Organic electroluminescent compound, organic electroluminescent material containing double host, and light-emitting device

Abstract

The present application provides an organic electroluminescent compound, an organic electroluminescent material containing a double host, and a light-emitting device, the organic electroluminescent material comprising a first host material and a second host material, the first host material being a compound having a structure represented by general formula (1), and the second host material being a compound having a structure represented by general formula (2), by using the specific combination of compounds as the host material in the organic electroluminescent device, the luminous efficiency and service life are improved.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent materials technology, and more specifically, to an organic electroluminescent compound, an organic electroluminescent material containing two main bodies, and a light-emitting device. Background Technology

[0002] Organic electroluminescent devices are self-emissive 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 fields such as smartphones and tablets, and will be expanded to large-size applications such as televisions. However, compared with the requirements of actual product applications, the performance of OLED, such as luminous efficiency and lifespan, still needs to be further improved.

[0004] The luminescent material of an organic light-emitting diode (OLED) device is the most important factor determining the device's luminous efficiency and can be functionally divided into host materials and dopant materials. Luminescent materials can be used by mixing host and dopant materials to improve color purity, luminous efficiency, and stability. Typically, devices with excellent electroluminescence (EL) characteristics have a structure in which a luminescent layer is formed by incorporating dopant into the host. When using such a dopant / host material system as the luminescent material, the selection of the host material is crucial because it significantly affects the efficiency and lifetime of the OLED device.

[0005] Therefore, the urgent task at present is to develop OLEDs with high efficiency and long lifespan. In particular, considering the EL characteristics required for medium and large OLED panels, it is imperative to develop highly superior luminescent materials that are better than conventional luminescent materials. Summary of the Invention

[0006] The purpose of this invention is to provide an organic electroluminescent compound, an organic electroluminescent material containing two main bodies, and a light-emitting device. The organic electroluminescent material includes a first main body material and a second main body material. The first main body material is a compound having the structure shown in general formula (1), and the second main body material is a compound having the structure shown in general formula (2). By using a specific combination of compounds as the main body material in an organic electroluminescent device, the luminous efficiency and service life are improved.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

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

[0009]

[0010] General formula (1)

[0011] Wherein, G is selected from hydrogen, substituted or unsubstituted C6-C. 30 The aryl group; G can be fused with or substituted with the adjacent benzene ring;

[0012] R is independently selected from substituted or unsubstituted C6-C. 30 aryl, C6-C 30 The heteroaryl group; wherein the heteroatom in the heteroaryl group is selected from O, N or S.

[0013] In one embodiment of the present invention, G is selected from hydrogen, substituted or unsubstituted benzene rings, fused with or substituted with adjacent benzene rings.

[0014] In one embodiment of the invention, R is independently selected from substituted or unsubstituted C6-C. 18 aryl, substituted or unsubstituted C6-C 15 The heteroaryl group; wherein the heteroatom in the heteroaryl group is selected from O or S.

[0015] 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 aryl groups.

[0016] In one embodiment of the present invention, all hydrogen atoms in general formula (1) may be completely unsubstituted by deuterium, completely substituted by deuterium, or partially substituted by deuterium.

[0017] In one embodiment of the present invention, the structure shown in formula (1) can be represented by formula I-1, I-2 or I-3.

[0018]

[0019] In equations I-1, I-2, and I-3, R is defined as described above.

[0020] In one embodiment of the present invention, the organic electroluminescent compound has any one of the following structures, but is not limited thereto:

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] .

[0027] The above are some specific structural forms of the main material, but are not limited to the chemical structures listed. All compounds with simple transformations of groups within the defined range based on the general structural formula shown in formula (1) should be included.

[0028] On the other hand, the present invention also provides an organic electroluminescent material containing two hosts, the organic electroluminescent material comprising a first host material and a second host material, wherein the first host material has at least one of the organic electroluminescent compounds shown in general formula (1).

[0029] The second main material has the structure shown in general formula (2):

[0030]

[0031] General formula (2)

[0032] Among them, L1 to L3 are selected from connecting bonds, substituted or unsubstituted (C6-C) 30 ) aryl, substituted or unsubstituted (C6-C 30 ) heteroaryl;

[0033] Ar1 to Ar3 are each independently selected from substituted or unsubstituted (C6-C) groups. 30 ) aryl, substituted or unsubstituted 6-30 membered heteroaryl groups, heteroaryl groups including monocyclic aromatic groups and polycyclic aromatic systems with at least one heteroatom, heteroatoms including but not limited to O, S, N; substituted or unsubstituted (C 10 -C 30 Fused ring groups.

[0034] In one embodiment of the present invention, Ar1 is selected from C6-C atoms that are unsubstituted or substituted with one or more deuterium, cyano, or methyl groups. 36 aryl, substituted or unsubstituted C3-C 30 Heteroaryl groups include monocyclic aromatic groups and polycyclic aromatic systems with at least one heteroatom, where the heteroatom includes, but is not limited to, O, S, and N.

[0035] Ar2 and Ar3 are selected from unsubstituted or substituted phenyl, biphenyl, and terphenyl groups; L2 and L3 are selected from linkages; L1 is selected from linkages and unsubstituted C6-C groups. 18 aryl, unsubstituted or substituted C6-C 18 The heteroaryl group, wherein the heteroatom is selected from O, S, and N.

[0036] The "substitution" is selected from deuterium, cyano, methyl, C6-C. 24 aryl, C6-C 24 The heteroaryl group, wherein the heteroatom is selected from O, S, and N.

[0037] In the above technical solution, the second main material has any one of the following structures, but is not limited to these:

[0038]

[0039]

[0040] 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), with simple transformations of groups L1 to L3 and Ar1 to Ar3 within the range of groups defined above, should be included.

[0041] This invention also provides a method for preparing an organic electroluminescent material containing two main bodies, specifically including methods for preparing the first main body material and the second main body material, the specific steps of which are as follows:

[0042] I. Preparation method of intermediate IA:

[0043] 3-Bromodibenzofuran (1 eq), chlorophenylboronic acid (1 eq), and K₂CO₃ (2 eq) were added to the reactor and purged with nitrogen three times. A mixture of H₂O and THF was added as a solvent and purged with nitrogen three times. Pd(PPh₃)₄ (0.01 eq) was then added and purged with nitrogen three times. The mixture was heated under reflux for 12 hours under nitrogen protection. After the reaction was complete, 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.

[0044]

[0045] The above intermediates (1 eq) were mixed with dichloromethane (CH2Cl2), and FeCl3 (10 eq) was added to the mixture. 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 I-A-1, I-A-2, and I-A-3.

[0046] II. Preparation method of intermediate IB:

[0047] IB-1 series (1 eq), IB-2 (1-1.1 eq), and sodium tert-butoxide (2-3 eq) were weighed and added sequentially to a reaction flask. The mixture was purged with nitrogen three times. Toluene was then added as solvent, and the mixture was purged with nitrogen three times. Pd2(dba)3 (0.02 eq) and P(t-Bu)3 (0.022 eq) were then added, and the mixture was purged with nitrogen three times. Under nitrogen protection, the mixture was heated to reflux and reacted for 24 h. After cooling to 25 °C, purified water was added, and the mixture was stirred for 30 min. The mixture was allowed to stand and separate into layers. The crude product was purified by column chromatography to obtain intermediate IB. The synthetic route is as follows:

[0048]

[0049] III. Synthesis of the first host material shown in general formulas I-1 and I-2:

[0050] IA series (1 eq), IB (1-1.1 eq), and sodium tert-butoxide (2-3 eq) were weighed and added sequentially to a reaction flask. The mixture was purged with nitrogen three times. Toluene was then added as solvent, and the mixture was purged with nitrogen three times. Pd₂(dba)₃ (0.02 eq) and P(t-Bu)₃ (0.022 eq) were then added, and the mixture was purged with nitrogen three times. Under nitrogen protection, the mixture was heated to reflux and reacted for 24 h. After cooling to 25 °C, purified water was added, and the mixture was stirred for 30 min. The mixture was allowed to stand and separate into layers. The crude product was purified by column chromatography to obtain general formulas I-1 and I-2. The synthetic route is as follows:

[0051]

[0052] IV. Synthesis of the first host material shown in general formula I-3:

[0053] (1) Synthesis of the first host material of general formula I-3-1

[0054] 2-Bromodibenzofuran (1 eq), chloroformylphenylboronic acid (1 eq), and K₂CO₃ (2 eq) were added to a reactor and purged with nitrogen three times. A mixture of H₂O and THF was added as a solvent and purged with nitrogen three times. Pd(Ph₃)₄ (0.01 eq) was then added and purged with nitrogen three times. The mixture was heated under reflux for 12 hours under nitrogen protection. After the reaction was complete, 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.

[0055] Intermediate Ib-4 (1 eq), (methoxymethyl)triphenylphosphine chloride (1.3 eq), and THF were added to a reaction vessel and stirred for 10 minutes. Potassium tert-butoxide solution was then slowly added dropwise at 0°C. The temperature was then slowly increased, and the mixture was stirred at room temperature for 3 hours. Distilled water was then added. After the reaction was complete, the organic layer was extracted with ethyl acetate, the organic phase was dried over sodium sulfate, and the solvent was removed by rotary evaporation. The mixture was then purified by column chromatography to obtain intermediate Ic-4.

[0056] Intermediate IA-4, boron trifluoride ether, and dichloromethane were added to a reaction vessel and stirred for 3 hours. After the reaction was complete, the organic layer was extracted with dichloromethane and water, dried with sodium sulfate, and the solvent was removed using a rotary evaporator. Subsequently, it was purified by column chromatography to obtain intermediate compound IA-4.

[0057] IA-4 series (1 eq), IB (1-1.1 eq), and sodium tert-butoxide (2-3 eq) were weighed and added sequentially to a reaction flask. The mixture was purged with nitrogen three times. Toluene was then added as solvent, and the mixture was purged with nitrogen three times. Pd2(dba)3 (0.02 eq) and P(t-Bu)3 (0.022 eq) were then added, and the mixture was purged with nitrogen three times. Under nitrogen protection, the mixture was heated to reflux and reacted for 24 h. After cooling to 25 °C, purified water was added, and the mixture was stirred for 30 min. The mixture was allowed to stand and separate into layers. The crude product was purified by column chromatography to obtain intermediate I-3-1. The synthetic route is as follows:

[0058]

[0059] (2) Synthesis of the first main material of general formula I-3-2

[0060] The synthesis method for I-3-2 can refer to the I-3-1 method described above, and will not be elaborated further here. The synthesis route is as follows:

[0061]

[0062] (3) Synthesis of the first main material of general formula I-3-3

[0063] 4-Bromo-5-fluoro-2-iodobenzaldehyde (1 eq), 2-formylphenylboronic acid (1 eq), and K₂CO₃ (2 eq) were added to a reactor and purged with nitrogen three times. Pd(Ph₃)₄ (0.02 eq) was then added and purged with nitrogen three times. A mixture of H₂O and THF was added as a solvent, and the mixture was placed under nitrogen atmosphere and heated to reflux for 12 hours. After the reaction was complete, 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.

[0064] Intermediate Id-6 (1 eq) was added to AcOH under nitrogen atmosphere and stirred while maintaining the temperature at 0°C. Hydrazine hydrate (1 eq) was slowly injected, followed by stirring and reflux for 12 h. The mixture was then 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.

[0065] Intermediate If-6 (1eq) and NCS (1eq) were added to a reactor and purged with nitrogen three times. Chloroform was added as solvent and purged with nitrogen three times. The mixture was stirred at room temperature for 6 hours. After washing twice with water, the organic layer was separated. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate If-6.

[0066] Intermediate If-6 (1 eq), 2-hydroxyphenylboronic acid (1 eq), and K₂CO₃ (2 eq) were added to a reactor and purged with nitrogen three times. Pd(Ph₃)₄ (0.02 eq) was then added and purged with nitrogen three times. A mixture of H₂O and THF was added as a solvent, and the mixture was placed under nitrogen atmosphere and heated to reflux for 12 hours. After the reaction was complete, 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 Ig-6.

[0067] Intermediate Ig-6 (1 eq) and K2CO3 (3 eq) were added to a reactor and purged with nitrogen three times. DMAc was added as a solvent, and the mixture was purged with nitrogen three times. The mixture was stirred and refluxed for 9 h, then 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.

[0068] IA-6 series (1 eq), IB (1-1.1 eq), and sodium tert-butoxide (2-3 eq) were weighed and added sequentially to a reaction flask. The mixture was purged with nitrogen three times. Toluene was then added as solvent, and the mixture was purged with nitrogen three times. Pd2(dba)3 (0.02 eq) and P(t-Bu)3 (0.022 eq) were then added, and the mixture was purged with nitrogen three times. Under nitrogen protection, the mixture was heated to reflux and reacted for 24 h. After cooling to 25 °C, purified water was added, and the mixture was stirred for 30 min. The mixture was allowed to stand and separate into layers. The crude product was purified by column chromatography to obtain intermediate I-3-3. The specific synthetic route is as follows:

[0069]

[0070] V. Synthesis of the Second Main Material

[0071] (1) Under a 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. 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 subjected to solid column chromatography to obtain intermediate 2-1.

[0072] (2) Under a nitrogen atmosphere, intermediate 2-1 (1 eq), reactant 3 (1 eq), and potassium carbonate (2 eq) were weighed and added to the reaction system in sequence. 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 intermediate 2-2.

[0073] (3) Under a 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. 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:

[0074]

[0075] On the other hand, the present invention also provides an organic electroluminescent material, wherein the organic electroluminescent material comprises the above-mentioned dual host material.

[0076] In one embodiment of the present invention, the organic electroluminescent material further includes a dopant material.

[0077] In one embodiment of the present invention, the mass ratio of the dual host material to the doped material in the organic electroluminescent material is (5~199):1; preferably (5~100):1, more preferably (5~15):1.

[0078] The present invention also provides an organic electroluminescent device, wherein the organic electroluminescent device comprises the dual host material or the organic electroluminescent material.

[0079] In one embodiment of the present invention, the organic electroluminescent device includes 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 sequentially; the material of the light-emitting layer includes the dual-host material according to the first aspect or the organic electroluminescent material according to the second aspect.

[0080] In one embodiment of the present invention, the method for preparing 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; here, solution coating means spin coating, dip coating, inkjet printing, screen printing, spraying, etc., but is not limited thereto.

[0081] In one embodiment of the present invention, the first electrode is an anode.

[0082] As the anode material, a material with a high work function is preferred to facilitate the injection of holes into the organic layer. Anode materials usable in this invention include: metals, such as vanadium, chromium, copper, zinc, 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 this invention, the anode is an ITO anode.

[0083] In one embodiment of the present invention, the material of the hole injection layer is selected from one or more of metalloporphyrin, oligothiophene, arylamine-based organic materials, benzonitrile-based organic materials, quinacridone-based organic materials, polyaniline-based and polythiophene-based conductive polymers.

[0084] The material of the hole injection layer is a material that receives holes from the anode at low voltage, and the highest occupied molecular orbital (HOMO) of the hole injection layer material is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer.

[0085] In one embodiment of the present invention, the material of the hole transport layer is selected from one or more of arylamine-based organic materials, conductive polymers, and block copolymers having both conjugated and non-conjugated portions. The material of the hole transport layer is capable of receiving holes from the anode or hole injection layer and transporting the holes to the light-emitting layer, exhibiting high hole mobility.

[0086] In one embodiment of the present invention, the electron transport layer is selected from one or more of 8-hydroxyquinoline Al complexes, organic free radical compounds, but is not limited thereto.

[0087] In one embodiment of the present invention, the thickness of the electron transport layer is 1 nm to 50 nm.

[0088] For example, 1 nm, 2 nm, 4 nm, 6 nm, 8 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40nm, 45 nm, 50nm.

[0089] The electron transport layer prevents a decrease in electron transport characteristics and avoids an increase in driving voltage due to excessive thickness, thus promoting electron transport. The material of the electron transport layer is used to receive electrons from the cathode and transport them to the light-emitting layer, exhibiting high electron mobility.

[0090] In one embodiment of the present invention, the electron-injected layer is selected from one or more of fluorenone, anthraquinone dimethane, biphenylquinone, thiamethane dioxide, imidazole, perylenetetracarboxylic acid, fluorenemethane, anthrone or its derivatives, metal complexes, and nitrogen-containing five-membered ring derivatives, but is not limited thereto.

[0091] The electron injection layer can promote electron injection, and the electron injection material preferably has the ability to transport electrons, has the electron injection effect from the cathode, has an excellent electron injection effect on the light-emitting layer or light-emitting material, prevents excitons generated in the light-emitting layer from migrating to the hole injection layer, and also has excellent thin film forming ability.

[0092] In one embodiment of the present invention, the second electrode is a cathode.

[0093] As a cathode material, a material with a low work function is generally preferred to facilitate the injection of electrons into the organic layer. 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 materials, such as LiF / Al or LiO2 / Al; but are not limited thereto. In some embodiments of the present invention, the cathode material is Al.

[0094] In one embodiment of the present invention, the organic electroluminescent device may be a top-emitting type, a bottom-emitting type, or a dual-sided emitting type.

[0095] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0096] The system refers to an equipment system, device system, or production device.

[0097] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0098] This invention provides an organic electroluminescent material with dual host materials. It uses a first host compound with a specific structure and a second host compound with a specific structure as a light-emitting layer material for an organic electroluminescent device. This material can reduce the driving voltage, improve the luminous efficiency of the organic electroluminescent device, and extend its service life. Attached Figure Description

[0099] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of compound H1-11 provided in the embodiments of the present invention. Detailed Implementation

[0100] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0101] Preparation of the first host compound H1-1

[0102] (1) 3-bromodibenzofuran (156 mmol), (3-chloro-[1,1-biphenyl]-2-yl)boronic acid (156 mmol), and potassium carbonate (312 mmol) were introduced into a reactor and purged with nitrogen three times. THF and water were added, and Pd(Ph3)4 (1.56 mmol) was added under nitrogen protection. The mixture was 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).

[0103] (2) Intermediate H1-a-1 (109 mmol) was mixed with dichloromethane (CH2Cl2), and FeCl3 (1.09 mol) was added to the mixture. 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).

[0104]

[0105] (3) Under nitrogen protection, 3,3-bicarbazole (59.81 mmol), bromobenzene (59.81 mmol), and sodium tert-butoxide (119.63 mmol) were weighed into a reaction flask, and 200 mL of toluene was added. Under nitrogen protection, catalysts Pd2(dba)3 (1.19 mmol) and P(t-Bu)3 (1.31 mmol) were added. The mixture was refluxed at 120 °C for 24 h under nitrogen protection, then cooled to 25 °C, and 200 mL of purified water was added. After stirring for 30 min, the mixture was allowed to stand for separation, and the layers were separated by column chromatography to obtain 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.

[0106]

[0107] (4) Under nitrogen protection, intermediates H1-A-1 (38.87 mmol), H1-B-1 (38.87 mmol), and sodium tert-butoxide (77.74 mmol) were weighed into a reaction flask, and 200 mL of toluene was added. Under nitrogen protection, catalysts Pd2(dba)3 (0.77 mmol) and P(t-Bu)3 (0.86 mmol) were added. The mixture was refluxed at 120 °C for 24 h under nitrogen protection, then cooled to 25 °C, and 200 mL of purified water was added. After stirring for 30 min, the mixture was allowed to stand for separation, and the layers were separated by 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.

[0108]

[0109] Preparation of the first host compound H1-11

[0110] (1) Under nitrogen protection, 3,3-bicarbazole (59.81 mmol), 4-bromobiphenyl-D9 (59.81 mmol), and sodium tert-butoxide (119.62 mmol) were weighed into a reaction flask, and 200 mL of toluene was added. Under nitrogen protection, catalysts Pd2(dba)3 (1.19 mmol) and P(t-Bu)3 (1.31 mmol) were added. The mixture was refluxed at 120 °C for 24 h under nitrogen protection, and then cooled to 25 °C. 200 mL of purified water was added, and the mixture was stirred for 30 min and allowed to stand for separation. The mixture was separated and subjected to column chromatography to obtain intermediate H1-B-1 (19.48 g, yield 66%, HPLC > 99%, mass spectrometry: theoretical value 493.66, test value 493.78). The reaction route is shown below.

[0111]

[0112] (2) Under nitrogen protection, intermediates H1-A-11 (39.46 mmol), H1-B-11 (39.46 mmol), and sodium tert-butoxide (78.92 mmol) were weighed into a reaction flask, and 200 mL of toluene was added. Under nitrogen protection, catalysts Pd2(dba)3 (0.79 mmol) and P(t-Bu)3 (0.87 mmol) were added. The mixture was refluxed at 120 °C for 24 h under nitrogen protection, then cooled to 25 °C, and 200 mL of purified water was added. After stirring for 30 min, the mixture was allowed to stand for separation, and the layers were separated by 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.

[0113]

[0114] Preparation of the second host compound H2-1

[0115] 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), and potassium carbonate (149.42 mmol) were introduced into a reactor, purged three times with nitrogen, and then THF and water were added. Pd(Ph3)4 (1.49 mmol) was added under nitrogen protection, and the mixture was refluxed for 12 hours. After the reaction was complete, 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 give the first main compound H2-1 (29.48 g, yield 71%, HPLC > 99%, mass spectrometry: theoretical value 555.70, measured value 555.83). The reaction route is shown below:

[0116]

[0117] Preparation of the second host compound H2-67

[0118] Under nitrogen protection, 2-chloro-4,6-diphenyl-1,3,5-triazine (74.71 mmol), 9-phenyl-2,3'-bicarbazole (74.71 mmol), and sodium tert-butoxide (149.42 mmol) were weighed into a reaction flask, and 200 mL of toluene was added. Under nitrogen protection, catalysts Pd₂(dba)₃ (1.49 mmol) and P(t-Bu)₃ (1.64 mmol) were added. The mixture was refluxed at 120 °C for 24 h under nitrogen protection, then cooled to 25 °C, and 200 mL of purified water was added. After stirring for 30 min, the mixture was allowed to stand for separation, and the layers were separated by column chromatography to obtain the first main compound H₂-67 (32.50 g, yield 68%, HPLC > 99%, mass spectrometry: theoretical value 639.76, measured value 639.98). The synthetic route is as follows:

[0119]

[0120] In addition, it should be noted that other compounds of the present invention can be obtained by referring to the synthesis methods of the examples listed above, so they will not be listed one by one here.

[0121] Examples 1-24, Comparative Examples 1-3, and Parallel Comparative Examples 1-10:

[0122] Examples 1-24, Comparative Examples 1-3, and Parallel Comparative Examples 1-10 each provide a host material, and the combination of the host materials is shown in Table 1. For the scheme with two host materials including a first host compound and a second host compound, the mass ratio of the first host compound and the second host compound is 60:40. In Table 1, "-" indicates that the host material does not contain the compound. The structures of D-1 and D-2 are shown below.

[0123]

[0124] Table 1

[0125]

[0126]

[0127] Fabrication of organic electroluminescent devices

[0128] The fabrication method of organic electroluminescent devices is as follows:

[0129] (1) The ITO (indium tin oxide) glass substrate with a thickness of 1500 angstroms was washed twice with distilled water and ultrasonically washed for 30 min. Then it was washed twice with distilled water and ultrasonically washed for 10 min. After washing, it was ultrasonically washed sequentially with methanol, acetone and isopropanol (5 min each time), dried, and then transferred to a plasma cleaner for 5 min to obtain the ITO anode.

[0130] (2) In a vapor deposition machine, HIL is vacuum-deposited onto the ITO anode surface obtained in step (1) to a thickness of 700 angstroms, resulting in a hole injection layer. The structure of HIL is as follows:

[0131]

[0132] (3) HTLs are vacuum-deposited on the surface of the hole injection layer obtained in step (2), with HTL1 having a thickness of 50 angstroms and HTL2 reaching a thickness of 700 angstroms to form a hole transport layer. The HTL structure is as follows:

[0133]

[0134] (4) A light-emitting layer material is deposited on the surface of the hole transport layer by evaporation using a multi-source co-evaporation method with a linear gradient co-evaporation thickness of 300 angstroms to obtain the light-emitting layer. The material of the light-emitting layer includes a dual host material and a doped 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 doped material is 10:1. The dual host materials are the host materials provided in Examples 1-24, Comparative Examples 1-3, and Parallel Comparative Examples 1-10, respectively. The structure of the doped material is as follows:

[0135]

[0136] (5) A 100 angstrom thickness of BAlq is deposited on the surface of the light-emitting layer obtained in step (4) to form a hole-blocking layer, with the following structure:

[0137]

[0138] (6) Vacuum evaporation of ETL on the surface of the hole blocking layer obtained in step (5) with a thickness of 300 angstroms is performed to obtain the electron transport layer. The ETL structure is as follows:

[0139]

[0140] (7) A Liq layer with a thickness of 15 angstroms is vacuum-deposited on the surface of the electron transport layer obtained in step (6); an electron injection layer is obtained.

[0141]

[0142] (8) A 1200 angstrom layer of Al is deposited on the surface of the electron injection layer obtained in step (7) to form a cathode, thereby obtaining the organic electroluminescent device.

[0143] The driving voltage, luminous efficiency, and time (lifetime; T95) of the organic electroluminescent device at a brightness of 15000 nits were tested. The test results are shown in Table 2.

[0144] Table 2

[0145]

[0146]

[0147] As can be seen from the comparison between Comparative Example 3 and Comparative Examples 1 and 2, the main material of the light-emitting layer is a combination of the first main compound and the second main compound, which can significantly improve the luminous efficiency and lifespan. Using only one of them will result in a significant reduction in the luminous efficiency of the device, a significant shortening of the lifespan, and an increase in voltage.

[0148] A comparison of Examples 1-24 with Parallel Comparative Examples 1-10 shows that the efficiency of Parallel Comparative Examples 1-10 is 34.0-36.8 cd / A, the driving voltage is 3.31-3.54 V, and the lifetime is 462-484 h. In contrast, the luminous efficiency of Examples 1-24 of the present invention is 37.8-43.8 cd / A, which is significantly higher than that of Parallel Comparative Examples 1-10; the driving voltage is 3.15-3.29 V, which is significantly lower than that of Parallel Comparative Examples 1-10; and the lifetime is 567-597 h, which is much higher than that of Parallel Comparative Examples 1-10.

[0149] Therefore, it can be seen that the main material of the light-emitting layer, which is a combination of a first main compound with a specific structure and a second main compound with a specific structure according to the present invention, can significantly improve luminous efficiency and lifespan. This is because the dual main material provided by the present invention has good hole transport capability and good electron transport capability. Therefore, 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 lifespan.

[0150] The specific embodiments described above have provided a detailed explanation of the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely 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 within the protection scope of the present invention.

Claims

1. An organic electroluminescent material containing two main components, characterized in that: It includes a first main body material and a second main body material, wherein the first main body material is represented by the following formula I-4 or I-5: ； R is independently selected from substituted or unsubstituted C6-C. 18 aryl, substituted or unsubstituted C6-C 15 The heteroaryl group; wherein the heteroatom in the heteroaryl group is selected from O or S; The substituents of the "substituted" group are 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 aryl groups; The second main material has any one of the following structures: 。 2. An organic electroluminescent material containing two main components, characterized in that: It comprises a first main material and a second main material, wherein the first main material has the following structure: ； The second main material has any one of the following structures: 。 3. The organic electroluminescent material containing two main bodies as described in claim 1, characterized in that: The organic electroluminescent material also includes a doped material; the mass ratio of the dual host material to the doped material is (5~199):

1.

4. The organic electroluminescent material containing two main bodies as described in claim 3, characterized in that: The mass ratio of the dual host material to the doped material is (5~100):

1.

5. The organic electroluminescent material containing two main bodies as described in claim 4, characterized in that: The mass ratio of the dual host material to the doped material is (5~15):

1.

6. An organic electroluminescent device, characterized in that: Including the organic electroluminescent material with a dual host as described in any one of claims 1-5.

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