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

Abstract

The invention provides an organic electroluminescent compound, an organic electroluminescent material containing double hosts and a luminescent device.The organic electroluminescent material comprises a first host material and a second host material, the first host material is a compound with a structure as shown in a general formula (1), the second host material is a compound with a structure as shown in a general formula (2), and the second host material is a compound with a structure as shown in a general formula (3). By using the specific combination of the compounds as the host material in the organic electroluminescent device, the luminous efficiency is improved and the service life is prolonged.

Description

Technical Field

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

[0002] Organic electroluminescent devices are self-luminous devices. Due to their characteristics such as low driving voltage, high resolution, high brightness, fast response time and flexibility, they have attracted widespread attention in the panel display device industry.

[0003] Currently, OLED display technology has been applied in smart phones, tablet computers and other fields, and will also expand to large-size application areas such as TVs. However, compared with actual product application requirements, OLED's luminous efficiency and service life and other performance still need to be further improved.

[0004] The luminescent material of an organic electroluminescent device (OLED) is the most important factor in determining the luminous efficiency of the device, and can be divided into a host material and a dopant material in terms of function. The luminescent material can be used by mixing the host and the dopant to improve color purity, luminous efficiency and stability. Generally, a device with excellent electroluminescent (EL) characteristics has a structure of a luminescent layer formed by doping a dopant into the host. When using this dopant / host material system as a luminescent material, the host material greatly affects the efficiency and life of the light-emitting device, so the selection is crucial.

[0005] Therefore, the current urgent task is to develop OLEDs with high efficiency and long life characteristics, especially considering the EL characteristics required for medium and large OLED panels, it is urgent to develop highly excellent light-emitting materials that are superior to conventional light-emitting materials. Summary of the invention

[0006] The object of the present invention is to provide an organic electroluminescent compound, an organic electroluminescent material containing a dual host, and a light-emitting device. The organic electroluminescent material comprises a first host material and a second host material, wherein the first host material is a compound having a structure represented by the general formula (1), and the second host material is a compound having a structure represented by the general formula (2). By using a specific combination of compounds as a host material in an organic electroluminescent device, the luminous efficiency and service life are improved.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] An organic electroluminescent compound, wherein the organic electroluminescent compound is a first host compound having a structure represented by general formula (1):

[0009]

[0010] wherein G is selected from hydrogen, substituted or unsubstituted C6-C 30 G may be fused with or substituted by an adjacent benzene ring;

[0011] R is independently selected from substituted or unsubstituted C6-C 30 Aryl, C6-C 30 wherein the heteroatom in the heteroaryl group is selected from O, N or S.

[0012] In one embodiment of the present invention, G is selected from hydrogen, a substituted or unsubstituted benzene ring, fused to an adjacent benzene ring or substituted.

[0013] In one embodiment of the present invention, R is independently selected from substituted or unsubstituted C6-C 18 aryl, substituted or unsubstituted C6-C 15 wherein the heteroatom in the heteroaryl is selected from O or S.

[0014] In one embodiment of the present invention, the substituent of the "substituted" group is selected from deuterium, fluorine, cyano, C1-C 10 Alkyl, C1-C 10 Alkoxy, C3-C 10 Cycloalkyl or C6-C 12 One or a combination of at least two of the aromatic groups.

[0015] In one embodiment of the present invention, all hydrogen atoms in the general formula (1) may be completely unsubstituted by deuterium, completely substituted by deuterium, or partially substituted by deuterium.

[0016] In one embodiment of the present invention, the structure represented by formula (1) can be represented by formula I-1, I-2 or I-3.

[0017]

[0018] In formulae I-1, I-2 and I-3, R is as defined above.

[0019] In one embodiment of the present invention, the organic electroluminescent compound has any one of the following structures, but is not limited thereto:

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038] 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.

[0039] On the other hand, the present invention also provides an organic electroluminescent material containing two hosts, wherein the organic electroluminescent material comprises a first host material and a second host material, wherein the first host material has at least one of the organic electroluminescent compounds represented by the general formula (1).

[0040] The second host material has a structure shown in general formula (2):

[0041]

[0042] Wherein, L1 to L3 are selected from connecting bonds, substituted or unsubstituted (C6-C 30 ) aryl, substituted or unsubstituted (C6-C 30 ) heteroaryl;

[0043] Ar1 to Ar3 are each independently selected from substituted or unsubstituted (C6-C 30) aryl, substituted or unsubstituted 6-30 membered heteroaryl, heteroaryl includes monocyclic aromatic groups and polycyclic aromatic systems with at least one heteroatom, heteroatoms include but are not limited to O, S, N; substituted or unsubstituted (C 10 -C 30 ) of a fused ring group.

[0044] In one embodiment of the present invention, Ar1 is selected from C6-C 36 Aryl, substituted or unsubstituted C3-C 30 Heteroaryl, which includes monocyclic aromatic groups and polycyclic aromatic systems having at least one heteroatom, including but not limited to O, S, and N;

[0045] Ar2 and Ar3 are selected from unsubstituted or substituted phenyl, biphenyl, terphenyl; L2 and L3 are selected from connecting bonds; L1 is selected from connecting bonds, unsubstituted C6-C 18 aryl, unsubstituted or substituted C6-C 18 The heteroaryl group is a heteroaryl group wherein the heteroatom is selected from O, S, and N.

[0046] The "substitution" is selected from deuterium, cyano, methyl, C6-C 24 Aryl, C6-C 24 The heteroaryl group is a heteroaryl group wherein the heteroatom is selected from O, S, and N.

[0047] In the above technical solution, the second main material has any one of the following structures, but is not limited thereto:

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062] The above is the specific structural formula of the second main material. The present invention prefers the above structure but is not limited to it. All compounds based on the structure shown in general formula (2) and in which L1 to L3 and Ar1 to Ar3 groups are simple transformations of all groups within the previously defined ranges should be included.

[0063] The present invention also provides a method for preparing an organic electroluminescent material containing two hosts, which specifically includes a method for preparing the first host material and the second host material, and the specific steps are as follows:

[0064] 1. Preparation method of intermediate IA:

[0065] 3-bromodibenzofuran (1 eq), chlorophenylboronic acid (1 eq), K2CO3 (2 eq) were added to the reactor and replaced with nitrogen three times, H2O and THF mixture was added as solvent and replaced with nitrogen three times, Pd(PPh3)4 (0.01 eq) was added and replaced with nitrogen three times, and heated to reflux for 12 hours under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediates Ia-1, Ia-2 and Ia-3.

[0066]

[0067] Separately, the above intermediate (1 eq) was mixed with dichloromethane (CH2Cl2), FeCl3 (10 eq) was added to the mixture, and the mixture was stirred for 1 hour. After the reaction was completed, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediates IA-1, IA-2 and IA-3.

[0068] 2. Preparation method of intermediate IB:

[0069] Weigh IB-1 series (1 eq), IB-2 (1-1.1 eq), sodium tert-butoxide (2-3 eq) and add them to the reaction bottle in sequence, replace the atmosphere with nitrogen three times, then add toluene as solvent, replace the atmosphere with nitrogen three times, then add Pd2(dba)3 (0.02 eq) and P(t-Bu)3 (0.022 eq), replace the atmosphere with nitrogen three times, heat to reflux reaction for 24 h under nitrogen protection, cool to 25 ° C, add purified water, stir for 30 min, let stand to separate, separate the layers, and purify the crude product by column chromatography to obtain intermediate IB, the synthesis route of which is as follows:

[0070]

[0071] 3. Synthesis of the first host material represented by general formula I-1 and I-2:

[0072] Weigh IA series (1 eq), IB (1-1.1 eq), sodium tert-butoxide (2-3 eq) and add them to the reaction bottle in sequence, replace with nitrogen three times, then add toluene as solvent, replace with nitrogen three times, then add Pd2(dba)3 (0.02 eq) and P(t-Bu)3 (0.022 eq), replace with nitrogen three times, under nitrogen protection, heat to reflux reaction for 24 h, cool to 25 ° C, add purified water, stir for 30 min, let stand to separate, separate the liquids, and purify the crude product by column chromatography to obtain general formula I-1 and I-2, the synthesis route is as follows:

[0073]

[0074] 4. Synthesis of the first host material shown in general formula I-3:

[0075] (1) Synthesis of the first host material of formula I-3-1

[0076] 2-Bromodibenzofuran (1 eq), chloroformylphenylboronic acid (1 eq), K2CO3 (2 eq) were added to the reactor and replaced with nitrogen three times, H2O and THF mixture was added as solvent and replaced with nitrogen three times, Pd(Ph3)4 (0.01 eq) was added and replaced with nitrogen three times, and heated to reflux for 12 hours under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate Ib-4.

[0077] Intermediate Ib-4 (1 eq), (methoxymethyl) triphenylphosphine chloride (1.3 eq) and THF were added to a reaction vessel and stirred for 10 minutes, and potassium tert-butoxide solution was slowly added dropwise at 0°C. Then, the temperature was slowly raised, and after stirring at room temperature for 3 hours, distilled water was added thereto. After the reaction was completed, the organic layer was extracted with ethyl acetate, the organic phase was dried with sodium sulfate, and the solvent was removed by a rotary evaporator; then it was purified by column chromatography to obtain compound intermediate Ic-4.

[0078] Compound intermediate Ic-4, boron trifluoride etherate 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 then the extracted organic layer was dried with sodium sulfate, and the solvent was removed by a rotary evaporator. Thereafter, it was purified by column chromatography to obtain intermediate compound IA-4.

[0079] Weigh IA-4 series (1 eq), IB (1-1.1 eq), sodium tert-butoxide (2-3 eq) and add them to the reaction bottle in sequence, replace the atmosphere with nitrogen three times, then add toluene as solvent, replace the atmosphere with nitrogen three times, then add Pd2(dba)3 (0.02 eq) and P(t-Bu)3 (0.022 eq), replace the atmosphere with nitrogen three times, and heat to reflux for 24 h under nitrogen protection, cool to 25 ° C, add purified water, stir for 30 min, let stand to separate, separate the layers, and purify the crude product by column chromatography to obtain intermediate I-3-1, the synthetic route of which is as follows:

[0080]

[0081] (2) Synthesis of the first host material of formula I-3-2

[0082] The synthesis method of I-3-2 can be synthesized by referring to the above-mentioned method of I-3-1, which will not be described in detail here. The synthesis route is as follows:

[0083]

[0084] (3) Synthesis of the first host material of formula I-3-3

[0085] 4-Bromo-5-fluoro-2-iodobenzaldehyde (1 eq), 2-formylphenylboronic acid (1 eq), K2CO3 (2 eq) were added to the reactor and replaced with nitrogen three times, Pd(Ph3)4 (0.02 eq) was added and replaced with nitrogen three times, and then H2O and THF mixture was added as solvent and placed under nitrogen, and then heated to reflux for 12 hours. After the reaction was completed, the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate Id-6.

[0086] Under nitrogen conditions, intermediate Id-6 (1 eq) was added to AcOH and stirred at 0°C, hydrazine hydrate (1 eq) was slowly injected, and then stirred and refluxed for 12 h, and the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate Ie-6.

[0087] Intermediate Ie-6 (1 eq) and NCS (1 eq) were added to a reactor and replaced with nitrogen three times. Chloroform was added as a solvent and replaced with nitrogen three times. The mixture was stirred at room temperature for 6 h. The organic layer was separated after washing with water twice. The solvent was then removed under reduced pressure and the crude product was purified by column chromatography to obtain intermediate If-6.

[0088] The intermediate If-6 (1 eq), 2-hydroxyphenylboronic acid (1 eq), K2CO3 (2 eq) were added to the reactor and replaced with nitrogen three times, Pd(Ph3)4 (0.02 eq) was added and replaced with nitrogen three times, and then H2O and THF mixture was added as solvent and placed under nitrogen, and then heated to reflux for 12 hours. After the reaction was completed, the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain the intermediate Ig-6.

[0089] Intermediate Ig-6 (1 eq) and K2CO3 (3 eq) were added to a reactor and replaced with nitrogen three times, DMAc was added as a solvent, replaced with nitrogen three times, stirred and refluxed for 9 h, and cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate IA-6.

[0090] Weigh IA-6 series (1eq), IB (1-1.1eq), sodium tert-butoxide (2-3eq) and add them to the reaction bottle in sequence, replace with nitrogen three times, then add toluene as solvent, replace with nitrogen three times, then add Pd2(dba)3 (0.02eq) and P(t-Bu)3 (0.022eq), replace with nitrogen three times, under nitrogen protection, heat to reflux reaction for 24h, cool to 25°C, add purified water, stir for 30min, stand for stratification, separate the liquids, and purify the crude product by column chromatography to obtain intermediate I-3-3. The specific synthetic route is as follows:

[0091]

[0092] 5. Synthesis of the Second Main Material

[0093] (1) Under nitrogen atmosphere, reactant 1 (1 eq), reactant 2 (1 eq), and potassium carbonate (2 eq) were weighed and added to the reaction system in sequence, and then toluene, ethanol, water (volume ratio = 2:1:1) and Pd(PPh3)4 (0.02 eq) were added. The mixture was refluxed at 90°C for 24 h under nitrogen protection, cooled to 25°C, filtered, and solid column chromatography was performed to obtain intermediate 2-1.

[0094] (2) Under a nitrogen atmosphere, weigh the intermediate 2-1 (1 eq), reactant 3 (1 eq), and potassium carbonate (2 eq) and add them to the reaction system in sequence, then add toluene, ethanol, water (volume ratio = 2:1:1) and Pd(PPh3)4 (0.02 eq), reflux at 90°C for 24 h under nitrogen protection, cool to 25°C, filter, and perform solid column chromatography to obtain the intermediate 2-2.

[0095] (3) Under nitrogen atmosphere, intermediate 2-2 (1 eq), reactant 4 (1 eq), and potassium carbonate (2 eq) were weighed and added to the reaction system in sequence, and toluene, ethanol, water (volume ratio = 2:1:1) and Pd(PPh3)4 (0.02 eq) were added. The mixture was refluxed at 90°C for 24 h under nitrogen protection, cooled to 25°C, filtered, and subjected to solid column chromatography to obtain general formula 2. The synthetic route is as follows:

[0096]

[0097] On the other hand, the present invention further provides an organic electroluminescent material, which comprises the above-mentioned dual host material.

[0098] In one embodiment of the present invention, the organic electroluminescent material further includes a doping material.

[0099] In one embodiment of the present invention, the mass ratio of the dual host material to the doping material in the organic electroluminescent material is (5-199):1; preferably (5-100):1, and more preferably (5-15):1.

[0100] The present invention also provides an organic electroluminescent device, which comprises the dual host material or the organic electroluminescent material.

[0101] In one embodiment of the present invention, the organic electroluminescent device comprises a first electrode, a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer and a second electrode arranged in sequence; the material of the light-emitting layer comprises the dual host material according to the first aspect or the organic electroluminescent material according to the second aspect.

[0102] In one embodiment of the present invention, the preparation method of the light-emitting layer includes but is not limited to forming the light-emitting layer from the organic electroluminescent material by solution coating and vacuum deposition; herein, solution coating refers to spin coating, dip coating, inkjet printing, screen printing, spraying, etc., but is not limited thereto.

[0103] In one embodiment of the present invention, the first electrode is an anode.

[0104] As the anode material, in order to enable holes to be smoothly injected into the organic layer, a material with a large work function is preferably used. Anode materials that can be used in the present invention include: metals, such as vanadium, chromium, copper, zinc and other metals or their alloys; metal oxides, such as zinc oxide, indium oxide, indium tin oxide (ITO) or indium zinc oxide (IZO); combinations of metals and oxides, such as ZnO / Al or SnO2 / Sb; conductive polymers, such as poly (3-methylthiophene), polypyrrole or polyaniline; but not limited thereto. In some embodiments of the present invention, the anode is an ITO anode.

[0105] In one embodiment of the present invention, the material of the hole injection layer is selected from one or more of metal porphyrins, oligothiophenes, arylamine-based organic materials, benzonitrile-based organic materials, quinacridone-based organic materials, polyaniline-based and polythiophene-based conductive polymers.

[0106] The material of the hole injection layer is a material that receives holes from the anode at a low voltage, and the highest occupied molecular orbital (HOMO) of the material of the hole injection layer is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer.

[0107] In one embodiment of the present invention, the material of the hole transport layer is selected from one or more of an organic material based on arylamine, a conductive polymer, and a block copolymer having both a conjugated portion and a non-conjugated portion. The material of the hole transport layer is 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.

[0108] In one embodiment of the present invention, the electron transport layer is selected from one or more of Al complexes of 8-hydroxyquinoline and organic free radical compounds, but is not limited thereto.

[0109] In one embodiment of the present invention, the thickness of the electron transport layer is 1 nm to 50 nm.

[0110] For example, 1nm, 2nm, 4nm, 6nm, 8nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm.

[0111] The electron transport layer can prevent the electron transport characteristics from decreasing and prevent the driving voltage from increasing due to the electron transport layer being too thick, thus promoting electron transport. The material of the electron transport layer is used to receive electrons from the cathode and transfer the electrons to the light-emitting layer, and has high electron mobility.

[0112] In one embodiment of the present invention, the electron injection layer is selected from one or more of fluorenone, anthraquinone dimethane, diphenoquinone, thiopyran dioxide, imidazole, perylene tetracarboxylic acid, fluorenyl methane, anthrone or its derivatives, metal complexes, and nitrogen-containing five-membered ring derivatives, but is not limited thereto.

[0113] The electron injection layer can promote electron injection, and the electron injection material preferably has the ability to transport electrons, has an effect of injecting electrons 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 excellent thin film forming ability.

[0114] In one embodiment of the present invention, the second electrode is a cathode.

[0115] In order to facilitate the injection of electrons into the organic layer, the cathode material is preferably a material with a small work function. Specific examples of cathode materials include: metals, such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, lead and other metals or alloys thereof; multilayer structure materials, such as LiF / Al or LiO2 / Al; but not limited thereto. In some embodiments of the present invention, the cathode material is Al.

[0116] In one embodiment of the present invention, the organic electroluminescent device may be a top emission type, a bottom emission type or a double-side emission type.

[0117] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0118] The system refers to an equipment system, a device system or a production device.

[0119] Compared with the prior art, the present invention has the following beneficial effects:

[0120] The present invention provides an organic electroluminescent material with dual host materials, which adopts a first host compound with a specific structure and a second host compound with a specific structure as the light-emitting layer material of an organic electroluminescent device, can reduce the driving voltage, improve the luminous efficiency of the organic electroluminescent device, and prolong the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0121] Figure 1 It is the hydrogen nuclear magnetic resonance spectrum of compound H1-11 provided in the examples of the present invention. DETAILED DESCRIPTION

[0122] 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.

[0123] Preparation of the first main compound H1-1

[0124] (1) 3-bromodibenzofuran (156 mmol), (3-chloro-[1,1-biphenyl]-2-yl)boric acid (156 mmol), and potassium carbonate (312 mmol) were introduced into a reactor and replaced with nitrogen three times. THF and water were added, and Pd(Ph3)4 (1.56 mmol) was added under nitrogen protection, and refluxed for 12 hours. After the reaction was completed, the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate H1-a-1. (38.96 g, yield 70%, HPLC>99%, mass spectrometry test: theoretical value 356.85, test value 356.79).

[0125] (2) Intermediate H1-a-1 (109 mmol) was mixed with dichloromethane (CH2Cl2), FeCl3 (1.09 mol) was added to the mixture, and the mixture was stirred for 1 hour. After the reaction was completed, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate H1-A-1 (24.22 g, yield 63%, HPLC>99%, mass spectrometry test: theoretical value 352.82, test value 352.88).

[0126]

[0127] (3) Under nitrogen protection, weigh the intermediate 3,3-bicarbazole (59.81 mmol), bromobenzene (59.81 mmol), sodium tert-butoxide (119.63 mmol) in a reaction bottle, add 200 mL of toluene, add catalysts Pd2(dba)3 (1.19 mmol) and P(t-Bu)3 (1.31 mmol) under nitrogen protection, reflux at 120°C for 24 h under nitrogen protection, then cool to 25°C, add 200 mL of purified water, stir for 30 min, let stand to separate, separate the layers, and perform column chromatography to obtain the intermediate H1-B-1 (15.88 g, yield 65%, HPLC>99%, mass spectrometry test: theoretical value 408.50, test value 408.75), the reaction route is shown below.

[0128]

[0129] (4) Under nitrogen protection, weigh the intermediate H1-A-1 (38.87 mmol), H1-B-1 (38.87 mmol), sodium tert-butoxide (77.74 mmol) into a reaction bottle, add 200 mL of toluene, add catalysts Pd2(dba)3 (0.77 mmol) and P(t-Bu)3 (0.86 mmol) under nitrogen protection, reflux at 120°C for 24 h under nitrogen protection, then cool to 25°C, add 200 mL of purified water, stir for 30 min, let stand to separate, separate the layers, and perform column chromatography to obtain the first main compound H1-1 (20.56 g, yield 73%, HPLC>99%, mass spectrometry test: theoretical value 724.86, test value 724.88), the reaction route is shown below.

[0130]

[0131] Preparation of the first host compound H1-11

[0132] (1) Under nitrogen protection, weigh the intermediate 3,3-bicarbazole (59.81 mmol), 4-bromobiphenyl-D9 (59.81 mmol), sodium tert-butoxide (119.62 mmol) in a reaction bottle, add 200 mL of toluene, add catalyst Pd2(dba)3 (1.19 mmol) and P(t-Bu)3 (1.31 mmol) under nitrogen protection, reflux at 120°C for 24 h under nitrogen protection, then cool to 25°C, add 200 mL of purified water, stir for 30 min, stand for stratification, separate the layers, and perform column chromatography to obtain the intermediate H1-B-1 (19.48 g, yield 66%, HPLC>99%, mass spectrometry test: theoretical value 493.66, test value 493.78), the reaction route is shown below.

[0133]

[0134] (2) Under nitrogen protection, weigh the intermediate H1-A-11 (39.46 mmol), H1-B-11 (39.46 mmol), sodium tert-butoxide (78.92 mmol) in a reaction bottle, add 200 mL of toluene, add catalysts Pd2(dba)3 (0.79 mmol) and P(t-Bu)3 (0.87 mmol) under nitrogen protection, reflux at 120°C for 24 h under nitrogen protection, then cool to 25°C, add 200 mL of purified water, stir for 30 min, let stand to separate, separate the layers, and perform column chromatography to obtain the first main compound H1-11 (24.30 g, yield 76%, HPLC>99%, mass spectrometry test: theoretical value 810.02, test value 810.21), the reaction route is shown below.

[0135]

[0136] Preparation of the second main compound H2-1

[0137] 2-Chloro-4,6-diphenyl-1,3,5-triazine (74.71 mmol), 3-(phenyl-2,3,4,5,6-D5)-9H-carbazole (74.71 mmol) potassium carbonate (149.42 mmol) were introduced into the reactor and replaced with nitrogen three times, THF and water were added, and Pd(Ph3)4 (1.49 mmol) was added under nitrogen protection and refluxed for 12 hours. After the reaction was completed, the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain the first main compound H2-1 (29.48 g, yield 71%, HPLC>99%, mass spectrometry test: theoretical value 555.70, test value 555.83), the reaction route is as follows:

[0138]

[0139] Preparation of the second host compound H2-67

[0140] Under nitrogen protection system, 2-chloro-4,6-diphenyl-1,3,5-triazine (74.71mmol), 9-phenyl-2,3'-bicarbazole (74.71mmol), sodium tert-butoxide (149.42mmol) were weighed into a reaction bottle, 200mL of toluene was added, catalyst Pd2(dba)3 (1.49mmol) and P(t-Bu)3 (1.64mmol) were added under nitrogen protection, refluxed at 120℃ for 24h under nitrogen protection, then cooled to 25℃, 200mL of purified water was added, stirred for 30min, and then allowed to stand for stratification, separated, and column chromatography was performed to obtain the first main compound H2-67 (32.50g, yield 68%, HPLC>99%, mass spectrometry test: theoretical value 639.76, test value 639.98), the synthesis route is as follows:

[0141]

[0142] In addition, it should be noted that other compounds of the present invention can be obtained by referring to the synthesis methods of the above-mentioned embodiments, so they are not listed one by one here.

[0143] Examples 1 to 24, Comparative Examples 1 to 3, Parallel Comparative Examples 1-10:

[0144] Examples 1 to 24, Comparative Examples 1 to 3, and Parallel Comparative Examples 1-10 respectively provide a main material, and the combination of the main materials is shown in Table 1, wherein, for the scheme in which the dual main material includes a first main compound and a second main compound, the mass ratio of the first main compound to the second main compound is 60:40; in Table 1, "-" indicates that the compound is not present in the main material; the structures of D-1 and D-2 are respectively shown below.

[0145]

[0146] Table 1

[0147]

[0148]

[0149] Preparation of organic electroluminescent devices

[0150] The preparation method of the organic electroluminescent device is as follows:

[0151] (1) An ITO (indium tin oxide) glass substrate with a thickness of 1500 angstroms was cleaned twice in distilled water and ultrasonically cleaned for 30 minutes. It was then repeatedly cleaned twice in distilled water and ultrasonically cleaned for 10 minutes. After washing, it was ultrasonically cleaned in methanol, acetone, and isopropanol in sequence (each time for 5 minutes), dried, and then transferred to a plasma cleaning machine for washing for 5 minutes to obtain an ITO anode.

[0152] (2) In an evaporation machine, vacuum evaporate HIL on the surface of the ITO anode obtained in step (1) to a thickness of 700 angstroms to obtain a hole injection layer. The HIL structure is as follows:

[0153]

[0154] (3) On the surface of the hole injection layer obtained in step (2), HTL is vacuum-evaporated to form a hole transport layer with a thickness of 50 angstroms for HTL1 and 700 angstroms for HTL2. The structure of HTL is as follows:

[0155]

[0156] (4) Evaporating the light-emitting layer material on the surface of the hole transport layer, using a multi-source co-evaporation method to perform linear gradient co-evaporation with a thickness of 300 angstroms to obtain a light-emitting layer; the material of the light-emitting layer includes a dual host material and a doping material, the mass ratio of the first host compound and the second host compound in the dual host material is 60:40, and the mass ratio of the dual host material to the doping material is 10:1, and the dual host materials are respectively the host materials provided in Examples 1 to 24, Comparative Examples 1 to 3, and Parallel Comparative Examples 1 to 10; the structure of the doping material is as follows:

[0157]

[0158] (5) BAlq was evaporated on the surface of the light-emitting layer obtained in step (4) to a thickness of 100 angstroms to form a hole blocking layer with the following structure:

[0159]

[0160] (6) Vacuum evaporation of ETL with a thickness of 300 angstroms was performed on the surface of the hole blocking layer obtained in step (5) to obtain an electron transport layer. The structure of the ETL is as follows:

[0161]

[0162] (7) Vacuum evaporating Liq on the surface of the electron transport layer obtained in step (6) to a thickness of 15 angstroms to obtain an electron injection layer.

[0163]

[0164] (8) 1200 angstroms of Al is evaporated on the surface of the electron injection layer obtained in step (7) to form a cathode, thereby obtaining the organic electroluminescent device.

[0165] The driving voltage, luminous efficiency, and time (lifetime; T95) of the organic electroluminescent device at a brightness of 15,000 nits were tested, and the test results are shown in Table 2.

[0166] Table 2

[0167]

[0168]

[0169] By comparing Comparative Example 3 with Comparative Examples 1 to 2, it can be seen that the main material of the light-emitting layer is a compound of the first main compound and the second main compound, which can greatly improve the luminous efficiency and service life. Selecting only any one of them will lead to a significant decrease in the luminous efficiency of the device, a significant shortening of the service life, and an increase in voltage.

[0170] By comparing Examples 1 to 24 with Parallel Comparison Examples 1-10, it can be seen that the efficiency of Parallel Comparison Examples 1-10 is 34.0-36.8 cd / A, the driving voltage is 3.31-3.54 V, and the lifespan is 462-484 h, while the luminous efficiency of Examples 1-24 of the present invention is 37.8-43.8 cd / A, which is significantly higher than Parallel Comparison Examples 1-10; the driving voltage is 3.15-3.29 V, which is significantly lower than Parallel Comparison Examples 1-10; and the lifespan is 567-597 h, which is much higher than Parallel Comparison Examples 1-10.

[0171] It can be seen that the main material of the light-emitting layer is a compound of the first main compound of the specific structure of the present invention and the second main compound of the specific structure, which can greatly improve the luminous efficiency and service life. This is because the dual main material provided by the present invention has good hole transport ability and good electron transport ability, so when holes are injected into the p-type main body and electrons are injected into the n-type main body, the driving voltage is reduced, which helps to enhance the life span.

[0172] The specific embodiments described above have detailed descriptions of the objectives, technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An organic electroluminescent compound, characterized in that: The organic electroluminescent compound is a first host compound having a structure represented by general formula (1): wherein G is selected from hydrogen, substituted or unsubstituted C6-C 30 G is fused with or substituted on the adjacent benzene ring; R is independently selected from substituted or unsubstituted C6-C 30 Aryl, C6-C 30 wherein the heteroatom in the heteroaryl group is selected from O, N or S.

2. The organic electroluminescent compound according to claim 1, characterized in that: G is selected from hydrogen, a substituted or unsubstituted benzene ring, and G is fused with or substituted to an adjacent benzene ring.

3. The organic electroluminescent compound according to claim 1, characterized in that: R is independently selected from substituted or unsubstituted C6-C 18 Aryl, substituted or unsubstituted C6-C 15 wherein the heteroatom in the heteroaryl is selected from O or S.

4. The organic electroluminescent compound according to claim 1 or 3, characterized in that: The first main compound of the structure represented by the general formula (1) is represented by the following formula I-1, I-2 or I-3:

5. The organic electroluminescent compound according to claim 1, characterized in that: The first main compound of the structure represented by the general formula (1) has the following structure:

6. An organic electroluminescent material containing a double host, characterized in that: comprising a first host material and a second host material, wherein the first host material is at least one of the organic electroluminescent compounds according to any one of claims 1 to 5; The second host material has a structure shown in general formula (2): Wherein, L1 to L3 are connecting bonds, each independently selected from substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C6-C 30 heteroaryl; Ar1 to Ar3 are each independently selected from substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted 6-30 membered heteroaryl, heteroaryl includes monocyclic aromatic groups and polycyclic aromatic systems with at least one heteroatom, the heteroatom is O, S, N; substituted or unsubstituted C 10 -C 30 A fused ring group.

7. The organic electroluminescent material according to claim 6, characterized in that: Ar1 is selected from C6-C 36 Aryl, substituted or unsubstituted C3-C 30 Heteroaryl, which includes monocyclic aromatic groups and polycyclic aromatic systems containing at least one heteroatom, wherein the heteroatom is O, S, or N; Ar2 and Ar3 are selected from substituted or unsubstituted phenyl, biphenyl, terphenyl; L2 and L3 are selected from connecting bonds; L1 is selected from connecting bonds, unsubstituted C6-C 18 aryl, substituted or unsubstituted C6-C 18 The heteroaryl group is a heteroaryl group, wherein the heteroatom is selected from O, S, and N.

8. The organic electroluminescent material according to claim 7, characterized in that: The second host material has any one of the following structures:

9. The organic electroluminescent material according to any one of claims 6 to 8, characterized in that: The organic electroluminescent material also includes a doping material; the mass ratio of the dual host material to the doping material is (5-199):1; preferably (5-100):1, and more preferably (5-15):

1.

10. An organic electroluminescent device, characterized in that: The invention comprises the organic electroluminescent compound according to any one of claims 1 to 5 or the organic electroluminescent material containing a double host according to any one of claims 6 to 9.

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