Carbazole compound, intermediate and organic electroluminescent device

Abstract

The invention provides a carbazole compound, an intermediate and an organic electroluminescent device. The carbazole compound has a structure as shown in a formula I. Through the design of the carbazole compound, the carbazole compound with excellent performance is prepared, and the organic electroluminescent device prepared by taking the carbazole compound as a material of a luminescent layer has relatively high current efficiency, relatively long service life and relatively low driving voltage.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescent materials, and in particular relates to a carbazole compound, an intermediate and an organic electroluminescent device. Background Art

[0002] Compared with other flat panel displays (for example, liquid crystal displays (LCDs), plasma display panels (PDPs), field emission displays (FEDs), etc.), organic electroluminescent devices (OLEDs) have a simpler structure, various processing advantages, higher brightness, excellent viewing angle characteristics, faster response speeds, and lower driving voltages. Therefore, they are also fully developed to be used as light sources for flat panel displays (for example, wall-mounted TVs, etc.), or as backlight units for displays, illuminators, billboards, etc.

[0003] The structure of an organic electroluminescent device specifically includes an anode, a cathode, and an organic layer therebetween. In order to improve the efficiency and stability of an organic electroluminescent element, the organic material layer includes multiple layers with different materials. In order to meet people's higher requirements for OLED devices, the field urgently needs to develop more types of materials to improve the performance of OLED devices in terms of current efficiency, life span, etc. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention aims to provide a carbazole compound, an intermediate and an organic electroluminescent device. The present invention designs the structure of the carbazole compound to prepare a carbazole compound with excellent performance, and the organic electroluminescent device prepared by using the carbazole compound as the material of the light-emitting layer has high current efficiency, long life and low driving voltage.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a carbazole compound having a structure shown in the following formula I:

[0007]

[0008] Among them, Ar 1 ,Ar 2 are each independently selected from any one or a combination of at least two of an H atom, a phenyl group, a naphthyl group, a biphenyl group, and a 9,9-dimethylfluorenyl group, and Ar 1 ,Ar 2 are not simultaneously selected from H atoms;

[0009] X is selected from O or S;

[0010] n is selected from 0 or 1;

[0011] The hydrogen atoms in the compound of formula I can be replaced by deuterium atoms (-D), -F, -CN, C1-C12 alkyl, C1-C12 alkoxy, triphenylsilyl ( The dotted line indicates the connection site, the same below), triphenylmethyl ( ), or at least one of the C6-C20 aromatic groups.

[0012] The invention designs the structure of the carbazole compound to prepare the carbazole compound with excellent performance. The organic electroluminescent device prepared by using the carbazole compound as the material of the light-emitting layer has high current efficiency, long life and low driving voltage.

[0013] In the present invention, C1-C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9 or C12.

[0014] C6-C20 can be C6, C10, C12, C15, C18 or C20, etc.

[0015] In the present invention, "D" represents a deuterium atom. Unless otherwise indicated in the present invention, H and hydrogen therein all represent "protium", and the same shall apply hereinafter.

[0016] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0017] As a preferred technical solution of the present invention, the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, butyl, pentyl, methylcyclopentyl, hexyl, methylcyclohexyl, heptyl, octyl or adamantyl, bicyclo[2.2.1]heptyl or bicyclo[2.2.2]octyl.

[0018] Preferably, the C1-C12 alkoxy group is selected from any one of methoxy, ethoxy, propoxy, butoxy, pentyloxy or hexyloxy.

[0019] Preferably, the C6-C20 aryl group is selected from any one of phenyl, naphthyl, biphenyl and 9,9-dimethylfluorenyl.

[0020] As a preferred technical solution of the present invention, the Ar 1 Any one selected from phenyl, naphthyl, biphenyl / 9,9-dimethylfluorenyl, wherein Ar 2 Selected from hydrogen atoms.

[0021] As a preferred technical solution of the present invention, the Ar 1 Any one selected from phenyl, naphthyl and biphenyl.

[0022] As a preferred technical solution of the present invention, the Ar 1 ,Ar 2 Each is independently selected from any one selected from phenyl, naphthyl and biphenyl.

[0023] As a preferred technical solution of the present invention, the Ar 1 ,Ar 2 Selected from phenyl.

[0024] As a preferred technical solution of the present invention, the n is selected from 0.

[0025] As a preferred technical solution of the present invention, the n is selected from 1.

[0026] As a preferred technical solution of the present invention, the X is selected from O.

[0027] As a preferred technical solution of the present invention, the X is selected from S.

[0028] As a preferred technical solution of the present invention, the hydrogen atoms in the compound of formula I can be replaced by at least one of a deuterium atom (-D), -F, -CN, a methoxy group, an ethoxy group, a propoxy group, a methyl group, an ethyl group, a propyl group, a tert-butyl group, a phenyl group, a biphenyl group, a naphthyl group, a 9,9-dimethylfluorenyl group or a triphenylsilyl group.

[0029] Preferably, the hydrogen atoms in the compound of formula I can be replaced independently by at least one of a deuterium atom (D), -F, -CN, a methyl group, an ethyl group, a propyl group, a tert-butyl group, a methoxy group, a phenyl group, a naphthyl group, a biphenyl group, a 9,9-dimethylfluorenyl group or a triphenylsilyl group.

[0030] As a preferred technical solution of the present invention, the carbazole compound has a structure shown in the following formula I-1 or formula I-2:

[0031]

[0032] Among them, Ar 1 ,Ar 2 , X, n have the same definitions as above;

[0033] The hydrogen atoms in the compound of formula I-1 and the compound of formula I-2 can each independently be substituted by at least one of a deuterium atom (-D), -F, -CN, a C1-C12 alkyl group, a C1-C12 alkoxy group, a triphenylsilyl group, a triphenylmethyl group, and a C6-C20 aryl group.

[0034] As a preferred technical solution of the present invention, the carbazole compound is selected from any one of the following substituted or unsubstituted compounds:

[0035]

[0036]

[0037] The substitution means that the hydrogen atoms in the above carbazole compounds can be independently replaced by deuterium atoms. Preferably, the carbazole compound is selected from any one of the following compounds:

[0038]

[0039]

[0040] It should be noted that in the present invention, there is no special limitation on the preparation method of the carbazole compounds, and any commonly used preparation methods in the art are applicable.

[0041] In a second aspect, the present invention provides an intermediate, wherein the intermediate comprises the following compound:

[0042]

[0043] Among them, X, Ar 1 ,Ar 2 has the same definition as above;

[0044] X 2 Any one selected from -F, -Cl, -Br, -I;

[0045] The hydrogen atoms in the compound of formula MA may be independently substituted by at least one of a deuterium atom (-D), -F, -CN, a C1-C12 alkyl group, a C1-C12 alkoxy group, a triphenylsilyl group, a triphenylmethyl group, and a C6-C20 aryl group;

[0046] The intermediate is used to prepare the carbazole compound as described in the first aspect.

[0047] As a preferred technical solution of the present invention, the intermediate includes the following compounds:

[0048]

[0049] It should be noted that in the present invention, there is no special limitation on the preparation method of the intermediate, and the preparation methods commonly used in the art are applicable.

[0050] The preparation method of the intermediate provided by the present invention includes the following steps:

[0051]

[0052] Among them, X, Ar 1 ,Ar 2 has the same definition as above;

[0053] X 1 , X 2 Each is independently selected from any one of -F, -Cl, -Br, and -I. Those skilled in the art can select X according to common knowledge. 1 , X 2 Specific types of

[0054] The hydrogen atoms in the compound of formula MA may be independently substituted by at least one of a deuterium atom, -F, -CN, a C1-C12 alkyl group, a C1-C12 alkoxy group, a triphenylsilyl group, a triphenylmethyl group, and a C6-C20 aryl group.

[0055] In a third aspect, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising an anode, a cathode and an organic thin film layer disposed between the anode and the cathode;

[0056] The material of the organic thin film layer includes the carbazole compound as described in the first aspect.

[0057] Preferably, the organic thin film layer comprises a light-emitting layer, and a main material of the light-emitting layer comprises the carbazole compound as described in the first aspect.

[0058] Preferably, the light-emitting layer is a phosphorescent light-emitting layer.

[0059] As a preferred technical solution of the present invention, the organic electroluminescent device is a blue light organic electroluminescent device.

[0060] The luminescent layer in the present invention includes a luminescent layer main material and a doping material, wherein the doping material is also called a dye or a phosphorescent luminescent material. The luminescent layer main material can be a single compound or a mixture of two or more compounds.

[0061] The light-emitting layer includes a phosphorescent light-emitting layer, and the phosphorescent light-emitting layer includes a green phosphorescent light-emitting layer, a red phosphorescent light-emitting layer, a yellow phosphorescent light-emitting layer, and a blue phosphorescent light-emitting layer.

[0062] The volume percentage of the main material in the phosphorescent layer is 60% to 99.9% (for example, it can be 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99.9%, etc.), preferably 70% to 99.5%, and more preferably 85% to 95%.

[0063] In the present invention, the doping material of the light-emitting layer may be a phosphorescent material, which is also called a triplet light-emitting material, and refers to the light emitted from a triplet excited state. The specific selection of the phosphorescent material in the present invention is not particularly limited, and the doping materials of the light-emitting layer commonly used in the art are applicable, including but not limited to: a compound having a structure shown in Formula PD:

[0064]

[0065] Wherein, M is selected from any one of Ir, Pt, Pd, Os, Ti, Zr, Hf, Eu, Tb, Tm, Cu or Au;

[0066] Y 1 -Y 4 are each independently selected from carbon or nitrogen;

[0067] Y 1 and Y 2 They can be connected by single or double bonds. 3 and Y 4 They can be connected by single or double bonds;

[0068] Cy 1 and Cy 2 Each is independently selected from any one of phenyl, naphthyl, fluorenyl, spirofluorenyl, indenyl, pyrrolyl, thienyl, furanyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, quinolyl, isoquinolyl, benzoquinolyl, quinoxalinyl, quinazolinyl, carbazolyl, benzimidazolyl, benzofuranyl, benzothienyl, isobenzothienyl, benzimidazolyl, benzoxazolyl, triazolyl, tetrazolyl, oxadiazolyl, triazine, dibenzofuranyl, dibenzothienyl, N-heterocarbazolyl, N-heterodibenzofuranyl, wherein Cy is 1 and Cy 2 may optionally be linked to each other via a single bond or an organic linking group;

[0069] Any two ligands of M, or more than two ligands, may be connected by a single bond or a double bond, or may be bridged by O or S, or may be connected by any chemical group or chemical structure to form a structural form that conforms to chemical principles;

[0070] R 91 and R 92 Each is independently selected from -H, -D, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidine, hydrazine, hydrazone, carboxylic acid, carboxylate, sulfonic acid, sulfonate, phosphoric acid, phosphate, -SF 5, substituted or unsubstituted C1-C60 (for example, C1, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) alkyl, substituted or unsubstituted C2-C60 (for example, C2, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) alkenyl, substituted or unsubstituted C2-C60 (e.g., C2, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55, or C60, etc.) alkynyl, substituted or unsubstituted C1-C60 (e.g., C1, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55, or C60, etc.) alkoxy, substituted or unsubstituted C2-C10 (for example, C2, C3, C4, C5, C6, C7, C8, C9 or C10) heterocycloalkyl, substituted or unsubstituted C6-C60 (for example, C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60, etc.) aryl, substituted or unsubstituted C6-C60 (for example, C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60, etc.) any one of a C24, C30, C32, C36, C40, C42, C54 or C60 (e.g., C24, C30, C32, C36, C40, C42, C54 or C60, etc.) aryloxy group, a substituted or unsubstituted C6-C60 (e.g., C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60, etc.) arylthio group, a substituted or unsubstituted monovalent non-aromatic fused polycyclic group, and a substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group.

[0071] a 1 and a 2 Each is independently an integer selected from 1-5, for example, 1, 2, 3, 4 or 5;

[0072] b is an integer selected from 0-4, for example, 0, 1, 2, 3 or 4;

[0073] a is selected from 1, 2 or 3;

[0074] L 1 It is a monovalent organic ligand, a divalent organic ligand or a trivalent organic ligand.

[0075] Preferably, the compound of formula PD is selected from any one of the following compounds:

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083] In the present invention, the organic thin film layer includes a hole layer, and the hole layer includes a hole injection layer, a hole transport layer and an electron blocking layer.

[0084] The hole injection layer material includes a P-type dopant. The P-type dopant refers to a dopant that coexists with the hole injection layer material in the OLED device and can oxidize the hole injection layer material, thereby acting as an electron acceptor and promoting the movement of holes in the hole injection layer to the anode. In the present invention, the difference between the absolute value of the LUMO of the P-type dopant and the absolute value of the HOMO of the hole layer material is greater than -0.2V, preferably greater than -0.1eV, more preferably greater than 0eV, more preferably greater than 0.1eV, and more preferably greater than 0.2eV.

[0085] The P-type dopant is present in the hole injection layer in a volume percentage of 1% to 10% (e.g., 1%, 2%, 4%, 6%, 8% or 10%). In the present invention, there is no particular limitation on the type of the P-type dopant, and illustratively, the compounds D-1 to D-13 disclosed in CN113728453A or the compounds HI-1 to HI-9 described below can be selected:

[0086]

[0087] In the present invention, the hole layer material (including the hole injection layer, the hole transport layer and the electron blocking layer) has a structure shown in the following formula HT-GH4:

[0088]

[0089] Among them, L 41 is selected from a single bond, a C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.) aryl, or a C6-C20 (e.g., C6, C8, C10, C12, C16, or C20, etc.) heteroaryl;

[0090] Ar 41 ,Ar 42Each is independently selected from C6-C40 (for example, C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) aryl, C6-C20 (for example, C6, C8, C10, C12, C16 or C20, etc.) heteroaryl;

[0091] X is selected from CR 41 R 42 or NR 43 , where R 41 , R 42 , R 43 Each is independently selected from substituted or unsubstituted phenyl (the substituted substituent is selected from C1-C6 (for example, C1, C2, C3, C4, C5 or C6) alkyl, C1-C6 (for example, C1, C2, C3, C4, C5 or C6) alkoxy, dibenzofuranyl), naphthyl, triphenylene, fluoranthene, 9,9-dimethylfluorenyl, biphenyl, substituted or unsubstituted dibenzofuranyl (the substituted substituent is phenyl), substituted or unsubstituted dibenzothienyl (the substituted substituent is phenyl), dibenzofuran-substituted thienyl, C1-C6 (for example, C1, C2, C3, C4, C5 or C6) alkyl, any one of R 41 , R 42 They can be linked to form rings via single bonds.

[0092] In the present invention, the hole layer material (including the hole injection layer, the hole transport layer and the electron blocking layer) also includes a compound having a structure shown in the following formula IA or a compound having a structure shown in the following formula IB:

[0093]

[0094] Wherein, L is selected from any one of C6-C40 (for example, C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) arylene, dibenzofuranyl or dibenzothiophenyl;

[0095] m is selected from an integer between 0 and 4 (for example, it can be 0, 1, 2, 3 or 4), and n is selected from 0 or 1;

[0096] Ar is selected from any one of triphenylene, fluoranthenylene, dibenzofuranylene or dibenzothiophenylene;

[0097] Ar 1 and Ar 2Each is independently selected from any one of a C6-C40 (for example, C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) aryl group, a dibenzofuranyl group or a dibenzothiophenyl group;

[0098] Ar 1 Between Ar and Ar 2 and Ar 1 ,Ar 2 Each of them can be independently connected by a single bond, O, S, CR 1 R 2 , NR connection or bridging.

[0099] R, R 1 , R 2 Each is independently selected from any one of C1-C20 (for example, C1, C2, C4, C6, C8, C10, C12, C14, C16, C18 or C20, etc.) alkyl, C6-C40 (for example, C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) aryl, dibenzofuranyl or dibenzothiophenyl;

[0100] The hydrogen atoms in the compound of formula IB and the compound of formula IA may each independently be replaced by at least one of -F, -CN, -D (deuterium atom), C1-C6 alkyl, C1-C6 alkoxy, phenyl, biphenyl, naphthyl, phenanthryl, anthracenyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, triphenylene, fluoranthenyl, pyrenyl, perylenyl, spirofluorenyl, indenofluorenyl or hydrogenated benzanthryl.

[0101] Preferably, Ar is a fluoranthenyl group, and m+n>1.

[0102] Preferably, H in the compound of formula IB and the compound of formula IA can be replaced by at least one of -F, -CN, -D, C1-C3 alkyl (for example, methyl, ethyl or propyl), C1-C3 alkoxy (for example, methoxy, ethoxy or propoxy), phenyl, biphenyl, triphenylene, and fluoranthene.

[0103] Preferably, the L, Ar 1 ,Ar 2 Each is independently selected from at least one of phenyl, biphenyl, naphthyl, phenanthryl, anthracenyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, triphenylene, fluoranthenyl, pyrenyl, peryl, spirofluorenyl, indenofluorenyl and hydrogenated benzanthryl.

[0104] Preferably, the compound of formula IB is selected from any one of the following compounds:

[0105]

[0106]

[0107] In the OLED device provided by the present invention, the hole layer material may include conventional hole materials in the art in addition to the compound described in formula HT-GH4, the compound of formula IB, and the compound of formula IA, without special restrictions. Exemplary includes but is not limited to: triarylamine compounds or carbazole compounds. Triarylamine compounds or carbazole compounds containing more than 3 N atoms are preferred, because the HOMO of triarylamine compounds or carbazole compounds containing more than 3 N atoms is higher (smaller absolute value), and is more suitable for use as hole injection layer materials. Triarylamine compounds or carbazole compounds containing 2 or 1 N atoms can be used as hole transport layer materials. Some compounds or carbazole compounds containing 1 N atom, if they have a higher LUMO, can also be used as electron blocking layer materials.

[0108] The triarylamine compound or the carbazole compound is used as the hole layer material, and the hole layer material includes the following structure:

[0109]

[0110] Among them, Ar 601 ~Ar 609 Each independently selected from a substituted or unsubstituted C6-C40 (for example, C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) aryl, a substituted or unsubstituted dibenzofuranyl, a substituted or unsubstituted dibenzothiophenyl, a substituted or unsubstituted naphthobenzofuranyl, a substituted or unsubstituted naphthobenzothiophenyl, a substituted or unsubstituted dinaphthofuranyl, a substituted or unsubstituted dinaphthothiophenyl;

[0111] And Ar 601 ~Ar 609 Ar atoms adjacent to or connected to the same N atom 601 ~Ar 609 , can be connected by single key or through O, S, CR 701 R 702 NR 703 bridging;

[0112] R 701 , R 702 , R 703is selected from C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.) aromatic groups, C6-C20 (e.g., C6, C8, C10, C12, C16, or C20, etc.) heteroaryl groups, C1-C6 (e.g., C1, C2, C3, C4, C5, or C6) alkyl groups, and R 701 , R 702 Can connect via one-touch.

[0113] The hole blocking layer (HBL) can confine holes and / or excitons within the EL to improve the current efficiency and lifetime of the device. Compared with the EL material closest to the HBL interface, the HBL material has a lower HOMO (larger absolute value) and / or higher triplet energy.

[0114] The electron transport layer (ETL) may include a material capable of transporting electrons. The electron transport layer may be intrinsic (undoped) or doped, and doping may be used to enhance conductivity. In the present invention, there is no particular restriction on the ETL material, and any metal complex or organic compound may be used as long as it can transport electrons. The general electron transport layer material contains the following structural fragments: at least one of a pyridine structure, a pyrimidine structure, a triazine structure, a benzimidazole structure, a benzoxazole structure, a benzothiazole structure, an N-naphthalene structure, an N-coffee structure, an N-carbazole structure, an N-dibenzofuran structure, and an N-dibenzothiophene structure.

[0115] In the present invention, there is no special restriction on the electron transport layer material, which exemplarily includes but is not limited to:

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123] In the present invention, the material of the cathode is a metal with a low work function (e.g., alkaline earth metal, alkali metal, main group metal or lanthanide element (e.g., Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.)), a metal alloy composed of multiple metals (alloy composed of alkali metal or alkaline earth metal and silver, such as an alloy composed of magnesium and silver) or a multilayer structure. If the cathode material is a multilayer structure, in addition to the metals mentioned above, other metals with relatively high work functions, such as Ag or Al, can also be used. In this case, a combination of the metals is usually used, such as Ca / Ag, Mg / Ag or Ba / Ag.

[0124] Alternatively, a thin intermediate layer of a material with a high dielectric constant may be introduced between the metal cathode and the organic semiconductor to form a multilayer structure; the material with a high dielectric constant may also be referred to as an electron injection material, and may be selected from fluorides of alkali metals or alkaline earth metals, and corresponding oxides or carbonates (e.g., LiF, Li 2 O.BaF 2 、MgO、NaF、CsF、Cs 2 CO 3 etc.) or lithium quinolate (LiQ).

[0125] Compared with the prior art, the present invention has the following beneficial effects:

[0126] In the present invention, the structure of the carbazole compound is designed to make it suitable as the main material of the light-emitting layer of the organic electroluminescent device, so that the organic electroluminescent device has higher current efficiency, longer life and lower driving voltage. DETAILED DESCRIPTION

[0127] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0128] Preparation Example 1 Synthesis of Intermediate P1-1

[0129] This preparation example provides an intermediate P1-1 and a synthesis method thereof, and the synthesis method thereof is as follows:

[0130]

[0131] Under nitrogen, 80 mL of toluene, 40 mL of ethanol and 25 mL of water were added to a three-necked flask, and then 4.0 g of the compound 2-bromo-4-iododibenzo[b,d]furan, 1.9 g of the compound biphenyl-2-boric acid, 2.12 g of sodium carbonate and 0.23 g of tetrakistriphenylphosphine palladium were added thereto. The temperature was slowly raised to 40°C for reaction for 6 hours, then raised to 60°C for reaction for 6 hours, then raised to 70°C for reaction for 2 hours, and then refluxed for reaction for 1 hour. The temperature was lowered to room temperature, and water was added to separate the organic layer, and then the organic layer was washed with water, dried with magnesium sulfate, and after removing the desiccant, concentrated to dryness, separated by silica gel column chromatography, and eluted with petroleum ether to obtain intermediate P1-1 (1.7 g).

[0132] The obtained intermediate P1-1 was subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) was measured to be 398.03.

[0133] Preparation Example 2-7

[0134] Intermediate Preparation Examples 2-7 respectively provide an intermediate and a synthesis method thereof. The synthesis method of the corresponding intermediate refers to the synthesis method of the intermediate P1-1 provided in Preparation Example 1, with the only difference being that different raw materials (see Table 1 below for details) are used for synthesis. The specific structures of raw materials 1 and 2 and the synthesized intermediates are shown in Table 1 below. The intermediates are subjected to mass spectrometry detection, and their mass-to-charge ratio data are also shown in Table 1 below.

[0135] Table 1

[0136]

[0137] Synthesis Example 1

[0138] This synthesis example provides compound P1 and its synthesis method, the synthesis method is as follows:

[0139]

[0140] Under nitrogen, dry toluene (50 mL), intermediate P1-1 (4.0 g), carbazole (1.9 g), Pd(dba) were added to a three-necked flask. 2 (bis(dibenzylideneacetonepalladium, 0.0575 g, 0.0001 mol), 10% tri-tert-butylphosphine toluene solution (the mass of tri-tert-butylphosphine solution is 0.4 g, and the amount of tri-tert-butylphosphine is 0.0002 mol) and sodium tert-butoxide (1.44 g, 0.015 mol), heated to reflux, reacted for 8 hours, cooled to room temperature, added water to separate, and then the organic layer was washed with water until neutral, dried with magnesium sulfate, filtered to remove magnesium sulfate, concentrated to dryness, and crystallized with a mixed solvent of ethanol and toluene to obtain compound P1 (3.6 g).

[0141] The mass spectrometry detection of compound P1 was performed: the mass-to-charge ratio (m / z) was measured to be 485.18.

[0142] Synthesis Example 2-9

[0143] Synthesis Examples 2-9 respectively provide a compound and a synthesis method thereof. The synthesis method of the corresponding compound refers to the synthesis of compound P1, and the raw material 3 and the raw material 4 are reacted to synthesize the corresponding compound, and the compound is subjected to mass spectrometry detection. The mass-to-charge ratio (m / z) is measured and is shown in Table 2.

[0144] Table 2

[0145]

[0146]

[0147] Other compounds whose specific synthesis methods are not listed can be synthesized by referring to the above embodiments in combination with common knowledge in the art.

[0148] The specific structures of some compounds used in the following application examples and comparative application examples are as follows:

[0149]

[0150] The synthesis method of D3 is as follows:

[0151]

[0152] (1) Synthesis of intermediate D3-1

[0153] Intermediate D3-1 was synthesized by referring to the synthesis of intermediate P1-1.

[0154] The compound D3-1 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 398.03.

[0155] (2) Synthesis of Compound D3

[0156] Compound D3 was synthesized by referring to the synthesis of compound P1.

[0157] The mass spectrometry detection of compound D3 showed that the mass-to-charge ratio (m / z) was 485.18.

[0158] The synthesis method of compound D4 is as follows:

[0159]

[0160] (1) Synthesis of intermediate D4-1

[0161] Intermediate D4-1 was synthesized by referring to the synthesis of intermediate P1-1.

[0162] The compound D4-1 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 474.06.

[0163] (2) Synthesis of Compound D4

[0164] Compound D4 was synthesized by referring to the synthesis of compound P1.

[0165] The mass spectrometry detection of compound D4 showed that the mass-to-charge ratio (m / z) was 561.21.

[0166] Application Example 1

[0167] This application example provides a blue light organic electroluminescent device, using the compound P1 provided by the present invention as a main material of the light-emitting layer, and the structure of the blue light organic electroluminescent device is:

[0168] ITO / HT-1: HI-2 [5%] (80nm) / HT-1 (30nm) / EB-1 (20nm) / host material: PBD-1 [5%] (35nm) / ETL-1 (25nm) / LiF (0.5nm) / Al (150nm).

[0169] The preparation method of the blue light organic electroluminescent device is as follows:

[0170] The material was placed in a vacuum chamber and evacuated to 1×10 -5 ~1×10 -6 Pa, vacuum evaporating the above materials onto the cleaned ITO substrate in sequence to prepare an OLED device.

[0171] Among them, PBD-1[5%] refers to the doping ratio of the dye, that is, the volume ratio of the main material to the dye PBD-1 is 95:5; HT-1:HI-2[5%] refers to the ratio of the P-type dopant, that is, the volume ratio of the hole material HT-1 and the P-type dopant HI-2 is 95:5, and HT-1 is a hole transport material; HT-1:HI-2[5%] is used as a hole injection layer material, and EB-1 is an electron blocking layer material.

[0172] Application Example 2-4

[0173] Application Examples 2-4 respectively provide a blue light organic electroluminescent device, which differs from Application Example 1 only in that the main material compound P1 of the light-emitting layer is replaced by other compounds (see Table 3 below for details), and the other preparation steps and conditions are the same as those of Application Example 1.

[0174] Comparative Application Example 1-2

[0175] Comparative Application Examples 1-2 respectively provide a blue light organic electroluminescent device, which differs from Application Example 1 only in that the main material compound P1 of the light-emitting layer is replaced by other compounds (see Table 3 below for details), and the other preparation steps and conditions are the same as those of Application Example 1.

[0176] Performance Testing

[0177] The brightness, driving voltage, current efficiency and LT95 of the organic electroluminescent device provided above were tested, wherein the current efficiency is the brightness of 1000cd / m 2 The corresponding value, LT95, refers to maintaining the initial current density of the device at 10mA / cm 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density, where the driving voltage, current efficiency and LT95 are relative values. The specific test results are shown in Table 3 below:

[0178] Table 3

[0179] Main material dye <![CDATA[Luminance / (cd / m 2 )]]> Driving voltage Current efficiency LT95 Application Example 1 P1 PBD-1 1000 0.97 1.02 1.09 Application Example 2 P3 PBD-1 1000 0.99 1.03 1.26 Application Example 3 P4 PBD-1 1000 0.92 1.06 1.17 Application Example 4 P5 PBD-1 1000 0.96 1.07 1.13 Comparative application example 1 D1 PBD-1 1000 1 1 1 Comparative Application Example 2 D3 PBD-1 1000 0.98 0.97 0.89

[0180] From the above content, it can be known that the structure of the carbazole compound is designed in the present invention to make it suitable as the main material of the light-emitting layer of the organic electroluminescent device, so that the organic electroluminescent device has higher current efficiency, longer life and lower driving voltage.

[0181] Application Examples 5-8, Comparative Application Example 3

[0182] Application Examples 5-8 and Comparative Application Example 3 respectively provide a blue light organic electroluminescent device, which differs from Application Example 1 only in that the main material compound P1 of the light-emitting layer is replaced by other compounds (see Table 4 below for details), and the other preparation steps and conditions are the same as those of Application Example 1.

[0183] Performance Testing

[0184] The brightness, driving voltage, current efficiency and LT95 of the organic electroluminescent device provided above were tested, wherein the current efficiency is the brightness of 1000cd / m 2 The corresponding value, LT95, refers to maintaining the initial current density of the device at 10mA / cm 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density, where the driving voltage, current efficiency and LT95 are relative values. The specific test results are shown in Table 4 below:

[0185] Table 4

[0186] Main material dye <![CDATA[Luminance / (cd / m 2 )]]> Driving voltage Current efficiency LT95 Application Example 5 P2 PBD-1 1000 0.98 1.03 1.12 Application Example 6 P6 PBD-1 1000 0.93 1.03 1.16 Application Example 7 P7 PBD-1 1000 0.82 1.04 1.01 Application Example 8 P8 PBD-1 1000 0.86 1.09 1.47 Comparative Application Example 3 D4 PBD-1 1000 1 1 1

[0187] From the above content, it can be known that the structure of the carbazole compound is designed in the present invention to make it suitable as the main material of the light-emitting layer of the organic electroluminescent device, so that the organic electroluminescent device has higher current efficiency, longer life and lower driving voltage.

[0188] Application 9-10, Comparative Application Example 4

[0189] Application Examples 9-10 and Comparative Application Example 4 respectively provide a blue light organic electroluminescent device, which differs from Application Example 1 only in that the main material compound P1 of the light-emitting layer is replaced by other compounds (see Table 5 below for details), and the other preparation steps and conditions are the same as those of Application Example 1.

[0190] Performance Testing

[0191] The brightness, driving voltage, current efficiency and LT95 of the organic electroluminescent device provided above were tested, wherein the current efficiency is the brightness of 1000cd / m 2 The corresponding value, LT95, refers to maintaining the initial current density of the device at 10mA / cm 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density, where the driving voltage, current efficiency and LT95 are relative values. The specific test results are shown in Table 5 below:

[0192] Table 5

[0193] Main material dye <![CDATA[Luminance / (cd / m 2 )]]> Driving voltage Current efficiency LT95 Application Example 9 P9 PBD-1 1000 0.99 1.09 1.19 Application Example 10 P10 PBD-1 1000 1.03 1.17 1.38 Comparative Application Example 4 D2 PBD-1 1000 1 1 1

[0194] From the above content, it can be known that the structure of the carbazole compound is designed in the present invention to make it suitable as the main material of the light-emitting layer of the organic electroluminescent device, so that the organic electroluminescent device has higher current efficiency, longer life and lower driving voltage.

[0195] Application 11-12

[0196] Application Examples 11-12 respectively provide a blue light organic electroluminescent device, which differs from Application Example 1 only in that the main material compound P1 of the light-emitting layer is replaced with other compounds (see Table 6 below for details), and the other preparation steps and conditions are the same as those of Application Example 1.

[0197] Performance Testing

[0198] The brightness, driving voltage, current efficiency and LT95 of the organic electroluminescent device provided above were tested, wherein the current efficiency is the brightness of 1000cd / m 2 The corresponding value, LT95, refers to maintaining the initial current density of the device at 10mA / cm 2The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density, where the driving voltage, current efficiency and LT95 are relative values. The specific test results are shown in Table 6 below:

[0199] Table 6

[0200] Main material dye <![CDATA[Luminance / (cd / m 2 )]]> Driving voltage Current efficiency LT95 Application Example 11 P11 PBD-1 1000 1 1 1 Application Example 12 P12 PBD-1 1000 1.09 1.19 1.06

[0201] From the above content, it can be known that the structure of the carbazole compound is designed in the present invention to make it suitable as the main material of the light-emitting layer of the organic electroluminescent device, so that the organic electroluminescent device has higher current efficiency, longer life and lower driving voltage.

[0202] The applicant declares that the present invention illustrates the detailed process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A carbazole compound, characterized in that The carbazole compound has a structure shown in the following formula I: wherein Ar1 and Ar2 are each independently selected from any one or a combination of at least two of an H atom, a phenyl group, a naphthyl group, a biphenyl group, and a 9,9-dimethylfluorenyl group, and Ar1 and Ar2 are not selected from an H atom at the same time; X is selected from O or S; n is selected from 0 or 1; The hydrogen atoms in the compound of formula I can be independently substituted by at least one of a deuterium atom, -F, -CN, a C1-C12 alkyl group, a C1-C12 alkoxy group, a triphenylsilyl group, a triphenylmethyl group, and a C6-C20 aryl group.

2. The carbazole compound according to claim 1, characterized in that The C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, butyl, pentyl, methylcyclopentyl, hexyl, methylcyclohexyl, heptyl, octyl or adamantyl, bicyclo[2.2.1]heptyl or bicyclo[2.2.2]octyl; Preferably, the C1-C12 alkoxy group is selected from any one of methoxy, ethoxy, propoxy, butoxy, pentyloxy or hexyloxy; Preferably, the C6-C20 aryl group is selected from any one of phenyl, naphthyl, biphenyl and 9,9-dimethylfluorenyl.

3. The carbazole compound according to claim 1 or 2, characterized in that The Ar1 is selected from any one of phenyl, naphthyl, biphenyl, and 9,9-dimethylfluorenyl, and the Ar2 is selected from a hydrogen atom; Preferably, Ar1 is selected from any one of phenyl, naphthyl, and biphenyl; Preferably, Ar1 and Ar2 are each independently selected from any one of phenyl, naphthyl and biphenyl; Preferably, Ar1 and Ar2 are selected from phenyl.

4. The carbazole compound according to any one of claims 1 to 3, characterized in that The n is selected from 0; Preferably, said n is selected from 1; Preferably, X is selected from O; Preferably, X is selected from S.

5. The carbazole compound according to any one of claims 1 to 4, characterized in that The hydrogen atoms in the compound of formula I may be replaced independently by at least one of a deuterium atom, -F, -CN, a methoxy group, an ethoxy group, a propoxy group, a methyl group, an ethyl group, a propyl group, a tert-butyl group, a phenyl group, a biphenyl group, a naphthyl group, a 9,9-dimethylfluorenyl group or a triphenylsilyl group; Preferably, the hydrogen atoms in the compound of formula I can be replaced independently by at least one of a deuterium atom (D), -F, -CN, a methyl group, an ethyl group, a propyl group, a tert-butyl group, a methoxy group, a phenyl group, a naphthyl group, a biphenyl group, a 9,9-dimethylfluorenyl group or a triphenylsilyl group.

6. The carbazole compound according to any one of claims 1 to 5, characterized in that: The carbazole compound has a structure shown in the following formula I-1 or formula I-2: Wherein, Ar1, Ar2, X, and n have the same definitions as in claim 1; The hydrogen atoms in the compound of formula I-1 and the compound of formula I-2 can each independently be substituted by at least one of a deuterium atom, -F, -CN, a C1-C12 alkyl group, a C1-C12 alkoxy group, a triphenylsilyl group, a triphenylmethyl group, and a C6-C20 aryl group.

7. The carbazole compound according to any one of claims 1 to 6, characterized in that: The carbazole compound is selected from any one of the following substituted or unsubstituted compounds: The substitution means that the hydrogen atoms in the above carbazole compounds can be independently replaced by deuterium atoms.

8. An intermediate, characterized in that The intermediates include the following compounds: Wherein, X, Ar1, and Ar2 have the same definitions as in claim 1; X2 is selected from any one of -F, -Cl, -Br, -I; The hydrogen atoms in the compound of formula MA may be independently substituted by at least one of a deuterium atom, -F, -CN, a C1-C12 alkyl group, a C1-C12 alkoxy group, a triphenylsilyl group, a triphenylmethyl group, and a C6-C20 aryl group; The intermediate is used to prepare the carbazole compound according to any one of claims 1 to 7.

9. The intermediate according to claim 8, characterized in that The intermediates include the following compounds:

10. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises an anode, a cathode and an organic thin film layer arranged between the anode and the cathode; The material of the organic thin film layer comprises the carbazole compound according to any one of claims 1 to 7; Preferably, the organic thin film layer comprises a light-emitting layer, and a main material of the light-emitting layer comprises the carbazole compound according to any one of claims 1 to 7.

Images