An organic electroluminescent compound, a double-host-containing organic electroluminescent material, and an organic electroluminescent device

Abstract

The application provides an organic electroluminescent compound, a double-host-containing organic electroluminescent material and an organic electroluminescent device, the organic electroluminescent compound has a structure shown in general formula 1, the double-host-containing organic electroluminescent material comprises a first host material and a second host material, the first host material is the organic electroluminescent compound as described above, and the second host material has a structure shown in general formula 2, the organic electroluminescent compound or the double-host-containing organic electroluminescent material of the application is applied to the organic electroluminescent device, so that the device has the characteristics of low driving voltage, high luminous efficiency and long service life.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of organic electroluminescent materials, and particularly relates to an organic electroluminescent compound, a double-host-containing organic electroluminescent material and an organic electroluminescent device. BACKGROUND

[0002] Organic Light Emitting Diode (OLED) technology is a type of electroluminescent technology that uses organic materials as the light-emitting layer. This technology has the advantages of low driving voltage, high brightness, high efficiency, and the ability to achieve large-area flat-panel color displays. The principle of organic electroluminescence is based on the injection of electrons and holes from the cathode and anode into the organic layer when a voltage is applied to the organic material. These electrons and holes recombine in the light-emitting layer to form excitons, which release energy during the relaxation process to produce photons, thereby achieving light emission. In recent years, significant progress has been made in the study of organic electroluminescent technology, including improvements in device efficiency, lifetime, and brightness, as well as reductions in cost and the realization of a wider color gamut. These advances have made organic electroluminescent technology a promising technology for display and lighting applications.

[0003] Organic electroluminescent efficiency generally refers to the ability of a device to convert electrical energy into light energy, and is mainly divided into internal quantum efficiency and external quantum efficiency. Internal quantum efficiency refers to the light-emitting efficiency of excitons in the light-emitting layer, while external quantum efficiency refers to the ratio of the number of photons extracted from the device to the number of electrons injected into the device.

[0004] Improving the efficiency of OLEDs is achieved by doping the host and guest in the light-emitting layer. This is because the radiative transition of most organic molecular triplets is forbidden, and contributes little to electroluminescence. By doping platinum, iridium, osmium, and other organic metal complexes, the triplet excitons of organic molecules can be transferred to the triplet state of the metal complex, greatly improving the efficiency of organic light-emitting devices. However, triplet-triplet annihilation (TTA) occurs during the transfer process, resulting in energy loss and causing efficiency roll-off in organic light-emitting devices.

[0005] Currently, the performance of organic electroluminescent devices is still poor, which is a technical problem that needs to be solved in the use process. For example, there are problems such as excessively high driving voltage, excessively low luminous efficiency, or short service life, which affect the application field of organic electroluminescent devices.

[0006] Therefore, how to develop a double-host-containing organic electroluminescent material with long service life, high efficiency, and low driving voltage, as well as a preparation method and an organic electroluminescent device, is a technical problem that needs to be solved by those skilled in the art. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application aims to provide an organic electroluminescent material, a double-host-containing organic electroluminescent material and an organic electroluminescent device. The organic electroluminescent compound or the double-host-containing organic electroluminescent material of the present application is applied to an organic electroluminescent device, so that the device has the characteristics of low driving voltage, high luminous efficiency and long service life.

[0008] To achieve the object of the present application, the present application adopts the following technical solutions:

[0009] In one aspect, the present application provides an organic electroluminescent compound, which has the structure shown in the following general formula 1:

[0010] ;

[0011] Among them:

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

[0013] A1 and A2 are each independently selected from substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C18 heteroaryl, substituted or unsubstituted C6-C18 deuterated aryl, and the heteroatom in the heteroaryl is selected from oxygen, nitrogen or sulfur; L is selected from a chemical bond, substituted or unsubstituted C6-C18 aryl;

[0014] Among them, any one of X and Y is selected from , and the other is selected from O or S;

[0015] All hydrogen atoms in general formula 1 are independently substituted with deuterium or not substituted with deuterium.

[0016] Preferably, the organic electroluminescent compound has the structure shown in any one of the following general formulae:

[0017] .

[0018] Preferably, A1 and A2 are each independently selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted anthracene, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted triphenyloxyl, substituted or unsubstituted tetraphenylsilicon, substituted or unsubstituted 1-(naphthyl)dibenzo[b,d] furanyl, substituted or unsubstituted 2-phenylnaphthalene, substituted or unsubstituted 3-(naphth-2-yl)naphtho[2,1-b]benzofuranyl, substituted or unsubstituted naphtho[2,1-b]benzofuran, substituted or unsubstituted 1,1':3',1'-terphenyl.

[0019] Preferably, L is selected from a connecting bond.

[0020] In the organic electroluminescent compound, the substituents in the defined substituted group are selected from the group consisting of deuterium, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, C3-C10 heterocycloalkyl whose heteroatoms are selected from O, N or S; or the substituents in the substituted group are selected from the group consisting of:

[0021] ;

[0022] wherein the dotted line represents the point of attachment of the group.

[0023] In the present application, heteroaryl is a monocyclic aromatic group and a polycyclic aromatic system including at least one heteroatom, including but not limited to O, S or N.

[0024] In the present application, the number of carbon atoms of aryl, heteroaryl, alkyl, cycloalkyl, heterocycloalkyl in the term "substituted or unsubstituted C6-C24 aryl", "substituted or unsubstituted C3-C18 heteroaryl", "substituted or unsubstituted C6-C18 deuterated aryl", "substituted or unsubstituted C6-C18 aryl", "substituted or unsubstituted C1-C10 alkyl", "substituted or unsubstituted C3-C10 cycloalkyl", "C3-C10 heterocycloalkyl" represents the total number of unsubstituted carbon atoms, without considering the number of carbon atoms in the substituents.

[0025] In the present application, the chemical bond refers to a single bond.

[0026] In the above technical solution, the organic electroluminescent compound is any one of the following compounds, but is not limited thereto:

[0027]

[0028]

[0029]

[0030]

[0031] ;

[0032] wherein D represents deuterium.

[0033] The above are some specific structural forms of the first host material, but are not limited to the listed chemical structures. Any compound whose structural general formula is based on Formula 1 and whose A1, A2 groups are simple variations of groups within the ranges defined above should be included.

[0034] In another aspect, the present application provides a double-host-containing organic electroluminescent material, the double-host-containing organic electroluminescent material including a first host material and a second host material, the first host material being an organic electroluminescent compound as described above, and the second host material having a structure represented by Formula 2:

[0035]

[0036] Formula (2)

[0037] wherein L1 to L3 are each independently selected from a bond, a substituted or unsubstituted C6-C30 aryl, a substituted or unsubstituted C6-C30 heteroaryl, wherein the heteroatom is at least one of O, S, or N;

[0038] Ar1 to Ar3 are each independently selected from a substituted or unsubstituted C6-C30 aryl, a substituted or unsubstituted C6-C30 heteroaryl, a substituted or unsubstituted C10-C30 fused ring group; wherein the heteroaryl is a monocyclic aromatic group or a polycyclic aromatic system including at least one heteroatom, and the heteroatom is at least one of O, S, or N.

[0039] The "substituted" means substituted with one or at least two substituents selected from the group consisting of deuterium, cyano, methyl, C6-C24 aryl, C6-C24 heteroaryl, wherein the heteroatom is selected from O, S, or N.

[0040] Further, Ar1 is selected from a C6-C36 aryl unsubstituted or substituted with one or more deuterium, cyano, methyl, a substituted or unsubstituted C3-C30 heteroaryl, the heteroaryl being a monocyclic aromatic group or a polycyclic aromatic system including at least one heteroatom, and the heteroatom includes but is not limited to O, S, N;

[0041] Ar2 and Ar3 are each independently selected from a substituted or unsubstituted phenyl, a biphenyl, a terphenyl;

[0042] L2 and L3 are each independently selected from a bond;

[0043] L1 is selected from a bond, an unsubstituted C6-C18 aryl, a substituted or unsubstituted C6-C 18heteroaryl, wherein the heteroatom is selected from O, S, N.

[0044] Preferably, the second host material is any one of the following compounds:

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051] ;

[0052] wherein D represents deuterium.

[0053] In the double-host-containing organic electroluminescent material of the present application, the mass ratio of the first host material to the second host is (10-90):(90-10), for example, 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 40:60, 45:55, 50:50, 60:40, 70:30, 80:20, or 90:10.

[0054] Preferably, the mass ratio of the first host compound to the second host compound is 30-70:70-30, and more preferably 60-40:40-60; for example, 40:60, 45:55, 50:50, 55:45, 60:40.

[0055] It should be noted that the substituted or unsubstituted in the present application means that the group can be unsubstituted or substituted with one or more substituents, the substitution means that the hydrogen atom bonded to the carbon atom of the compound is changed to another substituent, and the position of substitution has no limitation, as long as the position is the position of hydrogen atom being substituted, i.e. the position that the substituent can substitute, and when two or more substituents are substituted, the two or more substituents can be the same as or different from each other.

[0056] In the present application, by using double host materials to disperse triplet excitons on two hosts, triplet-triplet annihilation (TTA) is reduced, while the driving voltage of the organic electroluminescent device is reduced, the luminous efficiency and service life of the device are improved.

[0057] The present application also provides a preparation method of the first host material and the second host material, and the specific steps and conditions of the preparation method are as follows:

[0058] I. Synthesis of the first host material

[0059] Under a nitrogen protection system, the reactants 4 (1 eq), the intermediate (1 eq), and potassium carbonate (2-3 eq) were placed in the reaction system, toluene, ethanol, and water were added, a catalyst tetrakis(triphenylphosphine)palladium (0.01-0.04 eq) was added, and the system was refluxed at 80-90°C under nitrogen protection for 18 h. After cooling to 25°C, the compound of general formula 1 was obtained by recrystallization treatment, and the synthetic route is as follows:

[0060] .

[0061] II. Synthesis of the intermediate compound of the first host material

[0062] 1. Reaction 1 route:

[0063] 1.1 Under a nitrogen protection system, the reactants 1 (1 eq) and 2 (1 eq) and sodium tert-butoxide (2-3 eq) were placed in the reaction system, toluene (dry) was added, a catalyst tris(dibenzylideneacetone)dipalladium (0.01-0.04 eq) and tri-tert-butylphosphine (0.022-0.088 eq) were added, and the system was refluxed at 110-120°C under nitrogen protection for 24 h. After cooling to 25°C, A-1-1 was obtained by column chromatography treatment.

[0064] 1.2 Under a nitrogen protection system, A-1-1 (1 eq) was placed in the reaction system, N,N-dimethylformamide and TEMPO (2 eq) were added, and the system was refluxed at 110-120°C under nitrogen protection for 5 h. After cooling to 25°C, A-1-2 was obtained by column chromatography treatment.

[0065] 1.3 Under a nitrogen protection system, A-1-2 (1 eq) and reactant 3 (1 eq) and potassium carbonate (2-3 eq) were placed in the reaction system, toluene, ethanol, and water were added, tetrakis(triphenylphosphine)palladium (0.05-0.08 eq) was added, and the system was refluxed at 90-100°C under nitrogen protection for 24 h. After cooling to 25°C, A-1 was obtained by recrystallization treatment. The synthetic route is as follows:

[0066]

[0067] 2. Reaction 2 route:

[0068] 2.1 Under nitrogen protection system, take reactant 1 (1 eq), reactant 2 (1 eq), sodium tert-butoxide (2-3 eq) into the reaction system, add toluene (dry), catalyst tris (dibenzylideneacetone) palladium (0.01-0.04 eq) and tri-tert-butyl phosphine (0.022-0.088 eq), reflux at 110-120℃ for 24h under nitrogen protection, cool to 25℃, column chromatography to obtain the indicated A-8-1 after processing;

[0069] 2.2 Under nitrogen protection system, take A-8-1 (1 eq) into the reaction system, add N,N-dimethylformamide, TEMPO (2 eq), reflux at 110-120℃ for 5h under nitrogen protection, cool to 25℃, column chromatography to obtain the indicated A-8-2 after processing;

[0070] 2.3 Under nitrogen protection system, take A-8-2 (1 eq), reactant 3 (1 eq), potassium carbonate (2-3 eq) into the reaction system, add toluene, ethanol, water, tetrakis (triphenylphosphine) palladium (0.05-0.08 eq), reflux at 90-100℃ for 24h under nitrogen protection, cool to 25℃, recrystallization to obtain the indicated A-8-3 after processing;

[0071] 2.4 Under nitrogen protection system, take reactant Y-8-3 (1 eq) into the reaction system, add N,N-dimethylformamide, after adding, warm up to 75℃, control temperature, add NBS (1.2-2 eq) in batches, after adding, keep warm for 24h, TLC detects that the raw material reaction is complete, cool to 25℃, column chromatography, recrystallization to obtain the indicated compound A-8 after processing. The synthesis route is as follows:

[0072]

[0073] 3. Reaction 3 route:

[0074] 3.1 Under nitrogen protection system, take reactant 1 (1 eq), reactant 2 (1 eq), sodium tert-butoxide (2-3 eq) into the reaction system, add toluene (dry), catalyst tris (dibenzylideneacetone) palladium (0.01-0.04 eq) and tri-tert-butyl phosphine (0.022-0.088 eq), reflux at 110-120℃ for 24h under nitrogen protection, cool to 25℃, column chromatography to obtain the indicated C-7-1 after processing;

[0075] 3.2 Under nitrogen protection system, take C-7-1 (1 eq) into the reaction system, add N,N-dimethylformamide, TEMPO (2 eq), reflux at 110-120℃ for 5h under nitrogen protection, cool to 25℃, column chromatography to obtain the indicated C-7-2 after processing;

[0076] 3.3 Under a nitrogen protection system, C-7-2 (1 eq), reactant 3 (1 eq), potassium carbonate (2-3 eq) were weighed into a reaction system, toluene, ethanol, water, tetrakis(triphenylphosphine)palladium (0.05-0.08 eq) were added, and the system was refluxed at 90-100°C for 24 h under nitrogen protection, and then cooled to 25°C. After recrystallization treatment, the indicated C-7 was obtained. The synthetic route thereof is as follows:

[0077]

[0078] The synthesis and yield of the intermediates are shown in Table 1.

[0079] Table 1

[0080]

[0081]

[0082]

[0083]

[0084]

[0085] The synthesis route of the intermediates can be synthesized by referring to the methods of A-1, A-8, and C-7, and no more description is given here.

[0086] III. Synthesis of the second host material

[0087] (1) The reactants (1 eq), reactant 2 (1 eq), and sodium tert-butoxide (2 eq) were weighed into a reaction container in sequence, toluene was added as a reaction solvent, a catalyst Pd2(dba)3 (0.01 eq) and P(t-Bu)3 (0.02 eq) were added under nitrogen protection, the system was refluxed at 120°C for 24 h under nitrogen protection, and then cooled to 25°C. Pure water was added thereto, stirred for 30 min, and then allowed to stand to separate into layers. The liquid was separated by column chromatography to obtain the intermediate 2-1.

[0088] (2) The synthesis method of general formula 2 is the same as that of the synthesis of the intermediate 2-1, and no more description is given here.

[0089]

[0090] A third technical object of the present application is to provide an organic electroluminescent device comprising the organic electroluminescent compound or the double-host-containing organic electroluminescent material as described above.

[0091] Preferably, 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 dopant material and a host material, and the host material is an organic electroluminescent compound or a double-host-containing organic electroluminescent material as described above.

[0092] Preferably, the mass ratio of the host material to the dopant material is (1-99):(99-1), such as 1:99, 1:95, 1:90, 1:85, 1:83, 1:80, 1:75, 2:98, 5:95, 8:92, 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 38:62, 40:60, 45:55, 50:50, 55:45, 58:42, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 88:12, 90:10, 95:5, 98:2, or 99:1, etc.

[0093] In the present application, the organic electroluminescent device comprises an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode.

[0094] Specifically, the anode material is preferably a material with a large work function to facilitate the injection of holes into the organic material layer, and the anode material includes metals such as vanadium, chromium, copper, zinc, and gold, or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); combinations of metals and oxides such as ZnO:Al or nO2:Sb; conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrole, and polyaniline, but not limited thereto.

[0095] The cathode material is preferably a material with a small work function to facilitate the injection of electrons into the organic material layer, and the cathode material includes metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or alloys thereof; multi-layer structure materials such as LiF / Al or LiO2 / Al; but not limited thereto.

[0096] 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.

[0097] The hole injection layer material 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 porphyrin, oligothiophene, arylamine-based organic material, hexacenehexaazatriphenylene-based organic material, quinacridone-based organic material, perylene-based organic material, anthraquinone, and polyaniline- and polythiophene-based conductive polymers.

[0098] The hole transport layer material is a material capable of receiving holes from the anode or the hole injection layer and transporting the holes to the light emitting layer, and has a high hole mobility. The hole transport layer material includes arylamine-based organic material, conductive polymer, block copolymer having both conjugated and non-conjugated portions, but is not limited thereto.

[0099] The electron blocking layer is disposed between the hole transport layer and the light emitting layer, and the electron blocking layer material includes arylamine-based organic material.

[0100] The hole blocking layer is disposed between the hole transport layer and the light emitting layer, and the hole blocking layer material includes triazine-based compound.

[0101] The electron transport region includes an electron transport layer and an electron injection layer.

[0102] The electron transport layer has a function of facilitating electron transport, and the electron transport material is a material receiving electrons from the cathode and transporting the electrons to the light emitting layer, and has a high electron mobility. The electron transport material includes an Al complex of 8-hydroxyquinoline, a complex of Alq3, an organic radical compound, a hydroxyflavone-metal complex, but is not limited thereto. The thickness of the electron transport layer is 1 nm to 50 nm, and can prevent a decrease in electron transport characteristics and an increase in driving voltage.

[0103] The electron injection layer has a function of facilitating electron injection, and the electron injection material is a material having an electron transport ability, an excellent electron injection effect on the light emitting layer or light emitting material, preventing excitons generated in the light emitting layer from migrating to the hole injection layer, and an excellent thin film formation ability. The electron injection layer material includes ketone, anthraquinone dimethane, diphenylquinone, thiopyran dioxide, oxazole, diazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenylidenemethane, anthracene ketone, and derivatives thereof, metal complex, nitrogen-containing five-membered ring derivative, but is not limited thereto.

[0104] In the present application, the organic electroluminescent device can be a top emission type, a bottom emission type, or a dual side emission type.

[0105] The organic electroluminescent device can be used in an organic solar cell, electronic paper, organic photoreceptor, or organic thin film transistor.

[0106] Compared with the prior art, the present application has the following beneficial effects:

[0107] In the organic electroluminescent compound of the present application, when the triazine compound is connected to the oxazole or thiazole site, the structure tends to be planar, resulting in a lower T1 energy and slower mobility; thus, the prepared device has a low driving voltage, long service life and high luminous efficiency.

[0108] The double-host-containing organic electroluminescent material of the present application comprises a first host material and a second host material, and by using the double-host material, triplet excitons can be dispersed on the two hosts, and triplet-triplet annihilation (TTA) can be reduced, so that the application in an organic electroluminescent device can effectively reduce the driving voltage, and the luminous efficiency and service life of the device can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0109] Figure 1 The nuclear magnetic resonance hydrogen spectrum of the compound N033 prepared in Example 1 of the present application is shown. DETAILED DESCRIPTION

[0110] The technical solutions of the present application will be further described through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application, and should not be regarded as specific limitations on the present application.

[0111] It should be noted that the numerical values given in the following examples are as accurate as possible, but those skilled in the art understand that due to unavoidable measurement errors and experimental operation problems, each number should be understood as an approximate number, rather than an absolutely accurate number.

[0112] Example 1: Preparation of compound N033

[0113] (1) The reactants 1 (1 eq, CAS: 2169399-39-5), reactants 2 (1 eq, CAS: 100-46-9), and sodium tert-butoxide (2 eq) were placed into a reaction system, and nitrogen was replaced. Toluene (dry) and a catalyst tris(dibenzylideneacetone)dipalladium (0.02 eq) and tri-tert-butylphosphine (0.044 eq) were added under nitrogen protection, and the reaction was refluxed at 120°C for 24 h under nitrogen protection. TLC detection showed that the raw materials were completely reacted, and the reaction system was cooled to 25°C. Pure water was added, stirred for 0.5 h, and then separated into layers after standing. The aqueous phase was extracted with toluene, and the organic phases were combined. The solvent was removed under reduced pressure, and the obtained compound A-1-1 was purified by column chromatography, with a yield of 70%.

[0114] (2) Take the reactant A-1-1 (1 eq), N, N-dimethylformamide solvent (2 eq) into the reaction system, replace nitrogen, add TEMPO (2 eq) under nitrogen protection, replace nitrogen, reflux at 120°C under nitrogen protection for 5h, TLC detects that the raw material reaction is complete, cool to 25°C, dilute with AcOEt (ethyl acetate), wash with saturated sodium chloride (AQ) aqueous solution, dry with anhydrous Na2SO4. After filtration, the filtrate is concentrated under reduced pressure, and the residue is purified by column chromatography to obtain the compound A-1-2 as shown, with a yield of 85.4%.

[0115] (3) Take the reactant A-1-2 (1 eq), reactant 3 (1 eq, CAS: 1674380-71-2), potassium carbonate (3 eq) into the reaction system, replace nitrogen, add toluene, ethanol, and water under nitrogen protection, replace nitrogen, react at 100°C under nitrogen protection for 24h, TLC detects that the raw material reaction is complete, cool to 25°C, filter to obtain a solid, purify by column chromatography to obtain the compound A-1 as shown, with a yield of 75%.

[0116] (4) Take the reactant A-1 (1 eq), reactant 4 (1 eq, CAS: 2571626-02-7), sodium tert-butoxide (2 eq) into the reaction system, replace nitrogen, add toluene, ethanol, and water under nitrogen protection, add catalyst tetrakis(triphenylphosphine)palladium (0.02 eq), replace nitrogen, reflux at 90°C under nitrogen protection for 18h, TLC detects that the raw material reaction is complete, cool to 25°C, stand to separate layers, separate, filter, purify by recrystallization to obtain the compound N033 as shown, HPLC: 99.91%; mass spectrometry test value: 590.37; yield: 71.3% (C: 81.35%; H: 3.76%; N: 9.47%; O: 5.42%), the nuclear magnetic hydrogen spectrum is as shown, and the synthetic route is as follows: Figure 1

[0117]

[0118] Example 2: Preparation of the second host compound H2-28

[0119] ​N-([1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-3-amine (1 eq), 10-chloro-2-phenylphenanthro[3,4-d]oxazole (1 eq), sodium tert-butoxide (2 eq) were taken in a reaction flask, 200 mL of toluene was added, catalyst Pd2(dba)3(0.01 eq) and P(t-Bu)3(0.02 eq) were added under nitrogen protection, and then the mixture was refluxed at 120°C for 24 hours under nitrogen protection, and then cooled to 25°C. 200 mL of pure water was added to the mixture, stirred for 30 minutes, and then allowed to stand and separate into two layers. The product H2-28 (28.68 g, yield 78%, HPLC > 99%, mass spectrometry test value 614.96) was obtained by column chromatography. The reaction scheme is shown below.

[0120]

[0121] In addition, it should be noted that other compounds of the present application can be obtained by referring to the synthesis methods of the above-mentioned examples, and therefore will not be described here.

[0122] Application Example: Preparation of an Organic Electroluminescent Device

[0123] Device Application Example 1:

[0124] ITO anode: An ITO (indium tin oxide) glass substrate with a coating thickness of 1500 was cleaned twice in distilled water, ultrasonically washed for 30 min, and then cleaned repeatedly twice in distilled water, ultrasonically washed for 10 min. After washing, the substrate was ultrasonically washed in methanol, acetone, and isopropanol for 5 min each, dried, and then transferred to a plasma cleaning machine for washing for 5 min to obtain an ITO anode.

[0125] HIL (hole injection layer): 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA) was vacuum evaporated on the ITO anode to a thickness of 200 Å in an evaporation machine to form a hole injection layer.

[0126] HTL (hole transport layer): NPB (i.e., N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine) was vacuum evaporated on the hole injection layer to a thickness of 400 Å to form a hole transport layer.

[0127] Light-emitting layer: The light-emitting layer includes a first host material N033, a second host material H2-28, and a guest dopant Z1. After the hole injection layer and the hole transport layer are formed, the light-emitting layer is formed on the hole transport layer.

[0128] The first host compound and the second host compound are introduced into two chambers of a vacuum vapor deposition device as host materials, and the compound Z1 is introduced into another chamber as a dopant; the two host materials are evaporated at a rate of 1:1, and the dopant material is evaporated at a different rate at the same time, and is deposited at a doping amount of 3wt% 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 hole transport layer.

[0129] HBL (hole blocking layer): 100 A of bis(2-methyl-8-quinolinolato-N1, O8)-(1,1'-biphenyl-4-olato) aluminum (BAlq) is vacuum evaporated on the light-emitting layer to form a hole blocking layer.

[0130] ETL (electron transport layer): 400 A of aluminum quinolinol (Alq3) is vacuum evaporated on the hole blocking layer to form an electron transport layer.

[0131] EIL (electron injection layer): 210 A of LiF is vacuum evaporated on the electron transport layer to form an electron injection layer.

[0132] Cathode: 1500 A of Al is evaporated on the electron injection layer to form a cathode, thereby obtaining an organic electroluminescent device.

[0133] Referring to the organic electroluminescent device and the preparation method thereof provided in device example 1, the first host compound and the second host compound are replaced by the compounds of the present application to perform evaporation of the host materials, thereby obtaining an organic electroluminescent device of the corresponding compound.

[0134] The structures of the compounds used in the above device example 1 are as follows:

[0135]

[0136] Device examples 2-20, comparative examples 1-3 and parallel examples 1-2:

[0137] Device examples 2-20, comparative examples 1-5 and parallel examples 1-6 have the same device manufacturing process, and use the same substrate material and electrode material, and the film thickness of the electrode material is also consistent, the difference is that the two host materials are not the same, and the corresponding first host compound and second host compound in Table 1 are selected, and the specific parameters are shown in Table 2.

[0138] The structures of the compounds used in the above comparative examples and parallel examples are as follows:

[0139]

[0140] Table 2

[0141]

[0142] Performance test: the driving voltage, luminous efficiency and lifetime of the organic electroluminescent devices obtained from Comparative Examples 1-5, Parallel Examples 1-6 and Device Example 1-26 above were characterized at a brightness of 5000 (nits), and the test results are shown in Table 3 below.

[0143] Table 3

[0144]

[0145] As can be seen from Table 3, the driving voltage of the organic electroluminescent devices provided by Device Example 1-26 and Parallel Example 1-6 is 4.12-5.85 V, which is significantly lower than the driving voltage of Comparative Example 1-5, the luminous efficiency is between 31.1-38.8 cd / A, which is higher than that of Comparative Example 1-5, the lifetime ranges from 406-592 h, and the lifetime is significantly improved compared with Comparative Example 1-5. Therefore, the use of the first host compound with a specific structure and the second host compound with a specific structure in the host material of the light-emitting layer can greatly improve the luminous efficiency and service life. This is because the present application not only provides a first host material with a triazine and benzoxazole skeleton, which has a high glass transition temperature and molecular thermal stability, suitable HOMO and LUMO energy levels, and a high Eg, but also provides a second host with a triazine structure for matching, which can enhance the hole transport ability and provide good electron transport ability. Therefore, when the holes are injected into the p-type host and the electrons are injected into the n-type host, the driving voltage will be reduced and the lifetime will be enhanced.

[0146] The applicant declares that the organic electroluminescent compound, the double-host-containing organic electroluminescent material and the organic electroluminescent device of the present application are illustrated by the above examples, but the present application is not limited to the above examples, i.e. it does not mean that the present application must rely on the above examples to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of the selected materials, addition of auxiliary ingredients, selection of specific methods, etc. fall within the scope of protection and disclosure of the present application.

Claims

1. An organic electroluminescent compound, characterized by The organic electroluminescent compound is any one of the following compounds: ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； 。 2. A double-host containing organic electroluminescent material, characterized by The double-host-containing organic electroluminescent material comprises a first host material and a second host material, the first host material is the organic electroluminescent compound of claim 1, and the second host material is any one of the following compounds: ； ； ； ； ； 。 3. The bis-host-containing organic electroluminescent material according to claim 2, characterized in that, The mass ratio of the first host material to the second host is (10-90):(90-10).

4. An organic electroluminescent device, characterized by comprising The organic electroluminescent device comprises the organic electroluminescent compound of claim 1 or the double-host-containing organic electroluminescent material of claim 2.

5. The organic electroluminescent device according to claim 4, 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, the light-emitting layer comprises a dopant material and a host material, and the host material is the organic electroluminescent compound of claim 1 or the double-host-containing organic electroluminescent material of claim 2; The mass ratio of the host material to the dopant material is (1-99):(99-1).

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