Organic electroluminescent material, organic electroluminescent material containing double hosts and organic electroluminescent device

Abstract

The invention belongs to the field of organic electroluminescent materials, and discloses an organic electroluminescent material, an organic electroluminescent material containing double hosts and an organic electroluminescent device. In the organic electroluminescent device containing the double hosts, a first host material is shown as the organic electroluminescent material and has a structure shown as a general formula 1, and a second host material has a structure shown as a general formula 2. According to the organic electroluminescent device, triplet excitons are dispersed on two main bodies by using a double-main-body material, triplet-triplet annihilation is reduced, the driving voltage of the organic electroluminescent device is reduced, the luminous efficiency of the device can be improved, and the service life of the device can be prolonged.

Description

Technical Field

[0001] The present invention belongs to the field of organic electroluminescent materials, and in particular relates to an organic electroluminescent material, an organic electroluminescent material containing a double host, and an organic electroluminescent device. Background Art

[0002] Organic electroluminescent devices (OLEDs), as cutting-edge optoelectronic material systems that combine display and lighting functions, show broad market application prospects in new display products (such as smartphones and tablets) and new lighting products. However, under current technological conditions, core performance indicators such as luminous efficiency and service life still fall significantly short of actual product application requirements, urgently requiring technological breakthroughs.

[0003] The OLED structure consists of electrode material layers and organic functional materials sandwiched between them. As a current device, when a voltage is applied to the two electrodes of the OLED, the electric field separates the positive and negative charges in the organic functional material layer. The positive and negative charges then recombine in the light-emitting layer, generating electroluminescence from the OLED. Since the radiative transition of triplet excitons in most organic molecules is forbidden and contributes little to electroluminescence, doping with organometallic complexes such as platinum, iridium, and osmium allows the triplet excitons of organic molecules to transfer to the triplet state of the metal complex, thereby improving the efficiency of the organic light-emitting device. Therefore, the efficiency of OLEDs can be improved by host-guest doping in the light-emitting layer. However, triplet-triplet annihilation (TTA) occurs during the transfer of triplet excitons, resulting in energy loss and causing efficiency roll-off in the organic light-emitting device.

[0004] Currently, problems such as excessively high driving voltage, low luminous efficiency, and short lifespan have become key technical bottlenecks hindering the widespread application of organic electroluminescent devices. Therefore, the development of dual-host organic electroluminescent materials with long lifespan and low driving voltage characteristics, as well as their corresponding preparation methods and high-performance organic electroluminescent devices, has become a core technical challenge that urgently needs to be overcome in the field of optoelectronic materials and devices. Summary of the Invention

[0005] In light of this, the present invention provides an organic electroluminescent material, an organic electroluminescent material containing a dual host, and an organic electroluminescent device. By using a dual host material, triplet excitons are dispersed across two hosts, reducing triplet-triplet annihilation (TTA). This reduces the driving voltage of the organic electroluminescent device while also improving the device's luminous efficiency and service life.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The first technical purpose of the present invention is to provide an organic electroluminescent material, the structure of which is shown in Formula 1:

[0008]

[0009] in,

[0010] X is selected from -N=, -O- or -S-;

[0011] Y is selected from -N=, -O- or -S-;

[0012] R0 is selected from hydrogen or deuterium, n0 is selected from 0, 1, 2, 3, 4 or 5;

[0013] R1 and R2 are each independently selected from substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C6-C30 heteroaryl, wherein the heteroatom is selected from oxygen, nitrogen or sulfur;

[0014] L1, L2, and L3 are each independently selected from a linking bond, a substituted or unsubstituted C6-C18 aryl group, or a substituted or unsubstituted C6-C18 heteroaryl group, wherein the heteroatom is selected from oxygen, nitrogen, or sulfur.

[0015] Furthermore, the hydrogen atoms in the groups of the above general formula 1 are independently substituted by deuterium or not.

[0016] Further, when X is selected from -N=, Y is selected from -O- or -S-;

[0017] When Y is selected from -N=, X is selected from -O- or -S-.

[0018] Furthermore, the general formula 1 has the structural formulas I-1 to I-9:

[0019]

[0020]

[0021] In the formula, R1 and R2 are each independently selected from the following structures and any combination thereof:

[0022]

[0023] L1, L2, and L3 are each independently selected from the subunits of the following compounds which are chemically bonded, substituted or unsubstituted: benzene, biphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, fluorene, pyridine, pyridazine, pyrimidine, pyrazine, quinoline, isoquinoline, quinazoline, quinoxaline, cinnoline, naphthyridine, triazine, pyridopyrazine, furan, benzofuran, dibenzofuran, aza-dibenzofuran, thiophene, benzothiophene, dibenzothiophene, aza-dibenzothiophene, spirofluorene, aromatic amine, and carbazole.

[0024] In the above technical solution, the “substituted or unsubstituted” means that the group may not be substituted or may be substituted by one or more substituents, and the “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.

[0025] Furthermore, heteroaryl includes monocyclic aromatic groups and polycyclic aromatic ring systems having at least one heteroatom, and heteroatoms include but are not limited to O, S, and N.

[0026] The substituted group in the "substituted or unsubstituted" is selected from hydrogen, deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, C3-C10 heterocycloalkyl, and the heteroatom thereof is selected from oxygen, nitrogen, and sulfur.

[0027] Furthermore, the substituted group in "substituted or unsubstituted" is selected from hydrogen, deuterium, fluorine, methyl, ethyl, CD3, and the following structures:

[0028]

[0029] In the technical solution of the present invention, the general formula 1 specifically has the following structure, but is not limited thereto:

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045] The above are some specific structural forms of organic electroluminescent materials, but are not limited to the chemical structures listed. All compounds based on the general structural formula 1 and with simple changes in the groups within the defined range should be included.

[0046] A second technical object of the present invention is to provide an organic electroluminescent material containing a dual host, wherein the dual host organic electroluminescent material comprises the organic electroluminescent material (first host material) as described above and a second host material, wherein the mass ratio of the first host material to the second host material is 1:99-99:1; the first host material has a structure shown in Formula 1, and the second host material has a structure shown in Formula 2:

[0047]

[0048] 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, wherein the heteroatom is selected from oxygen, nitrogen, or sulfur;

[0049] L4, L5, and L6 are each independently selected from a linking bond, a substituted or unsubstituted C6-C18 aryl group, or a substituted or unsubstituted C6-C18 heteroaryl group, wherein the heteroatom is selected from oxygen, nitrogen, or sulfur.

[0050] Further, D1 and D2 are independently selected from substituted or unsubstituted C6-C18 aryl groups;

[0051] D3 is selected from a substituted or unsubstituted C6-C36 aryl group, and a substituted or unsubstituted C3-C24 heteroaryl group.

[0052] Furthermore, D1 is selected from the following substituted or unsubstituted groups: phenyl, biphenyl, terphenyl;

[0053] D2 is selected from the following substituted or unsubstituted groups: phenyl, naphthyl, biphenyl, terphenyl, triphenylene;

[0054] D3 is selected from the following substituted or unsubstituted groups: benzene, biphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, fluorene, pyridine, pyridazine, pyrimidine, pyrazine, quinoline, isoquinoline, quinazoline, quinoxaline, cinnoline, naphthyridine, triazine, pyridopyrazine, furan, benzofuran, dibenzofuran, aza-dibenzofuran, thiophene, benzothiophene, dibenzothiophene, aza-dibenzothiophene, 9,9-dimethylfluorene, spirofluorene, arylamine, carbazole;

[0055] L4, L5, and L6 are each independently selected from the subunits of the following compounds which are chemically bonded, substituted or unsubstituted: benzene, biphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, fluorene, pyridine, pyridazine, pyrimidine, pyrazine, quinoline, isoquinoline, quinazoline, quinoxaline, cinnoline, naphthyridine, triazine, pyridopyrazine, furan, benzofuran, dibenzofuran, aza-dibenzofuran, thiophene, benzothiophene, dibenzothiophene, aza-dibenzothiophene, aromatic amine, and carbazole.

[0056] In the above technical solution, the “substituted or unsubstituted” means that the group may not be substituted or may be substituted by one or more substituents, and the “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.

[0057] Heteroaryl includes monocyclic aromatic groups and polycyclic aromatic ring systems having at least one heteroatom, including but not limited to O, S, and N.

[0058] The substituted group in the "substituted or unsubstituted" is selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, C3-C10 heterocycloalkyl, and the heteroatom thereof is selected from oxygen, nitrogen, and sulfur.

[0059] Furthermore, the substituted group in "substituted or unsubstituted" is selected from hydrogen, deuterium, fluorine, methyl, ethyl, CD3, and the following structures:

[0060]

[0061] In the technical solution of the present invention, the second host material (Formula 2) is selected from any one of the following compounds:

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071] The present invention also provides a method for preparing the above-mentioned organic electroluminescent material containing two hosts, which specifically includes a method for preparing the first host material and the second host material, and the specific steps are as follows:

[0072] 1. Synthesis of intermediate compound II-1:

[0073]

[0074] Wherein, L1, L2, L3, R1, and R2 are each independently selected from the same range as in Formula 1;

[0075] (1) Reactant 1 (CAS: 108-77-0) (1 eq), reactant 2 (1 eq), and potassium carbonate (2 eq) were added to a reactor and replaced with nitrogen three times. A mixture of water and tetrahydrofuran was added as a solvent and replaced with nitrogen three times. Pd(Ph3)4 (0.01 eq) was then added and replaced with nitrogen three times. The mixture was heated to 80°C under nitrogen protection and reacted for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, and then the solvent was removed under reduced pressure. The crude product was purified by column chromatography to obtain intermediate II-a.

[0076] (2) Intermediate II-a (1 eq), reactant 3 (1 eq), and potassium carbonate (2 eq) were added to a reactor and replaced with nitrogen three times. A mixture of water and tetrahydrofuran was added as a solvent and replaced with nitrogen three times. Pd(Ph3)4 (0.01 eq) was then added and replaced with nitrogen three times. The mixture was heated to 80°C under nitrogen protection and reacted for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, and then the solvent was removed under reduced pressure. The crude product was purified by column chromatography to obtain intermediate II-b.

[0077] (3) Intermediate II-b (1 eq), reactant 4 (1 eq), and potassium carbonate (2 eq) were added to a reactor and replaced with nitrogen three times. A mixture of water and tetrahydrofuran was added as a solvent and replaced with nitrogen three times. Pd(Ph3)4 (0.01 eq) was then added and replaced with nitrogen three times. The mixture was heated to 80°C under nitrogen protection and reacted for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, and then the solvent was removed under reduced pressure. The crude product was purified by column chromatography to obtain the final product II-1.

[0078] 2. The synthesis method of the first host material general formula I-1, I-2, I-3, I-4, I-5, I-6, I-7, I-8 and I-9 is as follows:

[0079] Synthesis of formula I-1:

[0080]

[0081] (1) 2-iodo-1-hydroxy-naphthalene (1 eq) (CAS: 730952-28-0), reactant 1 (1 eq), sodium tert-butoxide (2 eq), tris(dibenzylideneacetone) palladium (0.02 eq) and tri-tert-butylphosphine (0.04 eq) were refluxed at 70° C. for 24 h under nitrogen protection. After the reaction solution was cooled to room temperature, it was treated and purified by silica gel column chromatography to obtain the intermediate compound of formula Ia-1.

[0082] (2) The intermediate compound Ia-1 (1 eq), copper (0.03 eq), and ammonium hexafluorophosphate (0.03 eq) were added to a three-necked flask and replaced with nitrogen three times. Subsequently, dichloromethane was added as a solvent to replace the nitrogen three times. The mixture was stirred and reacted at 23°C under nitrogen protection for 24 hours. After the temperature of the reaction solution was cooled to room temperature, it was treated and purified by silica gel column chromatography to obtain the intermediate compound Ia-2.

[0083] (3) Weigh the intermediate compound Ia-2 (1 eq) and N-bromosuccinimide (2.2 eq), dissolve the intermediate compound Ia-2 completely in the reaction system, add one-tenth of N-bromosuccinimide, add carbon tetrachloride, and catalyst benzoyl peroxide (0.04 eq), add the remaining N-bromosuccinimide at 40°C under nitrogen protection, reflux for 4 hours, then cool to 25°C, add purified water, stir for 30 minutes, let stand and separate, separate the layers, and perform column chromatography to obtain the intermediate compound Ia-3 shown;

[0084] (4) B,B'-(4-chloro-1,2-phenylene)bisboronic acid (CAS: 1674380-71-2), intermediate compound Ia-3, and potassium carbonate (4 eq) were placed in a reaction system, and THF, water, and a catalyst of tetrakis(triphenylphosphine)palladium (0.04 eq) were added. The mixture was refluxed at 70°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 separation, the mixture was separated, and column chromatography was performed to obtain intermediate compound Ia-4;

[0085] (5) The intermediate compound Ia-4 (1 eq), pinacol diboronate (1.5 eq) (CAS: 73183-34-3), and potassium acetate (2 eq) were added to a reactor and the atmosphere was replaced with nitrogen three times. 1,4-dioxane was added as a solvent and the atmosphere was replaced with nitrogen three times. Pd2(dba)3 (0.01 eq) and X-phos (0.08 eq) were then added and the atmosphere was replaced with nitrogen three times. The reaction was heated to 100°C under nitrogen protection for 12 hours. After the reaction was completed, the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain the intermediate compound Ia-5.

[0086] (6) Intermediate compound Ia-5 (1 eq), intermediate II-1 (1 eq), and potassium carbonate (2 eq) were added to a reactor and the atmosphere was replaced with nitrogen three times. A mixture of water and tetrahydrofuran was added as a solvent and the atmosphere was replaced with nitrogen three times. Pd(Ph3)4 (0.01 eq) was then added and the atmosphere was replaced with nitrogen three times. The temperature was raised to 80°C under nitrogen protection and the reaction was carried out for 12 hours. After the reaction was completed, the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain the final product I-1.

[0087] The synthetic routes of general formulae I-2 to I-9 can be synthesized by referring to the method of I-1, and will not be described in detail here.

[0088] Synthesis of formula I-2:

[0089]

[0090] Synthesis of formula I-3:

[0091]

[0092] Synthesis of formula I-4:

[0093]

[0094] Synthesis of formula I-5:

[0095]

[0096] Synthesis of Formula I-6:

[0097]

[0098] Synthesis of formula I-7:

[0099]

[0100] Synthesis of formula I-8:

[0101]

[0102] Synthesis of Formula I-9:

[0103]

[0104] 3. The preparation method of general formula 2 specifically comprises the following steps:

[0105] (1) Reactant (1 eq), reactant 2 (1 eq), and sodium tert-butoxide (2 eq) were weighed and added to a reaction vessel in sequence. Toluene was then added as a reaction solvent. Catalysts Pd2(dba)3 (0.01 eq) and P(t-Bu)3 (0.02 eq) were added under nitrogen protection. The mixture was refluxed at 120°C for 24 hours under nitrogen protection, then cooled to 25°C, purified water was added, stirred for 30 minutes, allowed to stand, separated, and subjected to column chromatography to obtain intermediate 2-1.

[0106] (2) The synthesis method of Formula 2 is the same as that of the synthetic intermediate 2-1, and will not be described in detail here. The specific synthetic route is as follows:

[0107]

[0108] Furthermore, the present invention also seeks to protect the use of the above-mentioned organic electroluminescent material containing a double host in the preparation of an organic electroluminescent device.

[0109] Specifically, the organic electroluminescent device includes a first electrode, a second electrode, and an organic electroluminescent material layer disposed between the first electrode and the second electrode; and the organic electroluminescent material layer includes a light-emitting layer; the light-emitting layer includes a doping material and the organic electroluminescent material containing a dual host as described above;

[0110] The mass ratio of the organic electroluminescent material containing the dual hosts to the doping material is (1-99):(99-1).

[0111] More specifically, the organic electroluminescent device includes an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode. The light-emitting layer includes a first host material of Formula 1 and a second host material of Formula 2.

[0112] As the anode material, a material with a large work function is generally preferred so that holes can be smoothly injected into the organic material layer. Anode materials that can be used for the first electrode of the organic electroluminescent device of the present invention 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; conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrrole and polyaniline, but are not limited thereto.

[0113] Cathode materials generally prefer materials with a low work function to facilitate electron injection into the organic material layer. Cathode materials that can be used for the second electrode of the organic electroluminescent device of the present invention include, but are not limited to, metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or alloys thereof; and multilayer structures such as LiF / Al or LiO2 / Al.

[0114] 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 metal porphyrins, oligothiophenes, organic materials based on arylamines, organic materials based on hexanitrile hexaazatriphenylene, organic materials based on quinacridone, organic materials based on perylene, anthraquinone, and conductive polymers based on polyaniline and polythiophene.

[0115] The hole transport layer material is a material that can receive holes from the anode or the hole injection layer and transport the holes to the light-emitting layer and has high hole mobility; and the hole transport layer material includes organic materials based on aromatic amines, conductive polymers, block copolymers having both conjugated and non-conjugated parts, etc., but is not limited thereto.

[0116] The electron blocking layer may be provided between the hole transport layer and the light emitting layer. As the electron blocking layer, materials known in the art, such as arylamine-based organic materials, may be used.

[0117] The host material of the light-emitting layer is selected from the structure of the present invention.

[0118] The hole blocking layer may be provided between the electron transport layer and the light emitting layer, and a material known in the art, such as a triazine-based compound, may be used.

[0119] The electron transport layer facilitates electron transport. Electron transport materials are materials with high electron mobility that favorably receive electrons from the cathode and transfer them to the light-emitting layer. Examples include, but are not limited to, Al complexes of 8-hydroxyquinoline; complexes containing Alq3; organic free radical compounds; and hydroxyflavone-metal complexes. The thickness of the electron transport layer can range from 1 nm to 50 nm. Electron transport layers with a thickness of 1 nm or greater have the advantage of preventing a decrease in electron transport properties, while thicknesses of 50 nm or less prevent an increase in driving voltage caused by an excessively thick electron transport layer.

[0120] The electron injection layer can facilitate electron injection, and the electron injection material preferably has the ability to transport electrons, has an electron injection effect from the cathode, has an excellent electron injection effect on the light-emitting layer or light-emitting material, prevents excitons generated in the light-emitting layer from migrating to the hole injection layer, and also has excellent thin film forming ability. Specific examples 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.

[0121] Depending on the materials used, the organic electroluminescent device may be a top emission type, a bottom emission type, or a double-side emission type.

[0122] Furthermore, the organic electroluminescent device of the present invention can be used in organic solar cells, electronic paper, organic photoreceptors or organic thin film transistors.

[0123] Through the above technical solutions, it can be seen that the present invention has the following beneficial effects:

[0124] The present invention provides an organic electroluminescent material having two host materials, wherein the organic electroluminescent material includes a first host material and a second host material, wherein the first host material is a compound having a structure represented by general formula 1, and the second host material is a compound having a structure represented by general formula 2. By using a specific combination of compounds as host materials in an organic electroluminescent device, the luminous efficiency and service life of the device can be effectively improved.

[0125] Specifically, the present invention adopts a compound of a first host compound with a specific structure and a second host compound with a specific structure, wherein the first host material adopts a molecule with a triazine skeleton, which has a high glass transition temperature and molecular thermal stability, suitable HOMO and LUMO energy levels, and a high Eg. At the same time, it is matched with a second host with a triarylamine structure, which has the ability to simultaneously enhance hole transport and electron transport. Therefore, when holes are injected into the p-type host and electrons are injected into the n-type host, the driving voltage is reduced while the lifespan is also enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0126] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0127] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum corresponding to compound R030 in Example 1 of the present invention. DETAILED DESCRIPTION

[0128] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention and the related drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0129] The embodiments of the present invention disclose an organic electroluminescent material and a method for preparing the organic electroluminescent material containing a double host.

[0130] In addition, it should be noted that the numerical values ​​given in the following examples are as accurate as possible, but those skilled in the art understand that due to unavoidable measurement errors and experimental operation problems, each number should be understood as an approximate number rather than an absolutely accurate value.

[0131] Example 1: Preparation of Compound R030

[0132] The reaction scheme is as follows:

[0133]

[0134] (1) 2-iodo-1-hydroxy-naphthalene (1 eq) (CAS: 730952-28-0), benzylamine (1 eq) (CAS: 100-46-9), sodium tert-butoxide (2 eq), tris(dibenzylideneacetone) palladium (0.02 eq) and tri-tert-butylphosphine (0.04 eq) were refluxed at 70° C. for 24 h under nitrogen protection. After the reaction solution was cooled to room temperature, it was treated and purified by silica gel column chromatography to obtain the intermediate compound R030-1 with a yield of 46%.

[0135] (2) The intermediate compound R030-1 (1 eq), copper (0.03 eq), and ammonium hexafluorophosphate (CAS: 16941-11-0) (0.03 eq) were added to a three-necked flask and replaced with nitrogen three times. Subsequently, dichloromethane was added as a solvent to replace the nitrogen three times. The reaction was stirred at 23°C under nitrogen protection for 24 hours. After the reaction solution temperature was cooled to room temperature, it was treated and purified by silica gel column chromatography to obtain the intermediate compound R030-2 with a yield of 68%.

[0136] (3) Weigh the intermediate compound R030-2 (1 eq) and N-bromosuccinimide (CAS: 128-08-5) (2.2 eq). First, completely dissolve the intermediate compound R030-2 in the reaction system, then add one-tenth of N-bromosuccinimide, carbon tetrachloride, and catalyst benzoyl peroxide (CAS: 94-36-0) (0.04 eq). Under nitrogen protection, add the remaining N-bromosuccinimide at 40° C., reflux for 4 h, then cool to 25° C., add purified water, stir for 30 min, stand for separation, separate the layers, and perform column chromatography to obtain the intermediate compound R030-3 (yield 65%).

[0137] (4) B,B'-(4-chloro-1,2-phenylene)bisboronic acid (CAS: 1674380-70-1) (1 eq), intermediate compound R030-3 (1 eq), and potassium carbonate (4 eq) were placed in a reaction system, and THF, water, and catalyst tetrakis(triphenylphosphine)palladium (0.04 eq) were added. The mixture was refluxed at 70°C for 24 h under nitrogen protection, then cooled to 25°C, purified water was added, and the mixture was stirred for 30 min, then allowed to stand for separation, and column chromatography was performed to obtain intermediate compound R030-4 (yield: 85%).

[0138] (5) The intermediate compound R030-4 (1 eq), pinacol diboron (1.5 eq) (CAS: 73183-34-3), and potassium acetate (2 eq) were added to the reactor and replaced with nitrogen three times. 1,4-dioxane was added as a solvent and replaced with nitrogen three times. Pd2(dba)3 (0.01 eq) and X-phos (0.08 eq) were added and replaced with nitrogen three times. The temperature was raised to 100° C. under nitrogen protection and the reaction was carried out for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, and then the solvent was removed under reduced pressure. The crude product was purified by column chromatography to obtain the intermediate compound R030-5 (yield: 82%).

[0139] (6) The intermediate compound R030-5 (1 eq), 2-(4-chlorophenyl)-4,6-diphenyl-1,3,5-triazine (CAS: 3114-52-1) (1 eq), and potassium carbonate (2 eq) were added to a reactor and replaced with nitrogen three times. A mixture of water and tetrahydrofuran was added as a solvent and replaced with nitrogen three times. Pd(Ph3)4 (0.01 eq) was then added and replaced with nitrogen three times. The mixture was heated to 80°C under nitrogen protection and reacted for 12 hours. After the reaction was completed, the mixture was cooled to room temperature. The solvent was then removed under reduced pressure, and the crude product was purified by column chromatography and recrystallized from toluene to obtain the final product R030 (yield 77%, HPLC>99%, mass spectrometry value 626.51, nuclear magnetic resonance hydrogen spectrum as shown in FIG. Figure 1 shown).

[0140] Example 2: Preparation of Compound R136

[0141] The reaction scheme is as follows:

[0142]

[0143] (1) 3-iodo-2-naphthol (1 eq) (CAS: 103027-41-4), 3-chlorobenzylamine (1 eq) (CAS: 4152-90-3), sodium tert-butoxide (2 eq), tris(dibenzylideneacetone) palladium (0.02 eq) and tri-tert-butylphosphine (0.04 eq) were refluxed at 70° C. for 24 h under nitrogen protection. After the reaction solution was cooled to room temperature, it was treated and purified by silica gel column chromatography to obtain the intermediate compound R136-1 (yield 47%).

[0144] (2) The intermediate compound R136-1 (1 eq), copper (0.03 eq), and ammonium hexafluorophosphate (CAS: 16941-11-0) (0.03 eq) were added to a three-necked flask and replaced with nitrogen three times. Subsequently, dichloromethane was added as a solvent to replace the nitrogen three times. The reaction was stirred at 23°C under nitrogen protection for 24 hours. After the reaction solution temperature was cooled to room temperature, it was treated and purified by silica gel column chromatography to obtain the intermediate compound R136-2 (yield: 68.5%).

[0145] (3) Weigh the intermediate compound R136-2 (1 eq) and N-bromosuccinimide (CAS: 128-08-5) (2.2 eq). First, completely dissolve the intermediate compound R136-2 in the reaction system, then add one-tenth of N-bromosuccinimide, carbon tetrachloride, and catalyst benzoyl peroxide (CAS: 94-36-0) (0.04 eq). Under nitrogen protection, add the remaining N-bromosuccinimide at 40° C., reflux for 4 h, then cool to 25° C., add purified water, stir for 30 min, stand for separation, separate the layers, and perform column chromatography to obtain the intermediate compound R136-3 (yield: 64.8%).

[0146] (4) Benzene-1,2-diboronic acid (CAS: 13506-87-7) (1 eq), intermediate compound R136-3 (1 eq), and potassium carbonate (4 eq) were placed in a reaction system, and THF, water, and a catalyst, tetrakis(triphenylphosphine)palladium (0.04 eq), were added. The mixture was refluxed at 70°C for 24 h under nitrogen protection, then cooled to 25°C, purified water was added, and the mixture was stirred for 30 min, then allowed to stand for separation, and column chromatography was performed to obtain the intermediate compound R136-4 (yield: 85%).

[0147] (5) The intermediate compound R136-4 (1 eq), pinacol diboronate (1.5 eq) (CAS: 73183-34-3), and potassium acetate (2 eq) were added to the reactor and replaced with nitrogen three times. 1,4-dioxane was added as a solvent and replaced with nitrogen three times. Pd2(dba)3 (0.01 eq) and X-phos (0.08 eq) were added and replaced with nitrogen three times. The temperature was raised to 100° C. under nitrogen protection and the reaction was carried out for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, and then the solvent was removed under reduced pressure. The crude product was purified by column chromatography to obtain the intermediate compound R136-5 (yield: 81.8%).

[0148] (6) The intermediate compound R136-5 (1 eq), 2-[1,1'-biphenyl]-4-yl-4-(3'-chloro[1,1'-biphenyl]-4-yl)-6-phenyl-1,3,5-triazine (CAS: 2246765-15-9) (1 eq), and potassium carbonate (2 eq) were added to a reactor and the atmosphere was replaced with nitrogen three times. A mixture of water and tetrahydrofuran was added as a solvent and the atmosphere was replaced with nitrogen three times. Pd(Ph3)4 (0.01 eq) was then added and the atmosphere was replaced with nitrogen three times. The reaction was heated to 80°C under nitrogen protection for 12 hours. After the reaction was completed, the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography and recrystallized from toluene to obtain the final product R136 (yield 78%, HPLC>99%, mass spectrometry value 778.42).

[0149] Example 3: Preparation of the second host compound H28

[0150] N-([1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-3-amine (1 eq), 10-chloro-2-phenylphenanthro[3,4-d]oxazole (1 eq), and sodium tert-butoxide (2 eq) were weighed into a reaction flask, toluene was added, and catalysts Pd2(dba)3 (0.01 eq) and P(t-Bu)3 (0.02 eq) were added under nitrogen protection. The mixture was refluxed at 120°C for 24 hours under nitrogen protection, then cooled to 25°C, 200 mL of purified water was added, and the mixture was stirred for 30 minutes, allowed to stand, separated, and subjected to column chromatography to obtain product H28 (yield 77%, HPLC>99%, mass spectrometry value 614.86). The reaction scheme is shown below:

[0151]

[0152] It should be noted that other compounds of the present invention can be obtained by referring to the synthesis methods listed above, so they will not be described here in detail. Device Example:

[0153] An organic electroluminescent device was prepared using the compound R030 prepared in Example 1 and the compound H28 prepared in Example 3. Specifically, the preparation method of the organic electroluminescent device is as follows:

[0154] ITO anode: The coating thickness is The ITO (indium tin oxide) glass substrate was cleaned twice in distilled water and ultrasonically washed for 30 minutes, then repeatedly cleaned twice with 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.

[0155] HIL (hole injection layer): 4,4',4"-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA) was vacuum-deposited on the ITO anode in an evaporation machine. A hole injection layer is formed.

[0156] HTL (hole transport layer): vacuum evaporation of NPB (i.e. N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine) on the hole injection layer A hole transport layer is formed.

[0157] The light-emitting layer comprises a first host material, a second host material, and a guest dopant. After forming a hole injection layer and a hole transport layer, a light-emitting layer is formed on the hole transport layer. The first and second host compounds, acting as hosts, are introduced into two chambers of a vacuum vapor deposition apparatus, respectively, while compound Z1, acting as a dopant, is introduced into another chamber. The two host materials are evaporated at a 1:1 ratio, while the dopant material is simultaneously evaporated at a different rate, deposited at a doping level of 3 wt% based on the total amount of host and dopant, to form a 40 nm thick light-emitting layer on the second hole transport layer.

[0158] HBL (hole blocking layer): bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq) was vacuum-deposited on the light-emitting layer. A hole blocking layer is formed.

[0159] ETL (Electron Transport Layer): Vacuum evaporation of 8-hydroxyquinoline aluminum (Alq3) on the hole blocking layer An electron transport layer is formed.

[0160] EIL (Electron Injection Layer): Vacuum deposition on the electron transport layer An electron injection layer is formed.

[0161] Cathode: Evaporated on the electron injection layer Al is added to form a cathode to obtain an organic electroluminescent device.

[0162] Referring to the preparation method of the organic electroluminescent device provided in Device Example 1, another 43 organic electroluminescent compounds were selected to replace Example 1 and Example 3 for evaporation of the host material to prepare organic electroluminescent devices of the corresponding compounds.

[0163] Red light doping material (Z1)

[0164]

[0165] The device manufacturing processes of device examples 1-30, comparative examples 1-7 and parallel examples 1-6 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 materials are different. The specific parameters are shown in Table 1. The structure of the comparative example is as follows:

[0166]

[0167]

[0168] Performance testing: The driving voltage, luminous efficiency, and lifespan of the organic electroluminescent devices obtained in Comparative Examples 1-7, Parallel Examples 1-6, and Device Examples 1-30 were characterized at a brightness of 5000 (nits). The test results are shown in Table 1.

[0169] Table 1

[0170]

[0171]

[0172]

[0173] As can be seen from Table 1, by comparing device example 1-30 with parallel example 1-6, the efficiency of parallel example 1-6 is 34.7-37.8 cd / A, the driving voltage is 4.06-4.73 V, and the lifespan is 507-598 h, while the luminous efficiency of embodiment 1-30 of the present invention is 53.2-59.9 cd / A, which is significantly higher than parallel example 1-6; the driving voltage is 2.82-3.56 V, which is significantly lower than parallel example 1-6; and the lifespan is 712-854 h, which is much higher than parallel example 1-6.

[0174] It can be seen that the main material of the light-emitting layer adopts the first main compound of the specific structure of the present invention and the second main compound of the specific structure to greatly improve the luminous efficiency and service life. This is because the present invention not only provides a first main material with triazine as the skeleton, with a higher glass transition temperature and molecular thermal stability, suitable HOMO and LUMO energy levels, and a higher Eg, but also provides a second main body of a triarylamine structure for matching, which can enhance the hole transport ability and provide good electron transport ability. Therefore, when holes are injected into the p-type host and electrons are injected into the n-type host, the driving voltage will be reduced and the lifespan will be enhanced.

[0175] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organic electroluminescent material, characterized in that: The structure of the organic electroluminescent material is shown in Formula 1: in, X is selected from -N=, -O- or -S-; Y is selected from -N=, -O- or -S-; The hydrogen atoms in the group of formula 1 are independently substituted by deuterium or not; R0 is selected from hydrogen or deuterium, n0 is selected from 0, 1, 2, 3, 4 or 5; R1 and R2 are each independently selected from substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C6-C30 heteroaryl, wherein the heteroatom is selected from oxygen, nitrogen or sulfur; L1, L2, and L3 are each independently selected from a linking bond, a substituted or unsubstituted C6-C18 aryl group, or a substituted or unsubstituted C6-C18 heteroaryl group, wherein the heteroatom is selected from oxygen, nitrogen, or sulfur.

2. The organic electroluminescent material according to claim 1, characterized in that General formula 1 has structural formulas I-1 to I-9: When X is selected from -N=, Y is selected from -O- or -S-; When Y is selected from -N=, X is selected from -O- or -S-; R1 and R2 are each independently selected from the following structures and any combination thereof: L1, L2, and L3 are each independently selected from the subunits of the following compounds which are chemically bonded, substituted or unsubstituted: benzene, biphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, fluorene, pyridine, pyridazine, pyrimidine, pyrazine, quinoline, isoquinoline, quinazoline, quinoxaline, cinnoline, naphthyridine, triazine, pyridopyrazine, furan, benzofuran, dibenzofuran, aza-dibenzofuran, thiophene, benzothiophene, dibenzothiophene, aza-dibenzothiophene, spirofluorene, aromatic amine, and carbazole.

3. The organic electroluminescent material according to claim 1, characterized in that The organic electroluminescent material specifically has the following structure, but is not limited thereto:

4. An organic electroluminescent material containing a double host, characterized in that: The dual-host organic electroluminescent material comprises a first host material and a second host material, and the mass ratio of the first host material to the second host material is 1:99-99:1; the first host material is the organic electroluminescent material according to claim 1, having a structure shown in general formula 1, and the second host material has a structure shown in general 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, wherein the heteroatom is selected from oxygen, nitrogen, or sulfur; L4, L5, and L6 are each independently selected from a linking bond, a substituted or unsubstituted C6-C18 aryl group, or a substituted or unsubstituted C6-C18 heteroaryl group, wherein the heteroatom is selected from oxygen, nitrogen, or sulfur.

5. The organic electroluminescent material containing a double host according to claim 4, characterized in that: D1 and D2 are independently selected from substituted or unsubstituted C6-C18 aryl groups; D3 is selected from a substituted or unsubstituted C6-C36 aryl group, and a substituted or unsubstituted C3-C24 heteroaryl group.

6. The organic electroluminescent material containing a double host according to claim 5, characterized in that: D1 is selected from the following substituted or unsubstituted groups: phenyl, biphenyl, terphenyl; D2 is selected from the following substituted or unsubstituted groups: phenyl, naphthyl, biphenyl, terphenyl, triphenylene; D3 is selected from the following substituted or unsubstituted groups: benzene, biphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, fluorene, pyridine, pyridazine, pyrimidine, pyrazine, quinoline, isoquinoline, quinazoline, quinoxaline, cinnoline, naphthyridine, triazine, pyridopyrazine, furan, benzofuran, dibenzofuran, aza-dibenzofuran, thiophene, benzothiophene, dibenzothiophene, aza-dibenzothiophene, 9,9-dimethylfluorene, spirofluorene, arylamine, carbazole; L4, L5, and L6 are each independently selected from the subunits of the following compounds which are chemically bonded, substituted or unsubstituted: benzene, biphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, fluorene, pyridine, pyridazine, pyrimidine, pyrazine, quinoline, isoquinoline, quinazoline, quinoxaline, cinnoline, naphthyridine, triazine, pyridopyrazine, furan, benzofuran, dibenzofuran, aza-dibenzofuran, thiophene, benzothiophene, dibenzothiophene, aza-dibenzothiophene, aromatic amine, and carbazole.

7. The organic electroluminescent material according to claim 1 or 4, characterized in that the heteroaryl group Monocyclic aromatic groups and polycyclic aromatic ring systems comprising at least one heteroatom, including but not limited to O, S, and N; The substituted group in the "substituted or unsubstituted" is selected from hydrogen, deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, C3-C10 heterocycloalkyl, and the heteroatom thereof is selected from oxygen, nitrogen, and sulfur.

8. The organic electroluminescent material containing a double host according to claim 4, characterized in that: The second main material specifically has the following structure, but is not limited thereto:

9. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the organic electroluminescent material containing a double host as claimed in claim 4.

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