An organic electroluminescent material and an organic electroluminescent device containing dual host materials

Abstract

The present invention provides an organic electroluminescent material and an organic electroluminescent device containing a dual host material, wherein the general structural formula of the organic electroluminescent host material is shown in general formula 1, and the compound structure of general formula 1 of the present invention has good stereoregularity, which avoids the aggregation quenching effect caused by the structural plane stacking during the structure evaporation process, and improves the lifespan; 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. The organic electroluminescent device of the present invention disperses triplet excitons on two hosts by using a dual host material, reduces triplet-triplet annihilation, and can improve the luminous efficiency and service life of the device while reducing the driving voltage of the organic electroluminescent device.

Description

Technical Field

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

[0002] Organic light-emitting devices (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 recombined in the light-emitting layer, which generates OLED electroluminescence. Since the radiative 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 and an organic electroluminescent device containing a dual host with a long life and low driving voltage is a technical problem that those skilled in the art need to solve urgently. Summary of the invention

[0006] In view of the deficiencies of the prior art, the object of the present invention is to provide an organic electroluminescent material and an organic electroluminescent device containing a dual-host material, in particular, to provide an organic electroluminescent device containing a dual-host organic electroluminescent material of indolecarbazole and triazine structure. Indolecarbazole is a larger conjugated plane, and still has a relatively planar 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 evaporation process of the structure, 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. The organic electroluminescent device of the present invention disperses triplet excitons on two hosts by using a dual-host material, reduces triplet-triplet annihilation (TTA), and can improve the luminous efficiency and service life of the device while reducing the driving voltage of the organic electroluminescent device.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In one aspect, the present invention provides an organic electroluminescent host material, the general structural formula of the organic electroluminescent host material is shown in Formula 1:

[0009] ;

[0010] General formula (1)

[0011] Wherein, ring A is selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 heteroaryl; R1 and R2 are independently selected from substituted or unsubstituted C6-C30 aryl, C3-C30 heteroaryl; and the heteroatom in the heteroaryl is selected from O, N or S.

[0012] Preferably, the A ring is selected from substituted or unsubstituted C6-C12 aryl, substituted or unsubstituted C6-C12 heteroaryl;

[0013] Preferably, R1 and R2 are independently selected from substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C3-C18 heteroaryl; the heteroatom in the heteroaryl is selected from O, N or S.

[0014] In the present invention, R1 and R2 may be the same or different.

[0015] In the present invention, the substituent of the "substituted" group is selected from one or a combination of at least two of deuterium, fluorine, cyano, C1-C10 alkyl, C1-C10 alkoxy, C3-C10 cycloalkyl or C6-C12 aryl.

[0016] In the present invention, all hydrogen atoms in Formula 1 may be all unsubstituted by deuterium, all substituted by deuterium, or partially substituted by deuterium.

[0017] Preferably, the organic electroluminescent host material is any one of the compounds with the following structures, but is not limited thereto:

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025] The above are some specific structural forms of the main materials, but they are not limited to the listed chemical structures. All compounds with simple changes of groups within the defined range based on the general structural formula as shown in formula (1) should be included.

[0026] In another aspect, the present invention provides an organic electroluminescent material containing a double host, wherein the organic electroluminescent material containing a double host comprises a first host material and a second host material, wherein the first host material is at least one of the organic electroluminescent host materials described above; and the mass ratio of the first host material to the second host material is 1:1;

[0027] The general structural formula of the second host material is shown in formula (2):

[0028] ;

[0029] Formula (2)

[0030] Wherein, D1, D2 and D3 are each independently selected from substituted or unsubstituted C6-C42 aromatic groups, substituted or unsubstituted C3-C30 heteroaromatic groups; substituted or unsubstituted C9-C60 fused aromatic groups, substituted or unsubstituted C9-C60 fused heteroaromatic groups, wherein the heteroatoms are selected from O, S, and N; L1 and L2 are each independently selected from connecting bonds, substituted or unsubstituted C6-C30 aromatic groups.

[0031] Preferably, D1 and D2 are each independently selected from substituted or unsubstituted C6-C18 aryl; D3 is selected from substituted or unsubstituted C6-C36 aryl, substituted or unsubstituted C3-C30 heteroaryl; L1 and L2 are each independently selected from a connecting bond, a C6-C18 substituted or unsubstituted aryl.

[0032] More preferably, D1 is selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, and substituted or unsubstituted terphenyl.

[0033] Preferably, D2 is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted triphenylenyl.

[0034] Preferably, D3 is selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C9-C30 fused aryl, and substituted or unsubstituted C9-C30 fused heteroaryl.

[0035] Preferably, L1 is a linking bond, and L2 is a linking bond, a phenyl group or a naphthyl group.

[0036] In the present invention, the heteroaryl group is a monocyclic aromatic group or a polycyclic aromatic group including at least one heteroatom, and the heteroatom includes but is not limited to O, S, and N.

[0037] In the second host material, the substituent in the substituted group is selected from deuterium, fluorine, C1-C10 alkyl, deuterium-substituted C1-C10 alkyl, C3-C10 cycloalkyl, three-membered to ten-membered heterocycloalkyl, and the heteroatom in the heterocycloalkyl is selected from O, S, and N; or any one or a combination of at least two of the following groups:

[0038]

[0039] The dashed lines represent the attachment sites of the groups.

[0040] All hydrogen atoms in formula (2) may be completely unsubstituted by deuterium, completely substituted by deuterium, or partially substituted by deuterium.

[0041] 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.

[0042] In the above technical solution, the second host material is any one of the compounds of the following structures, but is not limited thereto:

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] 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.

[0095] The present invention also provides a method for preparing the first host material and the second host material. The specific steps and conditions of the preparation method are as follows:

[0096] 1. Preparation method of intermediate product:

[0097] 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, 4-chlorophenylboronic acid (0.6 eq) [3-chlorophenylboronic acid (0.6 eq), 2-chlorophenylboronic 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 give 1-a-1 [1-a-2, 1-a-3].

[0098]

[0099] Under nitrogen atmosphere, 2-chloro-6-nitro-1,1'-biphenyl (1 eq), biboronic acid pinacol ester (2-2.2 eq), and 2-3 eq potassium acetate were weighed and added to the reaction bottle in sequence, and then dioxane, 0.02-0.04 eq tris(dibenzylideneacetone) palladium and 0.04-0.08 eq X-phos were added. Under nitrogen protection, the mixture was refluxed at 100-120°C for 24 h, cooled to 25°C, purified water was added, stirred for 30 min, and then allowed to stand for stratification. The mixture was separated, and column chromatography was performed using dichloromethane / petroleum ether as eluent to obtain compound A. The synthesis route is as follows:

[0100]

[0101] Under nitrogen atmosphere, compound A (1 eq), 4-chloro-2-iodo-1-nitrobenzene (1 eq), and (2-3 eq) potassium carbonate were weighed and added to a reaction flask in sequence, followed by toluene, ethanol, and water, and 0.02-0.04 eq of tetrakis(triphenylphosphine palladium) was added. Under nitrogen protection, the mixture was refluxed at 80°C for 24 h, cooled to 25°C, separated, and subjected to column chromatography using dichloromethane / petroleum ether as eluent to obtain 1-a-4. The synthetic route is as follows:

[0102]

[0103] 1-a series (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 series.

[0104]

[0105] 1-b series (1 eq), B (3 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 wet-triturated with boiling ethanol overnight to obtain 1-c series.

[0106]

[0107] 2. Synthesis of the first host material shown in general formula 1:

[0108] Under nitrogen atmosphere, weigh 1-c series (1 eq), C (1-1.1 eq), 2-3 eq sodium tert-butoxide and add them into the reaction bottle in sequence, then add toluene, add 0.02-0.04 eq tris(dibenzylideneacetone) palladium and 0.02-0.04 eq tri-tert-butylphosphine, reflux at 100-120°C for 24 h under nitrogen protection, cool to 25°C, add purified water, stir for 30 min, stand for stratification, separate the liquids, use dichloromethane / petroleum ether as eluent, column chromatography, and obtain general formula 1. Its synthetic route is as follows:

[0109] ;

[0110] 3. Synthesis of the Second Main Material

[0111] (1) Under nitrogen atmosphere, weigh 1 eq of reactant 1, 1-1.2 eq of reactant 2 containing a D1 substituent, and 3-4 eq of potassium carbonate and add them to the reaction system in sequence, then add toluene, ethanol, water (volume ratio = 2:1:1) and 0.05-0.08 eq of tetrakis(triphenylphosphine)palladium, 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;

[0112] (2) Under nitrogen atmosphere, weigh 1 eq H-1, 1-1.2 eq D2-containing reactant 2-1, and 3-4 eq potassium carbonate and add them to the reaction system in sequence, then add toluene, ethanol, water (volume ratio = 2:1:1) and 0.05-0.08 eq tetrakis(triphenylphosphine)palladium, 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;

[0113] (3) Under nitrogen atmosphere, weigh 1 eq H-2, 1-1.2 eq D3-containing reactant 2-2, and 3-4 eq potassium carbonate and add them to the reaction system in sequence, then add toluene, ethanol, water (volume ratio = 2:1:1) and 0.05-0.08 eq tetrakis(triphenylphosphine)palladium. 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. The synthetic route is as follows:

[0114] .

[0115] In another aspect, the present invention provides an organic electroluminescent device, wherein the organic electroluminescent device comprises the organic electroluminescent host material as described above or the organic electroluminescent material containing a dual host as described above.

[0116] The organic electroluminescent device comprises a first electrode (anode), an organic electroluminescent material layer, and a second electrode (cathode); the organic electroluminescent material layer comprises a light-emitting layer, and the light-emitting layer comprises a doping material and the organic electroluminescent host material as described above or the organic electroluminescent material containing a double host as described above.

[0117] Preferably, the mass ratio of the organic electroluminescent material containing a double host to the doping material is (1~99):(99~1), for example, 1:99, 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.

[0118] 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. Specifically,

[0119] 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), metal 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 is not limited thereto.

[0120] 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), metal alloys or multilayer structure materials (such as LiF / Al or LiO2 / Al); but is not limited thereto.

[0121] 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.

[0122] 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 material based on arylamine, organic material based on hexanitrile hexaazatriphenylene, organic material based on quinacridone, organic material based on perylene, anthraquinone, and conductive polymers based on polyaniline and polythiophene.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] The electron transport region includes an electron transport layer and an electron injection layer.

[0127] 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.

[0128] 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.

[0129] In the present invention, the organic electroluminescent device may be a top emission type, a bottom emission type or a double-side emission type.

[0130] The organic electroluminescent device can be used in organic solar cells, electronic paper, organic photoreceptors or organic thin film transistors.

[0131] Compared with the prior art, the present invention has the following beneficial effects:

[0132] The dual-host organic electroluminescent material of the present invention comprises a first host material and a second host material. By using the dual-host material, triplet excitons can be dispersed on two hosts, thereby reducing triplet-triplet annihilation (TTA). When applied to an organic electroluminescent device, the driving voltage can be effectively reduced, while the luminous efficiency and service life of the device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0133] Figure 1 This is the H NMR spectrum of compound G002. DETAILED DESCRIPTION

[0134] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0135] In addition, it should be noted that the numerical values ​​given in the following examples are as accurate as possible, but those skilled in the art understand that due to unavoidable measurement errors and experimental operation problems, each number should be understood as an approximate number rather than an absolutely accurate value.

[0136] Example 1: Preparation of intermediate product 1-c-1

[0137] 1-Iodo-2-nitrobenzene (35 g, 141 mmol), bicyclo[2.2.1]hept-2-ene (6.62 g, 70.3 mmol), Pd(OAc)2 (1.578 g, 7.03 mmol) and K2CO3 (38.9 g, 281 mmol) were added to DMF (100 ml), (4-chlorophenyl)boronic acid (13.19 g, 84 mmol) was added. It was 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 petroleum ether (PE) / dichloromethane (DCM) (volume ratio of 4 / 1 to 3 / 2) as eluent, and recrystallized from heptane to give (1-a-1) 4"-chloro-2,3'-dinitro-1,1':2',1"-terphenyl (16 g, 64%) as a yellow solid.

[0138]

[0139] A solution of 4"-chloro-2,3'-dinitro-1,1':2',1"-terphenyl (16 g, 45.1 mmol) and triphenylphosphine (47.3 g, 180 mmol) in o-dichlorobenzene (100 ml) was degassed under nitrogen and refluxed for 24 hours. The solvent was evaporated and the residue was purified by silica gel column chromatography with PE / DCM (volume ratio 4 / 1 to 2 / 3) as eluent. The crude product was recrystallized from heptane to give (1-b-1) 3-chloro-5,8-dihydroindole[2,3-c]carbazole (5.3 g, 40.4%) as a white solid.

[0140] 3-Chloro-5,8-dihydroindole [2,3-c] carbazole (5.3 g, 18.23 mmol), iodobenzene (6.10 ml, 54.7 mmol) and K3PO4 (19.35 g, 91 mmol) were added to o-xylene (100 ml), degassed, Cul (1.736 g, 9.11 mmol) and cyclohexane-1,2-diamine (1.041 g, 9.11 mmol) were added, and 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 white solid was wet-triturated with boiling ethanol overnight to obtain (1-c-1) 3-chloro-5,8-diphenyl-5,8-dihydroindole [2,3-c] carbazole (8 g, 99%) as a white solid.

[0141]

[0142] Example 2: Preparation of Compound G002

[0143] Under nitrogen atmosphere, weigh 22.58mmol of 1-c-1, 22.58mmol of C (CAS: 103012-26-6), 45.25mmol of sodium tert-butoxide and put them into the reaction system, add 150ml of toluene, 0.225mmol of catalyst tris(dibenzylideneacetone)palladium and 0.225mmol of tri-tert-butylphosphine, reflux at 120℃ for 24h under nitrogen protection, then cool to 25℃, add 150mL of purified water, stir for 30min, stand for stratification, separate the liquids, and perform column chromatography to obtain the compound G002 (test value: 10.6g, yield 72.2%). Its HPLC purity is greater than 99%, and the synthetic route is as follows:

[0144]

[0145] The H NMR spectrum of compound G002 is shown in Figure 1 shown.

[0146] Example 3: Preparation of Compound G003

[0147] Under nitrogen atmosphere, 22.58mmol of 1-c-1, 22.58mmol of C (CAS: 88590-00-5), 45.25mmol of sodium tert-butoxide were weighed and put into the reaction system, 150ml of toluene, 0.225mmol of catalyst tris(dibenzylideneacetone) palladium and 0.225mmol of tri-tert-butylphosphine were added, refluxed at 120℃ for 24h under nitrogen protection, then cooled to 25℃, 150mL of purified water was added, stirred for 30min, and then allowed to stand for stratification, separated, and column chromatography was performed to obtain the compound G003 (test value:, 9.8g, yield 66.8%). Its HPLC purity is greater than 99%, and the synthesis route is as follows:

[0148]

[0149] Example 4: Preparation of Compound G102

[0150] Under nitrogen atmosphere, weigh 22.58mmol of 1-c-1, 22.58mmol of C (CAS: 1204427-10-0), 45.25mmol of sodium tert-butoxide and put them into the reaction system, add 150ml of toluene, 0.225mmol of catalyst tris(dibenzylideneacetone)palladium and 0.225mmol of tri-tert-butylphosphine, reflux at 120℃ for 24h under nitrogen protection, then cool to 25℃, add 150mL of purified water, stir for 30min, stand for stratification, separate the liquids, and perform column chromatography to obtain the compound G102 (test value:, 10.1g, yield 63.9%). Its HPLC purity is greater than 99%, and the synthetic route is as follows:

[0151]

[0152] Example 5: Preparation of Compound G103

[0153] Under nitrogen atmosphere, 22.58mmol of 1-c-1, 22.58mmol of C (CAS: 1040882-75-4), 45.25mmol of sodium tert-butoxide were weighed and put into the reaction system, 150ml of toluene, 0.225mmol of catalyst tris(dibenzylideneacetone) palladium and 0.225mmol of tri-tert-butylphosphine were added, refluxed at 120℃ for 24h under nitrogen protection, then cooled to 25℃, 150mL of purified water was added, stirred for 30min, and then allowed to stand for stratification, separated, and column chromatography was performed to obtain the compound G103 (test value:, 9.7g, yield 61.3%). Its HPLC purity is greater than 99%, and the synthesis route is as follows:

[0154]

[0155] Example 6: Preparation of Compound H001

[0156] Under nitrogen atmosphere, weigh 271.14mmol of reactant 1 (CAS: 108-77-0), 813.43mmol of reactant 2 (CAS: 98-80-6), and 813.43mol of potassium carbonate into the reaction system, add 500ml of toluene, 250ml of ethanol, 250ml of water, and 13.56mmol of catalyst tetrakis(triphenylphosphine)palladium, reflux at 90°C for 24h under nitrogen protection, then cool to 25°C, filter, and solid column chromatography to 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:

[0157] .

[0158] Example 7: Preparation of Compound H002

[0159] Under nitrogen atmosphere, weigh 74.71mmol H001-2 (CAS: 3842-55-5), 74.71mmol reactant 2-2 (CAS: 5122-94-1), 224.12mol potassium carbonate into the reaction system, add 200ml toluene, 100ml ethanol, 100ml water, 3.74mmol catalyst tetrakis(triphenylphosphine)palladium, reflux at 90℃ for 24h under nitrogen protection, then cool to 25℃, filter, solid column chromatography, and obtain the compound H002 (test value: 385.47, 15.6g, yield 54.2%). Its HPLC purity is greater than 99%, and the synthesis route is as follows:

[0160] .

[0161] Example 8: Preparation of Compound H003

[0162] Under nitrogen atmosphere, weigh 74.71mmol H001-2, 74.71mmol reactant 2-2 (CAS: 13922-41-3), 224.12mol potassium carbonate into the reaction system, add 200ml toluene, 100ml ethanol, 100ml water, 3.74mmol catalyst tetrakis(triphenylphosphine)palladium, reflux at 90℃ for 24h under nitrogen protection, then cool to 25℃, filter, solid column chromatography, and obtain the compound H003 (test value: 359.43, 15.1g, yield 56.2%). Its HPLC purity is greater than 99%, and the synthesis route is as follows:

[0163] .

[0164] Example 9: Preparation of Compound H004

[0165] Under nitrogen atmosphere, weigh 74.71mmol H001-2, 74.71mmol reactant 2-2 (CAS: 374538-04-2), 224.12mol potassium carbonate into the reaction system, add 200ml toluene, 100ml ethanol, 100ml water, 3.74mmol catalyst tetrakis(triphenylphosphine)palladium, reflux at 90℃ for 24h under nitrogen protection, then cool to 25℃, filter, solid column chromatography, and obtain the compound H004 (test value: 391.52, 16g, yield 54.7%). Its HPLC purity is greater than 99%, and the synthesis route is as follows:

[0166] .

[0167] 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 in the mass spectrometry test in this application is Waters XEVO TQD, low precision, ESI source test.

[0168] Table 1

[0169]

[0170] Application example: Preparation of organic electroluminescent devices

[0171] Device Example 1:

[0172] ITO anode: The ITO (indium tin oxide) glass substrate with a coating thickness of 1500Å was cleaned twice in distilled water, ultrasonically washed for 30 minutes, and then repeatedly cleaned twice with distilled water and ultrasonically washed for 10 minutes. After washing, it was ultrasonically washed 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.

[0173] HIL (hole injection layer): In an evaporator, 200Å of 4,4',4'-tri(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA) was vacuum-deposited on the ITO anode to form a hole injection layer.

[0174] 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 form a hole transport layer.

[0175] Light-emitting layer: The light-emitting layer includes a first host material G002, 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.

[0176] 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.

[0177] HBL (hole blocking layer): 100Åm of bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq) was vacuum-deposited on the light-emitting layer to form a hole blocking layer.

[0178] ETL (electron transport layer): 400Å of 8-hydroxyquinoline aluminum (Alq3) was vacuum evaporated on the hole blocking layer to form an electron transport layer.

[0179] EIL (Electron Injection Layer): LiF2 10Å was vacuum evaporated on the electron transport layer to form an electron injection layer.

[0180] Cathode: 1500Å of Al is evaporated on the electron injection layer to form a cathode, and an organic electroluminescent device can be obtained.

[0181] 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.

[0182] The structure of the green light doping material Z1 is as follows:

[0183] .

[0184] Device Examples 2-20, Comparative Examples 1-9 and Parallel Examples 1-8:

[0185] 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.

[0186] Table 2

[0187]

[0188] The material structures involved in the comparative examples are shown in Table 3 below.

[0189] Table 3

[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 4 below.

[0193] Table 4

[0194]

[0195] It can be seen from Table 4 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 span are significantly improved compared with comparative examples 1-9.

[0196] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the organic electroluminescent material and the organic electroluminescent device containing the dual host material of the present invention, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An organic electroluminescent host material, characterized in that: The organic electroluminescent host material is any one of the compounds with the following structures: ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； 。 2. An organic electroluminescent material containing a double host, characterized in that: The organic electroluminescent material containing two hosts comprises a first host material and a second host material, wherein the first host material is at least one of the organic electroluminescent host materials according to claim 1; and the mass ratio of the first host material to the second host material is 1:1-2; The second host material is any one of the compounds with the following structures: ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； ； 。 3. An organic electroluminescent device, characterized in that: The organic electroluminescent device contains the organic electroluminescent material containing a double host as claimed in claim 2.

4. The organic electroluminescent device according to claim 3, characterized in that: The organic electroluminescent device comprises an anode, an organic electroluminescent material layer and a cathode; 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 as claimed in claim 2; The mass ratio of the organic electroluminescent material containing the dual host to the doping material is (1-99):(99-1); The organic electroluminescent material layer further comprises a hole transport region and an electron transport region; 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; The electron transport region includes an electron transport layer and an electron injection layer.

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