CN is vacuum-deposited on the anode; an 80 nm compound 1 of the present invention is vacuum-deposited on the hole transport layer to form a hole transport layer; a light-emitting layer of 35 nm BCzPh:Ir(piq)2(acac) (3wt%) is vacuum-deposited on the hole transport layer; a hole blocking layer of 5 nm NTAZ is vacuum-deposited on the light-emitting layer; an electron transport layer of 25 nm Alq3 is vacuum-deposited on the hole blocking layer; an electron injection layer of 1.0 nm Liq is vacuum-deposited on the electron transport layer; and a cathode of 130 nm Al is vacuum-deposited on the electron injection layer.

[0222] Examples 2-32: Fabrication of Organic Electroluminescent Devices 2-32

[0223] Replacing compound 1 in the hole transport layer of Example 1 with compounds 27, 38, 65, 72, 86, 88, 105, 133, 140, 165, 174, 187, 217, 222, 228, 255, 266, 295, 301, 307, 311, 337, 345, 359, 362, 366, 385, 392, 411, 425, and 436 respectively, while keeping the other steps the same, organic electroluminescent devices 2-32 are obtained.

[0224] Comparative Examples 1-5: Fabrication of Comparative Organic Electroluminescent Devices 1-5

[0225] By replacing compound 1 in the hole transport layer of Example 1 with HT-1, HT-2, HT-3, HT-4 or HT-5 respectively, and keeping the other steps the same, comparative organic electroluminescent devices 1 to 5 were obtained.

[0226]

[0227] The luminescence characteristics test results of the organic electroluminescent devices prepared in Examples 1 to 32 and Comparative Examples 1 to 5 of the present invention are shown in Table 1.

[0228] Table 1. Test data on the luminescence characteristics of organic electroluminescent devices.

[0229]

[0230]

[0231] Note: T95 refers to a current density of 10 mA / cm². 2 Under certain conditions, the time it takes for the device's brightness to decay to 95%;

[0232] As can be seen from Table 1, compared with comparative devices 1-5, when the compound of the present invention is used as the hole transport material of organic electroluminescent devices, it can effectively improve the driving voltage, luminous efficiency, and lifespan of organic electroluminescent devices, especially the lifespan of the devices is significantly improved. This is because the aromatic amine derivative of structural formula (1) of the present invention contains a methyl fluorene structure with 1- or 4-position linkage and aryl substitution within the benzene ring. This special linkage gives the compound of the present application a special spatial configuration. This special spatial structure can improve the hole transport efficiency and give the compound of the present application a higher hole mobility. Therefore, when the aromatic amine derivative of the present invention is used in the hole transport layer of organic electroluminescent devices, the devices will exhibit better photoelectric performance, especially with a significant improvement in lifespan.

[0233] It should be noted that the present invention has been specifically described with reference to individual embodiments, but those skilled in the art can make various forms or details of improvements to the present invention without departing from the principles of the present invention, and these improvements also fall within the protection scope of the present invention.

Claims

1. An aromatic amine derivative, characterized in that, It has the general formula shown in equation (1): Wherein, Ar1 is selected from any group represented by formula (2) or formula (3) below: R5 is independently selected from hydrogen, cyano, halogen, substituted or unsubstituted alkyl with 1 to 10 carbon atoms, substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl; R6 and R7 are independently selected from hydrogen, cyano, halogen, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms; The R a R b Independently selected from substituted or unsubstituted alkyl groups having 1 to 6 carbon atoms; The 'e' is selected from 0, 1, 2, 3, 4, or 5; the 'f' is selected from 0, 1, or 2; the 'g' is selected from 0, 1, 2, 3, or 4. The n is selected from 1; The asterisk (*) indicates a binding site with an adjacent atom. The Ar2 is selected from one of the following groups: The R8 is selected from hydrogen, cyano, halogen, substituted or unsubstituted groups of any one or more of the following: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, trimethylsilyl, triphenylsilyl, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, adamantane, norbornyl, phenyl, biphenyl; when substituted by multiple substituents, the multiple substituents may be the same as or different from each other; h1 is selected from 0, 1, 2, 3, 4, or 5; h2 is selected from 0, 1, 2, 3, or 4; h3 is selected from 0, 1, 2, or 3; h4 is selected from 0, 1, 2, 3, 4, 5, 6, or 7; h5 is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9; h8 is selected from 0, 1, or 2; h9 is selected from 0, 1, 2, 3, 4, 5, or 6; h 10 Selected from 0, 1, 2, 3, 4, 5, 6, 7, or 8; the h 11 Select from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; The L1 is selected from a single bond or one of the following groups: The L2 is selected from a single bond or one of the following groups: The R9 is selected from hydrogen, cyano, halogen, substituted or unsubstituted groups of the following: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and when substituted by multiple substituents, the multiple substituents may be the same or different from each other. The i1 is selected from 0, 1, 2, 3 or 4; R1, R2, R3, and R4 are independently selected from hydrogen, cyano, halogen, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted phenyl groups; or two adjacent groups are bonded to each other to form a substituted or unsubstituted benzene ring; a, b, and c are independently selected from 0, 1, 2, 3, or 4; d is selected from 0, 1, 2, or 3. The term "substituted or unsubstituted" means either unsubstituted or substituted with one or more substituents selected from the group consisting of: fluorine, chlorine, bromine, iodine, cyano, methyl, trifluoromethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, ... tert-butyl; The condition is that the aromatic amine derivative is not:

2. The aromatic amine derivative according to claim 1, characterized in that, The aromatic amine derivative is selected from the general formula shown in either formula (4) or formula (5) below: In Equations (4) and (5), L1, L2, Ar2, R1, R2, R3, R4, R5, R6, R7, a, b, c, d, e, f, and g are the same as those defined in claim 1.

3. The aromatic amine derivative according to claim 1, characterized in that, The Ar2 is selected from one of the following groups: The R8 is selected from hydrogen, substituted or unsubstituted groups of the following: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, trimethylsilyl, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, adamantane, norbornane; in the case of being substituted by multiple substituents, the multiple substituents may be the same as or different from each other.

4. The aromatic amine derivative according to claim 1, characterized in that, R1, R2, R3, and R4 are independently selected from hydrogen, substituted or unsubstituted groups of the following: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and when substituted by multiple substituents, the multiple substituents may be the same or different from each other.

5. An aromatic amine derivative according to claim 1, characterized in that, The L1 is selected from a single bond or one of the following groups: The L2 is selected from a single bond or one of the following groups: The R9 is selected from hydrogen, substituted or unsubstituted groups of the following: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and when substituted by multiple substituents, the multiple substituents may be the same or different from each other.

6. An aromatic amine derivative, characterized in that, The aromatic amine derivative is selected from one of the following structures:

7. An organic electroluminescent device, characterized in that, It includes an anode, an organic layer, and a cathode, wherein the organic layer is located between the anode and the cathode or outside one or more electrodes of the anode and the cathode, and the organic layer contains an aromatic amine derivative as described in any one of claims 1 to 6.

8. An organic electroluminescent device according to claim 7, characterized in that, The organic layer includes a hole transport region, which contains an aromatic amine derivative as described in any one of claims 1 to 6.

9. An organic electroluminescent device according to claim 8, characterized in that, The hole transport region includes a hole transport layer, and the hole transport layer contains the aromatic amine derivative as described in any one of claims 1 to 6.

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