An organic compound containing a carbazole structure and an organic electroluminescent device

Abstract

The present invention provides an organic compound containing a double-carbazole structure and an organic electroluminescent device. The organic compound has the structure shown in formula (I), has a relatively high triplet energy level, good carrier transport ability, appropriate HOMO / LUMO energy levels, as well as relatively high thermal stability and film-forming stability, and can be used as the host material of the light-emitting layer of an organic electroluminescent device to reduce the driving voltage of the device and improve the light-emitting efficiency of the device.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescence, and particularly relates to an organic compound containing a double-carbazole structure and an organic electroluminescent device. Background Art

[0002] Organic light-emitting diodes (OLEDs) have become the core components for the development of flat panel displays, solid-state lighting, and other fields due to their advantages such as low driving voltage, low power consumption, thinness, flexibility, low cost, diverse materials, and ease of large-area fabrication. Therefore, they have received extensive attention from both academia and industry. To meet the requirements of practical applications, the research focus of scientific researchers has always been on the preparation technologies of OLED materials and devices with "high efficiency and low cost".

[0003] As is well known, for organic electroluminescent materials, whether it is the initially discovered organic fluorescent materials, the most widely used organic phosphorescent materials, or the recently developed thermally activated delayed fluorescence (TADF) materials, there is a phenomenon of luminescence aggregation quenching. To overcome this phenomenon, it is a common practice to dope various types of organic electroluminescent materials into the host material to form a host-guest mixed emitting layer in the preparation of OLEDs. Therefore, it is very important to select a suitable host material during the preparation of OLEDs. For example, a wide-bandgap host material will cause an increase in the turn-on voltage of phosphorescent organic electroluminescent devices, and correspondingly high efficiency can be obtained. By selecting a suitable host material and then using the host-guest doping method to adjust the light color, brightness, and efficiency, the performance of organic electroluminescent display devices can be improved.

[0004] The host material has an important influence on the processes such as charge injection / transport, exciton formation / recombination, and energy transfer in OLED devices. Therefore, generally speaking, the necessary characteristics of the host material include: (1) a triplet energy level higher than that of the guest to prevent the reverse transfer of triplet energy from the guest to the host and effectively confine excitons in the emitting layer; (2) good carrier transport ability, trying to keep the hole and electron transport abilities close to balance the carriers in the emitting layer, broaden the recombination region, and increase the recombination probability, thereby improving the device performance; (3) appropriate HOMO / LUMO energy levels, matching the energy levels of adjacent carrier transport materials to reduce the injection and transport barriers of carriers and lower the driving voltage; (4) good thermal stability and film-forming properties to obtain a uniform, stable, and complete thin film by vacuum evaporation, which is beneficial to improving the efficiency and stability of the device.

[0005] At present, OLED displays and lighting have been widely commercialized, and the optoelectronic requirements of OLED panels by customer terminals are also continuously increasing. To meet such demands, in addition to the continuous improvement of the OLED panel manufacturing process, the development of OLED materials that can meet higher device specifications is particularly important. Therefore, developing stable and efficient host materials to reduce the driving voltage and improve the device luminescence efficiency will have important practical application value. Summary of the Invention

[0006] The object of the present invention is to provide an organic compound containing a dicarbazole structure. This organic compound has a relatively high triplet energy level, good carrier transport ability, appropriate HOMO / LUMO energy levels, and high thermal stability and film-forming stability. It can be used as the host material of the light-emitting layer in OLED devices, capable of reducing the driving voltage of the device and improving the device luminescence efficiency.

[0007] Specifically, in the first aspect, the present invention provides an organic electroluminescent material having a structure represented by the general formula (I):

[0008]

[0009] In formula (I):

[0010] Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6-C60 arylene groups; wherein, Ar1 and Ar2 may be the same or different;

[0011] The substituents in Ar1 and Ar2 are selected from one or a combination of at least two of deuterium, halogen, C1-C10 linear alkyl groups, C1-C10 linear deuterated alkyl groups, C3-C10 cycloalkyl groups, C3-C10 deuterated cycloalkyl groups, C1-C10 alkoxy groups, cyano groups, amino groups, C6-C30 arylamino groups, C3-C30 heteroarylamino groups, C6-C30 aryloxy groups, C3-C30 heteroaryloxy groups, C6-C30 aryl groups, C6-C30 deuterated aryl groups, C3-C30 heteroaryl groups, and C3-C30 deuterated heteroaryl groups;

[0012] R1, R2, R3 and R4 are each independently selected from one or a combination of hydrogen, deuterium, halogen, amino group, cyano group, C1-C20 linear alkyl groups, C3-C20 cycloalkyl groups, C3-C20 alkoxy groups, C3-C20 silyl groups, C3-C20 alkylamino groups, C6-C60 arylamine groups, C3-C60 heteroarylamine groups, C6-C60 aryl groups, and C3-C60 heteroaryl groups. Optionally, R1, R2, R3 and R4 are each independently fused or non-fused with the benzene ring to which they are attached, for example, they can form a fused ring or a bridged ring; R1, R2, R3 and R4 may be the same or different.

[0013] A has a structure represented by formula (II) or formula (III):

[0014]

[0015] R5 and R6 represent single-substituted or multi-substituted groups, and each independently selected from a combination of one or more of cyano, hydrogen, deuterium, halogen, amino, C1-C20 linear alkyl, C3-C20 cycloalkyl, C3-C20 alkoxy, C3-C20 silyl, C3-C20 alkylamino, C6-C60 arylamine, C3-C60 heteroarylamine, C6-C60 aryl, C3-C60 heteroaryl.

[0016] In formula (II) and formula (III), * represents the position where A is connected to its adjacent group.

[0017] According to some embodiments of the present invention, Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6-C20 arylene. Preferably, the substituents of the substituted group are selected from a combination of one or more of deuterium, halogen, C1-C8 linear alkyl, C1-C8 linear deuterated alkyl, C3-C8 cycloalkyl, C3-C8 deuterated cycloalkyl, C1-C8 alkoxy, cyano, amino, C6-C20 arylamino, C3-C20 heteroarylamino, C6-C20 aryloxy, C3-C20 heteroaryloxy, C6-C20 aryl, C6-C20 deuterated aryl, C3-C20 heteroaryl, C3-C20 deuterated heteroaryl.

[0018] According to some embodiments of the present invention, Ar1 and Ar2 are each independently selected from substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted anthrylene, substituted or unsubstituted phenanthrylene, substituted or unsubstituted pyrenylene. Preferably, the substituents of the substituted group are selected from a combination of one or more of C1-C8 linear alkyl, C1-C8 linear deuterated alkyl, C3-C8 cycloalkyl, C3-C8 deuterated cycloalkyl, C6-C20 aryl, C6-C20 deuterated aryl, C3-C20 heteroaryl, C3-C20 deuterated heteroaryl, more preferably a combination of one or more of deuterated methyl, methyl, deuterated ethyl, ethyl, deuterated propyl, propyl, deuterated isopropyl, isopropyl, deuterated n-butyl, n-butyl, deuterated isobutyl, isobutyl, deuterated tert-butyl, tert-butyl, deuterated n-pentyl, n-pentyl, deuterated isopentyl, isopentyl, deuterated neopentyl, neopentyl, cyclopropane, cyclopentane, cyclohexane, deuterated cyclopropane, deuterated cyclopentane, deuterated cyclohexane, phenyl, biphenyl, pyridyl, naphthyl, quinazolinyl, benzopyrazinyl, triazolyl, oxadiazolyl, benzimidazolyl, deuterated phenyl, deuterated biphenyl, deuterated pyridyl, deuterated naphthyl, deuterated quinazolinyl, deuterated benzopyrazinyl, deuterated triazolyl, deuterated oxadiazolyl, deuterated benzimidazolyl.

[0019] Preferably, Ar1 and Ar2 are the same.

[0020] Specifically, Ar1 and Ar2 are respectively and independently connected to the parent nucleus structure shown in the general formula (I) of the present invention through C atoms on the aromatic group.

[0021] According to a preferred embodiment of the present invention, the organic compound has the structure shown in formula (Ⅰ-1) or formula (Ⅰ-2):

[0022]

[0023] Wherein, in formula (I-1), n is the number of cyano groups, selected from 0, 1, 2 or 3; in formula (I-1) and formula (I-2), the definitions of R1, R2, R3, R4, Ar1 and Ar2 are the same as those in formula (I).

[0024] According to a more preferred embodiment of the present invention, the organic compound is selected from the structures shown in formula (Ⅰ-3) to formula (Ⅰ-6):

[0025]

[0026] Wherein, in formula (I-3) and formula (I-5), n is the number of cyano groups, selected from 1, 2 or 3; in formula (I-3) to formula (I-6), the definitions of R1, R2, R3, R4, Ar1 and Ar2 are the same as those in formula (I).

[0027] According to some embodiments of the present invention, R1, R2, R3 and R4 are each independently selected from one or more combinations of hydrogen, deuterium, halogen, cyano, amino, C1-C8 linear alkyl, C3-C8 cycloalkyl, C3-C8 alkoxy, C3-C8 silyl, C3-C8 alkylamino, C6-C20 arylamine, C3-C20 heteroarylamine, C6-C20 aryl, C3-C20 heteroaryl, preferably one or more combinations of hydrogen, deuterium, halogen, cyano, amino, C1-C8 linear alkyl, C3-C8 cycloalkyl, C6-C20 aryl, C3-C20 heteroaryl.

[0028] According to some preferred embodiments of the present invention, R1, R2, R3 and R4 are each independently selected from one or more combinations of hydrogen, deuterium, halogen, cyano, amino, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, cyclopropane, cyclopentane, cyclohexane, phenyl, biphenyl, naphthyl, anthracenyl, phenanthryl, pyridyl, furyl, thienyl, pyrrolyl, benzopyridyl, benzofuryl, benzothienyl, benzopyrrolyl, benzocyclopentyl, quinolinyl, isoquinolinyl, triazolyl, oxadiazolyl, benzimidazolyl, carbazolyl. Optionally, R1, R2, R3 and R4 each independently form a fused ring with the benzene ring to which they are attached.

[0029] According to a more preferred embodiment of the present invention, R1, R2, R3 and R4 are each independently selected from hydrogen, cyano, phenyl,

[0030]

[0031] According to some embodiments of the present invention, R5 and R6 are each independently selected from one or more combinations of cyano, hydrogen, deuterium, halogen, amino, C1-C8 linear alkyl, C3-C8 cycloalkyl, C3-C8 alkoxy, C3-C8 silyl, C3-C8 alkylamino, C6-C20 arylamine, C3-C20 heteroarylamine, C6-C20 aryl, C3-C20 heteroaryl, preferably one or more combinations of cyano, hydrogen, deuterium, halogen, amino, C1-C8 linear alkyl, C3-C8 cycloalkyl, C6-C20 aryl, C3-C20 heteroaryl.

[0032] According to a preferred embodiment of the present invention, R5 and R6 are each independently selected from one or more combinations of cyano, hydrogen, deuterium, halogen, amino, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, cyclopropane, cyclopentane, cyclohexane, phenyl, biphenyl, naphthyl, anthracenyl, phenanthryl, pyridyl, furyl, thienyl, pyrrolyl, benzopyridyl, benzofuryl, benzothienyl, benzopyrrolyl, benzocyclopentyl, quinolinyl, isoquinolinyl, triazolyl, oxadiazolyl, benzimidazolyl, carbazolyl.

[0033] According to a preferred embodiment of the present invention, in formula (I), are each independently selected from the following groups:

[0034]

[0035]

[0036] According to some preferred embodiments of the present invention, the structure shown in formula (II) is selected from the following groups:

[0037]

[0038] According to some preferred embodiments of the present invention, the structure shown in formula (III) is

[0039] In some specific embodiments, each of R1, R2, R3, R4, R5 and R6 is independently selected from one of the following groups: deuterium, hydrogen, difluoromethyl, trimethylsilyl, trifluoromethyl, methyl, deuterated methyl, ethyl, deuterated ethyl, deuterated propyl, propyl, deuterated isopropyl, isopropyl, deuterated n-butyl, n-butyl, deuterated isobutyl, isobutyl, deuterated tert-butyl, tert-butyl, deuterated n-pentyl, n-pentyl, deuterated isopentyl, isopentyl, deuterated neopentyl, neopentyl, cyclopropane, cyclopentane, cyclohexane, deuterated cyclopropane, deuterated cyclopentane, deuterated cyclohexane, phenyl, biphenyl, pyridyl, naphthyl, quinazolinyl, benzopyrazinyl, triazolyl, oxadiazolyl, benzimidazolyl, deuterated phenyl, deuterated biphenyl, deuterated pyridyl, deuterated naphthyl, deuterated quinazolinyl, deuterated benzopyrazinyl, deuterated triazolyl, deuterated oxadiazolyl or deuterated benzimidazolyl, cyano, benzofuranyl, benzothiophenyl, or a combination of two of the above groups; each of R1, R2, R3 and R4 is independently ring-formed or non-ring-formed with the benzene ring to which it is attached; R1 is the same as R3, R2 is the same as R4, and R1 and R2 may be the same or different.

[0040] Furthermore, the organic compounds of the present invention can preferably be the following specific structural compounds, and these compounds are only representative and do not limit the scope of the present invention:

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] In a second aspect, the present invention provides an application of the organic compound described in the first aspect.

[0051] Specifically, the organic compound is applied to an organic electronic device, and the organic electronic device includes an organic electroluminescent device, an optical sensor, a solar cell, a lighting element, an organic thin film transistor, an organic field effect transistor, an organic thin film solar cell, an information tag, an electronic artificial skin sheet, a sheet-type scanner, or an electronic paper.

[0052] Preferably, the organic compound of the present invention is applied to an organic electroluminescent device, and preferably used as a host material in the light-emitting layer of the organic electroluminescent device. The electroluminescent device prepared by using the compound of the present invention exhibits excellent properties of high purity, high brightness, and high efficiency.

[0053] In a third aspect, the present invention provides an organic electroluminescent device, the organic electroluminescent device includes a light-emitting layer, and the light-emitting layer includes the above-mentioned organic compound provided by the present invention as a light-emitting host material. Such organic electroluminescent devices exhibit excellent properties of high purity, high efficiency, and long lifespan.

[0054] Furthermore, the organic electroluminescent device provided by the present invention includes a substrate, and an anode layer, a plurality of light-emitting unit layers, and a cathode layer formed on the substrate in sequence; the light-emitting unit layer includes a light-emitting layer, and also includes one or several of a hole injection layer, a hole transport layer, an electron transport layer, an electron blocking layer, etc. The hole injection layer is formed on the anode layer, the hole transport layer is formed on the hole injection layer, the cathode layer is formed on the electron transport layer, and there are a plurality of light-emitting layers between the hole transport layer and the electron transport layer. Preferably, the light-emitting host material in the light-emitting layer is the organic compound of the present invention.

[0055] Specifically, the light-emitting layer of the device includes a host material and a dye material, and the host material includes the above-mentioned organic compound provided by the present invention.

[0056] In a fourth aspect, the present invention provides a display device including the organic electroluminescent device described in the first aspect.

[0057] In a fifth aspect, the present invention provides a lighting device including the organic electroluminescent device described in the first aspect.

[0058] The compounds of the present invention have a structure with a carbazole dimer and an electron-withdrawing group such as isoquinoline or cyanopyridine as the core. The carbazole dimer structure has a rigid structural unit, good thermal stability, appropriate HOMO and LUMO energy levels, and Eg. The isoquinoline or cyanopyridine structure has a relatively high triplet energy level, good electron mobility, and good thermal stability. Therefore, when the organic compounds of the present invention are used as organic electroluminescent materials in OLED devices, especially when used as host materials, the optoelectronic performance of OLED devices can be effectively improved. The OLED devices prepared with the compounds of the present invention can be applied to the fields of display or lighting.

[0059] As the host material of the light-emitting layer of the organic electroluminescent device, the organic compound of the present invention can increase the thermal stability of the compound, improve the purity, and at the same time improve the device efficiency and lifespan compared with the host materials in the prior art. Detailed implementation manners

[0060] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the embodiments. The specific embodiments described herein are only used to explain the present invention and do not constitute any limitation to the present invention.

[0061] It should be noted that in this specification, the expression of Ca~Cb means that the group has a carbon atom number of a~b. Generally speaking, unless otherwise specified, the carbon atom number does not include the carbon atom number of the substituent.

[0062] In the present invention, for the description of chemical elements, unless otherwise specified, it usually includes the concept of isotopes with the same chemical properties. For example, the expression of "hydrogen" also includes the concepts of "deuterium" and "tritium" with the same chemical properties. Carbon (C) includes 12 C, 13 C, etc., which will not be elaborated here.

[0063] The heteroaryl group in this specification refers to an aromatic cyclic group containing heteroatoms. The heteroatoms usually refer to those selected from N, O, S, P, Si, and Se, preferably selected from N, O, and S.

[0064] In this specification, unless otherwise specified, C6-C60 aryl groups and C3-C60 heteroaryl groups are aromatic groups that satisfy the π-conjugated system, including both monocyclic and polycyclic cases. A monocyclic group refers to a molecule containing at least one phenyl group. When the molecule contains at least two phenyl groups, the phenyl groups are independent of each other and are connected by single bonds. Exemplarily, they are phenyl, biphenyl, terphenyl, etc. A polycyclic group refers to a molecule containing at least two benzene rings, but the benzene rings are not independent of each other, but are fused together by sharing ring edges. Exemplarily, they are naphthyl, anthryl, phenanthryl, etc. A monocyclic heteroaryl group refers to a molecule containing at least one heteroaryl group. When the molecule contains a heteroaryl group and other groups (such as aryl, heteroaryl, alkyl, etc.), the heteroaryl group and other groups are independent of each other and are connected by single bonds. Exemplarily, they are pyridine, furan, thiophene, etc. A polycyclic heteroaryl group refers to a group formed by the fusion of at least one phenyl group and at least one heteroaryl group, or, formed by the fusion of at least two heteroaryl groups. Exemplarily, they are quinoline, isoquinoline, benzofuran, dibenzofuran, benzothiophene, dibenzothiophene, etc.

[0065] In this specification, the substituted or unsubstituted C6-C60 aryl group is preferably a C6-C30 aryl group. Exemplary preferred aryl groups are those selected from the group consisting of phenyl, naphthyl, anthryl, benzanthryl, phenanthryl, benzophenanthryl, pyrenyl, chrysenyl, perylenyl, fluoranthenyl, tetraphenyl, pentaphenyl, benzopyrenyl, biphenyl, terphenyl, triphenyl, tetraphenyl, fluorene, spirobifluorene, dihydrophenanthryl, dihydropyrenyl, tetrahydropyrenyl, cis- or trans-indeno[1,2-b]fluorene, truxene, isotruxene, spirotruxene, spiroisotruxene. The C6-C60 aryl group of the present invention can also be a group formed by combining the above groups through single bond connection or / and fusion.

[0066] In this specification, the substituted or unsubstituted C3-C60 heteroaryl group is preferably a C3-C30 heteroaryl group, and can be a nitrogen-containing heteroaryl group, an oxygen-containing heteroaryl group, a sulfur-containing heteroaryl group, etc. As preferred examples of the heterocyclic rings in the present invention, for example, they are furyl, thienyl, pyrrolyl, benzofuryl, benzothienyl, isobenzofuryl, indolyl, dibenzofuryl, dibenzothienyl, carbazolyl and its derivatives. Among them, the carbazolyl derivatives are preferably 9-phenylcarbazole, 9-naphthylcarbazole, benzocarbazole, dibenzocarbazole or indolocarbazole. The C3-C60 heteroaryl group of the present invention can also be a group formed by combining the above groups through single bond connection or / and fusion.

[0067] In this specification, the concept of alkyl includes linear alkyl, branched alkyl and cycloalkyl. Examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, adamantyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, pentafluoroethyl, 2,2,2-trifluoroethyl, etc.

[0068] In this specification, cycloalkyl includes monocyclic cycloalkyl and polycyclic cycloalkyl. Examples include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, etc.

[0069] In this specification, examples of C1-C20 alkoxy groups include: methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy, pentyloxy, isopentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, etc. Among them, methoxy, ethoxy, n-propoxy, isopropoxy, tert-butoxy, sec-butoxy, isobutoxy, isopentyloxy, etc. are preferred.

[0070] In this specification, as the aryloxy group of C6-C60, groups formed by connecting oxygen to each of the groups exemplified in the above-mentioned substituted or unsubstituted C6-C60 aryl groups can be cited. Specific examples can refer to the above examples and will not be elaborated here.

[0071] In this specification, examples of halogen include: fluorine, chlorine, bromine, iodine, etc.

[0072] In this specification, C6-C60 arylamino group and C3-C60 heteroarylamino group refer to groups obtained by substituting one or two H in amino -NH2 with the C6-C60 aryl group or C3-C60 heteroaryl group exemplified above.

[0073] Those skilled in the art can synthesize the compounds provided by the present invention by using common methods known in the art, and can prepare the organic electroluminescent devices of the present invention by using common methods known in the art. The present invention does not make special limitations in this regard. Unless otherwise specified, raw materials such as solvents, catalysts, bases, etc. used in the preparation process can be obtained through public commercial channels or synthesized by methods known in the art.

[0074] The organic electroluminescent device of the present invention has the same structure as the organic electroluminescent device in the prior art, and includes an anode layer, a plurality of light-emitting functional layers and a cathode layer; the plurality of light-emitting functional layers at least include a light-emitting layer, and the light-emitting functional layer includes at least one of a hole injection layer, a hole transport layer, a light-emitting layer, an electron blocking layer, and an electron transport layer, wherein the light-emitting layer contains the above-mentioned organic compound of the present invention.

[0075] In an embodiment of specifically preparing an organic electroluminescent device, a substrate can be used under the anode or above the cathode. The substrates are all glass or polymer materials with excellent mechanical strength, thermal stability, waterproofness, and transparency. In addition, thin-film transistors (TFTs) can also be provided on the substrate for a display.

[0076] The anode can be formed by sputtering or depositing a material used as the anode on the substrate. Oxide transparent conductive materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), etc., and any combination thereof can be used. The cathode material can be a metal or alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), etc., and any combination thereof.

[0077] Multiple light-emitting functional layers can be formed on the electrodes by methods such as vacuum thermal evaporation, spin coating, printing, etc. The compounds used as the organic material layer can be organic small molecules, organic macromolecules, and polymers, as well as combinations thereof.

[0078] The synthesis method of the compound of the present invention will be briefly described below. The compound represented by the general formula (I) of the present invention can be synthesized by a known organic synthesis method. The following gives an exemplary synthesis route, and according to the synthesis method of the compound of the present invention described below, the compound in the general formula (I) of the present invention can be synthesized. Those skilled in the art can also obtain it by other known methods, such as further selecting a suitable catalyst, solvent, determining appropriate reaction temperature, time, material ratio, etc.

[0079] Synthesis Example 1 Synthesis of Compound I-1

[0080]

[0081] The synthesis route is as follows:

[0082]

[0083] Under nitrogen protection, in a dry 2L three-necked flask, add 2,6-dibromo-4-cyanopyridine (26.2 g, 0.1 mol), 3-(9H-carbazol-9-yl)phenylboronic acid (57.4 g, 0.2 mol), and 500 mL of tetrahydrofuran. Add 34.5 g of potassium carbonate, 100 mL of deionized water, and 1.6 g of tetrakis(triphenylphosphine)palladium. Start stirring and heat to reflux for 15 h. After the reaction is completed, separate the organic phase, extract, dry, perform column chromatography, and evaporate the solvent to obtain 41.7 g of product I-1, with a yield of 71%.

[0084] 11H NMR (400 MHz, CDCl3) δ 8.33 - 8.29 (m, 2H), 8.13 (d, J = 7.4 Hz, 6H), 7.96 (s, 2H), 7.79 - 7.69 (m, 4H), 7.48 - 7.43 (m, 4H), 7.36 - 7.27 (m, 8H).

[0085] Product MS (m / e): 586.2; Elemental analysis (C42H26N4): Calculated C, 85.98; H, 4.47; N, 9.55; Found C: 85.82, H: 4.65, N: 9.37.

[0086] Synthesis Example 2 Synthesis of Compound I-4

[0087]

[0088] The synthesis route is as follows:

[0089]

[0090] (1) Synthesis of M1: Under nitrogen protection, in a dry 2 L three-necked flask, add 9H-carbazole-3-carbonitrile (19.2 g, 0.1 mol), 3-bromoiodobenzene (42.4 g, 0.15 mol) and 500 mL of DMF. Add 3.81 g of copper iodide, 41.4 g of potassium carbonate, and 7.2 g of 1,10-phenanthroline. Start stirring and heat to reflux for 24 h. After the reaction is completed, cool to room temperature, separate the organic phase, extract, dry, perform column chromatography, and evaporate the solvent to obtain 26.3 g of product M1, with a yield of 76%.

[0091] (2) Synthesis of M2: Under nitrogen protection, in a dry 2 L three-necked flask, add M1 (34.7, 0.1 mol), bis(pinacolato)diboron (30.5 g, 0.12 mol) and 500 mL of DMF. Add 2.82 g of pd(dppf)2Cl2 and 29.4 g of potassium acetate. Start stirring and heat to reflux for 24 h. After the reaction is completed, cool to room temperature, separate the organic phase, extract, dry, perform column chromatography, and evaporate the solvent to obtain 28.4 g of product M2, with a yield of 72%.

[0092] (2) Synthesis of I-4: Under nitrogen protection, in a dry 2 L three-necked flask, add 2,6-dibromo-4-carbonitrile pyridine (26.2 g, 0.1 mol), M2 (78.8 g, 0.2 mol) and 500 mL of tetrahydrofuran. Add 34.5 g of potassium carbonate, 100 mL of deionized water, and 1.6 g of tetrakis(triphenylphosphine)palladium. Start stirring and heat to reflux for 15 h. After the reaction is completed, separate the organic phase, extract, dry, perform column chromatography, and evaporate the solvent to obtain 43.9 g of product I-4, with a yield of 69%.

[0093] 1 1H NMR (400 MHz, CDCl3) δ 8.22 (m, 2H), 8.16 (d, J = 1.2 Hz, 2H), 7.97 - 7.86 (m, 4H), 7.78 (d, J = 6.1 Hz, 2H), 7.72 - 7.68 (m, 4H), 7.65 - 7.62 (m, 4H), 7.55 (m, 2H), 7.28 (m, 2H), 7.16 (m, 2H).

[0094] Product MS (m / e): 636.2; Elemental analysis (C44H24N6): Calcd. C, 83.00; H, 3.80; N, 13.20; Found C: 83.26, H: 3.64, N: 13.10.

[0095] Synthesis Example 3 Synthesis of Compound I-17

[0096]

[0097] The synthesis route is as follows:

[0098]

[0099] Using 9-[3-(pinacolboronate)phenyl] to replace 9H-carbazole-3-carbonitrile, p-bromoiodobenzene to replace 3-bromoiodobenzene, selecting an appropriate material ratio, and keeping other raw materials and steps the same as in Example 2, 49.5 g of product I-17 was obtained with a yield of 67%.

[0100] 1 1H NMR (400 MHz, CDCl3) δ 8.23 (d, 7.1 Hz, 4H), 8.06 (m, 2H), 7.97 (s, 2H), 7.89 - 7.86 (d, 6.8 Hz, 4H), 7.74 - 7.71 (m, 4H), 7.69 - 7.62 (m, 10H), 7.28 - 7.24 (m, 4H), 7.20 - 7.15 (m, 4H).

[0101] Product MS (m / e): 738.3; Elemental analysis (C54H34N4): Calcd. C, 87.78; H, 4.64; N, 7.58; Found C, 87.92, H, 4.56, N, 7.77.

[0102] Synthesis Example 4 Synthesis of Compound I-49

[0103]

[0104] The synthesis route is as follows:

[0105]

[0106] Replace 9H-carbazole-3-carbonitrile with 9-[2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-9H-carbazole, select an appropriate material ratio, and keep other raw materials and steps the same as in Example 2 to obtain 49.5 g of Product I-49 with a yield of 64%.

[0107] Product MS (m / e): 738.3; Elemental analysis (C54H34N4): Theoretical value C, 87.78; H, 4.64; N, 7.58; Measured value C, 87.89, H, 4.48, N, 7.65.

[0108] Synthesis of Compound I-79 in Synthesis Example 5

[0109]

[0110] The synthesis route is as follows:

[0111]

[0112] Replace 9H-carbazole-3-carbonitrile with 8H-benzo[f]carbazole[2,3-c]carbazole, select an appropriate material ratio, and keep other raw materials and steps the same as in Example 2 to obtain 51.38 g of Product I-79 with a yield of 67%.

[0113] Product MS (m / e): 766.2; Elemental analysis (C54H30N4O2): Theoretical value C, 84.58; H, 3.94; N, 7.31; Measured value C, 84.76, H, 4.02, N, 7.48.

[0114] Synthesis of Compound I-101 in Synthesis Example 6

[0115]

[0116] The synthesis route is as follows:

[0117]

[0118] Under nitrogen protection, add 4-bromo-1-chloroisoquinoline (24.3 g, 0.1 mol), 4-(9H-carbazol-9-yl)phenylboronic acid (57.4 g, 0.2 mol) and 500 mL of tetrahydrofuran to a dry 2 L three-necked flask. Add 34.5 g of potassium carbonate, 100 mL of deionized water, and 1.6 g of tetrakis(triphenylphosphine)palladium. Start stirring and heat to reflux for 15 h. After the reaction is completed, separate the organic phase, extract, dry, perform column chromatography, and evaporate the solvent to obtain 42.2 g of Product I-101 with a yield of 69%.

[0119] Product MS (m / e): 611.2; Elemental analysis (C45H29N3): theoretical value C, 88.35; H, 4.78; N, 6.87; measured value C: 88.53, H: 4.75, N: 6.72.

[0120] Synthesis Example 7 Synthesis of Compound I-102

[0121]

[0122] The synthesis route is as follows:

[0123]

[0124] Using 3-(9H-carbazol-9-yl)phenylboronic acid to replace 4-(9H-carbazol-9-yl)phenylboronic acid, selecting an appropriate material ratio, and keeping other raw materials and steps the same as in Example 6, 44.04 g of product I-102 was obtained with a yield of 72%.

[0125] Product MS (m / e): 611.24; Elemental analysis (C45H29N3): theoretical value C, 88.35; H, 4.78; N, 6.87; measured value C, 88.51, H, 4.67, N, 6.93.

[0126] Synthesis Example 8 Synthesis of Compound I-103

[0127]

[0128] The synthesis route is as follows:

[0129]

[0130] Using M2 to replace 4-(9H-carbazol-9-yl)phenylboronic acid, selecting an appropriate material ratio, and keeping other raw materials and steps the same as in Example 6, 43.68 g of product I-103 was obtained with a yield of 66%.

[0131] Product MS (m / e): 661.23; Elemental analysis (C47H27N5): theoretical value C, 85.30; H, 4.11; N, 10.58; measured value C, 85.17, H, 4.30, N, 10.72.

[0132] According to the synthesis methods of the above Synthesis Examples 1 to 8, only by simply replacing the corresponding raw materials and without changing any substantial operations, the synthesis of other compounds among the representative preferred compounds I-1 to I-159 of the present invention can be completed.

[0133] The following are examples of organic electroluminescent devices prepared by the present invention using the representative compounds of the present invention:

[0134] Device Embodiment 1:

[0135] This embodiment provides an OLED green light device, and the structure of the device is:

[0136] ITO / HI(10nm) / HT01(60nm) / EB(5nm) / EML(30nm) / HB(5nm) / ET01:QLi(1:1)(30nm) / QLi(1nm) / Al.

[0137] Among them: 1nm, 60nm, 30nm, etc. all represent the thickness of the functional layer; the light-emitting host material in the EML layer uses the compound I-1 prepared in the above Synthesis Embodiment 1.

[0138] The molecular structures of the materials of each functional layer are as follows:

[0139]

[0140] Prepare device OLED-1:

[0141] (1) Ultrasonically clean the glass substrate coated with ITO transparent conductive film in a cleaning solution, ultrasonically treat it in deionized water, ultrasonically degrease it in a mixed solvent of acetone:ethanol (volume ratio 1:1), bake it in a clean environment until all moisture is removed, etch and ozone-treat it with an ultraviolet lamp, and bombard the surface with a low-energy cation beam;

[0142] (2) Place the above glass substrate with the anode in a vacuum chamber, evacuate to 4×10 -5 ~6×10 -5 Pa, vacuum deposit HI as the first hole injection layer on the above anode layer film, with a deposition rate of 0.1nm / s and a total deposition film thickness of 10nm; then deposit a layer of HT01 as the hole transport layer, with a deposition rate of 0.1nm / s and a thickness of 60nm; deposit a layer of EB as the electron blocking layer on the above hole transport layer film, with a deposition rate of 0.1nm / s and a deposition film thickness of 5nm;

[0143] (3) Vacuum deposit EML as the light-emitting layer of the device above the electron blocking layer. In the EML, the compound I-1 of the present invention is used as the host material, and the light-emitting dye is the compound Ir(ppy)3, with a doping mass percentage concentration of 5%, to form the organic light-emitting layer of the device, with a deposition rate of 0.1nm / s and a total deposition film thickness of 30nm, to form the organic electroluminescent layer of the device; then deposit 5nm of HB to form the hole blocking layer, with a deposition rate of 0.1nm / s;

[0144] (4) On top of the hole blocking layer, ET01:QLi with a mass ratio of 1:1 is evaporated as the electron transport material for the device's electron transport layer. The evaporation rate is 0.1 nm / s, and the total film thickness is 30 nm.

[0145] (5) On the electron transport layer, a 1-nm-thick QLi is successively evaporated in vacuum as the electron injection layer, and a 150-nm-thick Al layer is used as the cathode of the device. After encapsulation, the OLED-1 organic electroluminescent device is obtained.

[0146] Device Examples 2 to Device Example 8:

[0147] The preparation method is the same as that of Device Example 1 above, except that the light-emitting host material in the light-emitting layer in step (3) is respectively replaced with other representative compounds of the present invention. For details, see Table 1 below. Thus, organic electroluminescent devices numbered OLED-2 to OLED-8 are respectively prepared.

[0148] Device Comparative Examples 1 and Comparative Example 2:

[0149] According to the same preparation method as Device Example 1 above, only the light-emitting layer host material in step (3) is replaced with compounds FBC and MBC in the prior art with similar structures, and the comparative devices OLED-1 and comparative device OLED-2 are prepared. The structural formulas of FBC and MBC are shown below:

[0150]

[0151] The performances of the above organic electroluminescent devices OLED-1 to OLED-8 and the comparative devices OLED-1 and comparative device OLED-2 were detected, and the results are shown in Table 1. The voltage, current efficiency, color coordinates, and peak wavelength in Table 1 were measured at a current density of 20 mA / cm 2 and the lifetime is the time required for the initial emission brightness of 20000 nit to decay to 95% of the initial brightness.

[0152] Table 1

[0153]

[0154] As can be seen from the data in Table 1, when comparing the compounds FBC and MBC, the compounds involved in the present invention have improved electron mobility and stability due to the introduction of electron-withdrawing groups such as cyano, cyanopyridine, and isoquinoline at the dicarbazole substitution positions. Accordingly, while the luminous efficiency of the device is improved, the lifetime is also significantly increased. Therefore, the phosphorescent light-emitting material provided by the present invention can effectively solve the problems existing in currently commonly used phosphorescent materials in terms of lifetime, luminous efficiency, etc. The organic electroluminescent device prepared using the phosphorescent light-emitting material of the present invention exhibits excellent properties of high purity, high lifetime, and high efficiency.

[0155] The present invention uses the above embodiments to illustrate the detailed method of the present invention, but the present invention is not limited to the above detailed method. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc. all fall within the protection scope of the present invention.

Claims

1. An organic compound containing a carbazole structure, and the organic compound is selected from the following compounds:

2. Use of the organic compound according to claim 1 in the preparation of an organic electroluminescent device.

3. The application according to claim 2, characterized in that, The compound is used as a host material for the light-emitting layer in an organic electroluminescent device.

4. An organic electroluminescent device, comprising a light-emitting layer, and the host material of the light-emitting layer contains the compound according to claim 1.

5. The organic electroluminescent device according to claim 4, wherein, The organic electroluminescent device includes: an anode, a cathode, and a light-emitting layer disposed between the anode and the cathode.

6. The organic electroluminescent device according to claim 5, wherein The organic electroluminescent device further includes one or more of a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

7. A display device or a lighting device, comprising the organic electroluminescent device according to any one of claims 4-6.

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