A carbazole derivative and use thereof

Abstract

This invention relates to the field of organic electroluminescent materials technology, and more particularly to a carbazole derivative and its application. The structural formula of the carbazole derivative is shown in formula (I); the carbazole derivative shown in formula (I) provided by this invention has a stable triplet energy level, which improves the thermal stability of the material and its ability to transport charge carriers; when this carbazole derivative is applied in organic electroluminescent elements, it can significantly reduce the driving voltage, improve the luminous efficiency and lifetime;

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent materials technology, and more particularly to a carbazole derivative and its applications. Background Technology

[0002] Generally speaking, organic light emission refers to the phenomenon that organic materials emit light when electrical energy is applied to them. That is, when an organic layer is placed between the anode and the cathode, if a voltage is applied between the two electrodes, holes will be injected from the anode into the organic layer, and electrons will be injected from the cathode into the organic layer. When the injected holes and electrons meet, they will form excitons. When the excitons transition to the ground state, they will emit light and heat.

[0003] In recent years, organic light-emitting diode (OLED) display technology has matured, and some products have entered the market. However, many problems still need to be solved in the process of industrialization. In particular, many issues remain unresolved regarding the various organic materials used to fabricate the elements, such as carrier injection and transport performance, electroluminescence properties, lifespan, color purity, and the matching between various materials and electrodes. Especially concerning is that the luminous efficiency and lifespan of the light-emitting elements do not yet meet the requirements for practical application, which greatly limits the development of OLED technology. While triplet-state phosphorescent materials possess high luminous efficiency, and their green and red light materials have met the requirements for use, these materials require matching with phosphorescent materials or hole materials with high triplet energy levels. Therefore, developing phosphorescent materials or hole materials with high triplet energy levels is an urgent need for the current development of OLEDs.

[0004] With current technological advancements, improvements are still needed for both fluorescent and phosphorescent materials, particularly in terms of operating voltage, efficiency, lifetime, and thermal stability during sublimation in organic electroluminescent devices.

[0005] Therefore, in order to overcome the technical problems mentioned above and further improve the characteristics of organic electroluminescent devices, there is a continued demand for the development of more stable and effective substances that can be used as phosphorescent or hole materials in organic electroluminescent devices.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a carbazole derivative that effectively improves the thermal stability and carrier transport capacity of materials. Organic electroluminescent devices prepared using this carbazole derivative can significantly reduce driving voltage, improve luminous efficiency, and increase lifetime. Another purpose of this invention is to provide applications of this carbazole derivative.

[0008] Specifically, the present invention provides the following technical solutions:

[0009] This invention provides a carbazole derivative, the structural formula of which is shown in formula (I):

[0010]

[0011] in,

[0012] R 1 Choose from hydrogen, deuterium, substituted or unsubstituted C1-C 40 Alkyl, substituted or unsubstituted C3-C 40 cycloalkyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 Fused aryl, substituted or unsubstituted C6-C 60 Aromatic amino group, substituted or unsubstituted C2-C 60 Groups composed of heterocyclic aryl groups;

[0013] R 2 R 3 R 4 R 5 Each is independently selected from hydrogen, deuterium, cyano, substituted or unsubstituted C1-C. 40 Alkyl, substituted or unsubstituted C3-C 40 cycloalkyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 Fused aryl, substituted or unsubstituted C6-C 60 Aromatic amino group, substituted or unsubstituted C2-C 60 A group consisting of heterocyclic aryl groups or groups represented by formula (II); two or more adjacent R groups 2 R 3 R 4 R 5 Optional joining or fusion can form substituted or unsubstituted rings;

[0014] The structural formula of equation (II) is as follows:

[0015]

[0016] Ar 1 Ar 2 Each can independently select either freely substituted or unsubstituted C6-C. 60 aryl, substituted or unsubstituted C6-C 60 Fused aryl, substituted or unsubstituted C6-C 60 Aromatic amino group, or substituted or unsubstituted C2-C 60 Groups composed of heterocyclic aryl groups; Ar 1 and Ar 2Optional joining or fusion can form substituted or unsubstituted rings;

[0017] m is selected from integers from 0 to 5;

[0018] L 1 Selected from single-bonded, substituted or unsubstituted C6-C 60 aryl, or substituted or unsubstituted C2-C 60 heteroaryl;

[0019] —* indicates the connection between equation (II) and equation (I).

[0020] In this invention, in the substituted or unsubstituted rings formed by the combination of adjacent groups, "ring" refers to a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle.

[0021] Preferably, the carbazole derivative is selected from the group consisting of the following structures:

[0022]

[0023] Among them, R 1 ~R 5 L 1 Ar 1 Ar 2 The meanings of 'm' and 'm' are the same as those defined above.

[0024] According to the present invention, "aryl" refers to and includes monocyclic aromatic hydrocarbon groups and polycyclic aromatic ring systems. A polycyclic system may have two or more rings in which two carbons are shared by two adjacent rings (the rings are "fused"), wherein at least one of the rings is an aromatic hydrocarbon group, and other rings may be cycloalkyl, cycloalkenyl, aryl, heterocyclic, and / or heteroaryl. Preferred aryl groups are those containing 6 to 30 carbon atoms, preferably 6 to 20 carbon atoms, more preferably 6 to 12 carbon atoms. Particularly preferred are aryl groups having six, ten, or twelve carbon atoms. Suitable aryl groups include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthyl, anthracene, ferroyl, phenanthryl, fluorenyl, pyrene, perylene, etc. The aryl group is preferably phenyl, biphenyl, terphenyl, triphenylene, fluorenyl, or naphthyl. Additionally, the aryl group may optionally be substituted.

[0025] In this invention, "heteroaryl" or "heterocyclic aryl" refers to a monocyclic aromatic group and a polycyclic aromatic ring system comprising at least one heteroatom. Heteroatoms include, but are not limited to, oxygen, sulfur, nitrogen, phosphorus, boron, silicon, or selenium. In many cases, oxygen, sulfur, or nitrogen are preferred heteroatoms. A monocyclic heteroaromatic system is preferably a monocycle having 5 or 6 ring atoms, and the rings may have one to six heteroatoms. A heteropolycyclic system may have two or more rings in which two atoms are shared by two adjacent rings (the rings are "fused"), wherein at least one of the rings is a heteroaryl group, and other rings may be cycloalkyl, cycloalkenyl, aryl, heterocyclic, and / or heteroaryl. A heteropolycyclic aromatic ring system may have one to six heteroatoms on each ring of the polycyclic aromatic ring system. Preferred heteroaryls are heteroaryls containing three to thirty carbon atoms, preferably three to twenty carbon atoms, more preferably three to twelve carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furanyl, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazolyl, indole-carbazolyl, pyridinylindole, pyrrolo-dipyridinyl, pyrazolyl, imidazolyl, triazolyl, oxazolyl, thiazolyl, oxadiazolyl, oxtriazolyl, dioxazolyl, thiazolyl, pyridinyl, pyrazinyl, triazinyl, oxazinyl, oxthiazolyl, oxadiazinyl, indoleyl, benzimidazolyl, indazole, indoxazinyl, benzoxazolyl, benzisoxazolyl, benzoxisoxazolyl, benzothiazolyl, quinolinyl, isoquinolinyl, cinolinyl, quinazolinyl, quinoxolinyl, naphthinyl, phthalazinyl. Pteridyl, xanthene, acridine, phenazinyl, phenothiazinyl, phenoxazinyl, benzofuranopyridyl, furanodipyridyl, benzothiophenopyridyl, thiophenodipyridyl, benzoselenophenepyridyl, selenophenedipyridyl, 1,2-azaborylyl, 1,3-azaborylyl, 1,4-azaborylyl, boronazynyl and their aza analogs, preferably dibenzothiophenyl, dibenzofuranyl, dibenzoselenopheneyl, carbazoyl, indolocarbazoyl, imidazoyl, pyridyl, triazinyl, benzimidazolyl, 1,2-azaborylyl, 1,3-azaborylyl, 1,4-azaborylyl, boronazynyl and their aza analogs. Additionally, heteroaryl groups may optionally be substituted.

[0026] The fused aryl or fused-ring aryl used in this invention refers to a monovalent functional group obtained by removing a hydrogen atom from an aromatic hydrocarbon with 6 to 60 carbon atoms that has two or more rings. In this case, the two or more rings can be simply attached to each other or attached in a condensed form. Non-limiting examples include phenanthrene, anthracene, fluoranthracene, pyrene, triphenylene, perylene, etc. Base, etc.

[0027] The aromatic amine group used in this invention refers to an amine substituted with an aryl group having 6 to 60 carbon atoms. Non-limiting examples of aromatic amine groups include diphenylamine, N-phenyl-1-naphthylamine, and N-(1-naphthyl)-2-naphthylamine. The heteroaryl amine group refers to an amine substituted with an aryl group having 6 to 60 carbon atoms or a heteroaryl group having 2 to 60 carbon atoms. Non-limiting examples of heteroaryl amine groups include N-phenylpyridin-3-amine, N-([1,1'-biphenyl]-4-yl)dibenzo[b,d]furan-2-amine, and N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-9H-fluorene-2-amine.

[0028] Preferably, the aryl, heterocyclic aryl, or heteroaryl group specifically refers to a group derived from the following substances: phenyl, naphthyl, anthracene, benzanthracene, phenanthryl, pyrene, etc. alkyl, perylene, fluoranyl, tetraphenyl, pentaphenyl, benzo[a]pyrene, biphenyl, azophenyl, terphenyl, trimerphenyl, tetraphenyl, fluorenyl, spirodifluorenyl, dihydrophenanthrene, triphenylene, dihydropyrene, tetrahydropyrene, cis or trans indo[a]fluorenyl, cis or trans indo[a]carbazoyl, cis or trans indole[a]carbazoyl, trimerinyl, isotrimerininyl, spirotrimerininyl, spiroisotrimerininyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole , isoindolyl, carbazolyl, pyridinyl, quinolinyl, isoquinolinyl, acridinel, phenanthridinel, benzo[5,6]quinolinyl, benzo[6,7]quinolinyl, benzo[7,8]quinolinyl, phenothiazinyl, phenotoxazinyl, pyrazolyl, indazole, imidazole, benzimidazole, naphthiazole, phenanthrimidazole, pyridinimidazole, pyrazinimidazole, quinoxolinimidazole, oxazolyl, benzoxoxazolyl, naphthiazole, anthraquinoxazolyl, phenanthrimidazole, isoxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, hexazolyl Azabenzophenanthryl, benzopyridinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthryl, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazaperyl, pyrazinyl, phenazinyl, phenoxazinyl, phenthiazinyl, fluoresceinyl, naphridinyl, azacarbazolyl, benzocarbazolyl, carbazolyl, phenanthrolinel, 1,2,3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl , 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetraazinyl, 1,2,3,4-tetraazinyl, 1,2,3,5-tetraazinyl, purine, pteridine, indazinyl, quinazolinyl, benzothiadiazolyl, or groups derived from combinations of these systems.

[0029] Preferably, the Ar 1 Ar 2Each of the following is independently selected from the group consisting of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted triphenyl, substituted or unsubstituted tetraphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthyl, substituted or unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted triphenylene, substituted or unsubstituted fluoranthyl, substituted or unsubstituted spirodifluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiopheneyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted indolyl, or substituted or unsubstituted carolinyl.

[0030] Preferably, the R 1 It is selected from the group consisting of hydrogen, deuterium, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, cyclopentyl, cyclohexyl, phenyl, biphenyl, benzofuranyl, dibenzofuranyl, benzothiophene, dibenzothiophene, naphthyl, phenanthryl, anthraceneyl, fluorenyl, spirodifluorenyl, or carbazoleyl.

[0031] Preferably, the R 2 R 3 R 4 R 5 Each is independently selected from the group consisting of hydrogen, deuterium, cyano, substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthyl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorenyl, substituted or unsubstituted spirodifluorenyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted carbazoyl, or substituted or unsubstituted carolinyl.

[0032] Furthermore, the R 2 R 3 R 4 R 5 Each is independently selected from hydrogen, deuterium, or the group shown in formula (II).

[0033] Preferably, the L 1 Selected from single bonds or groups consisting of the following III-1 to III-23 groups:

[0034]

[0035] In this context, the dashed lines represent the connection sites of functional groups.

[0036] Preferably, m is selected from 0, 1 or 2.

[0037] As used herein, “combination of” or “group” means that one or more members of the applicable list are combined to form a known or chemically stable arrangement that can be conceived by one of ordinary skill in the art from the applicable list. For example, alkyl and deuterium can be combined to form partially or fully deuterated alkyl groups; halogen and alkyl groups can be combined to form haloalkyl substituents, such as trifluoromethyl; and halogen, alkyl and aryl groups can be combined to form haloaralkyl groups.

[0038] In one instance, the term substitution includes a combination of two to four listed groups.

[0039] In this invention, the terms "halogen", "halogen", "halogen atom", and "halogen group" are used interchangeably and refer to fluorine, chlorine, bromine, or iodine.

[0040] In this invention, the term "substituted or unsubstituted" refers to a group selected from hydrogen, deuterium, halogen, hydroxyl, nitrile, nitro, amino, amidine, hydrazine, hydrazone, carboxyl or its carboxylate, sulfonic acid or its sulfonate, phosphate or its phosphate, C1-C 60 Alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl group, C1-C 60 alkoxy groups, C3-C 60 cycloalkyl, C3-C 60 Cycloalkenyl, C6-C 60 aryl, C6-C 60 aryloxy groups, C6-C 60 aryl sulfide group and C2-C 60 The heterocyclic aryl group is substituted or unsubstituted by one or more substituents, or is substituted or unsubstituted by a substituent formed by linking two or more substituents of the substituents exemplified above.

[0041] Preferably, the structural formula of the carbazole derivative is selected from the group consisting of C600 to C812:

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051] Wherein, *—X—* is independently selected from *—O—*, *—S—*, or one of the structures shown below:

[0052]

[0053] *— and —* represent connector keys.

[0054] The present invention also provides an organic electroluminescent material, the raw materials of which include the carbazole derivatives described above; the organic electroluminescent material including the carbazole derivatives of the present invention has the ability to transport charge carriers or extract light.

[0055] Preferably, the organic electroluminescent material is a hole injection layer material, a hole transport layer material, a hole blocking layer material, a light-emitting layer material, an electron transport layer material, an electron injection layer material, a capping layer (CPL), a light-refractive layer material, or an electron blocking layer material.

[0056] This invention also provides the application of the carbazole derivatives described above in the preparation of organic electroluminescent elements.

[0057] The present invention also provides an organic electroluminescent element, comprising: a first electrode, a second electrode, a CPL, and one or more organic layers disposed between the first electrode and the second electrode; at least one of the organic layers and the CPL comprises the carbazole derivative described above.

[0058] The organic electroluminescent element comprises a cathode, an anode, a CPL (Chemical Polarizing Layer), and at least one emitting layer. In addition to these layers, it may also comprise other layers, such as, in each case, one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers, electron blocking layers, and / or charge generation layers. An intermediate layer having, for example, exciton blocking functionality may also be introduced between two emitting layers. However, it should be noted that each of these layers is not necessarily required. The organic electroluminescent element described herein may comprise one emitting layer, or it may comprise multiple emitting layers. That is, various luminescent compounds capable of emitting light are used in the emitting layers. A system having three emitting layers is particularly preferred, wherein the three layers can exhibit blue, green, and red light emission. If more than one emitting layer is present, according to the invention, at least one of these layers comprises a compound of the invention.

[0059] Furthermore, the organic electroluminescent element according to the present invention does not contain a separate hole injection layer and / or hole transport layer and / or hole blocking layer and / or electron transport layer, that is, the light-emitting layer is directly adjacent to the hole injection layer or the anode, and / or the light-emitting layer is directly adjacent to the electron transport layer or the electron injection layer or the cathode.

[0060] In the other layers of the organic electroluminescent element according to the invention, particularly in the hole transport layer and the light-emitting layer, as well as in the CPL, all materials can be used in accordance with the manner commonly used in the prior art. Those skilled in the art will therefore be able to combine all materials known about organic electroluminescent elements in the light-emitting layer according to the invention without inventive effort.

[0061] Furthermore, the following organic electroluminescent elements are preferred, which can be applied with one or more layers by means of a sublimation method, wherein in a vacuum sublimation apparatus at temperatures below 10 -5 Pa, preferably below 10 -6 The material is applied by vapor deposition at an initial pressure of Pa. However, the initial pressure may be even lower, for example, below 10 Pa. -7 Pa.

[0062] The organic electroluminescent element, preferably as described below, can also be applied by means of organic vapor deposition or by means of carrier gas sublimation, wherein, in 10 -5 The material is applied at a pressure between Pa and 1 Pa. A particular example of this method is the organic vapor jet printing method, in which the material is applied directly through a nozzle and is therefore structured.

[0063] Furthermore, the following organic electroluminescent elements are preferred, which produce one or more layers from solution, for example by spin coating, or by any desired printing method such as screen printing, flexographic printing, offset printing, photoinitiated thermal imaging, thermal transfer, inkjet printing, or nozzle printing. Soluble compounds, for example, are obtained by means of compounds represented by suitable substitution formula (I). These methods are also particularly suitable for oligomers, dendritic macromolecules, and polymers. Additionally, mixing methods are feasible, in which one or more layers are applied from solution and one or more additional layers are applied by vapor deposition.

[0064] These methods are generally known to those skilled in the art, and they can be applied to organic electroluminescent elements containing compounds according to the invention without any inventive effort.

[0065] Therefore, the present invention also relates to a method of manufacturing an organic electroluminescent element according to the invention, comprising applying at least one layer by means of a sublimation method, and / or by means of an organic vapor deposition method or by means of carrier gas sublimation, and / or by means of spin coating or printing method from a solution to apply at least one layer.

[0066] Furthermore, the present invention relates to compounds comprising at least one of the compounds of the present invention as described above. The same preferred embodiments as noted above regarding organic electroluminescent elements apply to the compounds of the present invention. In particular, the compounds may also preferably contain other compounds. Processing the compounds of the present invention from the liquid phase, for example by spin coating or printing methods, requires formulations for processing the compounds of the present invention, which may be, for example, solutions, dispersions, or emulsions. For this purpose, mixtures of two or more solvents may preferably be used. Suitable and preferred solvents include, for example, toluene, anisole, o-xylene, m-xylene or p-xylene, methyl benzoate, mesitylene, naphthalene, o-dimethoxybenzene, tetrahydrofuran, methyltetrahydrofuran, tetrahydropyran, chlorobenzene, dioxane, phenoxytoluene, especially 3-phenoxytoluene, (-)-fenone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidone, 3-methyl anisole, 4-methyl anisole, 3,4-dimethyl anisole, 3,5-dimethyl anisole, acetophenone, α-terpenes. The solvents are benzothiazole, butyl benzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decahydronaphthalene, dodecylbenzene, ethyl benzoate, indane, methyl benzoate, 1-methylpyrrolidone, p-methylisopropylbenzene, phenethyl ether, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentabenzene, hexene, heptene, octene, 1,1-bis(3,4-dimethylphenyl)ethane, or mixtures of these solvents.

[0067] Preferably, the organic layer includes a hole injection layer, a hole transport layer, a hole blocking layer, a light-emitting layer, an electron transport layer, an electron injection layer, or an electron blocking layer.

[0068] Preferably, the light-emitting layer, hole transport layer, or electron blocking layer comprises the carbazole derivative of the present invention.

[0069] In addition, unless otherwise specified, all raw materials used in this invention can be obtained commercially available. Any range described in this invention includes the end value and any value between the end values, as well as any subrange formed by the end value or any value between the end values.

[0070] The beneficial effects achieved by this invention are as follows:

[0071] The carbazole derivative shown in formula (I) provided by this invention has a high triplet energy level, a low refractive index, high material thermal stability, and the ability to transport charge carriers. When this carbazole derivative is applied to organic electroluminescent devices, the driving voltage can be significantly reduced, and the luminous efficiency and lifetime can be improved. Attached Figure Description

[0072] Figure 1 A schematic diagram of an organic light-emitting device 100 is shown. The diagram is not necessarily drawn to scale. Device 100 may include a substrate 101, an anode layer 102, a hole injection layer 103, a hole transport layer 104, an electron blocking layer 105, a light-emitting layer 106, a hole blocking layer 107, an electron transport layer 108, an electron injection layer 109, a cathode layer 110, and a capping layer (CPL) 111. Device 100 can be fabricated by sequentially depositing the described layers.

[0073] Figure 2 A schematic diagram of an organic light-emitting device 200 with two light-emitting layers is shown. The device includes a substrate 201, an anode layer 202, a hole injection layer 203, a hole transport layer 204, a first light-emitting layer 205, an electron transport layer 206, a charge generation layer 207, a hole injection layer 208, a hole transport layer 209, a second light-emitting layer 210, an electron transport layer 211, an electron injection layer 212, and a cathode layer 213. The device 200 can be fabricated by sequentially depositing the described layers. Because most common OLED devices have one light-emitting layer, and device 200 has a first light-emitting layer and a second light-emitting layer, the emission peaks of the first and second light-emitting layers can be overlapping, cross-overlapping, or non-overlapping. Materials similar to those described with respect to device 100 can be used in the corresponding layers of device 200. Figure 2 An example of adding some layers from the structure of device 100 is provided. Detailed Implementation

[0074] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the invention.

[0075] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0076] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the experimental materials and related equipment used in the following embodiments are commercially available, and all percentages are by mass.

[0077] The following embodiments use the following testing instruments and methods for performance testing of OLED materials and components:

[0078] OLED component performance testing conditions:

[0079] Luminosity and chromaticity coordinates: tested using a PhotoResearch PR-715 spectral scanner;

[0080] Current density and turn-on voltage: tested using a Keithley 2420 digital source meter;

[0081] Power efficiency: Tested using NEWPORT 1931-C.

[0082] Example 1

[0083] The preparation method of compound C626 includes the following steps:

[0084] Step 1: Preparation of intermediate Int-1

[0085]

[0086] 20.0 mmol of 4-bromocarbazole (sub-1), 24.0 mmol of 1-fluoro-9-fluorenone (sub-2), 60.0 mmol of anhydrous potassium carbonate, and 60 mL of DMF were mixed, heated to 120 °C, and stirred for 12 hours. After cooling to room temperature, 200 mL of water was added, and the mixture was filtered. The filter cake was washed with water, and the solid was purified by silica gel column chromatography to give compound Int-1, a yellow solid, with a yield of 87%.

[0087] Step 2: Preparation of intermediate Int-2

[0088]

[0089] Under nitrogen protection, 20.0 mmol of Int-1 was dissolved in 50 mL of dry THF, cooled to 0 °C, and 24.0 mmol of 1 M methyl magnesium bromide THF solution was added dropwise. The mixture was then heated to room temperature and stirred for 2 hours. 20 mL of 2 M dilute hydrochloric acid aqueous solution was added dropwise, and the mixture was extracted with ethyl acetate. The organic phase was collected, dried, filtered, and the filtrate was concentrated under reduced pressure and dried. The filtrate was purified by silica gel column chromatography to give compound Int-2 as a yellow solid, yield: 86%.

[0090] Step 3: Preparation of intermediate Int-3

[0091]

[0092] Under nitrogen protection, 20.0 mmol of Int-2 was dissolved in 60 mL of dichloromethane, cooled to 0 °C, and 30.0 mmol of boron trifluoride diethyl ether solution was added dropwise. The mixture was then heated to room temperature and stirred for 2 hours. 20 mL of ice water was added, and the organic phase was separated. The aqueous phase was extracted with dichloromethane, and the organic phase was collected, dried, filtered, and the filtrate was concentrated under reduced pressure and dried. The filtrate was purified by silica gel column chromatography to give compound Int-3 as a yellow solid, with a yield of 90%.

[0093] Step 4: Preparation of compound C626

[0094]

[0095] Under nitrogen protection, 22.0 mmol of compound Int-3 was dissolved in 80 mL of dry toluene, and 20.0 mmol of sub-3, 30.0 mmol of sodium tert-butoxide, 0.2 mmol of Pd2(dba)3 and 0.4 mmol of XantPhos were added. The mixture was heated to 110 °C and stirred for 12 hours. After cooling to room temperature, 50 mL of water was added, and the organic phase was separated. The aqueous phase was extracted with ethyl acetate, the organic phase was dried, concentrated under reduced pressure, purified by silica gel column chromatography, and recrystallized from toluene / ethyl acetate to give compound C626.

[0096] X = FR, pale yellow solid, yield 82%, MS (TOF): m / z = 825.3209 [M+H] + ; 1 HNMR (δ, CDCl3): 8.08(1H,s); 7.92~7.86(6H,m); 7.75~7.71(2H,m); 7.61~7.58(1H,m); 7.56~7.50(5H,m); 7.48~7.39 (7H,m); 7.36~7.29(5H,m); 7.27~7.18(7H,m); 7.16~7.14(1H,d); 7.08~7.05(1H,m); 6.97~6.94(1H,m); 2.43(3H,s).

[0097] X = C(CH3)2, pale yellow solid, yield 85%, MS (TOF): m / z = 703.3047 [M+H] + ; 1HNMR (δ, CDCl3): 8.27(1H,s); 7.93~7.85(4H,m); 7.75~7.71(2H,m); 7.61~7.58(1H,m); 7.56~7.51(4H,m); 7.49~7.40(5H,m) ); 7.38~7.30(6H,m); 7.28~7.23(3H,m); 7.16~7.14(1H,d); 7.08~7.05(1H,m); 6.97~6.94(1H,m); 2.43(3H,s); 1.68(6H,s).

[0098] X = Ad, pale yellow solid, yield 83%, MS (TOF): m / z = 795.3677 [M+H] + ; 1 HNMR (δ, CDCl3): 8.27 (1H, s); 7.92~7.85 (4H, m); 7.75~7.71 (2H, m); 7.61 ~7.58(1H,m); 7.56~7.50(4H,m); 7.48~7.40(5H,m); 7.38~7.30(6H,m); 7 .28~7.23(3H,m); 7.16~7.14(1H,d); 7.08~7.05(1H,m); 6.97~6.94(1H,m ); 2.43(3H,s); 2.25~2.16(2H,m); 2.14~1.99(10H,m); 1.69~1.54(2H,m).

[0099] Example 2

[0100] The preparation method of compound C679 includes the following steps:

[0101] Step 1: Preparation of intermediate Int-4

[0102]

[0103] Under nitrogen protection, 20.0 mmol of Int-3' (prepared according to the synthesis method in Example 1), 24.0 mmol of triisopropyl borate, and 60 mL of dry THF were mixed and cooled to -78 °C. 24.0 mmol of 2.5 M n-butyllithium n-hexane solution was added dropwise, and the reaction was stirred for 1 hour. The mixture was then brought to room temperature, and 20 mL of 3 M dilute hydrochloric acid aqueous solution was added dropwise. The organic phase was separated, and the aqueous phase was extracted with ethyl acetate. The organic phase was collected, dried, concentrated under reduced pressure, and dispersed with 20 mL of n-pentane. The mixture was filtered, and the filter cake was washed with n-pentane to give compound Int-4, a yellow solid, with a yield of 78%.

[0104] Step 2: Preparation of compound C679

[0105]

[0106] Under nitrogen protection, 24.0 mmol of compound Int-4 was dissolved in 60 mL of toluene. 20.0 mmol of sub-4, 60.0 mmol of anhydrous sodium carbonate, 0.01 mmol of Pd132, 30 mL of ethanol, and 30 mL of water were added. The mixture was heated to reflux and stirred for 15 hours. After cooling to room temperature, 50 mL of water was added. The organic phase was separated, and the aqueous phase was extracted with ethyl acetate. The organic phase was dried, concentrated under reduced pressure, and purified by silica gel column chromatography to give compound C679 as a yellow solid, yield: 83%, MS (TOF): m / z = 713.2711 [M+H]. + ; 1 HNMR (δ, CDCl3): 8.96(1H,s); 8.78~8.73(4H,m); 8.47~8.44(1H,m); 8.06(1H,s); 7.96~7.94(1H,m); 7.86~7.84(1H,d ); 7.74~7.71(1H,m); 7.57~7.50(6H,m); 7.48~7.34(9H,m); 7.29~7.24(3H,m); 7.17~7.14(1H,m); 7.11~7.06(3H,m).

[0107] Example 3

[0108] Preparation of compound C732:

[0109]

[0110] Under nitrogen protection, 22.0 mmol of compound Int-3 (prepared according to the synthesis method in Example 1) was dissolved in 80 mL of dry toluene. 20.0 mmol of sub-5, 30.0 mmol of sodium tert-butoxide, 0.2 mmol of Pd2(dba)3, and 0.4 mmol of a 10% tri-tert-butylphosphide toluene solution were added. The mixture was heated to 100 °C and stirred for 12 hours. After cooling to room temperature, 50 mL of water was added, and the organic phase was separated. The aqueous phase was extracted with ethyl acetate, dried, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain compound C732 as a yellow solid in 86% yield. MS (TOF): m / z = 751.3053 [M+H] + ; 1HNMR (δ, CDCl3): 8.43(1H,s); 7.97(1H,s); 7.94~7.85(5H,m); 7.56~7.51(3H,m); 7.45~7.39(4H,m); 7.37~7 .32(4H,m); 7.29~7.21(7H,m); 7.19~7.14(4H,m); 7.11~7.02(6H,m); 6.98~6.95(2H,m); 6.92~6.89(1H,m).

[0111] Examples 4 to 213

[0112] Following a similar synthetic method to Examples 1 to 3 above, the following compounds were prepared:

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130] In the above embodiments, *—X—* is independently selected from *—O—*, *—S—*, or one of the structures shown below:

[0131]

[0132] *— and —* represent connector keys.

[0133] Example 214

[0134] An organic electroluminescent device 100, the structure of which is as follows: Figure 1 As shown, the device includes a substrate 101, an anode layer 102, a hole injection layer 108, a hole transport layer 104, an electron blocking layer 105, a light-emitting layer 106, a hole blocking layer 107, an electron transport layer 108, an electron injection layer 109, a cathode layer 110, and a capping layer (CPL) or a light-refracting layer 111. The fabrication method of the device, omitting the hole blocking layer 107, includes the following steps:

[0135] 1) The glass substrate coated with the ITO conductive layer was ultrasonically treated in the cleaning agent for 80 minutes, rinsed in deionized water, ultrasonically treated in the acetone / ethanol mixed solvent for 80 minutes, baked in a clean environment until completely dry, irradiated with a UV cleaner for 10 minutes, and bombarded with a low-energy cation beam.

[0136] 2) Place the prepared ITO glass substrate into a vacuum chamber and evacuate to a vacuum level less than 1 × 10⁻⁶. -5 Pa, metallic silver is deposited as the anode layer on the above ITO film, and the thickness of the deposited film is [missing information]. Vaporized compounds HI01 and HI102 were used as hole injection layers, wherein HI102 accounted for 3% of the mass of HI01, and the vapor-deposited film thickness was [missing information].

[0137] 3) The compound HTM is then deposited onto the aforementioned hole injection layer as a hole transport layer, with a deposition thickness of [missing information].

[0138] 4) The compounds of the present invention prepared in Examples 1 to 213 were further deposited on the hole transport layer as an electron blocking layer, and the deposited film thickness was [missing information].

[0139] 5) Continue to deposit compound PH011 as the host material and GD100 as the dopant on the electron blocking layer. GD100 accounts for 3% of the mass of compound PH011. This forms the organic light-emitting layer, with a film thickness of [missing information].

[0140] 6) A LiQ and ETO6 layer is deposited on the organic light-emitting layer as an electron transport layer, with a LiQ to ETO6 mass ratio of 50:50, and the deposited film thickness is [missing information].

[0141] 7) A LiF layer is deposited on top of the electron transport layer as an electron injection layer, with a deposition thickness of [missing information].

[0142] 8) Magnesium and silver are vapor-deposited as a transparent cathode layer on top of the electron injection layer, with a magnesium to silver mass ratio of 1:10, and the vapor-deposited film thickness is [missing information].

[0143] 9) An NPD (CAS: 123847-85-8) layer is deposited on top of the transparent cathode layer as the CPL of the element, with a deposition film thickness of [missing information]. The OLED element provided by this invention is obtained.

[0144] The structure of the compound used in Example 214 above is as follows:

[0145]

[0146] Example 215

[0147] An organic electroluminescent device 200, the structure of which is as follows: Figure 2 As shown, the device includes a substrate 201, an anode layer 202, a hole injection layer 208, a hole transport layer 204, a first light-emitting layer 205, an electron transport layer 206, a charge generation layer 207, a hole injection layer 208, a hole transport layer 209, a second light-emitting layer 210, an electron transport layer 211, an electron injection layer 212, and a cathode layer 213. The device 200 can be fabricated by sequentially depositing the described layers. Because most common OLED devices have one light-emitting layer, and device 200 has a first light-emitting layer and a second light-emitting layer, the emission peaks of the first and second light-emitting layers can be overlapping, cross-overlapping, or non-overlapping. Materials similar to those described with respect to device 100 can be used in the corresponding layers of device 200.

[0148] Comparative Example 1

[0149] Following the same steps as in Example 214, the compound prepared in step 4) of this invention was replaced with B-1 to obtain comparative element 1; the structural formula of B-1 is as follows:

[0150]

[0151] Comparative Example 2

[0152] Following the same steps as in Example 214, the compound prepared in step 4) of this invention was replaced with B-2 to obtain comparative element 2; the structural formula of B-2 is as follows:

[0153]

[0154] The organic electroluminescent elements prepared by the above process were subjected to the following performance tests:

[0155] The driving voltage and current efficiency, as well as the lifetime of the organic electroluminescent elements prepared in Examples 214, 215, Comparative Example 1, and Comparative Example 2, were measured using a digital source meter and a luminance meter. Specifically, the voltage was increased at a rate of 0.1 V per second, and the luminance of the organic electroluminescent element was measured when it reached 1000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is measured simultaneously; the ratio of luminance to current density is the luminous efficiency; the LT90% lifespan test is as follows: using a luminance meter at 10000 cd / m² 2 At a constant current under the given brightness, the brightness decay of the organic electroluminescent element was measured to be 9000 cd / m². 2 The time is in hours. The data listed in Table 1 are relative to Comparison Element 1.

[0156] Table 1 Performance test results of each component

[0157]

[0158]

[0159]

[0160]

[0161]

[0162]

[0163] As shown in Table 1, the light-emitting element prepared using the carbazole derivative of the present invention as the electron blocking layer material operates at the same current density of 10 mA / cm². 2 Under the same conditions, the driving voltage is lower than that of B-1, the luminous efficiency is higher, and the LT90% lifetime performance is excellent, indicating that the carbazole derivative of the present invention is a high-performance electron blocking layer material.

[0164] Compared with the comparative compounds B-1 and B-2, the carbazole derivative of the present invention differs in that, after fixing one benzene atom of indobenzoacrylidine to form indobenzoacrylidine, the rotation of the benzene ring is prevented, thereby reducing the steric hindrance of the molecule. It is superior to B-1 and B-2 in terms of molecular film formation and exciton blocking performance, and the charge transport in the light-emitting layer is more balanced. Therefore, the carbazole derivative of the present invention has superior performance in light-emitting elements.

[0165] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A carbazole derivative, characterized in that, The structural formula of the carbazole derivative is selected from the group consisting of C600 to C812: Wherein, *—X—* is independently selected from *—O—*, *—S—*, or one of the structures shown below: *— and —* represent connector keys.

2. An organic electroluminescent material, characterized in that, Its raw materials include the carbazole derivative as described in claim 1.

3. The use of the carbazole derivative according to claim 1 in the preparation of organic electroluminescent elements.

4. An organic electroluminescent element, characterized in that, It includes: The first electrode, the second electrode, the capping layer or the light-refracting layer, and one or more organic layers disposed between the first electrode and the second electrode; at least one of the organic layers and the light-refracting layer comprises the carbazole derivative as described in claim 1.

5. The organic electroluminescent element according to claim 4, characterized in that, The organic layer includes a hole injection layer, a hole transport layer, a hole blocking layer, a light-emitting layer, an electron transport layer, an electron injection layer, or an electron blocking layer, wherein the light-emitting layer, hole transport layer, or electron blocking layer includes the carbazole derivative as described in claim 1.

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