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

Abstract

The invention belongs to the technical field of organic electroluminescent materials, and provides a dual-host-containing organic electroluminescent material and a preparation method thereof, and the structural general formula of the host material is shown in the specification. According to the invention, triplet excitons can be dispersed on two main bodies by using a double-main-body material, triplet-triplet annihilation (TTA) can be reduced, the driving voltage of the organic electroluminescent device is reduced, the 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 particularly relates to a dual-host organic electroluminescent material, a preparation method thereof, and an organic electroluminescent device. Background Art

[0002] Organic Light Emission Devices (OLEDs) can be used to manufacture new display products or new lighting products, and are gradually replacing existing liquid crystal displays and fluorescent lamp lighting, with a very broad market application prospect. The structure of an OLED is like a sandwich, including electrode material layers and organic functional materials sandwiched between different electrode layers. These functional materials are stacked together according to different uses to form an OLED. As a current device, when a voltage is applied to the two electrodes of the OLED, positive and negative charges in the organic layer functional material layer are affected by the electric field, and the positive and negative charges further recombine in the light-emitting layer, resulting in the electroluminescence of the OLED.

[0003] Currently, OLED display technology has been applied in fields such as smartphones and tablets, and the next goal is to continue to expand into large-size application fields such as televisions. However, compared with the actual product application requirements, the performance of OLEDs such as luminous efficiency and service life still needs to be further improved.

[0004] The efficiency of OLEDs is improved through host-guest doping in the light-emitting layer. Since the radiative transition of triplet excitons of most organic molecules is forbidden and contributes little to electroluminescence, doping with organometallic complexes such as platinum, iridium, and osmium can transfer the triplet excitons of organic molecules to the triplet state of the metal complex, thereby greatly improving the efficiency of organic light-emitting devices. However, triplet-triplet annihilation (TTA) occurs during the transfer process of triplet excitons, resulting in energy loss and causing efficiency roll-off in organic light-emitting devices.

[0005] Currently, 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 too high driving voltage, too low luminous efficiency, or short lifespan, which all affect the application fields of organic electroluminescent devices.

[0006] Therefore, how to develop a dual-host organic electroluminescent material with a long lifespan and low driving voltage, a preparation method thereof, and an organic electroluminescent device is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the present invention provides a dual-host organic electroluminescent material and a preparation method thereof. When the dual-host organic electroluminescent material of the present invention is applied to a specific light-emitting device, it has a low driving voltage, high luminous efficiency, and long service life.

[0008] It should be noted that the present invention provides an organic electroluminescent device with a dual-host structure. By using this dual-host material, triplet excitons can be dispersed on two hosts, which can reduce triplet-triplet annihilation (TTA). While reducing the driving voltage of the organic electroluminescent device, it can also improve the efficiency and life of the device.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] The first technical object of the present invention is to provide a dual-host organic electroluminescent material. The dual-host organic electroluminescent material includes 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 has a structure shown in General Formula 1, and the second host material has a structure shown in General Formula 2:

[0011]

[0012] Wherein:

[0013] A1, B1, C1, D1, D2, D3 are each independently selected from substituted or unsubstituted (C6 - C42) aryl, substituted or unsubstituted (C3 - C30) heteroaryl;

[0014] L 1 、L 2 are a linking bond, substituted or unsubstituted (C6 - C30) aryl.

[0015] Further, the structure of General Formula 1 is as follows:

[0016]

[0017] In the formula, A1, B1-1, B1-2, C1-1, C1-2 are selected from (C6 - C18) substituted or unsubstituted aryl;

[0018] X is N, O, S;

[0019] Ar 1 is selected from hydrogen, substituted or unsubstituted (C6 - C36) aryl, substituted or unsubstituted (C3 - C30) heteroaryl. Further, D1, D2 are selected from (C6 - C18) substituted or unsubstituted aryl;

[0020] D3 is selected from substituted or unsubstituted (C6-C36) aryl, substituted or unsubstituted (C3-C30) heteroaryl;

[0021] L 1 and L 2 is selected from a linking bond, (C6-C18) substituted or unsubstituted aryl.

[0022] Furthermore, the structure of General Formula 1 is as follows:

[0023]

[0024] In the formula, A1 is selected from phenyl, naphthyl, biphenyl, deuterated phenyl, deuterated naphthyl, deuterated biphenyl;

[0025] C1-1 is selected from deuterated or non-deuterated phenanthryl;

[0026] Both B1-1 and B1-2 are selected from phenyl, deuterated phenyl;

[0027] C1-2 is selected from phenyl, deuterated phenyl, deuterated naphthyl;

[0028] Ar 1 is selected from hydrogen or the following groups:

[0029]

[0030] Furthermore, D1 is selected from substituted or unsubstituted phenyl, biphenyl, terphenyl;

[0031] D2 is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl, terphenyl, benzophenanthryl;

[0032] D3 is selected from substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (C3-C30) heteroaryl;

[0033] L 1 is a linking bond, and L 2 is a linking bond or phenyl, naphthyl.

[0034] In the above technical solution,

[0035] The "substituted or unsubstituted" means that the group may not be substituted or may be substituted by one or more substituents. The "substitution" means that a hydrogen atom bonded to a carbon atom of the compound becomes another substituent, and the substitution position 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. When two or more substituents are substituted, the two or more substituents may be the same or different from each other.

[0036] Heteroaryl includes monocyclic aromatic groups and polycyclic aromatic ring systems having at least one heteroatom, and the heteroatoms include, but are not limited to, O, S, and N.

[0037] The substituted groups in the "substituted or unsubstituted" are selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, 3- to 10-membered heterocycloalkyl, and the heteroatoms thereof are selected from oxygen, nitrogen, and sulfur; and the substituted groups in the "substituted or unsubstituted" may also be selected from the following structures:

[0038]

[0039] The general formula 1 specifically has the following structures, but is not limited thereto:

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058] General formula 2 is selected from any one of the following compounds:

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079] The second technical object of the present invention is to provide a preparation method of the above-mentioned dual-host organic electroluminescent material.

[0080] Among them, the preparation method of the general formula 1-1-1 specifically includes the following steps:

[0081] (1) Under nitrogen protection, reactant 1 (1 eq), reactant 2 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and placed in a reaction system, toluene, catalyst tris(dibenzylideneacetone) palladium (0.02-0.03 eq) and tri-tert-butylphosphine (0.04-0.06 eq) were added, refluxed at 90-100° C. for 24 h under nitrogen protection, then cooled to 25° C., purified water was added, stirred for 30 min, and then allowed to stand for stratification, separated, and subjected to column chromatography to obtain the compound R-1 shown;

[0082] (2) Under nitrogen protection, compound R-1 (1 eq), reactant 3 or reactant 4 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and placed in a reaction system, toluene, catalyst tris(dibenzylideneacetone) palladium (0.02-0.03 eq) and tri-tert-butylphosphine (0.04-0.06 eq) were added, refluxed at 90-100° C. for 24 h under nitrogen protection, then cooled to 25° C., purified water was added, stirred for 30 min, and then allowed to stand for stratification, separated, and subjected to column chromatography to obtain a compound represented by the general formula 1-1-1;

[0083] The specific synthetic route is as follows:

[0084]

[0085] The synthesis method of some reactants 3 and 4 in the general formula 1-1-1 specifically comprises the following steps:

[0086] Under nitrogen protection, reactant 3a (1 eq), 2-bromo-4-chlorobenzaldehyde (1 eq), potassium carbonate (3 eq), tetrakistriphenylphosphine palladium (0.05 eq), THF and H 2 O, reflux for 12 hours, separate the liquids after the reaction is completed, concentrate the organic layer, and separate by column chromatography to obtain intermediate 3b-2;

[0087] Add intermediate 3b-2 (1 eq), (methoxymethyl)triphenylphosphine chloride (1.3 eq) and THF to a reaction vessel and stir for 10 minutes, then slowly add potassium tert-butoxide dropwise at 0°C; slowly increase the temperature, and stir the reaction mixture at room temperature for 3 hours; after distilled water is added to the reaction solution to complete the reaction, extract the organic layer with ethyl acetate, dry the organic phase with sodium sulfate, remove the solvent with a rotary evaporator, and purify with column chromatography to obtain compound intermediate 3b-3;

[0088] Add compound intermediate 3b-3 (1 eq), boron trifluoride etherate (0.25 eq) and dichloromethane to a reaction vessel and stir for 3 hours; after the reaction is completed, extract the organic layer with dichloromethane and water, dry the extracted organic layer with sodium sulfate, remove the solvent using a rotary evaporator, and purify by column chromatography to obtain reactant 3;

[0089] Put reactant 3 (1 eq) into deuterated ethanol reagent, add sodium tert-butoxide (2 eq), reflux for 24 h, extract the organic layer with dichloromethane and water, dry the extracted organic layer with sodium sulfate, remove the solvent using a rotary evaporator, and purify by column chromatography to obtain reactant 4;

[0090] The specific synthesis route is as follows:

[0091]

[0092] Or,

[0093] Under a nitrogen protection system, add reactant 3a (1 eq), 2-bromo-4-chlorobenzaldehyde (1 eq), potassium carbonate (3 eq), tetrakis(triphenylphosphine)palladium (0.05 eq), THF and H 2 O to a round-bottom flask, reflux for 12 hours, separate the layers after the reaction ends, concentrate the organic layer, and separate by column chromatography to obtain intermediate 3c-2;

[0094] Add intermediate 3c-2 (1 eq), (methoxymethyl)triphenylphosphonium chloride (1.3 eq) and THF to a reaction vessel and stir for 10 minutes, then slowly add potassium tert-butoxide dropwise at 0 °C; slowly raise the temperature, stir the reaction mixture at room temperature for 3 hours; add distilled water to the reaction solution to complete the reaction, extract the organic layer with ethyl acetate, dry the organic phase with sodium sulfate, remove the solvent using a rotary evaporator, and purify by column chromatography to obtain compound intermediate 3c-3;

[0095] Add compound intermediate 3c-3 (1 eq), boron trifluoride etherate (0.25 eq) and dichloromethane to a reaction vessel and stir for 3 hours; after the reaction is completed, extract the organic layer with dichloromethane and water, dry the extracted organic layer with sodium sulfate, remove the solvent using a rotary evaporator, and purify by column chromatography to obtain reactant 3;

[0096] Put reactant 3 (1 eq) into deuterated ethanol reagent, add sodium tert-butoxide (2 eq), reflux for 24 h, extract the organic layer with dichloromethane and water, dry the extracted organic layer with sodium sulfate, remove the solvent using a rotary evaporator, and purify by column chromatography to obtain reactant 4;

[0097] The specific synthesis route is as follows:

[0098]

[0099] Furthermore, the preparation method of the general formula 2 specifically includes the following steps:

[0100] (1) Under a nitrogen protection system, weigh reactant 1 (1 eq), reactant 2 (1 - 1.2 eq), and potassium carbonate (3 - 4 eq) and put them into the reaction system. Add toluene, ethanol, water, and the catalyst tetrakis(triphenylphosphine)palladium (0.05 - 0.08 eq). Reflux at 90 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H-1;

[0101] (2) Under a nitrogen protection system, weigh H-1 (1 eq), reactant 2-1 (1 - 1.2 eq), and potassium carbonate (3 - 4 eq) and put them into the reaction system. Add toluene, ethanol, water, and the catalyst tetrakis(triphenylphosphine)palladium (0.05 - 0.08 eq). Reflux at 90 - 100 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H-2;

[0102] (3) Under a nitrogen protection system, weigh H-2 (1 eq), reactant 2-2 (1 - 1.2 eq), and potassium carbonate (3 - 4 eq) and put them into the reaction system. Add toluene, ethanol, water, and the catalyst tetrakis(triphenylphosphine)palladium (0.05 - 0.08 eq). Reflux at 90 - 100 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H (general formula 2);

[0103] The specific synthesis route is as follows:

[0104]

[0105] Moreover, the present invention also claims the application of the above-mentioned dual-host organic electroluminescent material in the preparation of organic electroluminescent devices.

[0106] 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; moreover, the organic electroluminescent material layer includes a light-emitting layer; the light-emitting layer includes a doping material and the dual-host organic electroluminescent material as claimed in claim 1;

[0107] Wherein, the mass ratio of the dual-host organic electroluminescent material to the doping material is (1 - 99):(99 - 1).

[0108] 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 shown in general formula 1 and a second host material shown in general formula 2.

[0109] As an anode material, a material having a large work function is generally preferred so that holes can be smoothly injected into the organic material layer. The 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 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 SnO 2 :Sb; conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrrole, and polyaniline, but not limited thereto.

[0110] As a cathode material, a material having a small work function is generally preferred so that electrons can be smoothly injected into the organic material layer. The cathode materials that can be used for the second electrode of the organic electroluminescent device of the present invention include: metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or their alloys; multi-layer structure materials such as LiF / Al or LiO 2 / Al; and so on, but not limited thereto.

[0111] 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 materials include metal porphyrins, oligothiophenes, arylamine-based organic materials, hexanitrile hexaazatriphenylene-based organic materials, quinacridone-based organic materials, perylene-based organic materials, anthraquinone, and conductive polymers based on polyaniline and polythiophene, etc.

[0112] 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 a high hole mobility; and the hole transport layer materials include arylamine-based organic materials, conductive polymers, block copolymers having both a conjugated part and a non-conjugated part, etc., but not limited thereto.

[0113] An electron blocking layer can be provided between the hole transport layer and the light-emitting layer. As the electron blocking layer, materials known in the art can be used, such as arylamine-based organic materials.

[0114] The host material of the light-emitting layer is selected from the structure of the present invention.

[0115] A hole blocking layer can be provided between the electron transport layer and the light-emitting layer, and materials known in the art can be used, such as triazine-based compounds.

[0116] The electron transport layer can play a role in promoting electron transport. The electron transport material is a material that favorably receives electrons from the cathode and transports the electrons to the light-emitting layer, and has a high electron mobility. It includes: Al complex of 8-hydroxyquinoline; complex containing Alq 3 ; organic radical compounds; hydroxyflavone-metal complexes, etc., but not limited thereto. The thickness of the electron transport layer can be 1 nm to 50 nm. The electron transport layer with a thickness of 1 nm or more has the advantage of preventing the degradation of electron transport characteristics, and the thickness of 50 nm or less has the advantage of preventing the increase in driving voltage caused by the too thick electron transport layer.

[0117] The electron injection layer can play a role in promoting electron injection, and the electron injection material preferably has the ability to transport electrons, has an injection electron effect from the cathode, has an 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 in addition, has an excellent thin film forming ability. Specific examples thereof include fluorenone, anthraquinone dimethane, biphenylquinone, thiopyran dioxide, oxazole, dioxazole, triazole, imidazole, perylene tetracarboxylic acid, fluoreneylidene methane, anthrone, etc. and their derivatives, metal complexes, nitrogen-containing five-membered ring derivatives, etc., but not limited thereto.

[0118] According to the materials used, the above-mentioned organic electroluminescent device can be a top-emission type, a bottom-emission type or a double-sided emission type.

[0119] In addition, the organic electroluminescent device described in the present invention can be used in organic solar cells, electronic papers, organic photoreceptors or organic thin film transistors.

[0120] Through the above technical solutions, compared with the prior art, the present invention has the following beneficial effects:

[0121] The organic electroluminescent material provided by the present invention is a dual-host organic compound. After being used in an organic electroluminescent device, it can reduce triplet-triplet annihilation (TTA), while reducing the driving voltage of the organic electroluminescent device, and improving the efficiency and lifespan of the device. Description of the Drawings

[0122] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0123] Figure 1 It is the nuclear magnetic resonance hydrogen spectrum of the compound R002 of the present invention.

[0124] Figure 2 The hydrogen nuclear magnetic resonance spectrum of compound R358 of the present invention is shown in FIG. DETAILED DESCRIPTION

[0125] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0126] The embodiment of the present invention discloses a method for preparing a dual-host organic electroluminescent material.

[0127] In addition, it should be noted that the numerical values ​​given in the following embodiments 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.

[0128] Example 1: Preparation of Compound R002

[0129]

[0130] Under nitrogen protection, reactant 1 (cas: 86-76-0) (202.35 mmol), reactant 2 (cas: 62-53-3) (202.35 mmol), sodium tert-butoxide (404.71 mol) were weighed and put into the reaction system, 500 ml of toluene, catalyst tri(dibenzylideneacetone) palladium (4.05 mmol) and tri-tert-butylphosphine (8.09 mmol) were added, refluxed at 100 ° C for 24 h under nitrogen protection, then cooled to 25 ° C, 500 mL of purified water was added, stirred for 30 min, then allowed to stand for stratification, separated, and column chromatography was performed to obtain the compound R002-1 shown (test value: 259.47, 41.2 g, yield 78.52%).

[0131]

[0132] Under nitrogen protection system, R002-1 (158.11 mmol), reactant 3 (cas: 2014391-79-6) (158.11 mmol), sodium tert-butoxide (316.23 mol) were weighed and put into the reaction system, 410 ml of toluene, catalyst tris(dibenzylideneacetone) palladium (3.16 mmol) and tri-tert-butylphosphine (6.32 mmol) were added, refluxed at 110 ° C for 24 h under nitrogen protection, then cooled to 25 ° C, 410 mL of purified water was added, stirred for 30 min, then allowed to stand for stratification, separated, and column chromatography was performed to obtain the compound R002 shown (test value: 525.61, 56 g, yield 67.38%), as shown in Figure 1 shown.

[0133] Example 2: Preparation of Compound R003

[0134]

[0135] Under nitrogen protection, reactant 1 (cas: 26608-06-0) (202.35 mmol), reactant 2 (cas: 62-53-3) (202.35 mmol), sodium tert-butoxide (404.71 mol) were weighed and put into the reaction system, 500 ml of toluene, catalyst tri(dibenzylideneacetone) palladium (4.05 mmol) and tri-tert-butylphosphine (8.09 mmol) were added, refluxed at 100 ° C for 24 h under nitrogen protection, then cooled to 25 ° C, 500 mL of purified water was added, stirred for 30 min, then allowed to stand for stratification, separated, and column chromatography was performed to obtain the compound R003-1 shown (test value: 259.48, 40 g, yield 76.23%).

[0136]

[0137] Under nitrogen protection system, R003-1 (146.54 mmol), reactant 3 (cas: 2014391-79-6) (146.54 mmol), sodium tert-butoxide (293.09 mol) were weighed and put into the reaction system, 380 ml of toluene, catalyst tri(dibenzylideneacetone) palladium (2.93 mmol) and tri-tert-butylphosphine (5.86 mmol) were added, refluxed at 110 ° C for 24 h under nitrogen protection, then cooled to 25 ° C, 380 mL of purified water was added, stirred for 30 min, then allowed to stand for stratification, separated, and column chromatography was performed to obtain the compound R003 shown (test value: 525.61, 51 g, yield 66.21%).

[0138] Example 3: Preparation of Compound R102

[0139]

[0140] Under nitrogen protection, reactant 1 (cas: 86-76-0) (202.35 mmol), reactant 2 (cas: 62-53-3) (202.35 mmol), sodium tert-butoxide (404.71 mol) were weighed and put into the reaction system, 500 ml of toluene, catalyst tri(dibenzylideneacetone) palladium (4.05 mmol) and tri-tert-butylphosphine (8.09 mmol) were added, refluxed at 100 ° C for 24 h under nitrogen protection, then cooled to 25 ° C, 500 mL of purified water was added, stirred for 30 min, then allowed to stand for stratification, separated, and column chromatography was performed to obtain the compound R002-1 shown (test value: 259.47, 41.2 g, yield 78.52%).

[0141]

[0142] Under nitrogen protection, R002-1 (158.11 mmol), reactant 3 (cas: 2029180-73-0) (158.11 mmol), sodium tert-butoxide (316.23 mol) were weighed and put into the reaction system, 410 ml of toluene, catalyst tri(dibenzylideneacetone) palladium (3.16 mmol) and tri-tert-butylphosphine (6.32 mmol) were added, refluxed at 110 ° C for 24 h under nitrogen protection, then cooled to 25 ° C, 410 mL of purified water was added, stirred for 30 min, then allowed to stand for stratification, separated, and column chromatography was performed to obtain the compound R102 shown (test value: 525.61, 56.5 g, yield 67.98%).

[0143] Example 4: Preparation of Compound R358

[0144] Synthesis of R358-1:

[0145]

[0146] Under nitrogen protection, reactant 1 (cas: 2230311-61-0) (196.75 mmol), reactant 2 (cas: 4165-61-1) (196.75 mmol), sodium tert-butoxide (393.49 mol) were weighed and put into the reaction system, 500 ml of toluene, catalyst tri(dibenzylideneacetone) palladium (3.93 mmol) and tri-tert-butylphosphine (7.87 mmol) were added, refluxed at 100 ° C for 24 h under nitrogen protection, then cooled to 25 ° C, 500 mL of purified water was added, stirred for 30 min, then allowed to stand for stratification, separated, and column chromatography was performed to obtain the compound R358-1 shown (test value: 271.38, 28.3 g, yield 53%).

[0147] Synthesis of reactant 3:

[0148] Under a nitrogen protection system, add the reactant 3a (365 mmol) to a round-bottom flask. Add 2-bromo-4-chlorobenzaldehyde (365 mmol), potassium carbonate (1.1 mmol), THF and H 2 O under nitrogen protection. Add tetrakis(triphenylphosphine)palladium (18.26 mmol) under nitrogen protection and reflux for 12 hours. After the reaction is completed, separate the layers by liquid separation. After concentrating the organic layer, separate it by column chromatography to obtain the reactant 3b-2 (test value: 313.96, 76 g, yield 66.32%).

[0149]

[0150] Add the reactant 3b-2 (239 mmol), (methoxymethyl)triphenylphosphonium chloride (310.7 mmol) and THF (750 mL) to a reaction vessel and stir for 10 minutes. Then, slowly add potassium tert-butoxide (1 M in THF, 240 mL) dropwise at 0 °C. Thereafter, slowly raise the temperature, and then stir the reaction mixture at room temperature for 3 hours. After completing the reaction by adding distilled water to the reaction solution, extract the organic layer with ethyl acetate. Dry the organic phase with sodium sulfate and remove the solvent with a rotary evaporator. Thereafter, purify it by column chromatography to obtain the reactant 3b-3 (test value: 342.02, 72 g, yield 88.24%).

[0151]

[0152] Add the compound reactant 3b-3 (204.77 mmol), boron trifluoride etherate (60 mL) and dichloromethane (860 mL) to a reaction vessel and stir for 3 hours. After the reaction is completed, extract the organic layer with dichloromethane and water together. After drying the extracted organic layer with sodium sulfate, remove the solvent with a rotary evaporator. Thereafter, purify it by column chromatography to obtain the intermediate reactant 3 (test value: 309.1, 38.2 g, yield 60.41%).

[0153]

[0154] Synthesis of R358:

[0155]

[0156] Under nitrogen protection, R358-1 (92.12 mmol), reactant 3 (92.12 mmol), sodium tert-butoxide (184.24 mol) were weighed and put into the reaction system, 260 ml of toluene, catalyst tri(dibenzylideneacetone) palladium (1.84 mmol) and tri-tert-butylphosphine (3.68 mmol) were added, refluxed at 110 ° C for 24 h under nitrogen protection, then cooled to 25 ° C, 260 mL of purified water was added, stirred for 30 min, then allowed to stand for stratification, separated, and column chromatography was performed to obtain the compound R358 shown (test value: 543.72, 38.5 g, yield 76.86%), as shown in Figure 2 .

[0157] Example 5: Preparation of Compound H001

[0158]

[0159] Under nitrogen protection, reactant 1 (cas: 108-77-0) (271.14 mmol), reactant 2 (cas: 98-80-6) (813.43 mmol), and potassium carbonate (813.43 mol) were weighed and put into the reaction system. 500 ml of toluene, 250 ml of ethanol, 250 ml of water, and catalyst tetrakis(triphenylphosphine)palladium (13.56 mmol) were added. The mixture was refluxed at 90 ° C for 24 h under nitrogen protection, and then cooled to 25 ° C, filtered, and solid column chromatography was performed to obtain the compound H001 shown (test value: 309.37, 83.88 g, yield 62%).

[0160] Its HPLC purity is greater than 99%,

[0161] Example 6: Preparation of Compound H002

[0162]

[0163] Under nitrogen protection, reactant 1 (cas: 108-77-0) (271.14 mmol), reactant 2 (cas: 98-80-6) (271.14 mmol), and potassium carbonate (813.43 mol) were weighed and put into the reaction system. 500 ml of toluene, 250 ml of ethanol, 250 ml of water, and catalyst tetrakis(triphenylphosphine)palladium (13.56 mmol) were added. The mixture was refluxed at 90 ° C for 24 h under nitrogen protection, and then cooled to 25 ° C, filtered, and solid column chromatography was performed to obtain the compound H001-1 shown (test value: 225.49, 39.4 g, yield 64%).

[0164]

[0165] Under a nitrogen protection system, weigh H001-1 (132.71 mmol), reactant 2-1 (cas: 98-80-6) (132.71 mmol), and potassium carbonate (398.12 mol) and place them into the reaction system. Add 500 ml of toluene, 250 ml of ethanol, 250 ml of water, and the catalyst tetrakis(triphenylphosphine)palladium (13.56 mmol). Reflux at 90 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H001-2 (measured value: 267.56, 23 g, yield 64%).

[0166]

[0167] Under a nitrogen protection system, weigh H001-2 (74.71 mmol), reactant 2-2 (cas: 5122-94-1) (74.71 mmol), and potassium carbonate (224.12 mol) and place them into the reaction system. Add 200 ml of toluene, 100 ml of ethanol, 100 ml of water, and the catalyst tetrakis(triphenylphosphine)palladium (3.74 mmol). Reflux at 90 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H002 (measured value: 385.47, 15.6 g, yield 54.17%).

[0168] Example 7: Preparation of Compound H003

[0169]

[0170] Under a nitrogen protection system, weigh reactant 1 (cas: 108-77-0) (271.14 mmol), reactant 2 (cas: 98-80-6) (271.14 mmol), and potassium carbonate (813.43 mol) and place them into the reaction system. Add 500 ml of toluene, 250 ml of ethanol, 250 ml of water, and the catalyst tetrakis(triphenylphosphine)palladium (13.56 mmol). Reflux at 90 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H001-1 (measured value: 225.49, 39.4 g, yield 64%).

[0171]

[0172] Under a nitrogen protection system, weigh H001-1 (132.71 mmol), reactant 2-1 (cas: 98-80-6) (132.71 mmol), and potassium carbonate (398.12 mol) and place them into the reaction system. Add 500 ml of toluene, 250 ml of ethanol, 250 ml of water, and the catalyst tetrakis(triphenylphosphine)palladium (13.56 mmol). Reflux at 90 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H001-2H001-2 (test value: 267.56, 23 g, yield 64%).

[0173]

[0174] Under a nitrogen protection system, weigh H001-2 (74.71 mmol), reactant 2-2 (cas: 13922-41-3) (74.71 mmol), and potassium carbonate (224.12 mol) and place them into the reaction system. Add 200 ml of toluene, 100 ml of ethanol, 100 ml of water, and the catalyst tetrakis(triphenylphosphine)palladium (3.74 mmol). Reflux at 90 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H003 (test value: 359.43, 15.1 g, yield 56.23%).

[0175] Example 8: Preparation of compound H004

[0176]

[0177] Under a nitrogen protection system, weigh reactant 1 (cas: 108-77-0) (271.14 mmol), reactant 2 (cas: 98-80-6) (271.14 mmol), and potassium carbonate (813.43 mol) and place them into the reaction system. Add 500 ml of toluene, 250 ml of ethanol, 250 ml of water, and the catalyst tetrakis(triphenylphosphine)palladium (13.56 mmol). Reflux at 90 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H001-1 (test value: 225.49, 39.4 g, yield 64%).

[0178]

[0179] Under a nitrogen protection system, weigh H001-1 (132.71 mmol), reactant 2-1 (cas: 98-80-6) (132.71 mmol), and potassium carbonate (398.12 mol) and put them into the reaction system. Add 500 ml of toluene, 250 ml of ethanol, 250 ml of water, and the catalyst tetrakis(triphenylphosphine)palladium (13.56 mmol). Reflux at 90 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H001-2 (test value: 267.56, 23 g, yield 64%).

[0180]

[0181] Under a nitrogen protection system, weigh H001-2 (74.71 mmol), reactant 2-2 (cas: 374538-04-2) (74.71 mmol), and potassium carbonate (224.12 mol) and put them into the reaction system. Add 200 ml of toluene, 100 ml of ethanol, 100 ml of water, and the catalyst tetrakis(triphenylphosphine)palladium (3.74 mmol). Reflux at 90 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H004 (test value: 391.52, 16 g, yield 54.7%).

[0182] The test data of other examples are shown in Table 1

[0183] Table 1

[0184]

[0185]

[0186] Use the compound R002 prepared in Example 1 and the compound H001 prepared in Example 5 to prepare an organic electroluminescent device. Specifically, the preparation method of the organic electroluminescent device is as follows:

[0187] ITO anode: The ITO (indium tin oxide) glass substrate with a coating thickness of is washed twice in distilled water, ultrasonically washed for 30 min, then repeatedly washed twice with distilled water, ultrasonically washed for 10 min. After the washing is completed, it is ultrasonically washed with methanol, acetone, and isopropyl alcohol in sequence (each washing for 5 min), dried, and then transferred to a plasma cleaner for washing for 5 min to obtain the ITO anode.

[0188] HIL (hole injection layer): In an evaporation coater, vacuum evaporate 4,4 , ,4 , ,4-tris(N-(3-methylphenyl)-N-phenylamino)triphenylamine (m-MTDATA) Form a hole injection layer.

[0189] HTL (hole transport layer): Vacuum deposit NPB (i.e., N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine) on the hole injection layer Form a hole transport layer.

[0190] Light-emitting layer: The light-emitting layer includes a first host material, a second host material, and a guest dopant. After forming the hole injection layer and the hole transport layer, form the light-emitting layer on the HTL: Introduce the first host compound and the second host compound as hosts into two chambers of a vacuum vapor deposition apparatus respectively, and introduce compound Z1 as a dopant into another chamber. Evaporate the two host materials at a rate of 1:1, and simultaneously evaporate the dopant material at different rates for deposition with a doping amount of 3 wt% based on the total amount of the host and the dopant to form a light-emitting layer with a thickness of 40 nm on the second hole transport layer.

[0191] HBL (hole blocking layer): Vacuum deposit bis(2-methyl-8-hydroxyquinolinato-N1,O8)-(1,1'-biphenyl-4-olato)aluminum (BAlq) on the light-emitting layer Form a hole blocking layer.

[0192] ETL (electron transport layer): Vacuum deposit tris(8-hydroxyquinolinato)aluminum (Alq 3 ) Form an electron transport layer.

[0193] EIL (electron injection layer): Vacuum deposit on the electron transport layer Form an electron injection layer.

[0194] Cathode: Evaporate Al on the electron injection layer to form a cathode, and an organic electroluminescent device can be obtained.

[0195] Referring to the organic electroluminescent devices and their preparation methods provided in Example 1 and Example 5, respectively select another 38 organic electroluminescent compounds to replace those in Example 1 and Example 5 for the evaporation of the host material, and prepare the organic electroluminescent devices of the corresponding compounds.

[0196] Red light dopant material (Z1)

[0197]

[0198] The device manufacturing processes of Device Examples 1-20, Comparative Examples 1-7, and Parallel Examples 1-6 are exactly the same, and the same substrate material and electrode material are used. The film thickness of the electrode material is also consistent. The difference lies in that: the two host materials are different, and the specific parameters are shown in Table 1.

[0199] Table 1 shows the parameters used in Device Examples 1-20, Comparative Examples 1-7, and Parallel Examples 1-6

[0200] Table 1

[0201]

[0202]

[0203] The structure of the comparative example is as follows:

[0204]

[0205]

[0206] Performance detection: At a brightness of 5000 (nits), the driving voltage, luminous efficiency, and lifetime of the organic light-emitting devices obtained from the above Comparative Examples 1-7, Parallel Examples 1-6, and Device Examples 1-20 were characterized, and the test results are shown in Table 2 below.

[0207] Table 2

[0208]

[0209]

[0210] As can be seen from Table 2, the driving voltages of the organic light-emitting devices provided by Device Examples 1-20 and Parallel Examples 1-6 of the present invention are 3.1V to 4.6V, which are significantly lower than the driving voltage of Comparative Example 1-7. At the same time, the luminous efficiency is higher than that of Comparative Example 1-7, and the lifetime is significantly improved compared with Comparative Example 1-7.

[0211] It can be seen from this that compared with the organic light-emitting devices prepared using comparative compounds E-1, E-2, E-3, F-1, F-2, and F-3 as the double host materials of the light-emitting layer, the organic light-emitting devices prepared using the organic light-emitting compounds provided by the present invention as the light-emitting layer materials have significantly reduced driving voltages, and the luminous efficiency and lifetime are significantly improved.

[0212] The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those 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. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organic electroluminescent material containing two hosts, It is 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 has a structure shown in Formula 1, and the second host material has a structure shown in Formula 2: in: A1, B1, C1, D1, D2, and D3 are each independently selected from substituted or unsubstituted (C6-C42)aryl, substituted or unsubstituted (C3-C30)heteroaryl; L 1 and L 2 are linking groups, substituted or unsubstituted (C6-C30) aryl groups.

2. The dual-host organic electroluminescent material according to claim 1, It is characterized in that The general structure of formula 1 is as follows: In the formula, A1, B1-1, B1-2, C1-1, C1-2 are selected from (C6-C18) substituted or unsubstituted aryl groups; X is N, O, S; Ar 1 selected from hydrogen, substituted or unsubstituted (C6-C36) aryl, and substituted or unsubstituted (C3-C30) heteroaryl.

3. The dual-host organic electroluminescent material according to claim 1 or 2, It is characterized in that D1 and D2 are selected from (C6-C18) substituted or unsubstituted aryl groups; D3 is selected from substituted or unsubstituted (C6-C36)aryl, substituted or unsubstituted (C3-C30)heteroaryl; L 1 and L 2 is selected from a linking key, a (C6-C18) substituted or unsubstituted aryl group.

4. The dual-host organic electroluminescent material according to claim 3, It is characterized in that The general structure of formula 1 is as follows: In the formula, A1 is selected from phenyl, naphthyl, biphenyl, deuterated phenyl, deuterated naphthyl, deuterated biphenyl; C1-1 is selected from deuterated or undeuterated phenanthrenyl; B1-1 and B1-2 are both selected from phenyl and deuterated phenyl; C1-2 is selected from phenyl, deuterated phenyl, deuterated naphthyl; Ar 1 selected from hydrogen or the following groups:

5. The dual-host organic electroluminescent material according to claim 3 or 4, It is characterized in that D1 is selected from substituted or unsubstituted phenyl, biphenyl, terphenyl; D2 is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl, terphenyl, triphenylene; D3 is selected from substituted or unsubstituted (C6-C30)aryl, substituted or unsubstituted (C3-C30)heteroaryl; L 1 is a linking key, L 2 is a linking key or phenyl or naphthyl.

6. The dual-host organic electroluminescent material according to claim 1, It is characterized in that Formula 1 is selected from any one of the following compounds:

7. The dual-host organic electroluminescent material according to claim 1, It is characterized in that Formula 2 is selected from any one of the following compounds:

8. A method for preparing a dual-host organic electroluminescent material as claimed in claim 1, It is characterized in that The preparation method of the general formula 1-1-1 specifically comprises the following steps: (1) Under nitrogen protection, reactant 1 (1 eq), reactant 2 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and placed in a reaction system, toluene, catalyst tris(dibenzylideneacetone) palladium (0.02-0.03 eq) and tri-tert-butylphosphine (0.04-0.06 eq) were added, refluxed at 90-100° C. for 24 h under nitrogen protection, then cooled to 25° C., purified water was added, stirred for 30 min, and then allowed to stand for stratification, separated, and subjected to column chromatography to obtain the compound R-1 shown; (2) Under nitrogen protection, compound R-1 (1 eq), reactant 3 or reactant 4 (1-1.2 eq), sodium tert-butoxide (2-3 eq) were weighed and placed in a reaction system, toluene, catalyst tris(dibenzylideneacetone) palladium (0.02-0.03 eq) and tri-tert-butylphosphine (0.04-0.06 eq) were added, refluxed at 90-100° C. for 24 h under nitrogen protection, then cooled to 25° C., purified water was added, stirred for 30 min, and then allowed to stand for stratification, separated, and subjected to column chromatography to obtain a compound represented by the general formula 1-1-1; The specific synthetic route is as follows: The synthesis method of some reactants 3 and 4 in the general formula 1-1-1 specifically comprises the following steps: Under a nitrogen protection system, add the reactants 3a (1 eq), 2-bromo-5-chlorobenzaldehyde (1 eq), potassium carbonate (3 eq), tetrakis(triphenylphosphine)palladium(0) (0.05 eq), THF and H 2 O to a round-bottom flask, reflux for 12 hours. After the reaction is completed, separate the layers by liquid separation. After concentrating the organic layer, separate and obtain the intermediate 3b-2 by column chromatography; Add intermediate 3b-2 (1 eq), (methoxymethyl)triphenylphosphine chloride (1.3 eq) and THF to a reaction vessel and stir for 10 minutes, then slowly add potassium tert-butoxide dropwise at 0°C; slowly increase the temperature, and stir the reaction mixture at room temperature for 3 hours; after distilled water is added to the reaction solution to complete the reaction, extract the organic layer with ethyl acetate, dry the organic phase with sodium sulfate, remove the solvent with a rotary evaporator, and purify with column chromatography to obtain compound intermediate 3b-3; Compound intermediate 3b-3 (1 eq), boron trifluoride etherate (0.25 eq) and dichloromethane 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 the extracted organic layer was dried with sodium sulfate and then the solvent was removed by a rotary evaporator, and purified by column chromatography to obtain reactant 3; The reactant 3 (1 eq) was placed in a deuterated ethanol reagent, and (2 eq) sodium tert-butoxide was added. After refluxing for 24 h, the organic layer was extracted with dichloromethane and water, and the extracted organic layer was dried with sodium sulfate and then the solvent was removed by a rotary evaporator, and purified by column chromatography to obtain the reactant 4; The specific synthetic route is as follows: or, Under a nitrogen protection system, add reactant 3a (1 eq), 2-bromo-4-chlorobenzaldehyde (1 eq), potassium carbonate (3 eq), tetrakis(triphenylphosphine)palladium(0) (0.05 eq), THF and H 2 O to a round-bottom flask, reflux for 12 hours. After the reaction is completed, separate the layers by liquid separation. Concentrate the organic layer and then separate it by column chromatography to obtain intermediate 3c-2; Add intermediate 3c-2 (1 eq), (methoxymethyl)triphenylphosphine chloride (1.3 eq) and THF to a reaction vessel and stir for 10 minutes, then slowly add potassium tert-butoxide dropwise at 0°C; slowly increase the temperature, and stir the reaction mixture at room temperature for 3 hours; after distilled water is added to the reaction solution to complete the reaction, extract the organic layer with ethyl acetate, and dry the organic phase with sodium sulfate and remove the solvent with a rotary evaporator, and purify with column chromatography to obtain compound intermediate 3c-3; Compound intermediate 3c-3 (1 eq), boron trifluoride etherate (0.25 eq) and dichloromethane 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 the extracted organic layer was dried with sodium sulfate and the solvent was removed by a rotary evaporator, and purified by column chromatography to obtain reactant 3; The reactant 3 (1 eq) was placed in a deuterated ethanol reagent, and (2 eq) sodium tert-butoxide was added. After refluxing for 24 h, the organic layer was extracted with dichloromethane and water, and the extracted organic layer was dried with sodium sulfate and then the solvent was removed by a rotary evaporator, and purified by column chromatography to obtain the reactant 4; The specific synthetic route is as follows:

9. The preparation method of the dual-host organic electroluminescent material according to claim 8, characterized in that, the preparation method of the general formula 2 specifically comprises the following steps: (1) Under a nitrogen protection system, weigh reactant 1 (1eq), reactant 2 (1 - 1.2eq), and potassium carbonate (3 - 4eq) and put them into the reaction system. Add toluene, ethanol, water, and the catalyst tetrakis(triphenylphosphine)palladium (0.05 - 0.08eq). Reflux at 90 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H-1; (2) Under a nitrogen protection system, weigh H-1 (1eq), reactant 2-1 (1 - 1.2eq), and potassium carbonate (3 - 4eq) and put them into the reaction system. Add toluene, ethanol, water, and the catalyst tetrakis(triphenylphosphine)palladium (0.05 - 0.08eq). Reflux at 90 - 100 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H-2; (3) Under a nitrogen protection system, weigh H-2 (1eq), reactant 2-2 (1 - 1.2eq), and potassium carbonate (3 - 4eq) and put them into the reaction system. Add toluene, ethanol, water, and the catalyst tetrakis(triphenylphosphine)palladium (0.05 - 0.08eq). Reflux at 90 - 100 °C for 24 h under nitrogen protection, then cool to 25 °C, filter by suction, and perform solid column chromatography to obtain the shown compound H (general formula 2); The specific synthesis route is as follows:

10. The application of the dual-host organic electroluminescent material according to claim 1 in the preparation of an organic electroluminescent device, characterized in that, 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 dual-host organic electroluminescent material according to claim 1; wherein, the mass ratio of the dual-host organic electroluminescent material to the doping material is (1 - 99):(99 - 1).

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