Host material, organic electroluminescent material containing double hosts and luminescent device

Abstract

The invention discloses a host material, an organic electroluminescent material containing double hosts and a luminescent device, and relates to the technical field of organic electroluminescent materials. The structure of the main body material is as shown in any one of formulas 1-1 to 1-4; wherein A is selected from a substituted or unsubstituted C6-C24 aryl group, and a substituted or unsubstituted C6-C24 heteroaryl group; b is selected from benzene rings; r1 and R2 are respectively and independently selected from a substituted or unsubstituted C6-C42 aryl group, a substituted or unsubstituted C6-C36 heteroaryl group, and a substituted or unsubstituted C10-C30 fused ring group; wherein the heteroaryl group comprises a monocyclic aromatic group or polycyclic aromatic system of at least one heteroatom, and the heteroatom comprises O, S or N. According to the present invention, the HOMO energy level of the compound can be adjusted, the good electron pushing ability is provided, and the hole transmission performance of the compound is significantly enhanced. As a hole transport layer material of a device, the luminous efficiency and the service life of the device are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescent materials, and in particular to a host material, an organic electroluminescent material containing two hosts, and a light-emitting device. Background Art

[0002] Organic electroluminescent devices are self-luminous devices that have attracted widespread attention in the panel display device industry due to their low driving voltage, high resolution, high brightness, fast response time, and flexibility. In addition, the raw materials have low production costs, are easy to process, and have high purity.

[0003] Currently, OLED display technology has been applied in fields such as smartphones and tablets, and will also expand to large-size application fields such as TVs. However, compared with actual product application requirements, OLED's luminous efficiency and service life and other performance still need to be further improved.

[0004] The luminescent material of an organic electroluminescent device (OLED) is the most important factor in determining the device's luminous efficiency. Functionally, it can be divided into a host material and a dopant material. By mixing a host and a dopant, the luminescent material can be used to improve color purity, luminous efficiency, and stability. Devices with excellent electroluminescent (EL) properties typically have a structure in which a luminescent layer is formed by doping a host with a dopant. When using such a dopant / host material system as the luminescent material, the host material significantly affects the efficiency and lifespan of the luminescent device, making the selection of a suitable host material crucial.

[0005] Therefore, the current urgent task is to develop OLEDs with high efficiency and long life characteristics, especially considering the EL characteristics required for medium and large OLED panels, it is urgent to develop light-emitting materials that are superior to conventional light-emitting materials and have excellent performance.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The object of the present invention is to provide a host material, an organic electroluminescent material containing dual hosts, and a light-emitting device.

[0008] The present invention is achieved in that: In a first aspect, the present invention provides a host material having a general structural formula as shown in any one of Formulas 1-1 to 1-4: ; Wherein, A is selected from substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C6-C24 heteroaryl; B is selected from benzene ring; R1 and R2 are each independently selected from a substituted or unsubstituted C6-C42 aryl group, a substituted or unsubstituted C6-C36 heteroaryl group, or a substituted or unsubstituted C10-C30 fused ring group; wherein the heteroaryl group includes a monocyclic aromatic group or a polycyclic aromatic system containing at least one heteroatom, and the heteroatom includes O, S or N.

[0009] The host material provided by the present invention contains a naphthoxazolyl nucleus, which is a fusion of a naphthalene ring (a 10-membered aromatic system composed of two benzene rings) and an oxazole ring. The naphthalene ring itself has a larger conjugated system and a more complex electron cloud distribution. After fusion with the oxazole ring, the overall conjugation length is longer, covering a wider range of luminescent colors. The rigidity and electron distribution of the naphthalene ring allow for longer charge transfer paths within the naphthoxazolyl molecule and potentially tighter π-π stacking, affecting charge mobility (electron / hole transport capacity), thereby changing the charge balance and luminous efficiency in the device. By attaching a triarylamine to the benzene ring of the naphthoxazolyl nucleus as a backbone, and also attaching groups such as carbazole, 9-phenyl-9H-carbazole, dibenzofuran, and a series of derivatives to the oxazole ring, the compound can better regulate the HOMO energy level and exhibit good electron push ability, significantly enhancing the compound's hole transport performance. As a hole transport layer material for devices, it will significantly improve the luminous efficiency and service life of organic light-emitting devices.

[0010] In some optional embodiments, the general structural formula of the host material is selected from any one of the following structural formulas: ; wherein A is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted 9-phenyl-9H-carbazolyl, or substituted or unsubstituted dibenzothiophenyl; R1 is selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heteroaryl; R2 is selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dimethylfluorene or substituted or unsubstituted 9-phenyl-9H-carbazolyl; The substitution in the "substituted or unsubstituted" in A, R1 and R2 is selected from at least one of deuterium, fluorine, cyano, methyl, trifluoromethyl, tert-butyl, C6-C24 aryl and C6-C24 heteroaryl, wherein the heteroatom is selected from O, S or N.

[0011] In some optional embodiments, R1 is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted pyrenyl, substituted or unsubstituted chrysyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted benzothienyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted 9-phenyl-9H-carbazolyl, substituted or unsubstituted dibenzothienyl, substituted or unsubstituted dimethylfluorenyl, substituted or unsubstituted benzocarbazolyl, substituted or unsubstituted naphthobenzofuranyl, substituted or unsubstituted naphthobenzothienyl, substituted or unsubstituted phenanthrothiazolyl, substituted or unsubstituted phenanthroxazolyl, substituted or unsubstituted benzodimethylfluorenyl, substituted or unsubstituted 9,9-spirobifluorenyl or substituted or unsubstituted 9,9-diphenylfluorenyl.

[0012] In some optional embodiments, the host material is any one of the following structures:

[0013] The above are some specific structural forms of the main materials, but are not limited to the chemical structures listed. All compounds with simple changes of groups within the defined range based on the general structural formulas shown in Formulas 1-1 to 1-4 should be included.

[0014] In a second aspect, the present invention provides an organic electroluminescent material containing a dual host, which comprises the host material according to any one of the above embodiments as a first host material and a second host material; The general structural formula of the second host material is shown in formula (2): Formula (2); Wherein, D1, D2, and D3 are each independently selected from a substituted or unsubstituted C6-C42 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a substituted or unsubstituted phosphinoyl group, a substituted or unsubstituted silyl group, and the heteroaryl group includes a monocyclic aromatic group and a polycyclic aromatic system with at least one heteroatom, and the heteroatom includes O, S, or N; L1 and L2 are selected from a connecting bond, a substituted or unsubstituted C6-C30 aryl group.

[0015] In the present invention, by combining a first host material with a second host having a triazine structure, when a donor with good hole transport (p-type host) and an acceptor with good electron transport ability (n-type host) are used as the host of the light-emitting layer, the driving voltage will be reduced and the lifespan will be enhanced.

[0016] In some optional embodiments, D1 and D2 are independently selected from substituted or unsubstituted C6-C18 aryl groups; D3 is selected from substituted or unsubstituted C6-C36 aryl groups, substituted or unsubstituted C3-C30 heteroaryl groups, substituted or unsubstituted phosphino groups, substituted or unsubstituted silyl groups; L1 and L2 are selected from connecting bonds, substituted or unsubstituted C6-C18 aryl groups; Further, D1 is selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl; D2 is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted triphenylenyl; D3 is selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted phosphinoyl, substituted or unsubstituted silanyl; L1 is a connecting bond, L2 is a connecting bond or phenyl, naphthyl; heteroaryl includes monocyclic aromatic groups and polycyclic aromatic systems with at least one heteroatom, and heteroatoms include but are not limited to O, S, and N.

[0017] The substituents in the “substituted or unsubstituted” in D1, D2, D3, L1, and L2 are selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, three-membered to ten-membered heterocycloalkyl, and phenyl, and the heteroatoms thereof are selected from O, S, and N; and the substituents in the substituted or unsubstituted may also be selected from the following structures: .

[0018] It should be noted that the term "substituted or unsubstituted" means that the group may not be substituted or may be substituted by one or more substituents. The term "substituted" means that the hydrogen atom bonded to the carbon atom of the compound is changed into another substituent, and the position of the substitution is not limited as long as the position is the position where the hydrogen atom is substituted, that is, the position where the substituent can be substituted, and when two or more substituents are substituted, the two or more substituents may be the same as or different from each other.

[0019] In some optional embodiments, the second host material is any one of the following structures, but is not limited thereto: .

[0020] The above are some specific structural forms of the second host material, but are not limited to these listed chemical structures. All compounds based on the general structural formula shown in formula (2) and where the D1, D2, D3, L1 and L2 groups are simple permutations of the groups within the previously defined range should be included.

[0021] In a third aspect, the present invention provides a method for preparing an organic electroluminescent material containing a dual host as described in any one of the above embodiments, comprising: S1. Preparation of the first main material: (1) Under a nitrogen atmosphere, the naphthylamine compound reactant 1, dichloromethane, carbonyl chlorobromide and pyridine were mixed and stirred at room temperature for 2-4 hours. After the reaction was completed, intermediates 1-1-a-1 to 1-1-c-1 were obtained. Under a nitrogen atmosphere, the intermediates 1-1-a-1 to 1-1-c-1, FeCl3, Na2S2O8, pyridine and DMSO were mixed, heated to 80-100°C and stirred for 4-8 hours. After the reaction was completed, intermediates 1-1-a-2 to 1-1-c-2 were obtained. The synthesis route is as follows: ; (2) Under nitrogen atmosphere, reactant 2 containing R1 substituent, reactant 3 containing R2 substituent, sodium tert-butoxide, toluene, tris(dibenzylideneacetone)dipalladium and tri-tert-butylphosphine were mixed, refluxed at 100-120°C for 24-48h, cooled to 20-30°C, added with purified water, stirred for 20-40min, allowed to stand for stratification, separated, and column chromatography was performed using dichloromethane / petroleum ether as eluent to obtain 1-1-a-3; under nitrogen atmosphere, the 1-1-a-3, the intermediates 1-1-a-2 to 1-1-c-2, sodium tert-butoxide, toluene, tris(dibenzylideneacetone)bispalladium and tri-tert-butylphosphine were mixed, stirred at 80-100°C for 12-24h, cooled to 20-30°C, added with purified water, stirred for 20-40min, and then allowed to stand for stratification. The liquids were separated and column chromatography was performed using dichloromethane / petroleum ether as eluent to obtain 1-1-a-4 to 1-1-c-4. The synthetic route is as follows: ; (3) Under nitrogen atmosphere, the above 1-1-a-4 to 1-1-c-4, indole compounds, sodium tert-butoxide, toluene, tris(dibenzylideneacetone)dipalladium and tri-tert-butylphosphine were mixed, refluxed at 100-120°C for 12-24h, cooled to 20-30°C, added with purified water, stirred for 20-40min, and allowed to stand for stratification. The liquids were separated and column chromatography was performed using dichloromethane / petroleum ether as eluent to obtain the general formula 1-1. The synthetic route thereof is as follows; ; (4) Under nitrogen atmosphere, 1-1-a-4 to 1-1-c-4, N-phenylindole borate or benzofuran borate, potassium carbonate, toluene, ethanol, water and tetrakis(triphenylphosphine)palladium were mixed, refluxed at 80-90°C for 12-24h, cooled to 20-30°C, filtered, and subjected to solid column chromatography to obtain compounds of the general formula 1-2 to 1-4. The synthetic routes thereof are as follows: ; S2. Preparation of the second main material: (1) Under nitrogen atmosphere, reactant 4, reactant 5-1 containing a D1 substituent, potassium carbonate, toluene, ethanol, water, and tetrakis(triphenylphosphine)palladium were mixed, refluxed at 60-90°C for 12-24h, cooled to 20-30°C, filtered, and subjected to solid column chromatography to obtain compound H-1; (2) Under nitrogen atmosphere, H-1, reactant 5-2 containing a D2 substituent, potassium carbonate, toluene, ethanol, water, and tetrakis(triphenylphosphine)palladium were mixed, refluxed at 60-90°C for 24 h, cooled to 20-30°C, filtered, and subjected to solid column chromatography to obtain compound H-2; (3) Under nitrogen atmosphere, H-2, reactant 5-3 containing a D3 substituent, potassium carbonate, toluene, ethanol, water and tetrakis(triphenylphosphine)palladium were mixed, refluxed at 60-90°C for 24 h, cooled to 20-30°C, filtered, and subjected to solid column chromatography to obtain the compound represented by formula (2). The synthetic route is as follows: ; S3. Mixing the first host material and the second host material.

[0022] In some optional embodiments, in step S1 (1), the equivalent ratio of the naphthylamine compound reactant 1, chlorocarbonyl bromide and pyridine is 1 eq: 1-1.2 eq: 2-2.4 eq; wherein, the amount of dichloromethane is not limited and can be added according to conventional operations. After the reaction of the naphthylamine compound reactant 1, chlorocarbonyl bromide and pyridine is completed, the mixture is extracted with dichloromethane, and then water is removed with MgSO4, and intermediates 1-1-a-1 to 1-1-c-1 are obtained by column chromatography (hexane: ethyl acetate = 4:1).

[0023] In some optional embodiments, in step S1 (1), the equivalent ratio of the intermediates 1-1-a-1 to 1-1-c-1, FeCl3, Na2S2O8 and pyridine is 1eq:0.1-0.2eq:1-1.4eq:2-2.4eq; wherein, the amount of DMSO is not limited and can be added according to conventional operations. After the reaction of the intermediates 1-1-a-1 to 1-1-c-1, FeCl3, Na2S2O8 and pyridine is completed, ethyl acetate is used for extraction, MgSO4 is used for dehydration, and column chromatography (hexane:ethyl acetate = 10:1) is used to obtain the intermediates 1-1-a-2 to 1-1-c-2.

[0024] And / or, in step S1 (2), the equivalent ratio of reactant 2 containing R1 substituent, reactant 3 containing R2 substituent, sodium tert-butoxide, tris(dibenzylideneacetone)dipalladium and tri-tert-butylphosphine is 1 eq: 1-1.2 eq: 2-3 eq: 0.02-0.04 eq: 0.04-0.06 eq; wherein, the amount of toluene is not limited and can be added according to conventional operation, and the entire reaction is carried out under nitrogen protection.

[0025] And / or, in step S1 (2), the equivalent ratio of 1-1-a-3, the intermediates 1-1-a-2 to 1-1-c-2, sodium tert-butoxide, tris(dibenzylideneacetone)dipalladium and tri-tert-butylphosphine is 1 eq: 1-1.2 eq: 2-3 eq: 0.02-0.04 eq: 0.04-0.06 eq; wherein, the amount of toluene used is not limited and can be added according to conventional operations, and the entire reaction is carried out under nitrogen protection.

[0026] And / or, in step S1 (3), the equivalent ratio of 1-1-a-4 to 1-1-c-4, indole compound, sodium tert-butoxide, tris(dibenzylideneacetone)dipalladium and tri-tert-butylphosphine is 1 eq: 1-1.2 eq: 2-3 eq: 0.02-0.04 eq: 0.04-0.06 eq; wherein, the amount of toluene is not limited and can be added according to conventional operations, and the entire reaction is carried out under nitrogen protection.

[0027] and / or, in step S1 (4), the equivalent ratio of 1-1-a-4 to 1-1-c-4, N-phenylindole borate or benzofuran borate, potassium carbonate and tetrakis(triphenylphosphine)palladium is 1 eq:1-1.2 eq:2-3 eq:0.02-0.03 eq, and the volume ratio of toluene, ethanol and water is 2:1:1; and / or, in step S2 (1), the equivalent ratio of reactant 4, reactant 5-1 containing a D1 substituent, potassium carbonate, and tetrakis(triphenylphosphine)palladium is 1 eq:1-1.2 eq:3-4 eq:0.05-0.08 eq, and the volume ratio of toluene, ethanol, and water is 2:1:1; and / or, in step S2 (2), the equivalent ratio of H-1, the reactant 5-2 containing a D2 substituent, potassium carbonate, and tetrakis(triphenylphosphine)palladium is 1 eq:1-1.2 eq:3-4 eq:0.05-0.08 eq, and the volume ratio of toluene, ethanol, and water is 2:1:1; and / or, in step S2 (3), the equivalent ratio of H-2, the reactant 5-3 containing a D3 substituent, potassium carbonate, and tetrakis(triphenylphosphine)palladium is 1 eq:1-1.2 eq:3-4 eq:0.05-0.08 eq, and the volume ratio of toluene, ethanol, and water is 2:1:1; And / or, in step S3, the mass ratio of the first host material to the second host material is 1:9-9:1.

[0028] In a third aspect, the present invention provides an organic electroluminescent device, comprising a first electrode, an organic electroluminescent material layer, and a second electrode; the organic electroluminescent material layer comprises a light-emitting layer, the light-emitting layer comprising a doping material and the organic electroluminescent material containing a double host as described in any one of the above embodiments, or the organic electroluminescent material containing a double host obtained by the method for preparing the organic electroluminescent material containing a double host as described in any one of the above embodiments; the mass ratio of the organic electroluminescent material containing a double host to the doping material is (1~99):(99~1).

[0029] In the present invention, the organic electroluminescent device includes an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode. Specifically, the anode material preferably has a material with a large work function to smoothly inject holes into the organic material layer. The anode materials include: metals such as vanadium, chromium, copper, zinc, and gold, or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); combinations of metals and oxides such as ZnO:Al or SnO2:Sb; and conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrrole, and polyaniline, but are not limited thereto.

[0030] The cathode material preferably has a material with a small work function so that electrons can be smoothly injected into the organic material layer. The cathode material includes: metals: such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin and lead, or their alloys; multilayer structure materials, such as LiF / Al or LiO2 / Al; but not limited to these.

[0031] The hole transport region includes a hole injection layer, a hole transport layer, an electron blocking layer and a hole blocking layer, and the light emitting layer is located between the electron blocking layer and the hole blocking layer.

[0032] The hole injection layer material is a material that receives holes from the anode at a low voltage, and the highest occupied molecular orbital (HOMO) of the hole injection material is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer. Hole injection materials include metalloporphyrins, oligothiophenes, arylamine-based organic materials, hexanitrile hexaazatriphenylene-based organic materials, quinacridone-based organic materials, perylene-based organic materials, anthraquinone, and polyaniline-based and polythiophene-based conductive polymers.

[0033] The hole transport layer material is a material that can receive holes from the anode or hole injection layer and transport them to the light-emitting layer, and has high hole mobility. Hole transport layer materials include, but are not limited to, organic materials based on arylamines, conductive polymers, and block copolymers having both conjugated and non-conjugated portions.

[0034] The electron blocking layer is disposed between the hole transport layer and the light emitting layer, and the electron blocking layer material includes an arylamine-based organic material.

[0035] The hole blocking layer is disposed between the hole transport layer and the light emitting layer, and the hole blocking layer material includes a triazine-based compound.

[0036] The electron transport region includes an electron transport layer and an electron injection layer.

[0037] The electron transport layer facilitates electron transport. Electron transport materials are materials with high electron mobility that receive electrons from the cathode and transfer them to the light-emitting layer. Examples of these materials include, but are not limited to, Al complexes of 8-hydroxyquinoline, Alq3 complexes, organic free radical compounds, and hydroxyflavone-metal complexes. The thickness of the electron transport layer ranges from 1 nm to 50 nm to prevent degradation of electron transport properties and increase in driving voltage.

[0038] The electron injection layer facilitates electron injection. The electron injection material is a material that has the ability to transport electrons, exhibits excellent electron injection into the light-emitting layer or light-emitting material, prevents excitons generated in the light-emitting layer from migrating to the hole injection layer, and exhibits excellent thin-film forming properties. Examples of materials for the electron injection layer include, but are not limited to, fluorenone, anthraquinone dimethane, diphenoquinone, thiopyran dioxide, azole, diazole, triazole, imidazole, perylenetetracarboxylic acid, fluorenylmethane, anthrone, and their derivatives, metal complexes, and nitrogen-containing five-membered ring derivatives.

[0039] In the present invention, the organic electroluminescent device may be a top emission type, a bottom emission type or a double-side emission type.

[0040] The organic electroluminescent device can be used in organic solar cells, electronic paper, organic photoreceptors or organic thin film transistors.

[0041] The present invention has the following beneficial effects: The host material provided by the present invention contains a naphthoxazolyl nucleus, which is a naphthalene ring (a 10-membered aromatic system composed of two benzene rings) fused with an oxazole ring. The naphthalene ring itself has a larger conjugated system and a more complex electron cloud distribution. After fusion with the oxazole ring, the overall conjugation length is longer, covering a wider range of luminescent colors. The rigidity and electron distribution of the naphthalene ring allow for a longer charge transfer path within the naphthoxazolyl molecule and potentially tighter π-π stacking, affecting charge mobility (electron / hole transport capacity), thereby changing the charge balance and luminous efficiency in the device. By attaching a triarylamine to the benzene ring of the naphthoxazolyl as a backbone, and also attaching groups such as carbazole, 9-phenyl-9H-carbazole, dibenzofuran, and a series of derivatives to the oxazole ring, the compound's HOMO energy level can be better adjusted, and its good electron push ability significantly enhances the compound's hole transport performance. As a hole transport layer material for devices, it will significantly improve the luminous efficiency and service life of organic light-emitting devices. In the present invention, by combining a first host material with a second host having a triazine structure, when a donor with good hole transport (p-type host) and an acceptor with good electron transport ability (n-type host) are used as the host of the light-emitting layer, the driving voltage will be reduced and the lifespan will be enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of compound R002 provided in the examples of the present invention. DETAILED DESCRIPTION

[0044] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0045] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0046] Example 1: Preparation of Compound R002 (1) Under nitrogen atmosphere, 1 eq of 7-bromo-2-naphthylamine was added to a round-bottom flask, and dichloromethane was added thereto. Then, 1 eq of carbonyl chlorobromide and 2 eq of pyridine were added dropwise to the round-bottom flask and stirred at room temperature for 2 h. After the reaction was completed, the mixture was extracted with dichloromethane, and then water was removed with MgSO4. The intermediate R002-1 was obtained by column chromatography (hexane: ethyl acetate = 4:1) (yield 76%, HPLC>95%, mass spectrometry value 283.17). The synthetic route is as follows: .

[0047] (2) Under nitrogen atmosphere, 1 eq of R002-1, 0.1 eq of FeCl3, 1 eq of Na2S2O8, 2 eq of pyridine, and DMSO were added to a round-bottom flask in sequence, and the temperature was raised to 80°C and stirred for 4 hours. After the reaction was completed, the mixture was extracted with ethyl acetate, dehydrated with MgSO4, and purified by column chromatography (hexane:ethyl acetate = 10:1) to obtain the intermediate R002-2 (yield 64%, HPLC>98%, mass spectrometry value 281.07). The synthetic route is as follows: .

[0048] (3) Under nitrogen atmosphere, 1 eq of diphenylamine (CAS: 122-39-4), 1 eq of R002-2, and 2 eq of sodium tert-butoxide were weighed and placed in a reaction system. Toluene, 0.02 eq of tris(dibenzylideneacetone)dipalladium, and 0.04 eq of tri-tert-butylphosphine were added. The mixture was stirred at 80°C for 24 h under nitrogen protection, then cooled to 25°C, purified water was added, stirred for 30 min, and then allowed to stand for stratification. The mixture was separated and subjected to column chromatography to obtain the intermediate R002-3 (yield 83%, HPLC>99%, mass spectrometry value 370.23). The synthetic route is as follows: .

[0049] (4) Under nitrogen atmosphere, 1 eq of R002-3, 1 eq of 9-hydrocarbazole (CAS: 115720-92-8), and 2 eq of sodium tert-butoxide were weighed and placed in a reaction system. Toluene, 0.02 eq of tris(dibenzylideneacetone)dipalladium, and 0.04 eq of tri-tert-butylphosphine were added. The mixture was refluxed at 120°C for 24 h under nitrogen protection, then cooled to 25°C, purified water was added, and the mixture was stirred for 30 min. After standing and layering, the mixture was separated and subjected to column chromatography to obtain the intermediate R002 (yield 83%, HPLC>99%, mass spectrometry value 501.43). The synthesis route is as follows: .

[0050] Example 2: Preparation of compound H001 Under a nitrogen atmosphere, 1 eq of reactant 4 (CAS: 108-77-0), 3 eq of reactant 5 (CAS: 98-80-6), and 3 eq of potassium carbonate were added to the reaction system. Toluene, ethanol, water, and 0.2 eq of tetrakis(triphenylphosphine)palladium were added. The mixture was refluxed at 90°C for 24 h under nitrogen protection, then cooled to 25°C, filtered, and purified by solid column chromatography to obtain compound H001 (assay value: 309.37, yield: 62.2%). Its HPLC purity was greater than 99%. The synthetic route is as follows: .

[0051] The synthesis methods of other compounds are the same as those in the above examples and are not described in detail here.

[0052] Device Example 1-15, Comparative Example 1-9, and Parallel Example 1-8: The device manufacturing processes of device examples 1-15, comparative examples 1-9, and parallel examples 1-8 are exactly the same, and the same substrate materials and electrode materials are used. The film thickness of the electrode materials is also consistent. The difference is that the two main body materials are different. The corresponding first main body material and second main body material in Table 1 are selected respectively. The specific parameters are as follows: Table 1. Statistics of host material selection used in organic electroluminescent devices of different examples

[0053] The comparative example structure is shown in Table 2: Table 2. Statistics of compounds represented by different numbers in comparative examples

[0054] Preparation of organic electroluminescent devices The preparation method of the organic electroluminescent device is as follows: (1) An ITO (indium tin oxide) glass substrate with a thickness of 1500 angstroms was cleaned twice in distilled water and ultrasonically washed for 30 minutes. It was then repeatedly cleaned twice in distilled water and ultrasonically washed for 10 minutes. After washing, it was ultrasonically washed in methanol, acetone, and isopropanol in sequence (5 minutes each time), dried, and then transferred to a plasma cleaning machine for washing for 5 minutes to obtain an ITO anode.

[0055] (2) In an evaporation machine, HIL is vacuum-deposited on the surface of the ITO anode obtained in step (1) to a thickness of 700 angstroms to obtain a hole injection layer.

[0056] (3) Vacuum-depositing HTL on the surface of the hole injection layer obtained in step (2) is performed by first evaporating HTL1 with a thickness of 50 angstroms and then evaporating HTL2 with a thickness of 700 angstroms on the surface thereof to form a hole transport layer.

[0057] (4) Evaporating the light-emitting layer material on the surface of the hole transport layer, and performing linear gradient co-evaporation by a multi-source co-evaporation method with a thickness of 300 angstroms to obtain a light-emitting layer; the material of the light-emitting layer includes an organic electroluminescent material containing a dual host and a doping material, the mass ratio of the first host compound to the second host compound in the organic electroluminescent material containing a dual host is 6:4, and the mass ratio of the organic electroluminescent material containing a dual host to the doping material is 10:1, and the organic electroluminescent material containing a dual host is the host material provided in device examples 1 to 15, comparative examples 1 to 9, and parallel examples 1 to 8, respectively.

[0058] (5) HBL is evaporated on the surface of the light-emitting layer obtained in step (4) to a thickness of 100 angstroms to form a hole blocking layer.

[0059] (6) Vacuum evaporate ETL on the surface of the hole blocking layer obtained in step (5) to a thickness of 300 angstroms to obtain an electron transport layer.

[0060] (7) EIL (Liq) was vacuum evaporated on the surface of the electron transport layer obtained in step (6) to a thickness of 15 angstroms to obtain an electron injection layer.

[0061] (8) 1200 angstroms of Al is evaporated on the surface of the electron injection layer obtained in step (7) to form a cathode, thereby obtaining the organic electroluminescent device.

[0062] The structures of the materials (HIL, HTL1, HTL2, dopant material, HBL, ETL, EIL) used in the preparation of the organic electroluminescent device are as follows: .

[0063] The driving voltage, luminous efficiency, and the time it takes for the brightness of the organic electroluminescent device to decrease from 100% to 95% (lifetime; T95) were tested at a brightness of 3000 nits. The test results are shown in Table 2.

[0064] Table 2

[0065] Comparisons of Comparative Examples 1-9 show that using a combination of the first and second host compounds as the host material for the light-emitting layer significantly improves luminous efficiency and service life. Using only one of these compounds significantly reduces the device's luminous efficiency, significantly shortens its service life, and increases its voltage. Comparisons of Comparative Examples 2, 4, 6, and 8 with Parallel Examples 1-2 show that the performance of devices made with the first host material of the present invention is significantly superior to that of Comparative Examples E-1 to E-4.

[0066] By comparing device examples 1 to 15 with parallel examples 3-8, it can be seen that the efficiency of parallel examples 3-8 is 36.6-38.8 cd / A, the driving voltage is 4.14-4.45 V, and the lifespan is 563-587 h, while the luminous efficiency of device examples 1-15 of the present invention is 46.7-48.6 cd / A, which is significantly higher than parallel examples 3-8; the driving voltage is 3.58-3.70 V, which is significantly lower than parallel examples 3-8; and the lifespan is 768-805 h, which is much higher than parallel examples 3-8.

[0067] The reason is that, E-1, E-2 and E-3 are ternary fused ring anthracene, phenanthrene and oxazole ring condense, phenyl is connected at oxazole ring, compared to the oxazole ring of the naphthooxazole parent core of the application, connected to carbazole, 9-phenyl-9H-carbazole, dibenzofuran and other groups, ternary fused ring anthracene, phenanthrene and oxazole ring condense have larger conjugated system, and the core naphthalene ring of the naphthooxazole of the application has smaller conjugated system than the core phenanthrene ring of phenanthrene or anthraoxazole. Smaller conjugated system generally means larger energy gap. Therefore, naphthooxazole derivatives generally have higher triplet energy level, can effectively limit exciton luminescence on guest molecule, prevent energy from being passed back to main body and cause energy loss, while on oxazole ring, connecting carbazole, 9-phenyl-9H-carbazole, dibenzofuran and other groups can better regulate the HOMO energy level of compound, energy gap matching is more flexible, contributes to reducing the energy loss at interface.

[0068] It can be seen that the main material of the light-emitting layer is a compound of a first main compound of a specific structure and a second main compound of a specific structure of the present invention, which can greatly improve the luminous efficiency and service life. This is because the present invention provides a first main material with a triarylamine skeleton, introduces groups such as carbazole, 9-phenyl-9H-carbazole, dibenzofuran and a series of derivatives on the parent nucleus of naphthoxazole, can better adjust the HOMO energy level of the compound, and has good electron push ability, which significantly enhances the hole transport performance of the compound. As a hole transport layer material of the device, it will greatly improve the luminous efficiency and service life of the organic light-emitting device. At the same time, a second main body with a triazine structure is also provided for matching. Therefore, when a donor with good hole transport (p-type main body) and an acceptor with good electron transport ability (n-type main body) are used as the main body of the light-emitting layer, the driving voltage will be reduced and the service life will be enhanced.

[0069] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A main body material, characterized in that: Its general structural formula is shown in any one of Formulas 1-1 to 1-4: ； Wherein, A is selected from substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C6-C24 heteroaryl; B is selected from benzene ring; R1 and R2 are each independently selected from a substituted or unsubstituted C6-C42 aryl group, a substituted or unsubstituted C6-C36 heteroaryl group, or a substituted or unsubstituted C10-C30 fused ring group; wherein the heteroaryl group includes a monocyclic aromatic group or a polycyclic aromatic system containing at least one heteroatom, and the heteroatom includes O, S or N.

2. The main body material according to claim 1, characterized in that The general structural formula of the host material is selected from any one of the following structural formulas: ； wherein A is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted 9-phenyl-9H-carbazolyl, or substituted or unsubstituted dibenzothiophenyl; R1 is selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heteroaryl; R2 is selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dimethylfluorene or 9-phenyl-9H-carbazolyl; The substitution or unsubstituted substitution in A, R1 and R2 is selected from at least one of deuterium, fluorine, cyano, methyl, trifluoromethyl, tert-butyl, C6-C24 aryl and C6-C24 heteroaryl, wherein the heteroatom is selected from O, S or N.

3. The main body material according to claim 1, characterized in that R1 is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted pyrenyl, substituted or unsubstituted chrysyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted benzothienyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted 9-phenyl-9H-carbazolyl, substituted or unsubstituted dibenzothienyl, substituted or unsubstituted dimethylfluorenyl, substituted or unsubstituted benzocarbazolyl, substituted or unsubstituted naphthobenzofuranyl, substituted or unsubstituted naphthobenzothienyl, substituted or unsubstituted phenanthrothiazolyl, substituted or unsubstituted phenanthroxazolyl, substituted or unsubstituted benzodimethylfluorenyl, substituted or unsubstituted 9,9-spirobifluorenyl or substituted or unsubstituted 9,9-diphenylfluorenyl.

4. The main body material according to claim 1, characterized in that The main material is any one of the following structures: 。 5. An organic electroluminescent material containing a double host, characterized in that: It comprises the host material according to any one of claims 1 to 4 as a first host material and a second host material; The general structural formula of the second host material is shown in formula (2): Formula (2); Wherein, D1, D2, and D3 are each independently selected from a substituted or unsubstituted C6-C42 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a substituted or unsubstituted phosphino group, a substituted or unsubstituted silyl group, and the heteroaryl group includes a monocyclic aromatic group and a polycyclic aromatic system with at least one heteroatom, and the heteroatom includes O, S, or N; L1 and L2 are selected from a connecting bond, a substituted or unsubstituted C6-C30 aryl group.

6. The organic electroluminescent material containing a double host according to claim 5, characterized in that: D1 and D2 are independently selected from substituted or unsubstituted C6-C18 aryl groups; D3 is selected from substituted or unsubstituted C6-C36 aryl groups, substituted or unsubstituted C3-C30 heteroaryl groups, substituted or unsubstituted phosphino groups, and substituted or unsubstituted silyl groups; L1 and L2 are selected from connecting bonds, substituted or unsubstituted C6-C18 aryl groups; The substituents in the "substituted or unsubstituted" in D1, D2, D3, L1, and L2 are selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, three-membered to ten-membered heterocycloalkyl, and phenyl, wherein the heteroatoms are selected from O, S, and N; and the substituents in the substituted or unsubstituted may also be selected from the following structures: 。 7. The organic electroluminescent material containing a double host according to claim 5, characterized in that: The second main material is any one of the following structures: 。 8. A method for preparing an organic electroluminescent material containing a double host according to any one of claims 5 to 7, characterized in that: It includes: S1. Preparation of the first main material: (1) Under a nitrogen atmosphere, the naphthylamine compound reactant 1, dichloromethane, carbonyl chlorobromide and pyridine were mixed and stirred at room temperature for 2-4 hours. After the reaction was completed, intermediates 1-1-a-1 to 1-1-c-1 were obtained. Under a nitrogen atmosphere, the intermediates 1-1-a-1 to 1-1-c-1, FeCl3, Na2S2O8, pyridine and DMSO were mixed, heated to 80-100°C and stirred for 4-8 hours. After the reaction was completed, intermediates 1-1-a-2 to 1-1-c-2 were obtained. The synthesis route is as follows: ； (2) Under nitrogen atmosphere, reactant 2 containing R1 substituent, reactant 3 containing R2 substituent, sodium tert-butoxide, toluene, tris(dibenzylideneacetone)dipalladium and tri-tert-butylphosphine were mixed, refluxed at 100-120°C for 24-48h, cooled to 20-30°C, added with purified water, stirred for 20-40min, allowed to stand for stratification, separated, and column chromatography was performed using dichloromethane / petroleum ether as eluent to obtain 1-1-a-3; under nitrogen atmosphere, the 1-1-a-3, the intermediates 1-1-a-2 to 1-1-c-2, sodium tert-butoxide, toluene, tris(dibenzylideneacetone)bispalladium and tri-tert-butylphosphine were mixed, stirred at 80-100°C for 12-24h, cooled to 20-30°C, added with purified water, stirred for 20-40min, and then allowed to stand for stratification. The liquids were separated and column chromatography was performed using dichloromethane / petroleum ether as eluent to obtain 1-1-a-4 to 1-1-c-4. The synthetic route is as follows: ； (3) Under nitrogen atmosphere, the above 1-1-a-4 to 1-1-c-4, indole compounds, sodium tert-butoxide, toluene, tris(dibenzylideneacetone)dipalladium and tri-tert-butylphosphine were mixed, refluxed at 100-120°C for 12-24h, cooled to 20-30°C, added with purified water, stirred for 20-40min, and allowed to stand for stratification. The liquids were separated and column chromatography was performed using dichloromethane / petroleum ether as eluent to obtain the general formula 1-1. The synthetic route thereof is as follows; ； (4) Under nitrogen atmosphere, 1-1-a-4 to 1-1-c-4, N-phenylindole borate or benzofuran borate, potassium carbonate, toluene, ethanol, water and tetrakis(triphenylphosphine)palladium were mixed, refluxed at 80-90°C for 12-24h, cooled to 20-30°C, filtered, and subjected to solid column chromatography to obtain compounds of the general formula 1-2 to 1-4. The synthetic routes thereof are as follows: ； S2. Preparation of the second main material: (1) Under nitrogen atmosphere, reactant 4, reactant 5-1 containing a D1 substituent, potassium carbonate, toluene, ethanol, water, and tetrakis(triphenylphosphine)palladium were mixed, refluxed at 60-90°C for 12-24h, cooled to 20-30°C, filtered, and subjected to solid column chromatography to obtain compound H-1; (2) Under nitrogen atmosphere, H-1, reactant 5-2 containing a D2 substituent, potassium carbonate, toluene, ethanol, water, and tetrakis(triphenylphosphine)palladium were mixed, refluxed at 60-90°C for 24 h, cooled to 20-30°C, filtered, and subjected to solid column chromatography to obtain compound H-2; (3) Under nitrogen atmosphere, H-2, reactant 5-3 containing a D3 substituent, potassium carbonate, toluene, ethanol, water and tetrakis(triphenylphosphine)palladium were mixed, refluxed at 60-90°C for 24 h, cooled to 20-30°C, filtered, and subjected to solid column chromatography to obtain the compound represented by formula (2). The synthetic route is as follows: ； S3. Mixing the first host material and the second host material.

9. The method for preparing an organic electroluminescent material containing a double host according to claim 8, characterized in that: In step S1 (1), the equivalent ratio of the naphthylamine compound reactant 1, carbonyl chloride bromide, and pyridine is 1 eq: 1-1.2 eq: 2-2.4 eq; the equivalent ratio of the intermediates 1-1-a-1 to 1-1-c-1, FeCl3, Na2S2O8, and pyridine is 1 eq: 0.1-0.2 eq: 1-1.4 eq: 2-2.4 eq; And / or, in step S1 (2), the equivalent ratio of the reactant 2 containing an R1 substituent, the reactant 3 containing an R2 substituent, sodium tert-butoxide, tris(dibenzylideneacetone)bispalladium and tri-tert-butylphosphine is 1 eq: 1-1.2 eq: 2-3 eq: 0.02-0.04 eq: 0.04-0.06 eq; the equivalent ratio of the 1-1-a-3, the intermediates 1-1-a-2 to 1-1-c-2, sodium tert-butoxide, tris(dibenzylideneacetone)bispalladium and tri-tert-butylphosphine is 1 eq: 1-1.2 eq: 2-3 eq: 0.02-0.04 eq: 0.04-0.06 eq; and / or, in step S1 (3), the equivalent ratio of 1-1-a-4 to 1-1-c-4, indole compound, sodium tert-butoxide, tris(dibenzylideneacetone)bispalladium and tri-tert-butylphosphine is 1 eq: 1-1.2 eq: 2-3 eq: 0.02-0.04 eq: 0.04-0.06 eq; and / or, in step S1 (4), the equivalent ratio of 1-1-a-4 to 1-1-c-4, N-phenylindole borate or benzofuran borate, potassium carbonate and tetrakis(triphenylphosphine)palladium is 1 eq:1-1.2 eq:2-3 eq:0.02-0.03 eq, and the volume ratio of toluene, ethanol and water is 2:1:1; and / or, in step S2 (1), the equivalent ratio of reactant 4, reactant 5-1 containing a D1 substituent, potassium carbonate, and tetrakis(triphenylphosphine)palladium is 1 eq:1-1.2 eq:3-4 eq:0.05-0.08 eq, and the volume ratio of toluene, ethanol, and water is 2:1:1; and / or, in step S2 (2), the equivalent ratio of H-1, the reactant 5-2 containing a D2 substituent, potassium carbonate, and tetrakis(triphenylphosphine)palladium is 1 eq:1-1.2 eq:3-4 eq:0.05-0.08 eq, and the volume ratio of toluene, ethanol, and water is 2:1:1; and / or, in step S2 (3), the equivalent ratio of H-2, the reactant 5-3 containing a D3 substituent, potassium carbonate, and tetrakis(triphenylphosphine)palladium is 1 eq:1-1.2 eq:3-4 eq:0.05-0.08 eq, and the volume ratio of toluene, ethanol, and water is 2:1:1; And / or, in step S3, the mass ratio of the first host material to the second host material is 1:9-9:

1.

10. An organic electroluminescent material, characterized in that: It includes a first electrode, an organic electroluminescent material layer and a second electrode; the organic electroluminescent material layer includes a light-emitting layer, and the light-emitting layer includes a doping material and an organic electroluminescent material containing a double host as described in any one of claims 5 to 7 or an organic electroluminescent material containing a double host obtained by the preparation method of the organic electroluminescent material containing a double host as described in any one of claims 8 to 9; the mass ratio of the organic electroluminescent material containing a double host to the doping material is (1~99):(99~1).

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