Nitrogen-containing compound, organic electroluminescent element, and electronic device

Abstract

The invention belongs to the technical field of organic electroluminescence, and relates to a nitrogen-containing compound, an organic electroluminescence device and an electronic device.The nitrogen-containing compound has a structure shown in the formula 1, and when the nitrogen-containing compound is used in the organic electroluminescence device, the performance of the organic electroluminescence device can be remarkably improved.

Description

Technical Field

[0001] This application relates to the field of organic compound technology, and more particularly to a nitrogen-containing compound and an organic electroluminescent device and electronic device containing the nitrogen-containing compound. Background Technology

[0002] With the development of electronic technology and the advancement of materials science, the application range of electronic components used to achieve electroluminescence is becoming increasingly wide. These electronic components typically include a cathode and an anode positioned opposite each other, and a functional layer disposed between the cathode and anode. This functional layer consists 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 sequentially. When a voltage is applied to the anode and cathode, an electric field is generated between the two electrodes. Under the influence of the electric field, electrons on the cathode side move towards the organic light-emitting layer, and holes on the anode side also move towards 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.

[0003] Existing technologies disclose host materials for fabricating organic light-emitting layers in organic electroluminescent devices. However, it remains necessary to continue developing novel materials to further improve the performance of organic electroluminescent devices. Summary of the Invention

[0004] To address the aforementioned problems, this application aims to provide a nitrogen-containing compound and an organic electroluminescent device and electronic device comprising the nitrogen-containing compound. The nitrogen-containing compound can improve the performance of the organic electroluminescent device and electronic device, such as reducing the driving voltage of the device and improving device efficiency and lifespan.

[0005] In a first aspect, this application provides a nitrogen-containing compound having the structure shown in Formula 1:

[0006]

[0007] Wherein, L is selected from substituted or unsubstituted aryl groups having 6 to 12 carbon atoms;

[0008] The substituent in L is selected from deuterium;

[0009] Ar is selected from substituted or unsubstituted aryl groups with 6 to 30 carbon atoms;

[0010] The substituents in Ar may be the same or different, and are independently selected from deuterium, halogen groups, cyano, alkyl with 1 to 10 carbon atoms, cycloalkyl with 3 to 10 carbon atoms, aryl with 6 to 12 carbon atoms, and deuterated aryl with 6 to 12 carbon atoms.

[0011] Each R1, each R2, and each R3 may be the same or different, and are independently selected from deuterium, halogen groups, cyano groups, alkyl groups with 1 to 10 carbon atoms, aryl groups with 6 to 12 carbon atoms, and deuterated aryl groups with 6 to 12 carbon atoms;

[0012] n1 is the number of R1s, selected from 0, 1, 2, 3, 4, 5, 6 or 7. When n1 is greater than 1, all R1s may be the same or different.

[0013] n2 is the number of R2s, selected from 0, 1, 2, 3, 4, 5, 6 or 7. When n2 is greater than 1, all R2s may be the same or different.

[0014] n3 is the number of R3s, selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8. When n3 is greater than 1, all R3s are either the same or different.

[0015] According to a second aspect of this application, an organic electroluminescent device is provided, comprising an anode and a cathode disposed opposite to each other, and a functional layer disposed between the anode and the cathode; the functional layer comprising the aforementioned nitrogen-containing compound.

[0016] According to a third aspect of this application, an electronic device is provided, including the organic electroluminescent device described in the second aspect.

[0017] The nitrogen-containing compound provided in this application has a core structure of a triple carbazole with a specific linkage, where the 9-position of the middle carbazole is connected to the 4-position of another carbazole via an arylene / deuterium-substituted arylene group. The triple carbazole structure used in this application exhibits excellent hole transport characteristics, and the tertiary link between the 9-position of the middle carbazole and the 4-position of the other carbazole via an arylene / deuterium-substituted arylene group improves the steric hindrance of the compound structure and enhances the film-forming properties of the material. When the nitrogen-containing compound of this application is used as the host material of the organic light-emitting layer in an organic electroluminescent device, it can improve the carrier balance in the organic light-emitting layer, broaden the carrier recombination region, improve exciton generation and utilization efficiency, and ultimately improve the device's luminous efficiency and lifetime.

[0018] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further understand this application and form part of the specification. They are used together with the following detailed description to explain this application, but do not constitute a limitation thereof.

[0020] Figure 1 This is a schematic diagram of the structure of an organic electroluminescent device according to this application.

[0021] Figure 2 This is a schematic diagram of the structure of an electronic device according to this application.

[0022] Figure Labels

[0023] 100, Anode 200, Cathode 300, Functional Layer 310, Hole Injection Layer

[0024] 320, Hole transport layer; 330, Electron blocking layer; 340, Organic light-emitting layer; 350, Electron transport layer

[0025] 360°, electron injection layer 400°, electronic device Detailed Implementation

[0026] In view of the above-mentioned problems existing in the prior art, the purpose of this application is to provide a nitrogen-containing compound and an organic electroluminescent device and electronic device containing the nitrogen-containing compound. The nitrogen-containing compound can improve the performance of the organic electroluminescent device and electronic device, such as reducing the driving voltage of the device and improving the device efficiency and lifespan.

[0027] In a first aspect, this application provides a nitrogen-containing compound having the structure shown in Formula 1:

[0028]

[0029] Wherein, L is selected from substituted or unsubstituted aryl groups having 6 to 12 carbon atoms;

[0030] The substituent in L is selected from deuterium;

[0031] Ar is selected from substituted or unsubstituted aryl groups with 6 to 30 carbon atoms;

[0032] The substituents in Ar may be the same or different, and are independently selected from deuterium, halogen groups, cyano, alkyl with 1 to 10 carbon atoms, cycloalkyl with 3 to 10 carbon atoms, aryl with 6 to 12 carbon atoms, and deuterated aryl with 6 to 12 carbon atoms.

[0033] Each R1, each R2, and each R3 may be the same or different, and are independently selected from deuterium, halogen groups, cyano groups, alkyl groups with 1 to 10 carbon atoms, aryl groups with 6 to 12 carbon atoms, and deuterated aryl groups with 6 to 12 carbon atoms;

[0034] n1 is the number of R1s, selected from 0, 1, 2, 3, 4, 5, 6 or 7. When n1 is greater than 1, all R1s may be the same or different.

[0035] n2 is the number of R2s, selected from 0, 1, 2, 3, 4, 5, 6 or 7. When n2 is greater than 1, all R2s may be the same or different.

[0036] n3 is the number of R3s, selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8. When n3 is greater than 1, all R3s are either the same or different.

[0037] In this application, the descriptive phrases "each...independently is," "...each independently is," and "...each independently is" are interchangeable and should be interpreted broadly. They can mean either that the specific options expressed by the same symbol in different groups do not affect each other, or that the specific options expressed by the same symbol in the same group do not affect each other. For example, In this formula, each q is independently 0, 1, 2 or 3, and each R is independently selected from hydrogen, deuterium, fluorine or chlorine. The meaning is as follows: Formula Q-1 indicates that there are q substituents R on the benzene ring. Each R can be the same or different, and the options of each R do not affect each other. Formula Q-2 indicates that there are q substituents R on each benzene ring of biphenyl. The number q of substituents R on the two benzene rings can be the same or different, and each R can be the same or different. 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 substituents (hereinafter, for ease of description, 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 aforementioned substituents, i.e., Rc, can be, for example, deuterium, cyano, halogen groups, alkyl, cycloalkyl, aryl, deuterated aryl, haloaryl, etc. The number of substituents can be one or more.

[0039] In this application, "multiple" means two or more, such as two, three, four, five, six, etc.

[0040] In this application, the number of carbon atoms in substituted or unsubstituted functional groups refers to the total number of carbon atoms. For example, if L1 is a substituted arylene with 12 carbon atoms, then the total number of carbon atoms in the arylene and its substituents is 12.

[0041] In this application, aryl refers to any optional functional group or substituent derived from an aromatic carbon ring. The aryl group can be a monocyclic aryl (e.g., phenyl) or a polycyclic aryl; in other words, the aryl group can be a monocyclic aryl, a fused-ring aryl, two or more monocyclic aryl groups linked by carbon-carbon bonds, a monocyclic aryl and a fused-ring aryl linked by carbon-carbon bonds, or two or more fused-ring aryl groups linked by carbon-carbon bonds. That is, unless otherwise stated, two or more aromatic groups linked by carbon-carbon bonds can also be considered as the aryl group in this application. Fused-ring aryl groups may include, for example, bicyclic fused aryl (e.g., naphthyl), tricyclic fused aryl (e.g., phenanthrene, fluorene, anthracene), etc. The aryl group 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, anthracene, phenanthryl, biphenyl, terphenyl, triphenylene, perylene, benzo[9,10]phenanthryl, pyrene, benzofluoranthracene, etc. Aryl, spirodifluorenyl, etc. In this application, the aryl group refers to a divalent group formed by the further loss of a hydrogen atom from an aryl group.

[0042] In this application, terphenyl includes

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

[0044] In this application, the number of carbon atoms in the substituted or unsubstituted aryl group can 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 with 6 to 30 carbon atoms; in other embodiments, the substituted or unsubstituted aryl group is a substituted or unsubstituted aryl group with 6 to 25 carbon atoms; in still other embodiments, the substituted or unsubstituted aryl group is a substituted or unsubstituted aryl group with 6 to 20 carbon atoms; and in yet another embodiment, the substituted or unsubstituted aryl group is a substituted or unsubstituted aryl group with 6 to 12 carbon atoms.

[0045] In this application, the aryl group used as a substituent for Ar is, for example, but not limited to, phenyl, naphthyl, etc.

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

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

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

[0049] In this application, the number of carbon atoms in cycloalkyl groups with 3 to 10 carbon atoms can be, for example, 3, 4, 5, 6, 7, 8, or 10. Specific examples of cycloalkyl groups include, but are not limited to, cyclopentyl, cyclohexyl, and adamantyl.

[0050] In this application, the non-positioned connecting key refers to the single bond extending from the loop system. This indicates that one end of the linker can be connected to any position in the ring system that the linker penetrates, and the other end is connected to the rest of the compound molecule. For example, as shown in equation (f) below, the naphthyl group represented by equation (f) is connected to other positions in the molecule through two non-positional linkers that penetrate the bicyclic ring. This means that any possible connection mode shown in equations (f-1) to (f-10) is included.

[0051]

[0052] For example, as shown in the following formula (X'), the dibenzofuran group represented by formula (X') is connected to other positions of the molecule through a non-positional linker extending from the middle of one side of the benzene ring. This means that any possible connection mode shown in formulas (X'-1) to (X'-4) is included.

[0053]

[0054] In some embodiments of this application, the nitrogen-containing compound is selected from the structure shown in Formula A, Formula B, Formula C, or Formula D:

[0055]

[0056]

[0057] In formulas A, B, C, and D, L is selected from substituted or unsubstituted aryl groups having 6 to 12 carbon atoms;

[0058] The substituent in L is selected from deuterium;

[0059] Ar is selected from substituted or unsubstituted aryl groups with 6 to 30 carbon atoms;

[0060] The substituents in Ar may be the same or different, and are independently selected from deuterium, halogen groups, cyano, alkyl with 1 to 10 carbon atoms, cycloalkyl with 3 to 10 carbon atoms, aryl with 6 to 12 carbon atoms, and deuterated aryl with 6 to 12 carbon atoms.

[0061] Each R1, each R2, and each R3 may be the same or different, and are independently selected from deuterium, halogen groups, cyano groups, alkyl groups with 1 to 10 carbon atoms, aryl groups with 6 to 12 carbon atoms, and deuterated aryl groups with 6 to 12 carbon atoms;

[0062] n1 is the number of R1s, selected from 0, 1, 2, 3, 4, 5, 6 or 7. When n1 is greater than 1, all R1s may be the same or different.

[0063] n2 is the number of R2s, selected from 0, 1, 2, 3, 4, 5, 6 or 7. When n2 is greater than 1, all R2s may be the same or different.

[0064] n3 is the number of R3s, selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8. When n3 is greater than 1, all R3s are either the same or different.

[0065] In some preferred embodiments of this application, the nitrogen-containing compound is selected from the nitrogen-containing compounds shown in Formula A.

[0066] In some embodiments of this application, L is selected from substituted or unsubstituted phenylene, substituted or unsubstituted naphthyl, or substituted or unsubstituted biphenylene.

[0067] In other embodiments of this application, L is selected from the group consisting of:

[0068]

[0069] In some specific embodiments of this application, L is selected from the group consisting of:

[0070]

[0071] In some embodiments of this application, Ar is selected from substituted or unsubstituted aryl groups having 6 to 20 carbon atoms.

[0072] Optionally, the substituents in Ar may be the same or different, and may be independently selected from deuterium, halogen groups, cyano groups, alkyl groups having 1 to 5 carbon atoms, phenyl groups, or pentadeuterated phenyl groups.

[0073] Further optionally, Ar is selected from substituted or unsubstituted aryl groups having 6 to 18 carbon atoms.

[0074] Further optionally, Ar is selected from substituted or unsubstituted aryl groups having 6 to 12 carbon atoms.

[0075] In other embodiments of this application, Ar is selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthyl, and substituted or unsubstituted fluorenyl.

[0076] Optionally, the substituents in Ar may be the same or different, and may be independently selected from deuterium, fluorine, cyano, methyl, ethyl, n-propyl, isopropyl, tert-butyl, phenyl or pentadeuterated phenyl.

[0077] In some embodiments of this application, Ar is selected from the group consisting of:

[0078]

[0079] In some specific embodiments of this application, Ar is selected from the group consisting of:

[0080]

[0081] In some embodiments of this application, each R1, each R2 and each R3 may be the same or different, and are independently selected from deuterium, phenyl or pentadeuterated phenyl.

[0082] In some embodiments of this application, n1, n2, and n3 are all 0.

[0083] Optionally, the nitrogen-containing compound is selected from the group consisting of:

[0084]

[0085]

[0086]

[0087]

[0088]

[0089] Secondly, this application provides an organic electroluminescent device, including an anode, a cathode, and a functional layer disposed between the anode and the cathode; wherein the functional layer contains the nitrogen-containing compound described in the first aspect of this application.

[0090] The nitrogen-containing compounds provided in this application can be used to form at least one organic film layer in the functional layer to improve the luminous efficiency and lifetime of organic electroluminescent devices.

[0091] Optionally, the functional layer includes an organic light-emitting layer, which includes the nitrogen-containing compound. The organic light-emitting layer can be composed of the organic compound provided in this application, or it can be composed of the nitrogen-containing compound provided in this application and other materials.

[0092] Optionally, the functional layer further includes a hole transport layer located between the anode and the organic light-emitting layer.

[0093] According to one specific embodiment, the organic electroluminescent device, such as Figure 1 As shown, an 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, which are stacked sequentially.

[0094] Optionally, the anode 100 comprises an anode material, preferably one with a high 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, and gold, or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); combinations of 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. Preferably, a transparent electrode comprising indium tin oxide (ITO) as the anode is included.

[0095] In this application, the hole transport layer may include one or more hole transport materials, which may be selected from carbazole polymers, carbazole-linked triarylamine compounds, or other types of compounds.

[0096] In one embodiment, the hole transport layer 320 may be composed of HT-1.

[0097] 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. This application does not impose any specific limitations on these materials. For example, in some embodiments of this application, the electron blocking layer 330 is composed of HT-2.

[0098] Alternatively, the electron blocking layer may also be called a hole buffer layer, hole adjustment layer, hole auxiliary layer, luminescence adjustment layer, luminescence auxiliary layer, or second hole transport layer.

[0099] 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 321. The hole injection layer 310 may be selected from benzidine derivatives, starburst-like aryl amine compounds, phthalocyanine derivatives, or other materials, and this application does not impose any special limitations on this. In one embodiment of this application, the hole injection layer 310 is composed of PD-1 and HT-1.

[0100] Optionally, the organic light-emitting layer 340 may be composed of a single light-emitting material, or it may include a host material and a guest material. Optionally, the organic light-emitting layer 340 is composed of a host material and a guest material. Holes injected into the organic light-emitting layer 330 and electrons injected into the organic light-emitting layer 340 can 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.

[0101] The host material of the organic light-emitting layer 340 may comprise metal chelating compounds, bis(styrene) derivatives, aromatic amine derivatives, dibenzofuran derivatives, or other types of materials. Optionally, the host material comprises the nitrogen-containing compounds of this application.

[0102] The guest material of the organic light-emitting layer 340 can be a compound with a condensed aryl ring or its derivative, a compound with a heteroaryl ring or its derivative, an aromatic amine derivative, or other materials; this application does not impose any special restrictions on this. The guest material is also called a dopant or dopant. According to the type of light emission, it can be divided into fluorescent dopant and phosphorescent dopant.

[0103] In this application, the dopant used in the organic light-emitting layer of the organic electroluminescent device is a phosphorescent dopant.

[0104] In one embodiment of this 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 and BH-N of this application, and the guest material is BD-01.

[0105] The electron transport layer 350 can be a single-layer structure or a multi-layer structure, and it can include one or more electron transport materials. The electron transport materials can be selected from, but are not limited to, ET-1, LiQ, benzimidazole derivatives, oxadiazole derivatives, quinoxaline derivatives or other electron transport materials. This application does not impose any special limitations on this comparison.

[0106] In one embodiment of this application, the electron transport layer 350 may be composed of ET-1 and LiQ.

[0107] In this application, the cathode 200 may include a cathode material that has a small work function and facilitates electron injection into the functional layers. 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, and lead or alloys thereof; or multilayer materials such as LiF / Al, Liq / Al, LiO2 / Al, LiF / Ca, LiF / Al, and BaF2 / Ca. Optionally, a metal electrode comprising magnesium and silver may be included as the cathode.

[0108] Optionally, an electron injection layer 350 may be disposed between the cathode 200 and the electron transport layer 340 to enhance the ability to inject electrons into the electron transport layer 340. The electron injection layer 350 may include inorganic materials such as alkali metal sulfides and alkali metal halides, or may include complexes of alkali metals and organic materials. In one embodiment of this application, the electron injection layer 350 may include ytterbium (Yb).

[0109] Thirdly, this application provides an electronic device including the organic electroluminescent device described in the second aspect of this application.

[0110] According to one implementation method, such as Figure 2 As shown, the provided electronic device is electronic device 400, which includes the aforementioned organic electroluminescent device. Electronic device 400 can be, for example, a display device, a lighting device, an optical communication device, or other types of electronic devices, such as including but not limited to computer screens, mobile phone screens, televisions, electronic paper, emergency lighting, optical modules, etc.

[0111] The following examples illustrate the synthesis method of the organic compounds of this application, but this disclosure is not limited thereto.

[0112] Synthesis Examples

[0113] Those skilled in the art will recognize that the chemical reactions described herein can be suitably used to prepare many of the organic compounds of this application, and other methods for preparing the compounds of this application are considered to be within the scope of this application. For example, the synthesis of those non-illustrative compounds according to this application can be successfully accomplished by those skilled in the art through modification methods, such as appropriately protecting interfering groups, utilizing other known reagents besides those described herein, or making some conventional modifications to the reaction conditions. The compounds synthesized by methods not mentioned in this application are all commercially available starting materials.

[0114] Synthesis of intermediate IM-1:

[0115]

[0116] Under nitrogen protection, (9-phenyl-9H-carbazole-4-yl)boric acid (5.0 g; 17.4 mmol), 4-bromochlorobenzene (3.5 g; 18.3 mmol), tetratetraphenylphosphine palladium (0.4 g; 0.3 mmol), potassium carbonate (4.8 g; 34.8 mmol), tetrabutylammonium bromide (1.1 g; 3.5 mmol), toluene (40 mL), ethanol (10 mL), and deionized water (10 mL) were added to a round-bottom flask. The mixture was heated to 75–80 °C and stirred for 16 hours. The reaction mixture was cooled to room temperature, deionized water was added, and the mixture was separated. The organic phase was washed with water and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure. The crude product was purified by silica gel column chromatography using a dichloromethane / n-heptane mixed solvent as the mobile phase to give a white solid intermediate IM-1 (4.8 g; yield: 78%).

[0117] Following the synthetic method for intermediate IM-1, reactant A was substituted for (9-phenyl-9H-carbazol-4-yl)boronic acid, and reactant B was substituted for 4-bromochlorobenzene to synthesize the intermediates shown in Table 1 below:

[0118] Table 1

[0119]

[0120]

[0121] Synthesis of Compound 1:

[0122]

[0123] Under nitrogen protection, intermediate IM-1 (4.5 g; 12.7 mmol), 3,9'-bicarbazole (4.2 g; 12.7 mmol), tris(dibenzylacetone)dipalladium (0.1 g; 0.1 mmol), 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (0.1 g; 0.3 mmol), sodium tert-butoxide (1.8 g; 19.1 mmol), and xylene (50 mL) were added to a round-bottom flask and stirred at 135 °C–140 °C for 12 hours. After cooling to room temperature, the reaction solution was washed with water and separated. The organic phase was dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography using dichloromethane / n-heptane as the eluent. Then, the sample was recrystallized and purified using a toluene / n-heptane mixed solvent as the mobile phase to obtain white solid compound 1 (5.9 g; yield: 71%).

[0124] Following the synthetic method of compound 1, reactant C was substituted for intermediate IM-1, and reactant D was substituted for 3,9'-bicarbazole to synthesize the compounds shown in Table 2 below:

[0125] Table 2

[0126]

[0127]

[0128]

[0129] Mass spectrometry data of some compounds are shown in Table 3 below.

[0130] Table 3

[0131] compound Mass spectrometry data compound Mass spectrometry data Compound 1 <![CDATA[m / z=650.3(M+H) + ]]> Compound 21 <![CDATA[m / z=726.3(M+H) + ]]> Compound 4 <![CDATA[m / z=726.3(M+H) + ]]> Compound 23 <![CDATA[m / z=665.4(M+H) + ]]> Compound 5 <![CDATA[m / z=650.3(M+H) + ]]> Compound 32 <![CDATA[m / z=726.3(M+H) + ]]> Compound 7 <![CDATA[m / z=726.3(M+H) + ]]> Compound 33 <![CDATA[m / z=650.3(M+H) + ]]> Compound 9 <![CDATA[m / z=650.3(M+H) + ]]> Compound 39 <![CDATA[m / z=726.3(M+H) + ]]> Compound 10 <![CDATA[m / z=726.3(M+H) + ]]> Compound 44 <![CDATA[m / z=726.3(M+H) + ]]> Compound 14 <![CDATA[m / z=726.3(M+H) + ]]> Compound 46 <![CDATA[m / z=654.3(M+H) + ]]> Compound 16 <![CDATA[m / z=726.3(M+H) + ]]> Compound 49 <![CDATA[m / z=650.3(M+H) + ]]> Compound 18 <![CDATA[m / z=726.3(M+H) + ]]> Compound 65 <![CDATA[m / z=726.3(M+H) + ]]> Compound 19 <![CDATA[m / z=726.3(M+H) + ]]> Compound 71 <![CDATA[m / z=662.3(M+H) + ]]>

[0132] Mass spectrometry data of some compounds are shown in Table 4 below.

[0133] Table 4

[0134]

[0135]

[0136] Fabrication of organic electroluminescent devices

[0137] Example 1: Fabrication of a blue organic electroluminescent device

[0138] At ITO / Ag / ITO thickness On the experimental substrate, surface treatment is performed using ultraviolet light, ozone, and O2:N2 ions to increase the work function of the anode. Organic solvents can be used to clean the surface of the experimental substrate to remove impurities and oil stains.

[0139] Compounds HT-1 and PD-1 were co-deposited on an experimental substrate at a deposition rate ratio of 97%:3%, forming a layer with a thickness of [missing information]. A hole injection layer is formed, and then compound HT-1 is deposited on the hole injection layer to form a layer with a thickness of [missing information]. The hole transport layer.

[0140] Compound HT-2 was deposited on the hole transport layer to form a thickness of [missing information]. The electron blocking layer.

[0141] Compound 1, compound BH-N, and BD-01 were co-deposited on the electron blocking layer at a deposition rate ratio of 70%:30%:10%, forming a layer with a thickness of [missing information]. The organic light-emitting layer.

[0142] On the organic light-emitting layer, compounds ET-1 and LiQ were co-deposited at a 50%:50% evaporation rate ratio to form a layer with a thickness of [missing information]. The electron transport layer.

[0143] Yb is deposited on the electron transport layer to form a thickness of An electron-injected layer is formed; then, magnesium (Mg) and silver (Ag) are co-deposited on the electron-injected layer at a deposition rate ratio of 10%:90%, forming a layer with a thickness of [missing information]. The cathode.

[0144] Compound CP-1 was deposited on the cathode to form a thickness of [missing information]. An organic coating layer is applied to complete the fabrication of a blue organic electroluminescent device.

[0145] Examples 2 to 20:

[0146] Except that, when preparing the organic light-emitting layer, compound X from Table 6 was used instead of compound 1 in Example 1, the organic electroluminescent device was prepared using the same method as in Example 1.

[0147] Comparative Examples 1 to 3:

[0148] Except that when preparing the organic light-emitting layer, compounds A, B, and C from Table 6 were used to replace compound 1 in Example 1, the organic electroluminescent device was prepared using the same method as in Example 1.

[0149] The structures of the compounds used in preparing the devices of the above embodiments and comparative examples are listed in Table 6 below:

[0150] Table 5

[0151]

[0152] The performance of the blue organic electroluminescent devices prepared in Examples 1-20 and Comparative Examples 1-3 was tested. Specifically, the IVL and T90 device lifetimes were tested under a brightness of 1000 nits. The test results are shown in Table 6 below:

[0153] Table 6

[0154]

[0155] Referring to Table 6 above, it can be seen that when the compounds of this application are used as the host material of the organic light-emitting layer of the blue organic electroluminescent device, the device performance is significantly improved. Specifically, compared with the organic electroluminescent devices of Comparative Examples 1 to 3, the organic electroluminescent devices of Examples 1 to 20 have an efficiency improvement of at least 14.4% and a lifetime T90 improvement of at least 14.3%.

[0156] Compared with Comparative Examples 1 and 2, the nitrogen-containing compound of this application uses an arylene / deuterium-substituted arylene linker between the two carbazoles. Using such a linker group makes the HOMO energy level coverage of the compound larger, making it easier to inject and transport holes, thereby improving the luminescence efficiency.

[0157] Compared with Comparative Example 3, in this application, the 9th position of the carbazole in the middle of the nitrogen-containing compound is connected to the 4th position of the carbazole above. This connection increases the steric hindrance of the compound, which can improve the film-forming properties of the material, resulting in higher efficiency and lifespan.

[0158] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various simple modifications can be made to the technical solution of this application, and these simple modifications all fall within the protection scope of this application.

Claims

1. A nitrogen-containing compound, characterized in that, The compound has the structure shown in Formula 1: Wherein, L is selected from substituted or unsubstituted aryl groups having 6 to 12 carbon atoms; The substituent in L is selected from deuterium; Ar is selected from substituted or unsubstituted aryl groups with 6 to 30 carbon atoms; The substituents in Ar may be the same or different, and are independently selected from deuterium, halogen groups, cyano, alkyl with 1 to 10 carbon atoms, cycloalkyl with 3 to 10 carbon atoms, aryl with 6 to 12 carbon atoms, and deuterated aryl with 6 to 12 carbon atoms. Each R1, each R2, and each R3 may be the same or different, and are independently selected from deuterium, halogen groups, cyano groups, alkyl groups with 1 to 10 carbon atoms, aryl groups with 6 to 12 carbon atoms, and deuterated aryl groups with 6 to 12 carbon atoms; n1 is the number of R1s, selected from 0, 1, 2, 3, 4, 5, 6 or 7. When n1 is greater than 1, all R1s may be the same or different. n2 is the number of R2s, selected from 0, 1, 2, 3, 4, 5, 6 or 7. When n2 is greater than 1, all R2s may be the same or different. n3 is the number of R3s, selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8. When n3 is greater than 1, all R3s are either the same or different.

2. The nitrogen-containing compound according to claim 1, characterized in that, The nitrogen-containing compound is selected from compounds represented by formula A, formula B, formula C, or formula D: In formulas A, B, C, and D, L, Ar, R1, R2, R3, n1, n2, and n3 are as defined in claim 1.

3. The nitrogen-containing compound according to claim 1, characterized in that, L is selected from substituted or unsubstituted phenylene, substituted or unsubstituted naphthyl, or substituted or unsubstituted biphenylene.

4. The nitrogen-containing compound according to claim 1, characterized in that, L is selected from the group consisting of the following groups: Optionally, L is selected from the group consisting of:

5. 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 triphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthyl, and substituted or unsubstituted fluorenyl. Optionally, the substituents in Ar may be the same or different, and may be independently selected from deuterium, fluorine, cyano, methyl, ethyl, n-propyl, isopropyl, tert-butyl, phenyl or pentadeuterated phenyl.

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

7. The nitrogen-containing compound according to claim 1, characterized in that, Each of R1, R2, and R3 may be the same or different, and each is independently selected from deuterium, phenyl, or pentadeuterated phenyl.

8. The nitrogen-containing compound according to claim 1, characterized in that, n1, n2, and n3 are all 0.

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, It includes an anode and a cathode arranged opposite to each other, and a functional layer disposed between the anode and the cathode; The functional layer comprises a nitrogen-containing compound as described in any one of claims 1 to 9; Optionally, the functional layer includes an organic light-emitting layer, which contains a nitrogen-containing compound as described in any one of claims 1 to 9.

11. An electronic device, characterized in that, Including the organic electroluminescent device as described in claim 10.

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