Organic electroluminescent material containing double hosts as well as preparation method and application of organic electroluminescent material

Abstract

The invention discloses a dual-host-containing organic electroluminescent material and a preparation method and application thereof.The dual-host-containing organic electroluminescent material comprises a first host material and a second host material, triplet-state excitons can be dispersed on the two hosts by using the dual-host material, and the dual-host-containing organic electroluminescent material has the advantages that the triplet-state excitons can be dispersed on the first host material and the second host material; according to the present invention, the organic light-emitting device main body material can reduce triplet-triplet annihilation (TTA), can effectively reduce the driving voltage when applied to the organic light-emitting device, can improve the light-emitting efficiency of the device, and can prolong the service life of the device, and the structure tends to be planar, such that the T1 energy level is low, and the mobility is slowed down; the prepared device is low in driving voltage, long in service life and high in luminous efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescent materials, and more particularly to an organic electroluminescent material containing two hosts, and a preparation method and application thereof. Background Art

[0002] Organic light-emitting diodes (OLEDs) can be used to manufacture new display products as well as new lighting products. The market application prospects are very broad. Currently, OLED display technology has been applied to smart phones, tablet computers and other fields. However, compared with the actual product application requirements, the performance of OLED, such as luminous efficiency and service life, needs to be further improved.

[0003] The OLED structure includes an electrode material film layer and an organic functional material sandwiched between different electrode film layers. As a current device, when a voltage is applied to the electrodes at both ends of the OLED, the positive and negative charges in the organic layer functional material film layer are separated by the electric field, and the positive and negative charges are further compounded in the light-emitting layer, that is, OLED electroluminescence is generated. Since the radiation transition of triplet excitons of most organic molecules is forbidden and contributes little to electroluminescence, the triplet excitons of organic molecules can be transferred to the triplet state of the metal complex by doping with organic metal complexes such as platinum, iridium, and osmium, thereby improving the efficiency of organic light-emitting devices. Therefore, the efficiency of OLEDs can be improved by doping with host and guest in the light-emitting layer. However, triplet excitons will produce triplet-triplet annihilation (TTA) during the transfer process, resulting in energy loss, causing the efficiency of organic light-emitting devices to roll off.

[0004] At present, the poor performance of organic electroluminescent devices is still a technical problem that needs to be urgently solved during their use. For example, there are problems such as excessively high driving voltage, low luminous efficiency or short life, which all affect the application areas of organic electroluminescent devices.

[0005] Therefore, how to provide an organic electroluminescent material containing a dual host with a long life and a low driving voltage and a preparation method thereof and an organic electroluminescent device is a technical problem that those skilled in the art need to solve urgently. Summary of the invention

[0006] In view of this, the present invention provides an organic electroluminescent material containing a double main body, and a preparation method and application thereof. Among them, indole carbazole is a larger conjugated plane, and still has a relatively flat configuration after being connected to the carbazole group. Adding benzene substitution at the carbazole position increases the stereoregularity of the structure, avoids the aggregation quenching effect caused by the plane stacking of the structure during the structure evaporation process, and improves the life; at the same time, the structure with stronger stereoregularity effectively reduces the evaporation temperature, ensures the thermal stability of the material during the evaporation process, and improves the service life of the material.

[0007] By using a dual host material to disperse triplet excitons on two hosts, triplet-triplet annihilation (TTA) is reduced, thereby reducing the driving voltage of the organic electroluminescent device while improving the luminous efficiency and service life of the device.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] An organic electroluminescent material containing two hosts, comprising: a first host material and a second host material, wherein the mass ratio of the first host material to the second host material is 1:1;

[0010] Wherein, the structure of the first main material is shown in Formula 1:

[0011]

[0012] In the above general formula 1, A is selected from hydrogen, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heteroaryl, and A is substituted or fused with an adjacent benzene ring;

[0013] R is selected from substituted or unsubstituted C6-C30 aryl, C3-C30 heteroaryl;

[0014] The structure of the second main material is shown in Formula 2:

[0015]

[0016] In the above general formula 2, D1, D2, and D3 are each independently selected from substituted or unsubstituted C6-C42 aryl groups, substituted or unsubstituted C3-C30 heteroaryl groups;

[0017] L1 and L2 are a connecting bond, a substituted or unsubstituted C6-C30 aryl group.

[0018] Preferably, A is selected from hydrogen, substituted or unsubstituted C6-C12 aryl;

[0019] The R is selected from substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C6-C18 heteroaryl, wherein the heteroatom is selected from O, N, S;

[0020] Wherein, the "substituted" group is selected from any one of hydrogen, deuterium, fluorine, cyano, C1-C10 alkyl, C1-C10 alkoxy, C3-C10 cycloalkyl, and C6-C12 aryl;

[0021] The D1 and D2 are 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;

[0022] The L1 and L2 are selected from a connecting bond, a substituted or unsubstituted C6-C18 aryl group.

[0023] Preferably, D1 is selected from substituted or unsubstituted phenyl, biphenyl, terphenyl;

[0024] The D2 is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl, terphenyl, triphenylene;

[0025] The D3 is selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl;

[0026] L1 is a connecting bond, L2 is a connecting bond or a phenyl group or a naphthyl group;

[0027] Heteroaryl includes monocyclic aromatic groups and polycyclic aromatic systems containing at least one heteroatom, including O, S, and N;

[0028] Preferably, in the second host material, the substituted or unsubstituted group is selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, three-membered to ten-membered heterocycloalkyl, and its heteroatom is selected from O, S, and N.

[0029] Preferably, the substituted or unsubstituted groups and their combinations are selected from the following structures:

[0030]

[0031] Preferably, the general formula 1 is selected from the general formula 1-1 and the general formula 1-2;

[0032]

[0033] The hydrogen in the radicals in Formula 1 and Formula 2 are independently substituted by deuterium or not substituted by deuterium.

[0034] It should be noted that the substituted or unsubstituted means that the group may not be substituted or may be substituted by one or more substituents, and the substitution 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.

[0035] Preferably, the first main material is selected from any one of the following structures:

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065] Preferably, the second main material is selected from any one of the following structures:

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079] The above are some specific structural forms of the second host material, but are not limited to the listed chemical structures. All compounds based on the general structural formula as shown in formula (2) and where the D1, D2, D3, L1 and L2 groups are simple changes of the groups within the previously defined range should be included.

[0080] Another object of the present invention is to provide a method for preparing the above-mentioned dual-host organic electroluminescent material, characterized in that:

[0081] The preparation method of the first host material of general formula 1-1 comprises:

[0082] 1. Synthesis of intermediate H1-A

[0083] Compound A (1 eq), chlorophenylboronic acid (1 eq), and K2CO3 (2 eq) were added to a reactor and replaced with nitrogen three times. Pd(Ph3)4 (0.01 eq) was added and replaced with nitrogen three times. A mixture of H2O and THF was added as a solvent and placed under nitrogen. The mixture was then heated under reflux 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 intermediate H1-a;

[0084] Intermediate H1-a (1 eq) was mixed with dichloromethane (CH2Cl2), FeCl3 (10 eq) was added to the mixture, and the mixture was stirred for 1 hour. After the reaction was completed, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate H1-A;

[0085] The synthetic route is as follows:

[0086]

[0087] The compound A includes compound A-1 to compound A-7; the H1-a includes H1-a-1 to H1-a-4; the H1-A includes H1-A-1 to H1-A-4;

[0088] 2. Synthesis of intermediate 1-c

[0089] 1-iodo-2-nitrobenzene (1 eq), bicyclo[2.2.1]hept-2-ene (0.5 eq), Pd(OAc)2 (0.01 eq) and K2CO3 (2 eq) were added to DMF, phenylboronic acid (0.6 eq) was added, degassed and heated at 105°C for 16 hours. After cooling to room temperature, the reaction mixture was diluted with water and ethyl acetate. The organic phase was separated, washed with brine, and dried over MgSO4. The solvent was evaporated, and the residue was purified by silica gel column chromatography with PE / DCM (4 / 1 to 3 / 2, v / v) as eluent and recrystallized from heptane to obtain intermediate 1-a;

[0090] 1-a (1 eq) and triphenylphosphine (4 eq) were dissolved in o-dichlorobenzene, degassed under nitrogen and refluxed for 24 hours. The solvent was evaporated, and the residue was purified by silica gel column chromatography using PE / DCM (4 / 1 to 2 / 3, v / v) as eluent. The crude product was recrystallized from heptane to obtain 1-b;

[0091] 1-b (1 eq), B (0.5 eq) and K3PO4 (5 eq) were added to o-xylene, degassed, and Cul (0.5 eq) and cyclohexane-1,2-diamine (0.5 eq) were added. The reaction mixture was refluxed under nitrogen for 3 hours. It was diluted with toluene, filtered through a short silica gel column, and the solvent was evaporated. The solid was triturated with boiling ethanol overnight to give 1-c;

[0092] The synthetic route is as follows:

[0093]

[0094] In the above formula, X is a halogen, specifically any one of fluorine, chlorine, bromine and iodine.

[0095] 3. Synthesis Formula 1-1

[0096] Weigh H1-A series (1 eq), 1-c (1-1.1 eq), sodium tert-butoxide (2-3 eq) and add them to the reaction bottle in sequence, replace the atmosphere with nitrogen three times, then add toluene as solvent, replace the atmosphere with nitrogen three times, then add Pd2(dba)3 (0.02-0.04 eq) and P(t-Bu)3 (0.02-0.04 eq), replace the atmosphere with nitrogen three times, and heat to reflux for 24 h under nitrogen protection, cool to 25 ° C, add purified water, stir for 30 min, let stand to separate, separate the liquids, and purify the crude product by column chromatography to obtain general formula 1-1;

[0097] The synthetic route is as follows:

[0098]

[0099] The preparation method of the first host material of general formula 1-2 comprises:

[0100] (1) Synthesis of intermediate H1-C

[0101] 2-Bromodibenzofuran (1 eq), chloroformylphenylboronic acid (1 eq), and K2CO3 (2 eq) were added to the reactor and replaced with nitrogen three times. Pd(Ph3)4 (0.02 eq) was added and replaced with nitrogen three times. A mixture of H2O and THF was added as solvent and placed under nitrogen, and then heated to reflux 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 intermediate H1-C-1;

[0102] Add intermediate H1-C-1 (1 eq), (methoxymethyl) triphenylphosphine chloride (1.3 eq) and THF to a reaction vessel and stir for 10 minutes, slowly add 120 mL of potassium tert-butoxide solution (potassium tert-butoxide is dissolved in THF to a concentration of 1 M / L) dropwise at 0°C. Then, slowly increase the temperature and stir at room temperature for 3 hours. Add distilled water, extract the organic layer with ethyl acetate, dry the organic phase with sodium sulfate, and remove the solvent with a rotary evaporator; then, purify it with column chromatography to obtain intermediate H1-C-2;

[0103] Add the compound intermediate H1-C-2, boron trifluoride etherate and dichloromethane to a reaction vessel and stir for 3 hours; after the reaction is completed, extract the organic layer with dichloromethane and water, then dry the extracted organic layer with sodium sulfate, and remove the solvent with a rotary evaporator. Thereafter, purify it with column chromatography to obtain the intermediate compound H1-C;

[0104] The synthetic route is as follows:

[0105]

[0106] H1-D and H1-E were synthesized by the method of synthesizing H1-C. The synthetic route is as follows:

[0107]

[0108] (2) Synthesis of intermediate H1-F

[0109] 4-Bromo-5-fluoro-2-iodobenzaldehyde (1 eq), 2-formylphenylboronic acid (1 eq), and K2CO3 (2 eq) were added to the reactor and replaced with nitrogen three times. Pd(Ph3)4 (0.02 eq) was added and replaced with nitrogen three times. A mixture of H2O and THF was added as a solvent and placed under nitrogen, and then heated to reflux 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 intermediate H1-f-1;

[0110] Under nitrogen conditions, the intermediate H1-f-1 (1 eq) was added to AcOH and stirred at 0°C, hydrazine hydrate (1 eq) was slowly injected, and then stirred and refluxed for 12 h, and 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 H1-f-2;

[0111] The intermediate H1-f-2 (1 eq) and NCS (1 eq) were added to a reactor and replaced with nitrogen three times. Chloroform was added as a solvent and replaced with nitrogen three times. The mixture was stirred at room temperature for 6 h. The organic layer was separated after washing with water twice. The solvent was then removed under reduced pressure and the crude product was purified by column chromatography to obtain the intermediate H1-f-3.

[0112] The intermediate H1-f-3 (1 eq), 2-hydroxyphenylboronic acid (1 eq), and K2CO3 (2 eq) were added to the reactor and replaced with nitrogen three times. Pd(Ph3)4 (0.02 eq) was added and replaced with nitrogen three times. A mixture of H2O and THF was added as a solvent and placed under nitrogen, and then heated to reflux 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 H1-f-4;

[0113] The intermediate H1-f-4 (1 eq) and K2CO3 (3 eq) were added to the reactor and replaced with nitrogen three times. DMAc was added as solvent, replaced with nitrogen three times, stirred and refluxed for 9 h, and 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 H1-F;

[0114] The synthetic route is as follows:

[0115]

[0116] (3) Synthesis of general formula 1-2

[0117] Under nitrogen atmosphere, weigh H1-C, D, E or F (1 eq), 1-C (1-1.1 eq), sodium tert-butoxide (2-3 eq) and add them to the reaction bottle in sequence, then add toluene, add tris(dibenzylideneacetone) palladium (0.02-0.04 eq) and tri-tert-butylphosphine (0.02-0.04 eq), reflux at 100-120°C for 24 h under nitrogen protection, cool to 25°C, add purified water, stir for 30 Lmin, let stand to separate, separate the liquids, use dichloromethane / petroleum ether as eluent, and perform column chromatography to obtain general formula 1-2;

[0118] The synthetic route is as follows:

[0119]

[0120] The preparation method of the second main material comprises:

[0121] S1 Under nitrogen atmosphere, weigh reactant 1 (1 eq), reactant 2 containing D1 substituent (1-1.2 eq), and potassium carbonate (3-4 eq) and add them to the reaction system in sequence, then add toluene, ethanol, water (2:1:1) and tetrakis(triphenylphosphine)palladium (0.05-0.08 eq), reflux at 90°C for 24 h under nitrogen protection, cool to 25°C, filter, and perform solid column chromatography to obtain compound H-1;

[0122] S2 Under nitrogen atmosphere, weigh H-1 (1 eq), reactant 2-1 containing D2 substituent (1-1.2 eq), and potassium carbonate (3-4 eq) and add them to the reaction system in sequence, add toluene, ethanol, water (2:1:1) and tetrakis(triphenylphosphine)palladium (0.05-0.08 eq), reflux at 90-100°C for 24 h under nitrogen protection, cool to 25°C, filter, and perform solid column chromatography to obtain compound H-2;

[0123] S3 Under nitrogen atmosphere, weigh H-2 (1 eq), reactant 2-2 containing D3 substituent (1-1.2 eq), potassium carbonate (3-4 eq) and add them to the reaction system in sequence, add toluene, ethanol, water (2:1:1) and tetrakis(triphenylphosphine)palladium (0.05-0.08 eq), reflux at 90-100°C for 24 h under nitrogen protection, cool to 25°C, filter, and perform solid column chromatography to obtain general formula 2;

[0124] The synthetic route is as follows:

[0125]

[0126] The structures of the substituents in the above synthesis route are consistent with the above-mentioned organic electroluminescent material containing two hosts.

[0127] Another object of the present invention is to provide the use of the above-mentioned dual-host organic electroluminescent material in the preparation of an organic electroluminescent device, wherein the organic electroluminescent device comprises a first electrode, an organic electroluminescent material layer, and a second electrode;

[0128] The organic electroluminescent material layer comprises a light-emitting layer, and the light-emitting layer comprises a doping material and the organic electroluminescent material containing a double host;

[0129] The mass ratio of the organic electroluminescent material containing the dual hosts to the doping material is (1-99):(99-1).

[0130] In the present invention, the organic electroluminescent device comprises an anode, a hole transport region, a light emitting layer, an electron transport region and a cathode.

[0131] Specifically,

[0132] The anode material preferably has a material with a large work function so that holes can be smoothly injected into the organic material layer. The anode material includes: metals: such as vanadium, chromium, copper, zinc and gold, or their alloys; 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.

[0133] 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.

[0134] 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.

[0135] Wherein, 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, organic materials based on arylamine, 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.

[0136] 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. The hole transport layer material includes an organic material based on arylamine, a conductive polymer, and a block copolymer having both a conjugated part and a non-conjugated part, but is not limited thereto.

[0137] 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.

[0138] 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.

[0139] The electron transport region includes an electron transport layer and an electron injection layer.

[0140] The electron transport layer has the function of promoting electron transport. The electron transport material is a material with high electron mobility that 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 free radical compound, and a hydroxyflavone-metal complex, but is not limited thereto. The thickness of the electron transport layer is 1 nm to 50 nm, which can prevent the electron transport characteristics from decreasing and prevent the driving voltage from increasing.

[0141] The electron injection layer has the function of promoting electron injection, and the electron injection material is a material that has the ability to transport electrons, has excellent electron injection effect on the light-emitting layer or the light-emitting material, prevents the excitons generated in the light-emitting layer from migrating to the hole injection layer, and has excellent thin film forming ability. The electron injection layer material includes fluorenone, anthraquinone dimethane, diphenoquinone, thiopyran dioxide, azole, diazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenyl methane, anthrone, etc. and their derivatives, metal complexes, nitrogen-containing five-membered ring derivatives, but is not limited thereto.

[0142] In the present invention, the organic electroluminescent device may be a top emission type, a bottom emission type or a double-side emission type.

[0143] The organic electroluminescent device can be used in organic solar cells, electronic paper, organic photoreceptors or organic thin film transistors.

[0144] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0145] In the main material disclosed in the present invention, the structure tends to be planar, resulting in low T1 energy and slow mobility; so that the prepared device has low driving voltage, long life and high luminous efficiency.

[0146] The invention discloses an organic electroluminescent material containing a double host, comprising a host material (a first host material) and a second host material. By using the double host material, triplet excitons can be dispersed on two hosts, thereby reducing triplet-triplet annihilation (TTA). The application of the double host material in an organic electroluminescent device can effectively reduce the driving voltage and improve the luminous efficiency and service life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0147] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0148] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of Example 2 of the present invention. DETAILED DESCRIPTION

[0149] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0150] Example 1: Preparation of intermediate products

[0151] (1) 3-bromodibenzofuran (156 mmol), (3-chloro-[1,1-biphenyl]-2-yl)boric acid (156 mmol), potassium carbonate (312 mmol) were introduced into a reactor and replaced with nitrogen three times, THF and water were added, and Pd(Ph3)4 (1.56 mmol) was added under nitrogen protection, and refluxed 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 intermediate H1-a-1. (38.96 g, yield 70%, HPLC>99%, mass spectrometry test: theoretical value 356.85, test value 356.79).

[0152] Intermediate H1-a-1 (109 mmol) was mixed with dichloromethane (CH2Cl2), FeCl3 (1.09 mol) was added to the mixture, and the mixture was stirred for 1 hour. After the reaction was completed, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate H1-A-1 (24.22 g, yield 63%, HPLC>99%, mass spectrometry test: theoretical value 352.82, test value 352.76).

[0153]

[0154] Referring to the above method, another intermediate H1-A-1 (23 g, yield 59.8%, HPLC>99%, mass spectrometry test: theoretical value 352.82, test value 352.97) can be obtained.

[0155]

[0156] 2-bromodibenzofuran (156mmol), 4-chloro-2-formylphenylboronic acid (156mmol), K2CO3 (312mmol) were added to the reactor and nitrogen was replaced three times, H2O and THF mixture was added as solvent and nitrogen was replaced three times, Pd(Ph3)4 (1.56mmol) was added and nitrogen was replaced three times, and heated to reflux for 12 hours under nitrogen protection. 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 intermediate H1-C-1 (34.93g, productive rate was 73%, HPLC>99%, mass spectrum test: theoretical value was 306.75, and test value was 306.69).

[0157] The intermediate H1-C-1 (113.87 mmol), (methoxymethyl) triphenylphosphine chloride (148.03 mmol) and THF were added to a reaction vessel and stirred for 10 minutes. A potassium tert-butoxide solution (13.47 g potassium tert-butoxide dissolved in 120 ml THF) was slowly added dropwise at 0°C. Then, the temperature was slowly raised and stirred at room temperature for 3 hours. Distilled water was added thereto. After the reaction was completed, the organic layer was extracted with ethyl acetate in sequence, the organic phase was dried with sodium sulfate, the solvent was removed by a rotary evaporator, and then purified by column chromatography to obtain the intermediate H1-C-2 (26.30 g, yield 69%, HPLC>99%, mass spectrometry test: theoretical value 334.80, test value 334.76).

[0158] Intermediate H1-C-2 (78.55 mmol), boron trifluoride etherate (20 mL) and dichloromethane (800 mL) were added to a reaction vessel and stirred for 3 hours; after the reaction was completed, the organic layer was extracted with dichloromethane and water, and then the extracted organic layer was dried with sodium sulfate, and the solvent was removed by a rotary evaporator. Thereafter, it was purified by column chromatography to obtain intermediate compound H1-C (14.98 g, yield 63%, HPLC>99%, mass spectrometry test: theoretical value 302.76, test value 302.68).

[0159]

[0160] Example 2: Preparation of Compound G001

[0161] Under nitrogen atmosphere, weigh 28.34mmol of H1-A-1, 28.34mmol of 1-c (cas: 1637752-63-6), 56.69mmol of sodium tert-butoxide and put them into the reaction system, add 300ml of toluene, 0.519mmol of catalyst tris(dibenzylideneacetone)palladium and 1.13mmol of tri-tert-butylphosphine, reflux at 120℃ for 24h under nitrogen protection, then cool to 25℃, add mL of purified water, stir for 30min, stand for stratification, separate, column chromatography, and obtain the compound G001 shown (test value: 648.93, 15g, yield 81.75%). Its HPLC purity is greater than 99%, and the synthetic route is as follows:

[0162]

[0163] Example 3: Preparation of Compound H001

[0164] Under nitrogen atmosphere, weigh 271.14mmol of reactant 1 (cas: 108-77-0), 813.43mmol of reactant 2 (cas: 98-80-6), 813.43mol of potassium carbonate into the reaction system, add 500ml of toluene, 250ml of ethanol, 250ml of water, 13.56mmol of catalyst tetrakis(triphenylphosphine)palladium, reflux at 90°C for 24h under nitrogen protection, then cool to 25°C, filter, solid column chromatography, and obtain the compound H001 shown (test value: 309.37, 83.9g, yield 62.2%). Its HPLC purity is greater than 99%, and the synthetic route is as follows:

[0165]

[0166] The following compounds G and H were synthesized by referring to the synthesis method in the embodiment of the present invention, and their molecular formulas and mass spectra are shown in Table 1. The mass spectrometer model used for mass spectrometry testing in this application is Waters XEVO TQD, low precision, ESI source testing.

[0167] Table 1

[0168] Example Compound Mass spectrometry Example Compound Mass spectrometry Example 4 Compound G007 725.01 Example 7 Compound H002 385.47 Example 5 Compound G052 725.03 Example 8 Compound H003 359.43 Example 6 Compound G196 674.95 Example 9 Compound H004 391.52 Example 10 Compound G002 698.98 Embodiment 26 Compound H012 324.52 Embodiment 11 Compound G008 725.01 Embodiment 27 Compound H039 399.32 Example 12 Compound G009 725.03 Embodiment 28 Compound H041 445.37 Example 13 Compound G029 653.95 Embodiment 29 Compound H050 575.67 Embodiment 14 Compound G052 725.01 Embodiment 30 Compound H054 526.60 Embodiment 15 Compound G074 653.96 Embodiment 31 Compound H069 542.66 Example 16 Compound G078 734.07 Embodiment 32 Compound H075 499.57 Embodiment 17 Compound G102 801.11 Embodiment 33 Compound H078 523.60 Embodiment 18 Compound G142 725.01 Embodiment 34 Compound H093 598.71 Embodiment 19 Compound G144 725.01 Embodiment 35 Compound H095 598.74 Embodiment 20 Compound G203 603.91 Embodiment 36 Compound H140 497.69 Embodiment 21 Compound G204 684.01 Embodiment 37 Compound H141 521.47 Embodiment 22 Compound G205 598.86 Embodiment 38 Compound H146 601.71 Embodiment 23 Compound G214 648.92 Embodiment 39 Compound H221 631.83 Embodiment 24 Compound G220 648.92 Embodiment 40 Compound H237 611.8 Embodiment 25 Compound G222 653.95 Embodiment 41 Compound H245 590.77

[0169] Application example: Preparation of organic electroluminescent devices

[0170] Device Example 1:

[0171] ITO anode: The coating thickness is The ITO (indium tin oxide) glass substrate was cleaned twice in distilled water, ultrasonically cleaned for 30 minutes, and then repeatedly cleaned twice with distilled water and ultrasonically cleaned for 10 minutes. After washing, it was ultrasonically cleaned with methanol, acetone, and isopropanol for 5 minutes in sequence, dried, and then transferred to a plasma cleaning machine for washing for 5 minutes to obtain an ITO anode.

[0172] HIL (hole injection layer): 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA) was vacuum-deposited on the ITO anode in a vapor deposition machine. A hole injection layer is formed.

[0173] 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.

[0174] Light-emitting layer: The light-emitting layer includes a first host material G001, a second host material H001 and a guest dopant. After the hole injection layer and the hole transport layer are formed, the light-emitting layer is formed on the hole transport layer.

[0175] The first host compound organic electroluminescent device and the second host compound organic electroluminescent device were introduced as hosts into two small chambers of a vacuum vapor deposition device respectively, and compound Z1 was introduced as a dopant into another small chamber; the two host materials were evaporated at a rate of 1:1, and the dopant materials were evaporated simultaneously at different rates, and a doping amount of 3wt% based on the total amount of the host and the dopant was deposited to form a light-emitting layer with a thickness of 40nm on the hole transport layer.

[0176] HBL (hole blocking layer): Vacuum evaporation of bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq) on the light-emitting layer A hole blocking layer is formed.

[0177] ETL (Electron Transport Layer): Vacuum evaporation of 8-hydroxyquinoline aluminum (Alq3) on the hole blocking layer An electron transport layer is formed.

[0178] EIL (Electron Injection Layer): Vacuum evaporation of LiF on the electron transport layer An electron injection layer is formed.

[0179] Cathode: Evaporation on the electron injection layer Al is added to form a cathode to obtain an organic electroluminescent device.

[0180] Referring to the organic electroluminescent device and its preparation method provided in Device Application Example 1, the compounds of the present invention are selected to replace the first host compound organic electroluminescent device and the second host compound organic electroluminescent device for evaporation of the host material to prepare organic electroluminescent devices of the corresponding compounds.

[0181] Green light doping material (Z1)

[0182]

[0183] Device Examples 2-20, Comparative Examples 1-9 and Parallel Examples 1-8:

[0184] The device manufacturing processes of device examples 2-20, 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 materials are different, and the corresponding first main compound and second main compound in Table 1 are selected respectively. The specific parameters are shown in Table 2.

[0185] Table 2

[0186]

[0187]

[0188] The comparative example structure is as follows:

[0189]

[0190]

[0191]

[0192] Performance testing: The driving voltage, luminous efficiency and life of the organic electroluminescent devices obtained in the above-mentioned comparative examples 1-9, parallel examples 1-8 and device examples 1-20 were characterized at a brightness of 15000 (nits). The test results are shown in Table 3 below.

[0193] Table 3

[0194]

[0195]

[0196] It can be seen from Table 3 that the driving voltage of the organic electroluminescent devices provided by device examples 1-20 of the present invention and parallel examples 1-8 is significantly lower than the driving voltage of comparative examples 1-9, and the luminous efficiency and life are significantly improved compared with comparative examples 1-9.

[0197] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be 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 will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organic electroluminescent material containing a double host, characterized in that: include: A first host material and a second host material, wherein the mass ratio of the first host material to the second host material is 1:1; Wherein, the structure of the first main material is shown in Formula 1: In the above general formula 1, A is selected from hydrogen, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heteroaryl, and A is substituted or fused with an adjacent benzene ring; R is selected from substituted or unsubstituted C6-C30 aryl, C3-C30 heteroaryl; The structure of the second main material is shown in Formula 2: In the above general formula 2, D1, D2, and D3 are each independently selected from substituted or unsubstituted C6-C42 aryl groups, substituted or unsubstituted C3-C30 heteroaryl groups; L1 and L2 are a connecting bond, a substituted or unsubstituted C6-C30 aryl group.

2. The dual-host organic electroluminescent material according to claim 1, characterized in that: A is selected from hydrogen, substituted or unsubstituted C6-C12 aryl; The R is selected from substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C6-C18 heteroaryl, wherein the heteroatom is selected from O, N, S; Wherein, the "substituted" group is selected from any one of hydrogen, deuterium, fluorine, cyano, C1-C10 alkyl, C1-C10 alkoxy, C3-C10 cycloalkyl, and C6-C12 aryl; The D1 and D2 are 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; The L1 and L2 are selected from a connecting bond, a substituted or unsubstituted C6-C18 aryl group.

3. The dual-host organic electroluminescent material according to claim 2, characterized in that: The D1 is selected from substituted or unsubstituted phenyl, biphenyl, terphenyl; The D2 is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl, terphenyl, triphenylene; The D3 is selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; L1 is a connecting bond, L2 is a connecting bond or a phenyl group or a naphthyl group; Heteroaryl includes monocyclic aromatic groups and polycyclic aromatic systems having at least one heteroatom, including O, S, and N.

4. The dual-host organic electroluminescent material according to claim 3, characterized in that: In the second host material, the substituted or unsubstituted group is selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, three-membered to ten-membered heterocycloalkyl, and its heteroatom is selected from O, S, and N.

5. The dual-host organic electroluminescent material according to claim 1, characterized in that: The substituted or unsubstituted groups and their combinations are selected from the following structures:

6. The dual-host organic electroluminescent material according to claim 1, characterized in that: The general formula 1 is selected from the general formula 1-1 and the general formula 1-2; The hydrogen in the radicals in Formula 1 and Formula 2 are independently substituted by deuterium or not substituted by deuterium.

7. The dual-host organic electroluminescent material according to claim 6, characterized in that: The first host material is selected from any one of the following structures:

8. The dual-host organic electroluminescent material according to claim 1, characterized in that: The second main material is selected from any one of the following structures:

9. A method for preparing a dual-host organic electroluminescent material as claimed in claim 7 or 8, characterized in that: The preparation method of the first host material of general formula 1-1 comprises:

1. Synthesis of intermediate H1-A Compound A and K2CO3 were added to the reactor and replaced with nitrogen three times, Pd(Ph3)4 was added and replaced with nitrogen three times, and then a mixture of H2O and THF was added as a solvent and placed under nitrogen, and then heated to reflux. After the reaction was completed, intermediate H1-a was obtained; The intermediate H1-a is mixed with dichloromethane, FeCl3 is added to the mixture, and the mixture is stirred. After the reaction is completed, the intermediate H1-A is obtained; The synthetic route is as follows: The compound A includes compound A-1 to compound A-7; the H1-a includes H1-a-1 to H1-a-4; the H1-A includes H1-A-1 to H1-A-4; 2. Synthesis of intermediate 1-c 1-iodo-2-nitrobenzene, bicyclo[2.2.1]hept-2-ene, Pd(OAc)2 and K2CO3 were added to DMF, phenylboronic acid was added, the mixture was degassed and heated to react for a period of time to obtain intermediate 1-a; 1-a and triphenylphosphine were dissolved in o-dichlorobenzene, degassed under nitrogen and refluxed to obtain intermediate 1-b; 1-b, B and K3PO4 were added to o-xylene, degassed, Cul and cyclohexane-1,2-diamine were added, and the reaction mixture was refluxed under nitrogen to obtain 1-c; The synthetic route is as follows: In the above formula, X is a halogen; 3. Synthesis Formula 1-1 Weigh H1-A, 1-c, and sodium tert-butoxide and add them to the reaction bottle in sequence, replace the atmosphere with nitrogen three times, then add toluene as solvent, replace the atmosphere with nitrogen three times, then add Pd2(dba)3 and P(t-Bu)3, replace the atmosphere with nitrogen three times, and heat to reflux for a period of time under nitrogen protection to obtain general formula 1-1; The synthetic route is as follows: The preparation method of the first host material of general formula 1-2 comprises: (1) Synthesis of intermediate H1-C 2-Bromodibenzofuran, chloroformylphenylboronic acid, and K2CO3 were added to a reactor and replaced with nitrogen three times, Pd(Ph3)4 was added and replaced with nitrogen three times, and then a mixture of H2O and THF was added as a solvent and placed under nitrogen, and then heated under reflux for a period of time to obtain the intermediate H1-C-1; The intermediate H1-C-1, (methoxymethyl) triphenylphosphine chloride and THF were added to a reaction vessel and stirred for 10 minutes, and the potassium tert-butoxide solution was slowly added dropwise at 0°C, and then the temperature was slowly increased. After stirring at room temperature for 3 hours, distilled water was added thereto, and the mixture was reacted for a period of time to obtain the intermediate H1-C-2; Add the intermediate H1-C-2, boron trifluoride etherate and dichloromethane into a reaction vessel and stir; after the reaction is completed, H1-C is obtained; The synthetic route is as follows: H1-D and H1-E were synthesized by the method of synthesizing H1-C. The synthetic route is as follows: (2) Synthesis of intermediate H1-F 4-bromo-5-fluoro-2-iodobenzaldehyde, 2-formylphenylboronic acid, and K2CO3 were added to the reactor and replaced with nitrogen three times, Pd(Ph3)4 was added and replaced with nitrogen three times, and then a mixture of H2O and THF was added as a solvent and placed under nitrogen, and then heated under reflux for a period of time to obtain intermediate H1-f-1; Under nitrogen conditions, the intermediate H1-f-1 was added to AcOH, stirred and the temperature was controlled at 0°C, hydrazine hydrate was slowly injected, and then stirred and refluxed for a period of time to obtain the intermediate H1-f-2; Add intermediate H1-f-2 and NCS into the reactor and replace with nitrogen three times. Add chloroform as solvent and replace with nitrogen three times. Stir and react at room temperature for a period of time to obtain intermediate H1-f-3. The intermediate H1-f-3, 2-hydroxyphenylboronic acid, and K2CO3 were added to the reactor and replaced with nitrogen three times, Pd(Ph3)4 was added and replaced with nitrogen three times, and then a mixture of H2O and THF was added as a solvent and placed under nitrogen, and then heated under reflux for a period of time to obtain the intermediate H1-f-4; The intermediate H1-f-4 and K2CO3 were added to the reactor and replaced with nitrogen three times, DMAc was added as solvent, and the nitrogen was replaced three times, and the mixture was stirred and refluxed for a period of time to obtain the intermediate H1-F; The synthetic route is as follows: (3) Synthesis of general formula 1-2 Under nitrogen atmosphere, intermediate H1-C, H1-D, H1-E or H1-F, intermediate 1-c, sodium tert-butoxide are sequentially added to a reaction flask, and then toluene, tris(dibenzylideneacetone)bispalladium and tri-tert-butylphosphine are added, and under nitrogen protection, reflux at a certain temperature for a period of time to obtain general formula 1-2; The synthetic route is as follows: The preparation method of the second main material comprises: S1: Under a nitrogen atmosphere, reactant 1, reactant 2 containing a D1 substituent, and potassium carbonate are added to the reaction system in sequence, and then toluene, ethanol, water, and tetrakis(triphenylphosphine)palladium are added, and reflux reaction is carried out at a certain temperature for a period of time to obtain compound H-1; S2 Under a nitrogen atmosphere, H-1, reactant 2-1 containing a D2 substituent, and potassium carbonate are sequentially added to the reaction system, and toluene, ethanol, water, and tetrakis(triphenylphosphine)palladium are added, and refluxed at a certain temperature for a period of time to obtain compound H-2; S3 Under a nitrogen atmosphere, H-2, reactant 2-2 containing a D3 substituent, and potassium carbonate are sequentially added to the reaction system, and toluene, ethanol, water, and tetrakis(triphenylphosphine)palladium are added, and refluxed at a certain temperature for a period of time to obtain general formula 2; The synthetic route is as follows: The structure of each substituent in the above synthesis route is consistent with the dual-host organic electroluminescent material described in claim 7 or 8.

10. Use of the dual-host organic electroluminescent material according to claim 7 or 8 in preparing an organic electroluminescent device, characterized in that: The organic electroluminescent device comprises a first electrode, an organic electroluminescent material layer, and a second electrode; The organic electroluminescent material layer comprises a light-emitting layer, and the light-emitting layer comprises a doping material and the organic electroluminescent material containing a double host; The mass ratio of the organic electroluminescent material containing the dual hosts to the doping material is (1-99):(99-1).

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