A host material, an organic electroluminescent material containing a double host, and a light-emitting device

Abstract

The application discloses a host material, an organic electroluminescent material containing a double host and a light-emitting device, and relates to the technical field of organic electroluminescent materials. The structure of the host material is shown in any one of formulae 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 a benzene ring; R1 and R2 are each independently selected from substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C6-C36 heteroaryl, and substituted or unsubstituted C10-C30 fused ring group; wherein the heteroaryl includes a monocyclic aromatic group or a polycyclic aromatic system with at least one heteroatom, and the heteroatom includes O, S or N. The application can adjust the HOMO energy level of the compound, has good electron pushing ability, and significantly enhances the hole transport performance of the compound. As a hole transport layer material of a device, the application greatly improves the luminous efficiency and service life of the device.

Description

TECHNICAL FIELD

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

[0002] The organic electroluminescent device is a self-luminous device, which is widely concerned in the panel display device industry due to low driving voltage, high resolution, large brightness, fast response time, and the like, and low production cost of raw materials, easy processing, and high purity.

[0003] Currently, the OLED display technology has been applied in the fields of smart phones, tablet computers and the like, and will be extended to large-size application fields such as televisions, but compared with the actual product application requirements, the performance of OLED such as luminous efficiency and service life needs to be further improved.

[0004] The light-emitting material of the organic electroluminescent device (OLED) is the most important factor to determine the light-emitting efficiency of the device, and in terms of function, can be divided into a host material and a dopant material, and the light-emitting material can be used by mixing the host and the dopant, so as to improve color purity, light-emitting efficiency and stability. The device with excellent electroluminescent (EL) properties usually has a structure of a light-emitting layer formed by doping a dopant into a host, and when such a dopant / host material system is used as a light-emitting material, the host material greatly affects the efficiency and the life of the light-emitting device, so it is crucial to select a suitable host material.

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

[0006] In view of this, the present application is proposed. SUMMARY

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

[0008] The present application is realized as follows:

[0009] In a first aspect, the present application provides a host material, the structure of which is shown in any one of formulae 1-1 to 1-4:

[0010] ;

[0011] wherein A is selected from substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C6-C24 heteroaryl; B is selected from a benzene ring;

[0012] R1, R2 are each independently selected from substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C6-C36 heteroaryl, substituted or unsubstituted C10-C30 fused ring group; wherein the heteroaryl comprises a monocyclic aromatic group or a polycyclic aromatic system with at least one heteroatom comprising O, S or N.

[0013] The host material provided by the application contains a naphthoxazole mother nucleus, which is a fusion of a naphthalene ring (a 10-membered aromatic system fused by 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 conjugated length is longer, which can cover a wider range of light-emitting color intervals. The rigidity and electron distribution of the naphthalene ring make the intramolecular charge transport path of the naphthoxazole longer and the π-π stacking more compact, which affects the charge mobility (electron / hole transport capacity) and further changes the charge balance and light-emitting efficiency in the device. By connecting a triarylamine as a skeleton on the benzene ring of the naphthoxazole and further connecting a carbazole, 9-phenyl-9H-carbazole, diphenylfuran and a series of derivatives thereof on the oxazole ring, the HOMO energy level of the compound can be better adjusted, and the hole transport performance of the compound is significantly enhanced due to the good electron push ability. As a hole transport layer material of a device, the light-emitting efficiency and service life of the organic light-emitting device are greatly improved.

[0014] In some optional embodiments, the structural general formula of the host material is selected from any one of the following structural formulae:

[0015] ;

[0016] wherein A is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthryl, substituted or unsubstituted phenanthryl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted 9-phenyl-9H-carbazolyl or substituted or unsubstituted dibenzothiophenyl;

[0017] R1 is selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heteroaryl;

[0018] 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;

[0019] A, R1and R2in said "substituted or unsubstituted" are selected from at least one of deuterium, fluorine, cyano, methyl, trifluoromethyl, t-butyl, C6-C24aryl and C6-C24heteroaryl, wherein the heteroatom is selected from O, S or N.

[0020] In some alternative embodiments, R1is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted anthryl, substituted or unsubstituted pyrenyl, substituted or unsubstituted chrysenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted 9-phenyl-9H-carbazolyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dimethylfluorenyl, substituted or unsubstituted benzocarbazolyl, substituted or unsubstituted naphthobenzofuranyl, substituted or unsubstituted naphthobenzothiophenyl, substituted or unsubstituted phenanthrolthiazolyl, substituted or unsubstituted phenanthrolthoxazolyl, substituted or unsubstituted benzdifluorenyl, substituted or unsubstituted 9,9-spirobifluorenyl, or substituted or unsubstituted 9,9-diphenylfluorenyl.

[0021] In some alternative embodiments, the host material is any one of the following structures:

[0022] .

[0023] The above are some specific structural forms of the host material, but are not limited to the listed chemical structures. Any compound with simple variations of the groups within the defined ranges based on the structural general formulae shown in Formulae 1-1 to 1-4 should be included.

[0024] In a second aspect, the present application provides a double-host-containing organic electroluminescent material, which comprises the host material according to any one of the above embodiments as a first host material and a second host material;

[0025] The structural general formula of the second host material is shown as formula (2):

[0026] Formula (2);

[0027] wherein D1, D2, D3 are each independently selected from substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted phosphine oxide, substituted or unsubstituted silyl, a monocyclic aromatic group and a polycyclic aromatic system comprising at least one heteroatom, and the heteroatom includes O, S or N; L1, L2 are selected from a bond, substituted or unsubstituted C6-C30 aryl.

[0028] In the present application, by matching the first host material and the second host material with a triazine structure, when a donor (p-type host) with good hole transport and an acceptor (n-type host) with good electron transport capability are used as the host of the light-emitting layer, the driving voltage is reduced and the lifetime is enhanced.

[0029] In some optional embodiments, D1, D2 are independently selected from substituted or unsubstituted C6-C18 aryl; D3 is selected from substituted or unsubstituted C6-C36 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted phosphine oxide, substituted or unsubstituted silyl; L1, L2 are selected from a bond, substituted or unsubstituted C6-C18 aryl;

[0030] 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 phosphine oxide, substituted or unsubstituted silyl; L1 is a bond, and L2 is a bond or phenyl, naphthyl; the heteroaryl includes a monocyclic aromatic group and a polycyclic aromatic system comprising at least one heteroatom, and the heteroatom includes but is not limited to O, S, N.

[0031] In the above D1, D2, D3, L1, L2, the substituent groups in "substituted or unsubstituted" are selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, three-ten-membered heterocycloalkyl, phenyl, and the heteroatom thereof is selected from O, S, N; and the substituted groups in the "substituted or unsubstituted" can also be selected from the following structures:

[0032] .

[0033] It should be noted that the substituted or unsubstituted means that the group can not be substituted, or substituted with one or more substituents, the substitution means that the hydrogen atom bonded to the carbon atom of the compound is changed to another substituent, and the position of substitution is not limited as long as it is the position of the hydrogen atom which is substituted, that is, the position which the substituent can substitute, and when two or more substituents are substituted, the two or more substituents can be the same as or different from each other.

[0034] In some optional embodiments, the second host material is any one of the following structures, but is not limited thereto:

[0035] .

[0036] The above are some specific structural forms of the second host material, but are not limited to the chemical structures listed. Any compound having a structure as shown in formula (2) as a basis and simple variations of the D1, D2, D3, L1 and L2 groups within all the ranges defined above should be included.

[0037] In a third aspect, the present application provides a method for preparing the double-host-containing organic electroluminescent material according to any one of the above embodiments, which comprises:

[0038] S1, preparing the first host material:

[0039] (1) mixing the naphthylamine compound reactant 1, dichloromethane, carbonyl bromide chloride and pyridine under a nitrogen atmosphere, stirring at room temperature for 2-4 h, and obtaining the intermediates 1-1-a-1 to 1-1-c-1 after the reaction is completed; mixing the intermediates 1-1-a-1 to 1-1-c-1, FeCl3, Na2S2O8, pyridine and DMSO under a nitrogen atmosphere, stirring at 80-100°C for 4-8 h, and obtaining the intermediates 1-1-a-2 to 1-1-c-2 after the reaction is completed, and the synthesis route is as follows:

[0040] ;

[0041] (2) mixing the reactant 2 containing the R1 substituent, the reactant 3 containing the R2 substituent, sodium tert-butoxide, toluene, tris(dibenzylideneacetone)dipalladium and tri-tert-butylphosphine under a nitrogen atmosphere, refluxing at 100-120°C for 24-48 h, cooling to 20-30°C, adding pure water, stirring for 20-40 min, and then standing to separate the layers, separating the layers, using dichloromethane / petroleum ether as the eluent, and column chromatography to obtain 1-1-a-3; mixing the 1-1-a-3, the intermediates 1-1-a-2 to 1-1-c-2, sodium tert-butoxide, toluene, tris(dibenzylideneacetone)dipalladium and tri-tert-butylphosphine under a nitrogen atmosphere, stirring at 80-100°C for 12-24 h, cooling to 20-30°C, adding pure water, stirring for 20-40 min, and then standing to separate the layers, separating the layers, using dichloromethane / petroleum ether as the eluent, and column chromatography to obtain 1-1-a-4 to 1-1-c-4, and the synthesis route is as follows:

[0042] ;

[0043] (3) under nitrogen atmosphere, the 1-1-a-4 to 1-1-c-4, indole compound, sodium tert-butoxide, toluene, tris (dibenzylideneacetone) palladium and tri-tert-butyl phosphine are mixed, refluxed at 100-120 DEG C for 12-24h, cooled to 20-30 DEG C, pure water is added, stirred for 20-40 min, then separated, eluted with dichloromethane / petroleum ether as eluent, column chromatography to obtain general formula 1-1, the synthetic route is as follows:

[0044] ;

[0045] (4) under nitrogen atmosphere, 1-1-a-4 to 1-1-c-4, N-phenyl indole borate or benzofuran borate, potassium carbonate, toluene, ethanol, water and tetrakis (triphenylphosphine) palladium are mixed, refluxed at 80-90 DEG C for 12-24h, cooled to 20-30 DEG C, filtered, solid column chromatography to obtain compound general formula 1-2 to 1-4, the synthetic route is as follows:

[0046] ;

[0047] S2, preparation of the second host material:

[0048] (1) under nitrogen atmosphere, the reactant 4, the reactant 5-1 containing D1 substituent, potassium carbonate, toluene, ethanol, water and tetrakis (triphenylphosphine) palladium are mixed, refluxed at 60-90 DEG C for 12-24h, cooled to 20-30 DEG C, filtered, solid column chromatography to obtain compound H-1;

[0049] (2) under nitrogen atmosphere, H-1, the reactant 5-2 containing D2 substituent, potassium carbonate, toluene, ethanol, water and tetrakis (triphenylphosphine) palladium are mixed, refluxed at 60-90 DEG C for 24h, cooled to 20-30 DEG C, filtered, solid column chromatography to obtain compound H-2;

[0050] (3) under nitrogen atmosphere, H-2, the reactant 5-3 containing D3 substituent, potassium carbonate, toluene, ethanol, water and tetrakis (triphenylphosphine) palladium are mixed, refluxed at 60-90 DEG C for 24h, cooled to 20-30 DEG C, filtered, solid column chromatography to obtain the compound shown in formula (2), the synthetic route is as follows:

[0051] ;

[0052] S3, the first host material and the second host material are mixed.

[0053] In some alternative embodiments, in (1) of step S1, the equivalent ratio of the naphthylamine compound reactant 1, chloroformyl bromide, and pyridine is 1 eq: 1-1.2 eq: 2-2.4 eq; wherein the amount of dichloromethane is not limited, and it can be added according to conventional operation. After the reaction of the naphthylamine compound reactant 1, chloroformyl bromide, and pyridine is completed, the mixture is extracted with dichloromethane, then dehydrated with MgSO4, and then column chromatography (hexane: ethyl acetate = 4: 1) is performed to obtain the intermediates 1-1-a-1 to 1-1-c-1.

[0054] In some alternative embodiments, in (1) of step S1, the equivalent ratio of the naphthylamine compound reactant 1, chloroformyl bromide, and pyridine is 1 eq: 1-1.2 eq: 2-2.4 eq; wherein the amount of dichloromethane is not limited, and it can be added according to conventional operation. After the reaction of the naphthylamine compound reactant 1, chloroformyl bromide, and pyridine is completed, the mixture is extracted with dichloromethane, then dehydrated with MgSO4, and then column chromatography (hexane: ethyl acetate = 4: 1) is performed to obtain the intermediates 1-1-a-1 to 1-1-c-1.

[0055] In (2) of step S1, the equivalent ratio of the reactant 2 containing the R1 substituent, the reactant 3 containing the 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 it can be added according to conventional operation. The entire reaction is carried out under nitrogen protection.

[0056] In (2) of step S1, the equivalent ratio of the reactant 2 containing the R1 substituent, the reactant 3 containing the 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 it can be added according to conventional operation. The entire reaction is carried out under nitrogen protection.

[0057] In (2) of step S1, the equivalent ratio of the reactant 2 containing the R1 substituent, the reactant 3 containing the 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 it can be added according to conventional operation. The entire reaction is carried out under nitrogen protection.

[0058] and / or, in (4) of step S1, the equivalent ratio of the 1-1-a-4 to 1-1-c-4, N-phenyl indole boronate or benzofuran boronate, 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;

[0059] and / or, in (1) of step S2, the equivalent ratio of the reactant 4, the reactant 5-1 containing the substituent D1, 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;

[0060] and / or, in (2) of step S2, the equivalent ratio of H-1, the reactant 5-2 containing the substituent D2, 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;

[0061] and / or, in (3) of step S2, the equivalent ratio of H-2, the reactant 5-3 containing the substituent D3, 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;

[0062] and / or, in step S3, the mass ratio of the first host material and the second host material is 1:9-9:1.

[0063] In a third aspect, the present application 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 comprises a dopant material and a double-host-containing organic electroluminescent material as described in any one of the above embodiments or a double-host-containing organic electroluminescent material prepared by the preparation method of the double-host-containing organic electroluminescent material as described in any one of the above embodiments; the mass ratio of the double-host-containing organic electroluminescent material and the dopant material is (1-99):(99-1).

[0064] 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 is preferably a material having a large work function to smoothly inject holes into the organic material layer, and includes a metal such as vanadium, chromium, copper, zinc, and gold, or an alloy thereof; a metal oxide such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); a combination of a metal and an oxide such as ZnO:Al or SnO2:Sb; a conductive polymer such as poly(3-methylthiophene), poly[3,4-(ethylen-1,2-dioxy)thiophene] (PEDOT), polypyrrole, and polyaniline, but is not limited thereto.

[0065] The cathode material is preferably a material having a small work function to smoothly inject electrons into the organic material layer, and includes a metal such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or an alloy thereof; a multi-layered structure material such as LiF / Al or LiO2 / Al; but is not limited thereto.

[0066] 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.

[0067] Among them, 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. The hole injection material includes metal porphyrin, oligothiophene, arylamine-based organic material, hexacene hexaazatriphenylene-based organic material, quinacridone-based organic material, perylene-based organic material, anthraquinone, and polyaniline-based and polythiophene-based conductive polymers.

[0068] The hole transport layer material is a material capable of receiving holes from the anode or the hole injection layer and transporting the holes to the light emitting layer, and has a high hole mobility. The hole transport layer material includes arylamine-based organic material, conductive polymer, block copolymer having both conjugated and non-conjugated portions, but is not limited thereto.

[0069] The electron blocking layer is disposed between the hole transport layer and the light emitting layer, and the electron blocking layer material includes arylamine-based organic material.

[0070] The hole blocking layer is disposed between the hole transport layer and the light emitting layer, and the hole blocking layer material includes triazine-based compounds.

[0071] The electron transport region includes an electron transport layer and an electron injection layer.

[0072] The electron transport layer has a function of promoting electron transport, and the electron transport material is a material having a high electron mobility which receives electrons from the cathode and transports the electrons to the light emitting layer. The electron transport material includes an Al complex of 8-hydroxyquinoline, a complex of Alq3, an organic radical compound, a hydroxyflavone-metal complex, but is not limited thereto. The electron transport layer has a thickness of 1 nm to 50 nm, and prevents a decrease in electron transport characteristics and an increase in driving voltage.

[0073] The electron injection layer has a function of promoting electron injection, and the electron injection material is a material having an ability to transport electrons, an excellent electron injection effect on the light emitting layer or light emitting material, a function of preventing excitons generated in the light emitting layer from migrating to the hole injection layer, and an excellent thin film formation ability. The electron injection layer material includes fluorenone, anthraquinone dimethane, diphenylquinone, thiopyran dioxide, oxazole, diazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenylidene methane, anthrone, and derivatives thereof, a metal complex, a nitrogen-containing five-membered ring derivative, but is not limited thereto.

[0074] In the present application, the organic electroluminescent device can be a top emission type, a bottom emission type, or a dual side emission type.

[0075] The organic electroluminescent device can be used in an organic solar cell, electronic paper, an organic photoreceptor, or an organic thin film transistor.

[0076] The present application has the following advantages:

[0077] The host material provided by the present application contains a naphthoxazole mother nucleus, which is a 10-membered aromatic system fused by a naphthalene ring (two benzene rings) and an oxazole ring. The naphthalene ring itself has a larger conjugated system and a more complex electron cloud distribution. After being fused with the oxazole ring, the overall conjugated length is longer, which can cover a wider range of light emitting colors. The rigidity and electron distribution of the naphthalene ring make the charge transport path in the naphthoxazole molecule longer and the π-π stacking more compact, which affects the charge mobility (electron / hole transport capacity) and further changes the charge balance and light emitting efficiency in the device. By connecting a triarylamine as a skeleton on the benzene ring of the naphthoxazole and further connecting a carbazole, 9-phenyl-9H-carbazole, diphenyl furan and a series of derivatives thereof on the oxazole ring, the HOMO level of the compound can be better adjusted, and the hole transport performance of the compound is significantly enhanced due to the good electron pushing ability. As a hole transport layer material of the device, the light emitting efficiency and service life of the organic light emitting device will be greatly improved. In the present application, the first host material and the second host material with a triazine structure are matched. When a donor (p-type host) with good hole transport and an acceptor (n-type host) with good electron transport capacity are used as the host of the light emitting layer, the driving voltage will be reduced and the service life will be enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0078] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0079] Figure 1 The nuclear magnetic resonance hydrogen spectrum of the compound R002 provided in the embodiments of the present application. DETAILED DESCRIPTION

[0080] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below. The specific conditions not mentioned in the embodiments are carried out according to the conventional conditions or the conditions suggested by the manufacturers. The reagents or instruments not mentioned by the manufacturers are all conventional products that can be obtained by market purchase.

[0081] The features and performances of the present application will be further described in detail below in combination with the embodiments.

[0082] Embodiment 1: Preparation of compound R002

[0083] (1) Under the nitrogen atmosphere, 1 eq of 7-bromo-2-naphthylamine was added to a round-bottom flask, and dichloromethane was added thereto, and then 1 eq of chloroformyl bromide and 2 eq of pyridine were added dropwise to the round-bottom flask, and the reaction was 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, and then column chromatography (hexane: ethyl acetate = 4:1) was performed to obtain the intermediate R002-1 (the yield was 76%, HPLC > 95%, the mass spectrometry test value was 283.17). The synthetic route is as follows:

[0084] .

[0085] (2) Under the nitrogen atmosphere, 1 eq of R002-1, 0.1 eq of FeCl3, 1 eq of Na2S2O8, 2 eq of pyridine, DMSO were sequentially added to a round-bottom flask, and then the temperature was raised to 80°C and stirred for 4 h. After the reaction was completed, ethyl acetate was extracted, and then water was removed with MgSO4, and then column chromatography (hexane: ethyl acetate = 10:1) was performed to obtain the intermediate R002-2 (the yield was 64%, HPLC > 98%, the mass spectrometry test value was 281.07). The synthetic route is as follows:

[0086] .

[0087] (3) Under nitrogen atmosphere, 1 eq of diphenylamine (CAS: 122-39-4), 1 eq of R002-2, 2 eq of sodium tert-butoxide were weighed into the reaction system, toluene was added, 0.02 eq of tris(dibenzylideneacetone)dipalladium and 0.04 eq of tri-tert-butylphosphine were added, and stirring was carried out at 80°C for 24 h under nitrogen protection, and then cooled to 25°C, pure water was added, stirred for 30 min, and then separated by layering, column chromatography was carried out, and the intermediate R002-3 was obtained (yield 83%, HPLC > 99%, mass spectrometry test value 370.23). The synthesis route is as follows:

[0088] .

[0089] (4) Under nitrogen atmosphere, 1 eq of R002-3, 1 eq of 9- hydrogencarbazole (CAS: 115720-92-8), 2 eq of sodium tert-butoxide were weighed into the reaction system, toluene was added, 0.02 eq of tris(dibenzylideneacetone)dipalladium and 0.04 eq of tri-tert-butylphosphine were added, and stirring was carried out at 120°C for 24 h under nitrogen protection, and then cooled to 25°C, pure water was added, stirred for 30 min, and then separated by layering, column chromatography was carried out, and the intermediate R002 was obtained (yield 83%, HPLC > 99%, mass spectrometry test value 501.43). The synthesis route is as follows:

[0090] .

[0091] Example 2: Preparation of compound H001

[0092] Under nitrogen atmosphere, 1 eq of reactant 4 (CAS: 108-77-0), 3 eq of reactant 5 (CAS: 98-80-6), 3 eq of potassium carbonate were weighed into the reaction system, toluene, ethanol, water, 0.2 eq of tetrakis(triphenylphosphine)palladium were added, and stirring was carried out at 90°C for 24 h under nitrogen protection, and then cooled to 25°C, filtered, and column chromatography was carried out on the solid to obtain the compound H001 (test value: 309.37, yield 62.2%). The HPLC purity is greater than 99%, and the synthesis route is as follows:

[0093] .

[0094] The synthesis methods of other compounds are the same as those in the above examples, which will not be described here.

[0095] Device examples 1-15, comparative examples 1-9 and parallel examples 1-8:

[0096] The device manufacturing processes of device examples 1-15, comparative examples 1-9 and parallel examples 1-8 are completely the same, and the same substrate material and electrode material are used, and the film thickness of the electrode material is consistent, the difference is that the two host materials are not the same, and the corresponding first host material and second host material in Table 1 are selected respectively, and the specific parameters are as follows:

[0097] Table 1. Statistics table of host materials used in organic electroluminescent devices of different examples

[0098]

[0099] The comparative example structure is shown in Table 2:

[0100] Table 2. Statistics table of compounds referred to by different numbers in comparative examples

[0101]

[0102] Preparation of organic electroluminescent device

[0103] The preparation method of the organic electroluminescent device is as follows:

[0104] (1) The ITO (indium tin oxide) glass substrate with a thickness of 1500 angstroms was cleaned in distilled water for 2 times, ultrasonic washing for 30 minutes, and then distilled water was repeatedly cleaned for 2 times, ultrasonic washing for 10 minutes. After washing, methanol, acetone and isopropanol were sequentially ultrasonic washed (each for 5 minutes), dried, and then transferred to a plasma cleaning machine for washing for 5 minutes to obtain an ITO anode.

[0105] (2) In the evaporation machine, the surface of the ITO anode obtained in step (1) was vacuum evaporated to form a hole injection layer with a thickness of 700 angstroms.

[0106] (3) The surface of the hole injection layer obtained in step (2) was vacuum evaporated to form a hole transport layer, first evaporated to a thickness of 50 angstroms HTL1, and then evaporated to a thickness of 700 angstroms HTL2 on the surface to form a hole transport layer.

[0107] (4) The surface of the hole transport layer was evaporated with a linear gradient co-evaporation method to form a light-emitting layer with a thickness of 300 angstroms; the light-emitting layer material includes a double-host-containing organic electroluminescent material and a doping material, the mass ratio of the first host compound and the second host compound in the double-host-containing organic electroluminescent material is 6:4, and the mass ratio of the double-host-containing organic electroluminescent material and the doping material is 10:1, and the double-host-containing organic electroluminescent material is provided by the host materials of device examples 1-15, comparative examples 1-9, and parallel examples 1-8.

[0108] (5) Depositing HBL on the surface of the light-emitting layer obtained in step (4) by evaporation to a thickness of 100 angstroms to form a hole-blocking layer.

[0109] (6) Depositing ETL on the surface of the hole-blocking layer obtained in step (5) by vacuum evaporation to a thickness of 300 angstroms to obtain an electron transport layer.

[0110] (7) Depositing EIL (Liq) on the surface of the electron transport layer obtained in step (6) by vacuum evaporation to a thickness of 15 angstroms to obtain an electron injection layer.

[0111] (8) Depositing 1200 angstroms of Al on the surface of the electron injection layer obtained in step (7) to form a cathode, thereby obtaining the organic electroluminescent device.

[0112] The structures of the materials (HIL, HTL1, HTL2, doping material, HBL, ETL, EIL) used in the preparation of the organic electroluminescent device described above are as follows:

[0113] .

[0114] The driving voltage, luminous efficiency, and time taken for the luminance to decrease from 100% to 95% (lifetime; T95) of the organic electroluminescent device were tested at a luminance of 3000 nits, and the test results are shown in Table 2.

[0115] Table 2

[0116]

[0117] As can be seen from the comparison of Comparative Examples 1-9, the use of the first host compound and the second host compound in combination as the host material of the light-emitting layer can greatly improve the luminous efficiency and service life, and the use of only one of them will result in a significant decrease in the luminous efficiency of the device, a significant shortening of the service life, and an increase in the voltage. As can be seen from the comparison of Comparative Examples 2, 4, 6, and 8 with Parallel Examples 1-2, the performance of the device using the first host material of the application is significantly better than that of Comparative Examples E-1 to E-4.

[0118] As can be seen from the comparison of Device Examples 1-15 with Parallel Examples 3-8, the luminous efficiency of Parallel Examples 3-8 is 36.6-38.8 cd / A, the driving voltage is 4.14-4.45 V, and the lifetime is 563-587 h, while the luminous efficiency of Device Examples 1-15 of the application is 46.7-48.6 cd / A, which is significantly higher than that of Parallel Examples 3-8; the driving voltage is 3.58-3.70 V, which is significantly lower than that of Parallel Examples 3-8; and the lifetime is 768-805 h, which is much higher than that of Parallel Examples 3-8.

[0119] The reason is that E-1, E-2 and E-3 are all three-membered fused ring anthracene, phenanthrene and oxazole ring, and the phenyl group is connected to the oxazole ring. Compared with the oxazole ring of the naphthoxazole mother nucleus of the present application, the oxazole ring is connected to the carbazole, 9-phenyl-9H-carbazole, dibenzofuran and other groups, the three-membered fused ring anthracene, phenanthrene and oxazole ring has a larger conjugated system, and the core naphthalene ring of the naphthoxazole of the present application has a smaller conjugated system than the core phenanthrene ring of the phenanthroxazole. Smaller conjugated system usually means larger energy gap. Therefore, the naphthoxazole derivative usually has a higher triplet energy level, which can effectively limit the excitation on the guest molecule to emit light, prevent energy back to the host to cause energy loss, and connecting carbazole, 9-phenyl-9H-carbazole, dibenzofuran and other groups on the oxazole ring can better adjust the HOMO energy level of the compound, and the energy gap matching is more flexible, which helps to reduce the energy loss at the interface.

[0120] Therefore, it can be seen that the host material of the light-emitting layer is compounded by the first host compound with a specific structure and the second host compound with a specific structure of the present application, which can greatly improve the luminous efficiency and service life. Because the present application provides a first host material with a triarylamine skeleton, introduces carbazole, 9-phenyl-9H-carbazole, dibenzofuran and other groups and a series of derivatives thereof on the mother nucleus of naphthoxazole, which can better adjust the HOMO energy level of the compound, and has good electron pushing ability, which significantly enhances the hole transport performance of the compound. As the hole transport layer material of the device, it can greatly improve the luminous efficiency and service life of the organic light-emitting device. Meanwhile, the second host with triazine structure is also provided, so when the donor (p-type host) with good hole transport and the acceptor (n-type host) with good electron transport ability are used as the light-emitting layer host, the driving voltage will be reduced and the service life will be enhanced.

[0121] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A main material, characterized in that, The structural formula of the main material is selected from any of the following structural formulas: ； Wherein, A is selected from substituted or unsubstituted phenyl groups; R1 is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted anthrayl, substituted or unsubstituted pyrene, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted 9-phenyl-9H-carbazolyl. R2 is selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted triphenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted 9-phenyl-9H-carbazoyl; The substitutions or unsubstituted substitutions in A, R1, and R2 are selected from at least one of deuterium, methyl, tert-butyl, and C6 aryl.

2. The main material according to claim 1, characterized in that, The main material is any one of the following structures: 。 3. An organic electroluminescent material containing two main components, characterized in that, It includes a first main material and a second main material, wherein the structure of the first main material is the main material as described in any one of claims 1-2; The second main material is any one of the following structures: 。 4. 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, the light-emitting layer includes a doped material and the organic electroluminescent material containing a dual host as described in claim 3; the mass ratio of the organic electroluminescent material containing the dual host to the doped material is (1~99):(99~1).

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