Carbazole compound and organic electroluminescent device

Abstract

The invention provides a carbazole compound and an organic electroluminescent device, and the carbazole compound has a structure as shown in a formula I. The carbazole compound with excellent performance is prepared by designing the carbazole compound; the organic electroluminescent device prepared by using the carbazole compound as the material of the luminescent layer has high current efficiency and long service life.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescent materials, and in particular relates to a carbazole compound 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 and an organic electroluminescent device. The present invention prepares a carbazole compound with excellent performance by designing the carbazole compound, and the organic electroluminescent device prepared by using the carbazole compound as the material of the light-emitting layer has high current efficiency and long life.

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

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

[0007]

[0008] wherein one of Ar1 and Ar2 is selected from H, and the other is selected from any one of phenyl, naphthyl, biphenyl, triphenylene, fluoranthene, 9,9-dimethylfluorenyl, carbazolyl, N-phenyl-substituted carbazolyl, N-biphenyl-substituted carbazolyl, dibenzofuranyl or dibenzothiophenyl, or a combination of at least two thereof;

[0009] Ar3, Ar4, Ar5, Ar6 are independently selected from any one of H, phenyl, naphthyl, biphenyl, triphenylene, fluoranthene, 9,9-dimethylfluorenyl, carbazolyl, N-phenyl-substituted carbazolyl, N-biphenyl-substituted carbazolyl, dibenzofuranyl, or dibenzothiophenyl, or a combination of at least two thereof;

[0010] The hydrogen atoms in the compounds of formula I shown in the figure 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 The compound is substituted with at least one of a C6-C20 aryl group or a C6-C20 heteroaryl group.

[0011] In the carbazole compound of the present invention, there are two carbazole groups at the ortho-substituted position on the benzene ring in Formula I, so that the two carbazole groups are in a relatively parallel position, and the carbazole group is an electron-donating group, so that the two carbazole groups at the ortho-substituted position on the benzene ring and the partial structure of the benzene ring between them have a larger electron cloud density distribution, which is more suitable for transferring charges. In addition, an aryl group or a heteroaryl group is selected to be connected at Ar1 or Ar2, so that the material further has more suitable HOMO and LUMO energy levels and better film-forming properties, so that the organic electroluminescent device prepared by using the carbazole compound as the material of the light-emitting layer has lower voltage, higher current efficiency and longer life.

[0012] In the present invention, C1-C12 may be C1, C2, C3, C4, C5, C6, C7, C8, C9 or C12. C6-C20 may be C6, C10, C12, C15, C18 or C20, etc.

[0013] In the present invention, "D" represents a deuterium atom, and the same shall apply hereinafter.

[0014] 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.

[0015] 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.

[0016] Preferably, the C1-C12 alkoxy group is selected from any one of methoxy, ethoxy, propoxy, butoxy, pentyloxy or hexyloxy.

[0017] Preferably, the C6-C20 aryl group is selected from any one of phenyl, naphthyl, biphenyl and 9,9-dimethylfluorenyl.

[0018] Preferably, the C6-C20 heteroaryl group is selected from any one of a carbazolyl group, a dibenzofuranyl group or a dibenzothiophenyl group.

[0019] As a preferred technical solution of the present invention, the hydrogen atoms in the compound of formula I can be independently replaced by at least one of a deuterium atom (D) -F, -CN, methoxy, tert-butyl, phenyl, biphenyl, naphthyl, dibenzofuranyl, carbazole, and triphenylsilyl.

[0020] As a preferred technical solution of the present invention, the carbazole compound is selected from any one of the following substituted or unsubstituted compounds:

[0021]

[0022]

[0023]

[0024] The substitution means that the hydrogen atoms in the carbazole compound can be independently replaced by deuterium atoms. Preferably, the carbazole compound is selected from any one of the following compounds:

[0025]

[0026] In the present invention, there is no special limitation on the preparation method of the carbazole compound, and any commonly used preparation method in the art is applicable.

[0027] In a second aspect, the present invention provides an intermediate for preparing the carbazole compound according to any one of claims 1 to 5, wherein the intermediate has a structure shown in formula MA:

[0028]

[0029] Ar3, Ar4, Ar5, Ar6 are as defined in Formula I;

[0030] X1 is selected from any one of F, Cl, Br or I;

[0031] The hydrogen atoms in MA can be replaced independently by deuterium atoms (D), -F, -CN, C1-C12 alkyl, C1-C12 alkoxy, triphenylsilyl Triphenylmethyl At least one of C6-C20 aryl or C6-C20 heteroaryl is substituted;

[0032] The intermediates do not include:

[0033]

[0034] The intermediate is used to prepare the carbazole compound as described in the first aspect.

[0035] Preferably, the intermediate includes the following compounds:

[0036]

[0037] In the present invention, the synthetic route of the intermediate as described above is provided as follows:

[0038]

[0039] In the present invention, the intermediate MA is used to synthesize the carbazole compound of the present invention, and the synthesis route thereof is as follows:

[0040]

[0041] wherein Ar1, Ar2, Ar3, Ar4, Ar5, Ar6 are as defined above;

[0042] X1 and X2 are independently selected from F, Cl, Br, and I;

[0043] The hydrogen atoms in MA and Formula I can be replaced by deuterium atoms (D), -F, -CN, C1-C12 alkyl, C1-C12 alkoxy, triphenylsilyl Triphenylmethyl The compound is substituted with at least one of a C6-C20 aryl group or a C6-C20 heteroaryl group.

[0044] 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;

[0045] The material of the organic thin film layer includes the carbazole compound as described in the first aspect.

[0046] 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.

[0047] Preferably, the light-emitting layer is a phosphorescent light-emitting layer.

[0048] As a preferred technical solution of the present invention, the organic electroluminescent device is a blue light organic electroluminescent device.

[0049] As a preferred technical solution of the present invention, the organic electroluminescent device is a green organic electroluminescent device.

[0050] The luminescent layer of 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 carbazole compounds as described in the first aspect.

[0051] 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.

[0052] 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%.

[0053] 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:

[0054]

[0055] Wherein, M is selected from any one of Ir, Pt, Pd, Os, Ti, Zr, Hf, Eu, Tb, Tm, Cu or Au;

[0056] Y1-Y4 are each independently selected from carbon or nitrogen;

[0057] Y1 and Y2 can be connected by a single bond or a double bond, and Y3 and Y4 can be connected by a single bond or a double bond;

[0058] Cy1 and Cy2 are each independently selected from 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 Cy1 and Cy2 may be optionally linked to each other via a single bond or an organic linking group;

[0059] 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;

[0060] R 91 and R 92 each independently selected from -H, -D, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazine, hydrazone, carboxylic acid, carboxylate, sulfonic acid, sulfonate, phosphoric acid, phosphate, -SF5, substituted or unsubstituted C1-C60 (e.g., C1, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) alkyl, substituted or unsubstituted C2-C6 C2-C60 (for example, C2, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) alkynyl, substituted or unsubstituted C1-C60 (for example, C1, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) 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) aryl, substituted or unsubstituted C6-C60 (for example, C2, C3, C4, C5, C6, C7, C8, C9 or C10) For example, it may be any one of C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60) aryloxy, substituted or unsubstituted C6-C60 (for example, it may be C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60) arylthio, substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group;

[0061] a1 and a2 are each independently an integer selected from 1-5, for example, 1, 2, 3, 4 or 5;

[0062] b is an integer selected from 0-4, for example, 0, 1, 2, 3 or 4;

[0063] a is selected from 1, 2 or 3;

[0064] L1 is a monovalent organic ligand, a divalent organic ligand or a trivalent organic ligand.

[0065] Preferably, the compound of formula PD is selected from any one of the following compounds:

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073] The organic thin film layer of the organic electroluminescent device of the present invention further comprises at least one of a hole injection layer, a hole transport layer, an electron blocking layer or an electron transport layer.

[0074] 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.

[0075] The hole injection layer material includes a P-type dopant, and 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.

[0076] 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:

[0077]

[0078]

[0079] 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:

[0080]

[0081] 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;

[0082] Ar 41 ,Ar 42 Each 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;

[0083] X is selected from CR 41 R 42 or NR 43 , where R 41 , R 42 , R 43 Each 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.

[0084] 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:

[0085]

[0086] 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;

[0087] m is selected from an integer between 0 and 4 (for example, 0, 1, 2, 3 or 4), and n is selected from 0 or 1;

[0088] Ar is selected from any one of triphenylene, fluoranthenylene, dibenzofuranylene or dibenzothiophenylene;

[0089] Ar1 and Ar2 are each independently selected from any one of a C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) aryl group, a dibenzofuranyl group or a dibenzothiophenyl group;

[0090] Ar1 and Ar, Ar2 and Ar, and Ar1 and Ar2 can each independently be connected or bridged by a single bond, O, S, CR1R2, or NR.

[0091] R, R1, and R2 are each independently selected from any one of a C1-C20 (e.g., C1, C2, C4, C6, C8, C10, C12, C14, C16, C18, or C20, etc.) alkyl group, a C6-C40 (e.g., C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.) aryl group, a dibenzofuranyl group, or a dibenzothiophenyl group;

[0092] 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.

[0093] Preferably, Ar is a fluoranthenyl group, and m+n>1.

[0094] 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.

[0095] Preferably, L, Ar1, Ar2 are each independently selected from at least one of phenyl, biphenyl, naphthyl, phenanthryl, anthracenyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, triphenylene, fluoranthenyl, pyrene, perylenyl, spirofluorenyl, indenofluorenyl or hydrogenated benzanthryl.

[0096] Preferably, the compound of formula IB is selected from any one of the following compounds:

[0097]

[0098]

[0099] 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.

[0100] The triarylamine compound or carbazole compound is used as the hole layer material, and the hole layer material includes a compound having any of the following structures:

[0101]

[0102] 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;

[0103] 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 R702 NR 703 bridging;

[0104] R 701 , R 702 , R 703 is 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.

[0105] 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.

[0106] 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.

[0107] In the present invention, there is no special restriction on the electron transport layer material, which exemplarily includes but is not limited to:

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] 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.

[0116] It is also possible to introduce a thin intermediate layer of a material with a high dielectric constant between the metal cathode and the organic semiconductor to form a multilayer structure; the material with a high dielectric constant can also be called an electron injection material, and fluorides of alkali metals or alkaline earth metals, and corresponding oxides or carbonates (such as LiF, Li2O, BaF2, MgO, NaF, CsF, Cs2CO3, etc.) or lithium quinoline (LiQ) can be selected.

[0117] Compared with the prior art, the present invention has the following beneficial effects:

[0118] 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 and longer life. DETAILED DESCRIPTION

[0119] The technical solution of the present invention is further described below by specific implementation methods. 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.

[0120] Preparation Example 1

[0121] This preparation example provides an intermediate P1-1 and a synthesis method thereof, the synthesis method is as follows:

[0122]

[0123] Under a nitrogen atmosphere, dry toluene (60 mL), intermediate P1-0 (3.3 g), o-dibromobenzene (2.3 g), Pd(dba)2 (bis(dibenzylideneacetonepalladium, 0.1 g), 8 g of 10% tri-tert-butylphosphine toluene solution by mass (the mass of tri-tert-butylphosphine solution is 0.8 g) and sodium tert-butoxide (1.2 g) were added to a three-necked flask, heated to reflux temperature, reacted for 4 h, cooled to room temperature, separated by adding water, and then the organic layer was washed with water until neutral, dried with magnesium sulfate, filtered to remove magnesium sulfate, concentrated to dryness, separated by silica gel column chromatography, and eluted with petroleum ether: ethyl acetate = 20: 1 (volume ratio) to obtain intermediate P1-1 (3.1 g).

[0124] The intermediate P1-1 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 486.07.

[0125] Preparation Example 2

[0126] This preparation example provides an intermediate P2-1 and a synthesis method thereof, the synthesis method is as follows:

[0127]

[0128] Referring to the synthesis method of intermediate P1-1, intermediate P2-1 was prepared by using corresponding raw materials.

[0129] The intermediate P2-1 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 486.07.

[0130] Preparation Example 3

[0131] This preparation example provides an intermediate P3-1 and a synthesis method thereof, the synthesis method is as follows:

[0132]

[0133] Referring to the synthesis method of intermediate P1-1, intermediate P3-1 was prepared by using corresponding raw materials.

[0134] The intermediate P3-1 was subjected to mass spectrometry detection: the mass-to-charge ratio (m / z) was measured to be 562.10.

[0135] Synthesis Example 1

[0136] This synthesis example provides compound P1 and its synthesis method, the synthesis method is as follows:

[0137]

[0138] Under a nitrogen atmosphere, dry toluene (110 mL), intermediate P1-1 (4.9 g), intermediate P1-2 (2.5 g), Pd(dba)2 (bis(dibenzylideneacetonepalladium, 0.1 g), 8 g of 10% tri-tert-butylphosphine toluene solution by mass percentage (the mass of tri-tert-butylphosphine solution is 0.8 g) and sodium tert-butoxide (1.2 g) were added to a three-necked flask, heated to reflux temperature, reacted for 6 h, cooled to room temperature, divided by water, and then the organic layer was washed with water until neutral, dried with magnesium sulfate, filtered to remove magnesium sulfate, concentrated to dryness, separated by silica gel column chromatography, and eluted with petroleum ether: ethyl acetate = 20: 1 (volume ratio) to obtain compound P1 (5.5 g).

[0139] The mass spectrometry detection of compound P1 was performed: the mass-to-charge ratio (m / z) was measured to be 649.25.

[0140] Synthesis Example 2-10

[0141] Synthesis Examples 2-10 provide a compound respectively. The synthesis method of the compound can refer to the synthesis method of compound P1 provided in Synthesis Example 1, and the corresponding raw materials are reacted to prepare the corresponding compound, as shown in Table 1 below.

[0142] The obtained compounds were respectively subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) data are shown in Table 1 below.

[0143] Table 1

[0144]

[0145]

[0146] Other compounds for which the specific synthesis method is not listed can be synthesized by referring to the above examples in combination with the common knowledge in the art. The specific structures of some compounds used in the following application examples and comparative application examples are as follows:

[0147]

[0148]

[0149] Synthesis of compound D3:

[0150]

[0151] Referring to the synthesis method of compound P1 provided in Synthesis Example 1, corresponding raw materials were used to react and the corresponding compound D3 was prepared.

[0152] The mass spectrometry detection of compound D3 showed that the mass-to-charge ratio (m / z) was 649.25.

[0153] Application Example 1

[0154] 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:

[0155] 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).

[0156] The preparation method of the blue light organic electroluminescent device is as follows:

[0157] 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.

[0158] 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.

[0159] Application Example 2-11

[0160] Application Examples 2-11 each 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 1 below for details), and the other preparation steps and conditions are the same as those of Application Example 1.

[0161] Comparative Application Examples 1-3

[0162] Comparative Application Examples 1-3 each provide an 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 2 below for details), and the other preparation steps and conditions are the same as those of Application Example 1.

[0163] Performance Testing

[0164] 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 is constant, where voltage, current efficiency and LT95 are relative values ​​(with application example 1 as the reference standard). The specific test results are shown in Table 2 below.

[0165] Table 2

[0166] Main material dye <![CDATA[Luminance / (cd / m 2 )]]> Voltage Current efficiency LT95 Application Example 1 P1 PBD-1 1000 1 1 1 Application Example 2 P11 PBD-1 1000 1.02 0.96 1.09 Application Example 3 P12 PBD-1 1000 1.04 0.97 1.11 Application Example 4 P13 PBD-1 1000 0.97 1.02 1.01 Application Example 5 P14 PBD-1 1000 1.93 1.05 0.96 Application Example 6 P15 PBD-1 1000 1.02 1.29 1.02 Application Example 7 P16 PBD-1 1000 1.06 1.08 1.57 Application Example 8 P17 PBD-1 1000 1.05 1.24 1.22 Application Example 9 P18 PBD-1 1000 1.01 0.98 1.17 Application Example 10 P2 PBD-1 1000 0.90 1.02 0.87 Application Example 11 P21 PBD-1 1000 1.02 1.09 0.98 Application Example 12 P3 PBD-1 1000 1.03 0.97 1.15 Comparative application example 1 D1 PBD-1 1000 1.13 0.87 0.86 Comparative Application Example 2 D2 PBD-1 1000 1.11 0.76 0.71 Comparative Application Example 3 D3 PBD-1 1000 1.26 0.81 0.80

[0167] Comparison between Application Example 1 and Application Example 10 shows that the change in the leftmost carbazole connection position of the compound P2 used in Application Example 10 makes the organic electroluminescent device prepared using the compound P2 in Application Example 10 have a lower voltage.

[0168] Application Examples 6 and 8 have better efficiencies, and Application Example 7 has better lifespan. It can be seen that when one of Ar1 and Ar2 in Formula I is selected from a carbazole group, the device performance is better.

[0169] By comparing Application Example 6 with Application Example 8, and by comparing Application Example 1 with Application Example 9, it can be seen that when Ar2 in Formula I is selected from H or D, the device life is improved.

[0170] Compared with Application Example 10, when Application Example 11 is substituted by triphenylsilyl, the device efficiency and lifespan are improved.

[0171] Compared with Application Example 1, Application Example 12 shows that when at least one of Ar3, Ar4, Ar5, and Ar6 in Formula I is not selected from H, the device life is improved.

[0172] 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 and longer life.

[0173] The applicant declares that the present invention illustrates the carbazole compounds and organic electroluminescent devices of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments 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 one of Ar1 and Ar2 is selected from H, and the other is selected from any one of phenyl, naphthyl, biphenyl, triphenylene, fluoranthene, 9,9-dimethylfluorenyl, carbazolyl, N-phenyl-substituted carbazolyl, N-biphenyl-substituted carbazolyl, dibenzofuranyl or dibenzothiophenyl, or a combination of at least two thereof; Ar3, Ar4, Ar5, Ar6 are independently selected from any one of H, phenyl, naphthyl, biphenyl, triphenylene, fluoranthene, 9,9-dimethylfluorenyl, carbazolyl, N-phenyl-substituted carbazolyl, N-biphenyl-substituted carbazolyl, dibenzofuranyl, or dibenzothiophenyl, or a combination of at least two thereof; The hydrogen atoms in the compound of formula I shown 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, a C6-C20 aryl group or a C6-C20 heteroaryl 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 or 9,9-dimethylfluorenyl; Preferably, the C6-C20 heteroaryl group is selected from any one of a carbazolyl group, a dibenzofuranyl group or a dibenzothiophenyl group.

3. The carbazole compound according to claim 1 or 2, characterized in that The hydrogen atoms in the compound of formula I can be independently substituted by at least one of a deuterium atom -F, -CN, a methoxy group, a tert-butyl group, a phenyl group, a biphenyl group, a naphthyl group, a dibenzofuranyl group, a carbazolyl group, and a triphenylsilyl group.

4. The carbazole compound according to any one of claims 1 to 3, 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 carbazole compound can be independently replaced by deuterium atoms.

5. The carbazole compound according to any one of claims 1 to 4, characterized in that The carbazole compound is selected from any one of the following compounds:

6. An intermediate for preparing the carbazole compound according to any one of claims 1 to 5, characterized in that: The intermediate has the structure shown in formula MA: Wherein, Ar3, Ar4, Ar5, Ar6 are as defined in Formula I; X1 is selected from any one of F, Cl, Br or I; The hydrogen atoms in the intermediate MA may 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, a C6-C20 aryl group or a C6-C20 heteroaryl group; The intermediates do not include the following compounds: Preferably, the intermediate includes the following compounds:

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises an anode, a cathode and an organic thin film layer disposed 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 5.

8. The organic electroluminescent device according to claim 7, characterized in that: 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 5.

9. The organic electroluminescent device according to claim 8, characterized in that: The light-emitting layer is a phosphorescent light-emitting layer; Preferably, the light-emitting layer further comprises a doping material; Preferably, the volume percentage of the host material in the light-emitting layer is 60% to 99.9%, preferably 70% to 99.5%, and more preferably 85% to 95%.

10. The organic electroluminescent device according to claim 8, characterized in that: The organic thin film layer further comprises at least one of a hole injection layer, a hole transport layer, an electron blocking layer or an electron transport layer; Preferably, the organic electroluminescent device is a blue organic electroluminescent device; Preferably, the organic electroluminescent device is a green organic electroluminescent device.

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