Nitrogen-containing compound, organic electroluminescent device and electronic apparatus

Abstract

The application belongs to the technical field of organic electroluminescence, and relates to a nitrogen-containing compound, an organic electroluminescent device and an electronic apparatus. The nitrogen-containing compound has a structure represented by formula 1. By using the nitrogen-containing compound in the organic electroluminescent device, the performance of the organic electroluminescent device can be remarkably improved.

Description

Nitrogen-containing compounds, organic electroluminescent devices and electronic devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202311644296.6 filed on December 4, 2023. The full text of the above-mentioned Chinese patent application is hereby cited as part of this application. Technical Field

[0003] The present application relates to the technical field of organic compounds, and in particular to a nitrogen-containing compound and an organic electroluminescent device and an electronic device comprising the nitrogen-containing compound. Background Art

[0004] With the development of electronic technology and the progress of materials science, the application range of electronic components for realizing electroluminescence is becoming more and more extensive. Such electronic components generally include a cathode and an anode arranged opposite to each other, and a functional layer arranged between the cathode and the anode. The functional layer is composed of multiple organic or inorganic film layers, and generally includes an organic light-emitting layer, a hole transport layer located between the organic light-emitting layer and the anode, and an electron transport layer located between the organic light-emitting layer and the cathode. Taking an organic electroluminescent device as an example, it generally includes an anode, a hole transport layer, an electron blocking layer, an organic light-emitting layer, an electron transport layer and a cathode stacked in sequence. When a voltage is applied to the cathode and the cathode, the two electrodes generate an electric field. Under the action of the electric field, electrons on the cathode side move toward the organic light-emitting layer, and holes on the anode side also move toward the organic light-emitting layer. Electrons and holes combine in the organic light-emitting layer to form excitons. The excitons are in an excited state and release energy outward, thereby causing the organic light-emitting layer to emit light outward.

[0005] The prior art discloses host materials that can be used to prepare organic light-emitting layers in organic electroluminescent devices. However, there is still a need to continue to develop new materials to further improve the performance of organic electroluminescent devices.

[0006] Summary of the Invention

[0007] To solve the above problems, the present application aims to provide a nitrogen-containing compound and an organic electroluminescent device and an electronic device containing the organic compound, wherein the nitrogen-containing compound can improve the performance of the organic electroluminescent device and the electronic device, for example, reduce the driving voltage of the device and increase the efficiency and life of the device.

[0008] In a first aspect of the present application, a nitrogen-containing compound is provided, which has a structure as shown in Formula 1:

[0009] wherein L is selected from a single bond or a substituted or unsubstituted arylene group having 6 to 30 carbon atoms;

[0010] The substituents in L are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a deuterated aryl group having 6 to 12 carbon atoms;

[0011] Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group;

[0012] The substituents in Ar are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a deuterated aryl group having 6 to 12 carbon atoms;

[0013] R is selected from substituted or unsubstituted aryl groups having 6 to 20 carbon atoms;

[0014] The substituents in R are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a deuterated aryl group having 6 to 12 carbon atoms;

[0015] D stands for deuterium;

[0016] n is selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8;

[0017] m is selected from 0, 1, 2, 3, 4, 5 or 6.

[0018] In a second aspect of the present application, an organic electroluminescent device is provided, comprising an anode and a cathode arranged opposite to each other, and a functional layer arranged between the anode and the cathode; the functional layer comprises the nitrogen-containing compound described in the first aspect of the present application.

[0019] In a third aspect of the present application, an electronic device is provided, comprising the organic electroluminescent device described in the second aspect of the present application.

[0020] The nitrogen-containing compound provided in the present application has a core structure of a bicarbazole connected in a specific manner, and the 5-position of one of the bicarbazole groups is connected to an aryl substituent, and the 9-position (N atom) is connected to an electron-donating group. The bicarbazole structure used in the present application has excellent hole transport properties. At the same time, the 5-position of one of the bicarbazole groups is connected to an aryl substituent, which can improve the steric hindrance of the compound structure and the film-forming property of the material. When the nitrogen-containing compound of the present application is used as the main material of the organic light-emitting layer in an organic electroluminescent device, the carrier balance in the organic light-emitting layer can be improved, the carrier recombination area can be widened, the exciton generation and utilization efficiency can be improved, and the luminous efficiency and life of the device can be improved.

[0021] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide further understanding of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present application, but do not constitute a limitation to the present application.

[0023] FIG1 is a schematic structural diagram of an organic electroluminescent device of the present application.

[0024] FIG2 is a schematic structural diagram of an electronic device of the present application.

[0025] Reference numerals 100, anode 200, cathode 300, functional layer 310, hole injection layer 320, hole transport layer 330, electron blocking layer 340, organic light emitting layer 350, electron transport layer 360, electron injection layer 400, electronic device DETAILED DESCRIPTION

[0026] The exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these examples are provided so that this application will be more comprehensive and complete and will fully convey the concepts of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of the embodiments of this application.

[0027] In a first aspect of the present application, a nitrogen-containing compound is provided, which has a structure as shown in Formula 1:

[0028] wherein L is selected from a single bond or a substituted or unsubstituted arylene group having 6 to 30 carbon atoms;

[0029] The substituents in L are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a deuterated aryl group having 6 to 12 carbon atoms;

[0030] Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group;

[0031] The substituents in Ar are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a deuterated aryl group having 6 to 12 carbon atoms;

[0032] R is selected from substituted or unsubstituted aryl groups having 6 to 20 carbon atoms;

[0033] The substituents in R are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a deuterated aryl group having 6 to 12 carbon atoms;

[0034] D stands for deuterium;

[0035] n is selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8;

[0036] m is selected from 0, 1, 2, 3, 4, 5 or 6.

[0037] In this application, the descriptions “each independently is”, “each independently is” and “each independently is” are interchangeable and should be understood in a broad sense. They can mean that in different groups, the specific options expressed by the same symbols do not affect each other, or in the same group, the specific options expressed by the same symbols do not affect each other. For example, Wherein, each q is independently 0, 1, 2 or 3, and each R" is independently selected from hydrogen, deuterium, fluorine, and chlorine. The meaning is: Formula Q-1 represents that there are q substituents R" on the benzene ring, and each R" can be the same or different, and the options of each R" do not affect each other; Formula Q-2 represents that there are q substituents R" on each benzene ring of biphenyl, and the number q of R" substituents on the two benzene rings can be the same or different, and each R" can be the same or different, and the options of each R" do not affect each other.

[0038] In this application, the term "substituted or unsubstituted" means that the functional group described after the term may or may not have a substituent (hereinafter, for ease of description, the substituents are collectively referred to as Rc). For example, "substituted or unsubstituted aryl" refers to an aryl group having a substituent Rc or an unsubstituted aryl group. The substituent Rc can be, for example, deuterium, a cyano group, a halogen group, an alkyl group, a cycloalkyl group, an aryl group, a deuterated aryl group, a halogenated aryl group, or the like. The number of substituents can be one or more.

[0039] In this application, "plurality" refers to two or more, for example, 2, 3, 4, 5, 6, etc.

[0040] In this application, the number of carbon atoms in a substituted or unsubstituted functional group refers to the total number of carbon atoms. For example, if L is a substituted arylene group with 12 carbon atoms, the total number of carbon atoms in the arylene group and its substituents is 12.

[0041] In the present application, aryl refers to an optional functional group or substituent derived from an aromatic carbocyclic ring. Aryl can be a monocyclic aryl (such as phenyl) or a polycyclic aryl. In other words, aryl can be a monocyclic aryl, a condensed ring aryl, two or more monocyclic aryl groups connected by a carbon-carbon bond, a monocyclic aryl and a condensed ring aryl connected by a carbon-carbon bond, two or more condensed ring aryl groups connected by a carbon-carbon bond. That is, unless otherwise indicated, two or more aromatic groups connected by a carbon-carbon bond can also be considered as aryl of the present application. Wherein, condensed ring aryl, for example, can include dicyclic condensed aryl (such as naphthyl), tricyclic condensed aryl (such as phenanthrenyl, fluorenyl, anthracenyl) etc. Aryl does not contain heteroatoms such as B, N, O, S, P, Se and Si. Examples of aryl groups may include, but are not limited to, phenyl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl, biphenyl, terphenyl, triphenylene, peryl, benzo[9,10]phenanthrenyl, pyrenyl, benzofluoranthenyl, In the present application, the arylene group refers to a divalent group formed by further losing a hydrogen atom from an aryl group.

[0042] In this application, terphenyl includes

[0043] In the present application, the number of carbon atoms of a substituted aryl group refers to the total number of carbon atoms of the aryl group and the substituents on the aryl group. For example, a substituted aryl group with 18 carbon atoms refers to the total number of carbon atoms of the aryl group and the substituents on the aryl group.

[0044] In the present application, the number of carbon atoms of the substituted or unsubstituted aryl group may be 6, 10, 12, 13, 14, 15, 16, 17, 18, 20, 24, 25 or 30. In some embodiments, the substituted or unsubstituted aryl group is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, in other embodiments, the substituted or unsubstituted aryl group is a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, in other embodiments, the substituted or unsubstituted aryl group is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and in other embodiments, the substituted or unsubstituted aryl group is a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.

[0045] In the present application, examples of aryl groups as substituents of L, Ar and R include, but are not limited to, phenyl, naphthyl and the like.

[0046] In the present application, the alkyl group having 1 to 10 carbon atoms may include a straight-chain alkyl group having 1 to 10 carbon atoms and a branched-chain alkyl group having 3 to 10 carbon atoms. The number of carbon atoms in the alkyl group may be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. Specific examples of the alkyl group include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, and the like.

[0047] In the present application, the halogen group may be, for example, fluorine, chlorine, bromine, or iodine.

[0048] In the present application, a deuterated aryl group refers to an aryl group containing at least one deuterium substituent. Specific examples of the deuterated aryl group include, but are not limited to, pentadeuterated phenyl and pentadeuterated biphenyl.

[0049] In this application, no single bond extending from the ring system is involved in the positioning of the connecting bond. This means that one end of the link can be connected to any position in the ring system that the link passes through, and the other end is connected to the rest of the compound molecule. For example, as shown in the following formula (f), the naphthyl represented by formula (f) is connected to other positions of the molecule via two non-positional linkers that pass through the bicyclic ring. The meaning of this includes any possible connection method shown in formulas (f-1) to (f-10).

[0050] For another example, as shown in the following formula (X'), the dibenzofuranyl group represented by formula (X') is connected to other positions in the molecule through a non-positional connecting bond extending from the middle of one side of the benzene ring, and the meaning represented by it includes any possible connection method shown in formulas (X'-1) to (X'-4).

[0051] In some embodiments of the present application, the nitrogen-containing compound is selected from the structure shown in Formula A or Formula B:

[0052] In formula A and formula B, L is selected from a single bond or a substituted or unsubstituted arylene group having 6 to 30 carbon atoms;

[0053] The substituents in L are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a deuterated aryl group having 6 to 12 carbon atoms;

[0054] Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group;

[0055] The substituents in Ar are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a deuterated aryl group having 6 to 12 carbon atoms;

[0056] R is selected from substituted or unsubstituted aryl groups having 6 to 20 carbon atoms;

[0057] The substituents in R are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a deuterated aryl group having 6 to 12 carbon atoms;

[0058] D stands for deuterium;

[0059] n is selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8;

[0060] m is selected from 0, 1, 2, 3, 4, 5 or 6.

[0061] In some embodiments of the present application, L is selected from a single bond or a substituted or unsubstituted arylene group having 6 to 12 carbon atoms.

[0062] Optionally, the substituents in L are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 5 carbon atoms, a phenyl group or a pentadeuterated phenyl group.

[0063] In other embodiments of the present application, L is selected from a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or a substituted or unsubstituted biphenylene group.

[0064] Optionally, the substituents in L are the same or different and are independently selected from deuterium, phenyl or pentadeuterated phenyl.

[0065] In some embodiments of the present application, L is selected from a single bond or the following group:

[0066] In some embodiments of the present application, L is selected from a single bond or the following groups:

[0067] In some embodiments of the present application, Ar is selected from a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group.

[0068] Optionally, the substituents in Ar are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 5 carbon atoms, a phenyl group or a pentadeuterated phenyl group.

[0069] In other embodiments of the present application, Ar is selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl or substituted or unsubstituted dibenzothiophenyl.

[0070] Optionally, the substituents in Ar are the same or different and are independently selected from deuterium, methyl, ethyl, n-propyl, isopropyl, tert-butyl, phenyl or pentadeuterated phenyl.

[0071] In some embodiments of the present application, Ar is selected from the group consisting of:

[0072] In some specific embodiments of the present application, Ar is selected from the group consisting of the following groups:

[0073] In some embodiments of the present application, Selected from the group consisting of:

[0074] In some specific embodiments of this application, Selected from the group consisting of

[0075] In some embodiments of the present application, R is selected from substituted or unsubstituted aryl groups having 6 to 12 carbon atoms.

[0076] Optionally, the substituents in R are the same or different and are independently selected from deuterium, phenyl or pentadeuterated phenyl.

[0077] In other embodiments of the present application, R is selected from substituted or unsubstituted phenyl or substituted or unsubstituted biphenyl.

[0078] Optionally, the substituents in R are the same or different and are independently selected from deuterium, phenyl or pentadeuterated phenyl.

[0079] In some embodiments of the present application, R is selected from the group consisting of:

[0080] In some specific embodiments of the present application, R is selected from the group consisting of the following groups:

[0081] In some embodiments of the present application, the nitrogen-containing compound is selected from the group consisting of the following compounds:

[0082] In a second aspect, the present application provides an organic electroluminescent device comprising an anode, a cathode, and a functional layer disposed between the anode and the cathode; wherein the functional layer comprises the nitrogen-containing compound described in the first aspect of the present application.

[0083] The nitrogen-containing compound provided in the present application can be used to form at least one organic film layer in the functional layer to improve the luminous efficiency, lifespan and other characteristics of the organic electroluminescent device.

[0084] Optionally, the functional layer includes an organic light-emitting layer, and the organic light-emitting layer includes the nitrogen-containing compound. The organic light-emitting layer can be composed of the nitrogen-containing compound provided in this application, or can be composed of the nitrogen-containing compound provided in this application and other materials.

[0085] Optionally, the functional layer further includes a hole transport layer, and the hole transport layer is located between the anode and the organic light-emitting layer.

[0086] According to a specific embodiment, the organic electroluminescent device is shown in Figure 1, and the organic electroluminescent device may include an anode 100, a hole injection layer 310, a hole transport layer 320, an electron blocking layer 330, an organic light-emitting layer 340, an electron transport layer 350, an electron injection layer 360 and a cathode 200 stacked in sequence.

[0087] Optionally, the anode 100 includes the following anode materials, which are preferably materials with a large work function that facilitates hole injection into the functional layer. Specific examples of anode materials include: metals such as nickel, platinum, vanadium, chromium, copper, zinc, gold, or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); combined metals and oxides such as ZnO:Al or SnO2:Sb; or conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDT), polypyrrole, and polyaniline, but are not limited thereto. The anode 100 preferably includes a transparent electrode comprising indium tin oxide (ITO).

[0088] In the present application, the hole transport layer may include one or more hole transport materials, and the hole transport layer material may be selected from carbazole polymers, carbazole-linked triarylamine compounds or other types of compounds. In one embodiment of the present application, the hole transport layer 320 may be composed of HT-1.

[0089] Optionally, the electron blocking layer 330 may include one or more hole transport materials, which may be selected from carbazole polymers, carbazole-linked triarylamine compounds, or other types of compounds, and this application does not impose any particular limitation on this. For example, in some embodiments of this application, the electron blocking layer 330 is composed of HT-2.

[0090] Optionally, the electron blocking layer is also referred to as a hole buffer layer, a hole adjustment layer, a hole auxiliary layer, a luminescence adjustment layer, a luminescence auxiliary layer or a second hole transport layer.

[0091] Optionally, a hole injection layer 310 may be provided between the anode 100 and the hole transport layer 320 to enhance the ability to inject holes into the hole transport layer 320. The hole injection layer 310 may be made of a benzidine derivative, a starburst arylamine compound, a phthalocyanine derivative, or other materials, and this application does not impose any particular limitation thereto. The material of the hole injection layer 310 may be selected from the following compounds or any combination thereof, for example:

[0092] In one embodiment of the present application, the hole injection layer 310 is composed of PD-1 and HT-1.

[0093] Alternatively, the organic light-emitting layer 340 may be composed of a single light-emitting material, or may include a host material and a guest material. Alternatively, the organic light-emitting layer 340 may be composed of a host material and a guest material. Holes and electrons injected into the organic light-emitting layer 340 may recombine in the organic light-emitting layer 340 to form excitons. The excitons transfer energy to the host material, and the host material transfers energy to the guest material, thereby enabling the guest material to emit light.

[0094] The host material of the organic light-emitting layer 340 may include metal chelate compounds, bisphenylethylene derivatives, aromatic amine derivatives, dibenzofuran derivatives, or other types of materials. Optionally, the host material includes the nitrogen-containing compound of the present application.

[0095] The guest material of the organic light-emitting layer 340 can be a compound having a condensed aryl ring or its derivative, a compound having a heteroaryl ring or its derivative, an aromatic amine derivative, or other materials, and this application does not impose any specific restrictions on this. Guest materials are also called dopant materials or dopants. They can be divided into fluorescent dopants and phosphorescent dopants based on the type of luminescence.

[0096] In the present application, the dopant used in the organic light-emitting layer of the organic electroluminescent device is a phosphorescent dopant.

[0097] In one embodiment of the present application, the organic electroluminescent device is a blue organic electroluminescent device. In a more specific embodiment, the host material of the organic light-emitting layer 340 comprises the nitrogen-containing compound of the present application and BH—N, and the guest material is BD-01.

[0098] The electron transport layer 350 may be a single-layer structure or a multi-layer structure, and may include one or more electron transport materials. The electron transport material may be selected from, but not limited to, ET-1, LiQ, benzimidazole derivatives, oxadiazole derivatives, quinoxaline derivatives or other electron transport materials.

[0099] In one embodiment of the present application, the electron transport layer 350 may be composed of ET-1 and LiQ.

[0100] In the present application, cathode 200 may include a cathode material having a small work function that facilitates electron injection into the functional layer. Specific examples of cathode materials include, but are not limited to, metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, lead, or alloys thereof; or multilayer materials such as LiF / Al, Liq / Al, LiO2 / Al, LiF / Ca, LiF / Al, and BaF2 / Ca. Alternatively, a metal electrode containing magnesium and silver may be included as the cathode.

[0101] Optionally, an electron injection layer 360 may be provided between the cathode 200 and the electron transport layer 350 to enhance the ability to inject electrons into the electron transport layer 350. The electron injection layer 360 may include an inorganic material such as an alkali metal sulfide or an alkali metal halide, or may include a complex of an alkali metal and an organic matter. In one embodiment of the present application, the electron injection layer 360 may include ytterbium (Yb).

[0102] In a third aspect, the present application provides an electronic device comprising the organic electroluminescent device described in the second aspect of the present application.

[0103] According to one embodiment, as shown in FIG2 , an electronic device provided is electronic device 400, which includes the above-mentioned organic electroluminescent device. Electronic device 400 may be, for example, a display device, a lighting device, an optical communication device, or other types of electronic devices, including but not limited to computer screens, mobile phone screens, televisions, electronic paper, emergency lighting, optical modules, etc.

[0104] The following is a detailed description of the synthesis method of the nitrogen-containing compound of the present application in conjunction with the synthesis examples, but the present application is not subject to any limitation.

[0105] Synthesis Example

[0106] Those skilled in the art will recognize that the chemical reactions described herein can be used to appropriately prepare many of the nitrogen-containing compounds described herein, and that other methods for preparing the compounds described herein are considered within the scope of this application. For example, the synthesis of compounds not exemplified herein can be successfully accomplished by one skilled in the art through modifications such as appropriate protection of interfering groups, the use of known reagents other than those described herein, or conventional modifications of reaction conditions. Compounds not described herein are derived from commercially available raw materials.

[0107] Synthesis of intermediate IM-1

[0108] 3-Chloro-5-phenyl-9-carbazole (5.0 g; 18.0 mmol), 4-bromobiphenyl (4.6 g; 19.8 mol), tris(dibenzylideneacetone)dipalladium (0.2 g; 0.2 mmol), 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (0.2 g; 0.4 mmol), sodium tert-butoxide (2.6 g; 27.0 mmol) and xylene (50 mL) were added to a round-bottom flask and stirred at 135° C. to 140° C. under nitrogen protection for 12 hours. The reaction mixture was cooled to room temperature, washed with water and then separated. The organic phase was dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography using dichloromethane / n-heptane as an eluent, and the obtained sample was recrystallized and purified using a dichloromethane / n-heptane solvent system to obtain intermediate IM-1 (6.0 g; yield: 78%) as a white solid.

[0109] Referring to the synthesis method of intermediate IM-1, reactant A in Table 1 was substituted for 3-chloro-5-phenyl-9-hydroxycarbazole, and reactant B was substituted for 4-bromobiphenyl to synthesize the intermediates shown in Table 1 below:

[0110] Table 1

[0111] Synthesis of compound A2:

[0112] The intermediate IM-1 (5.8 g; 13.5 mmol), carbazole (2.4 g; 14.2 mmol), tris(dibenzylideneacetone)dipalladium (0.1 g; 0.1 mmol), 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (0.1 g; 0.3 mmol), sodium tert-butoxide (1.9 g; 20.2 mmol) and xylene (60 mL) were added to a round-bottom flask and stirred at 135°C to 140°C for 48 hours under nitrogen protection; the reaction mixture was cooled to room temperature, washed with water and then separated, the organic phase was dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure to obtain a crude product; the crude product was purified by silica gel column chromatography using dichloromethane / n-heptane as eluent, and the obtained sample was recrystallized and purified using a toluene / n-heptane solvent system to obtain a white solid compound A2 (5.1 g; yield: 67%).

[0113] Referring to the synthesis method of compound A2, the intermediate IM-1 was replaced by reactant C to synthesize the compounds shown in Table 2 below:

[0114] Table 2

[0115] The mass spectrometry data of some compounds are shown in Table 3 below:

[0116] Table 3

[0117] The NMR data of some compounds are shown in Table 4 below:

[0118] Table 4

[0119] Preparation of organic electroluminescent devices

[0120] Example 1: Preparation of a blue organic electroluminescent device

[0121] The device was prepared by the following process

[0122] When the thickness of ITO / Ag / ITO is On the experimental substrate, ultraviolet, ozone and O2:N2 plasma are used for surface treatment to increase the work function of the anode, and organic solvents can be used to clean the surface of the experimental substrate to remove impurities and oil stains on the surface of the experimental substrate.

[0123] Compounds HT-1 and PD-1 were co-evaporated on the experimental substrate at an evaporation rate ratio of 98%:2% to form a film with a thickness of The hole injection layer is then deposited with compound HT-1 to form a hole injection layer with a thickness of hole transport layer.

[0124] Compound HT-2 is evaporated on the hole transport layer to form a layer with a thickness of electron blocking layer.

[0125] On the electron blocking layer, compound A2, compound BH-N, and BD-01 were co-evaporated at an evaporation rate ratio of 60%:40%:10% to form a film with a thickness of organic light-emitting layer.

[0126] On the organic light emitting layer, compound ET-1 and LiQ were co-evaporated at an evaporation rate ratio of 50%:50% to form a film with a thickness of electron transport layer.

[0127] Yb is evaporated on the electron transport layer to form a layer with a thickness of Then, magnesium (Mg) and silver (Ag) were co-evaporated on the electron injection layer at an evaporation rate ratio of 10%:90% to form a thickness of cathode.

[0128] Compound CP-1 is evaporated on the cathode to form a thickness of An organic covering layer is formed, thereby completing the preparation of a blue organic electroluminescent device.

[0129] Example 2 to Example 28:

[0130] An organic electroluminescent device was prepared using the same method as in Example 1, except that Compound X in Table 6 was used instead of Compound A2 in Example 1 when preparing the organic light-emitting layer.

[0131] Comparative Examples 1 to 3:

[0132] An organic electroluminescent device was prepared using the same method as in Example 1, except that Compound 1, Compound 2, and Compound 3 in Table 5 were used instead of Compound A2 in Example 1 when preparing the organic light-emitting layer.

[0133] The structures of the compounds used in preparing the devices of the above embodiments and comparative examples are listed in Table 5 below:

[0134] Table 5

[0135] The performance of the blue organic electroluminescent devices prepared in Examples 1 to 28 and Comparative Examples 1 to 3 was tested. Specifically, the IVL and T90 device lifespans were tested under a brightness of 1000 nit. The test results are shown in Table 6 below:

[0136] Table 6

[0137] As shown in Table 6 above, when the compounds of the present application are used as the host material for the organic light-emitting layer of a blue organic electroluminescent device, the device performance is significantly improved. Specifically, compared to the organic electroluminescent devices of Comparative Examples 1 to 3, the organic electroluminescent devices of Examples 1 to 28 have an efficiency improvement of at least 14.2% and a lifespan (T90) improvement of at least 11.9%.

[0138] Compared with Comparative Example 1, the nitrogen-containing compound of the present application is connected to an aromatic substituent at the 5-position of the carbazolyl group, which increases the steric hindrance of the compound, can improve the film-forming property of the material, and make the device have higher efficiency and lifespan.

[0139] Compared with Comparative Examples 2 and 3, the nitrogen-containing compound of the present application does not contain electron-withdrawing groups, which improves the hole transport properties and charge transport balance of the compound. It is applied to the main material of the organic light-emitting layer of phosphorescent organic electroluminescent devices (especially blue organic electroluminescent devices), which improves the efficiency of the recombination of holes and electrons to form excitons, thereby reducing the operating voltage and improving the current efficiency and service life of the device.

[0140] The above describes in detail some embodiments of the present application in conjunction with the accompanying drawings. However, the present application is not limited to the specific details of the above embodiments. Within the technical concept of the present application, various simple modifications can be made to the technical solution of the present application, and these simple modifications all fall within the scope of protection of the present application.

Claims

1. A nitrogen-containing compound, characterized in that The nitrogen-containing compound has a structure as shown in Formula 1: Wherein, L is selected from a single bond or a substituted or unsubstituted arylene group having 6 to 30 carbon atoms; The substituents in L are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a deuterated aryl group having 6 to 12 carbon atoms; Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group; The substituents in Ar are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a deuterated aryl group having 6 to 12 carbon atoms; R is selected from substituted or unsubstituted aromatic groups having 6 to 20 carbon atoms; The substituents in R are the same or different and are independently selected from deuterium, a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a deuterated aryl group having 6 to 12 carbon atoms; D stands for deuterium; n is selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8; m is selected from 0, 1, 2, 3, 4, 5 or 6.

2. The nitrogen-containing compound according to claim 1, characterized in that L is selected from a single bond, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted biphenylene group; Optionally, the substituents in L are the same or different and are independently selected from deuterium, phenyl or pentadeuterated phenyl.

3. The nitrogen-containing compound according to claim 1, characterized in that L is selected from a single bond or the following group: Optionally, L is selected from a single bond or the group consisting of:

4. The nitrogen-containing compound according to claim 1, characterized in that Ar is selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl or substituted or unsubstituted dibenzothiophenyl; Optionally, the substituents in Ar are the same or different and are independently selected from deuterium, methyl, ethyl, n-propyl, isopropyl, tert-butyl, phenyl or pentadeuterated phenyl.

5. The nitrogen-containing compound according to claim 1, characterized in that Ar is selected from the group consisting of: Optionally, Ar is selected from the group consisting of:

6. The nitrogen-containing compound according to claim 1, characterized in that Selected from the group consisting of: Optionally, Selected from the group consisting of:

7. The nitrogen-containing compound according to claim 1, characterized in that R is selected from substituted or unsubstituted phenyl or substituted or unsubstituted biphenyl; Optionally, the substituents in R are the same or different and are independently selected from deuterium, phenyl or pentadeuterated phenyl.

8. The nitrogen-containing compound according to claim 1, characterized in that R is selected from the group consisting of: Optionally, R is selected from the group consisting of:

9. The nitrogen-containing compound according to claim 1, characterized in that The nitrogen-containing compound is selected from the group consisting of the following compounds:

10. An organic electroluminescent device, characterized in that: The invention comprises an anode and a cathode arranged opposite to each other, and a functional layer arranged between the anode and the cathode; The functional layer comprises the nitrogen-containing compound according to any one of claims 1 to 9; Optionally, the functional layer comprises an organic light-emitting layer, and the organic light-emitting layer comprises the nitrogen-containing compound according to any one of claims 1 to 9.

11. An electronic device, characterized in that The organic electroluminescent device according to claim 10.

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