Host compound, double-host material and organic electroluminescent device

Abstract

The invention provides a host compound, a dual-host material and an organic electroluminescent device, and belongs to the technical field of organic photoelectric materials, the host compound has a structure as shown in formula I. The dual-host material comprises a first host compound and a second host compound, the first host compound is a host compound with a structure as shown in a formula I; and the second host compound has a structure as shown in a formula II. The first host compound with the specific structure has higher hole mobility, the second host compound has higher electron mobility, and the first host compound and the second host compound with the specific structures are compounded, so that the hole mobility and the electron mobility can be balanced; by adding excitons in the light-emitting layer, the double-main-body material not only can improve the light-emitting efficiency and prolong the service life of a device, but also can reduce the driving voltage.

Description

Technical Field

[0001] This invention belongs to the field of organic optoelectronic materials technology, specifically relating to a host compound, a dual host material, and an organic electroluminescent device. Background Technology

[0002] Since its discovery, organic light-emitting diode (OLED) technology has achieved rapid development over the past few decades thanks to its unique advantages in the display and lighting fields, such as high contrast and wide viewing angle brought by self-emissive properties, as well as its thinness and flexibility.

[0003] Organic electroluminescent devices typically consist of a multilayer structure, including a substrate, an anode, a hole injection layer (HIL), a hole transport layer (HTL), an emissive layer (EML), an electron transport layer (ETL), an electron injection layer (EIL), and a cathode. When a voltage is applied to the anode and cathode, an electric field is generated between the electrodes. Under the influence of this electric field, electrons on the cathode side move towards the emissive layer, and holes on the anode side also move towards the emissive layer. Electrons and holes combine in the emissive layer to form excitons. These excitons are in an excited state and release energy, causing the emissive layer to emit light. The host material in the emissive layer has a significant impact on device performance. Traditional single-host materials need to simultaneously perform electron and hole transport functions. However, single-host materials cannot meet the high-performance requirements in terms of efficiency and lifespan, leading to the development of dual-host materials.

[0004] However, in dual-host luminescent materials, the energy matching and charge transfer processes between the different host and guest components are not yet perfect. In some cases, incomplete energy transfer or charge accumulation in the host material can occur, preventing some excitons from being effectively converted into photons, thus reducing the overall luminescent efficiency and limiting further improvements in the luminescent efficiency and lifetime of dual-host materials.

[0005] Organic electroluminescent dual-host materials still face many challenges in current research and application. There is an urgent need for more dual-host materials to solve the problems existing in the above-mentioned technologies and promote the further development of OLED technology in the fields of display and lighting. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a host compound, a dual-host material, and an organic electroluminescent device. The first host compound of the present invention exhibits a faster hole mobility, and the second host compound exhibits a faster electron mobility. By combining the first and second host compounds with specific structures, the present invention can balance hole and electron mobilities. This allows the dual-host material to increase excitons in the light-emitting layer, thereby improving the device's luminous efficiency and lifespan while reducing the driving voltage.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] On one hand, the present invention provides a host compound having the structure shown in Formula I:

[0009] ;

[0010] Wherein, ring A is selected from substituted or unsubstituted phenanthrene, substituted or unsubstituted anthracene;

[0011] Ring B and ring C are each independently selected from substituted or unsubstituted C6~C42 aryl, substituted or unsubstituted C6~C30 heteroaryl, substituted or unsubstituted C10~C30 fused ring, or substituted or unsubstituted C10~C42 aromatic amino; and at least one of ring B and ring C is selected from substituted or unsubstituted C10~C42 aromatic amino.

[0012] Z is selected from O or S;

[0013] m is selected from 0 or 1;

[0014] L1 and L2 are each independently selected from any one of the following: a linking bond, a substituted or unsubstituted C6-C30 arylene, a substituted or unsubstituted C6-C30 heteroarylene, a substituted or unsubstituted C10-C30 fused ring, or a substituted or unsubstituted C10-C42 arylamino.

[0015] In Formula I, all hydrogen atoms are either unsubstituted by deuterium, partially substituted by deuterium, or completely substituted by deuterium.

[0016] In this invention, the connecting key refers to a single key.

[0017] More preferably, ring B and ring C are each independently selected from substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C6-C18 heteroaryl, substituted or unsubstituted C10-C18 fused ring, or substituted or unsubstituted C10-C42 aromatic amino group; and at least one of ring B and ring C is selected from substituted or unsubstituted C10-C42 aromatic amino group.

[0018] More preferably, L1 and L2 are each independently selected from any one of the following: a linking bond, a substituted or unsubstituted C6-C18 arylene, a substituted or unsubstituted C6-C18 heteroarylene, a substituted or unsubstituted C10-C18 fused ring, or a substituted or unsubstituted C10-C30 arylamine.

[0019] According to one embodiment of the present invention, the host compound has a structure shown in any one of formulas IA-IJ:

[0020] ;

[0021] Wherein, ring B and ring C are each independently selected from the following groups that are completely substituted with deuterium, partially substituted with deuterium, or unsubstituted: phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiophene, phenanthryl, benzene-substituted naphthyl, benzene-substituted dibenzofuranyl, benzene-substituted dibenzothiophene, or the following groups:

[0022] ;

[0023] ;

[0024] L1 and L2 are each independently selected from the linking bond and are either completely or partially substituted by deuterium, or unsubstituted, of the following groups: phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiophene, phenanthryl, benzene-substituted naphthyl, benzene-substituted dibenzofuranyl, benzene-substituted dibenzothiophene, or the following groups:

[0025] ;

[0026] in This is the group linkage site, where D represents deuterium.

[0027] Furthermore, the host compound has a structure shown in any one of formulas IH-1 to IH-8:

[0028] .

[0029] In this invention, the heteroaryl group is a monocyclic aromatic group containing at least one heteroatom and / or a polycyclic aromatic cyclic group containing at least one heteroatom, wherein the heteroatom is O, S, N, P, Si or B.

[0030] The term "substitution" means substitution by one, two or more substituents selected from the following or by at least two substituents linked together: cyano, methyl, ethyl, propyl, butyl, tert-butyl, cyclopentane, cyclohexane, phenyl, biphenyl, naphthyl, fluorenyl, dimethylfluorenyl, phenanthrene, triphenylene, furanyl, thiophene, pyrrole, pyridyl, benzofuranyl, benzothiophene, isobenzofuranyl, dibenzofuranyl or dibenzothiophene.

[0031] In this invention, the host compound is any one of the compounds shown in formula H1-1 to formula H1-528, but is not limited thereto:

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038] ;

[0039] Where D represents deuterium.

[0040] In a second aspect, the present invention also provides a dual-host material, the dual-host material comprising a first host compound and a second host compound, wherein the first host compound is the host compound as described above;

[0041] The second host compound has the structure shown in Formula II:

[0042] ;

[0043] L3 and L4 are each independently selected from any one of the following: a linking bond, a substituted or unsubstituted C6-C30 arylene, a substituted or unsubstituted C6-C30 heteroarylene, or a substituted or unsubstituted C10-C30 fused ring group;

[0044] Ar1 and Ar2 are each independently selected from any one of the following: substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C6-C42 heteroaryl, substituted or unsubstituted phosphoxy, substituted or unsubstituted silyl, and substituted or unsubstituted C10-C42 fused cyclic groups;

[0045] Ar3 is selected from substituted or unsubstituted C6-C42 aryl and substituted or unsubstituted C3-C42 heteroaryl groups;

[0046] The heteroaryl group is a monocyclic aromatic group containing at least one heteroatom and / or a polycyclic aromatic ring group containing at least one heteroatom, wherein the heteroatom is O, S, N, P, B or Si.

[0047] The substituents include deuterium, fluorine, cyano, or C1-C6 straight-chain or branched alkyl groups and phenyl groups.

[0048] Furthermore, L3 and L4 are each independently selected from any one of the following: a linking bond, a substituted or unsubstituted C6-C18 arylene, a substituted or unsubstituted C6-C18 heteroarylene, or a substituted or unsubstituted C10-C18 fused ring group.

[0049] Furthermore, Ar1 and Ar2 are each independently selected from any one of substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C6-C18 heteroaryl, substituted or unsubstituted phosphoxy, substituted or unsubstituted silyl, or substituted or unsubstituted C10-C18 fused cyclic groups.

[0050] Furthermore, Ar3 is selected from substituted or unsubstituted C6-C18 aryl groups and substituted or unsubstituted C3-C18 heteroaryl groups.

[0051] Furthermore, L3 and L4 are each independently selected from any one of the following: linking bond, phenylene, naphthylene, thiopheneyl, and furanylene.

[0052] Ar1 and Ar2 are independently selected from phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, anthracene, biphenyl, thiophene, chromyl, furanyl, phenyl-furanyl, furanyl-deuterated phenyl, naphthiophene, phenanthiophene, tri-benzofuranyl, pyrene-furanyl, phenanthiophene, tert-butylphenyl, benzoxazine, phenyl-thiophene, fluorenyl, diphenyl-fluorenyl, dibenzocarbazoyl, naphthiobenzocarbazoyl, phenanthiobenzocarbazoyl, phenylbenzoxazole, phenylnaphthoxazole, and benzene, respectively. The following groups are included: phenanthrene-1, phenylcarbazo-1, phenylnaphtho-1, phenyldibenzofuran-1, phenyldrozo-1, phenyldibenzofluoren-1, phenyltriphenyl-1, phenylbenzothiazole, phenylnaphthothiazole, phenylphenanthrene-1, fluoranyl, phenylyl, pyrene, naphthobenzofluorenyl, peryl, naphthothianyl, triphenylene, phenylnaphthyl, dibenzofuranyl, dibenzothiopheneyl, cyanophenyl, benzophenanthryl, tetraphenylgermanyl, benzonaphthoselenophenolyl, or any one of the following groups:

[0053]

[0054] in This is the group linkage site.

[0055] In this invention, the second host compound is any one of the compounds shown in formula H2-1 to formula H2-408, but is not limited thereto:

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066] ;

[0067] Where D represents deuterium.

[0068] In one embodiment of the present invention, the mass ratio of the first main compound to the second main compound is (10~90):(90~10), for example 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 40:60, 45:55, 50:50, 60:40, 70:30, 80:20 or 90:10, preferably 60~40:40~60.

[0069] In this invention, the defined carbon number range of a group refers to any integer number of carbon atoms included within the defined range. For example, C6-C30 means that the number of carbon atoms in the group can be 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30. The defined carbon number range of other groups is analogous.

[0070] Thirdly, the present invention also provides a method for preparing a host compound having the structure shown in Formula I.

[0071] Synthesis of compound formula I:

[0072] The reaction route for compound I is as follows:

[0073]

[0074] Specific preparation method of compound formula I:

[0075] Under nitrogen protection, raw material A1 (1 eq), raw material A2 (1-1.1 eq), and potassium carbonate (2.5-3 eq) were weighed and added to the reaction system. Toluene, ethanol, water, and catalyst tetra(triphenylphosphine)palladium (0.05-0.1 eq) were added. The mixture was refluxed at 90-100℃ for 20-24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, and purified water was added. After stirring, the mixture was allowed to stand and separate into layers. After separation, the mixture was purified by column chromatography to obtain the intermediate compound I-1 shown.

[0076] Under nitrogen protection, raw material A3 (1 eq), raw material A4 (1-1.1 eq), and potassium carbonate (2.5-3 eq) were weighed and added to the reaction system. Toluene, ethanol, water, and catalyst tetra(triphenylphosphine)palladium (0.05-0.1 eq) were added. The mixture was refluxed at 90-100℃ for 20-24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, and purified water was added. After stirring, the mixture was allowed to stand and separate into layers. After separation, the mixture was purified by column chromatography to obtain the intermediate compound I-2 shown.

[0077] Under nitrogen protection, intermediate compound I-1 (1 eq), raw material A5 (1-1.2 eq), and potassium acetate (2.5-3.0 eq) were added to the reaction system, along with 1,4-dioxane, catalyst tris(dibenzylacetone)dipalladium (0.01-0.02 eq), and ligand x-phos (2-bicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, 0.04-0.08 eq). The reaction was refluxed at 100-110 °C for 18-24 h. After the reaction was completed, the temperature was lowered to 25 °C, purified water was added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain intermediate compound I-3 as shown.

[0078] Under nitrogen protection, intermediate compound I-2 (1 eq), starting material A5 (1-1.2 eq), and potassium acetate (2.5-3.0 eq) were added to the reaction system, along with 1,4-dioxane, catalyst tris(dibenzylacetone)dipalladium (0.01-0.02 eq), and ligand x-phos (2-bicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, 0.04-0.08 eq). The reaction was refluxed at 100-110 °C for 18-24 h. After the reaction was completed, the temperature was lowered to 25 °C, purified water was added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain intermediate compound I-4 as shown.

[0079] Under nitrogen protection, intermediate compound I-3 (1 eq), raw material A6 (1-1.1 eq), and potassium carbonate (2.5-3 eq) were weighed and added to the reaction system. Toluene, ethanol, water, and catalyst tetra(triphenylphosphine)palladium (0.05-0.1 eq) were added. The mixture was refluxed at 90-100℃ for 20-24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, purified water was added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain intermediate compound I-5 as shown.

[0080] Under nitrogen protection, intermediate compound I-5 (1 eq), intermediate compound I-4 (1-1.1 eq), and potassium carbonate (2.5-3.0 eq) were added to the reaction system, along with toluene, ethanol, water, and the catalyst tetra(triphenylphosphine)palladium (0.05-0.1 eq). The mixture was refluxed at 90-100°C for 20-24 hours under nitrogen protection. After the reaction was completed, the mixture was cooled to 25°C, and purified water was added. The mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain compound I.

[0081] In this formula, rings A, B, C, L1, L2, m, and Z are each independently selected from the same range as in Formula I; X is selected from halogens; the halogens include fluorine, chlorine, bromine, or iodine, preferably chlorine or bromine, and most preferably chlorine.

[0082] Fourthly, the present invention also provides a method for preparing a host compound having the structure shown in Formula II.

[0083] In one embodiment of the present invention, the reaction route of the second host compound having the structure shown in Formula II is as follows:

[0084] .

[0085] Specific preparation methods include:

[0086] (1) Under nitrogen protection, reactant 1 (1 eq), reactant 2 (1-1.1 eq), potassium carbonate (2.5-3 eq) were weighed and placed into the reaction system. Toluene, ethanol, water and catalyst tetra(triphenylphosphine)palladium (0.02-0.05 eq) were added. The mixture was refluxed at 90-100℃ for 20-24 h under nitrogen protection. After the reaction was completed, the mixture was cooled to 25℃, purified water was added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain the intermediate compound II-1 shown.

[0087] (2) Under nitrogen protection, weigh intermediate compound II-1 (1 eq), reactant 2-1 (1-1.1 eq), potassium carbonate (2.5-3 eq) and add them to the reaction system. Add toluene, ethanol, water and catalyst tetra(triphenylphosphine)palladium (0.02-0.05 eq). Reflux at 90-100℃ for 20-24 h under nitrogen protection. After the reaction is completed, cool to 25℃, add pure water, stir and let stand to separate the layers. After separation, purify by column chromatography to obtain intermediate compound II-2 as shown.

[0088] (3) Under nitrogen protection, weigh intermediate compound II-2 (1 eq), reactant 2-2 (1-1.1 eq), potassium carbonate (2.5-3 eq) and add them to the reaction system. Add toluene, ethanol, water and catalyst tetra(triphenylphosphine)palladium (0.02-0.05 eq). Reflux at 90-100℃ for 20-24 h under nitrogen protection. After the reaction is completed, cool to 25℃, add pure water, stir and let stand to separate the layers. After separation, purify by column chromatography to obtain the second main compound with the structure shown in formula II.

[0089] Fifthly, the present invention also provides an organic electroluminescent material, wherein the organic electroluminescent material comprises the dual host material.

[0090] Preferably, the organic electroluminescent material further includes a dopant material.

[0091] Preferably, the mass ratio of the dual host material to the dopant material in the organic electroluminescent material is (5~199):1, for example, 5:1, 8:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1, 100:1, 120:1, 130:1, 140:1, 150:1, 160:1, 170:1, 180:1, 190:1, or 199:1. More preferably, it is (5~100):1, and even more preferably, it is (5~15):1.

[0092] In a sixth aspect, the present invention also provides an organic electroluminescent device, the organic electroluminescent device comprising a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode, the organic layer comprising a light-emitting layer, the light-emitting layer comprising the dual host material as described above or the organic electroluminescent material.

[0093] In this invention, the organic layer further includes any one or a combination of at least two of the following: a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

[0094] In this 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; the solution coating method refers to spin coating, dip coating, inkjet printing, screen printing, spraying, etc., but is not limited to these.

[0095] In this invention, the first electrode is the anode.

[0096] In this invention, the anode material is preferably a material with a high work function in order to enable holes to be smoothly injected into the organic layer.

[0097] In this invention, the anode material includes: 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 is not limited thereto.

[0098] In this invention, the anode is an ITO anode.

[0099] In this invention, 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 hole injection layer material is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer.

[0100] In this invention, the hole injection material includes metalloporphyrin, oligothiophene, arylamine-based organic materials, benzonitrile-based organic materials, quinacridone-based organic materials, and conductive polymers based on polyaniline or polythiophene.

[0101] In this invention, the hole transport layer material is a material that can receive holes from the anode or hole injection layer and transport the holes to the light-emitting layer, and has a high hole mobility.

[0102] In this invention, the hole transport layer material includes, but is not limited to, arylamine-based organic materials, conductive polymers, block copolymers having both conjugated and non-conjugated portions.

[0103] In this invention, the electron transport layer plays a role in promoting electron transport. The electron transport layer material is a material with high electron mobility used to receive electrons from the cathode and transport them to the light-emitting layer.

[0104] In this invention, the material of the electron transport layer includes an Al complex of 8-hydroxyquinoline and an organic free radical compound.

[0105] In this invention, the thickness of the electron transport layer is set to 1 nm to 50 nm, for example, 1 nm, 2 nm, 4 nm, 6 nm, 8 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm.

[0106] The electron transport layer can prevent the electron transport characteristics from degrading and prevent the driving voltage from increasing due to the electron transport layer being too thick.

[0107] In this invention, 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 has excellent thin film forming ability.

[0108] In this invention, the material of the electron injection layer includes one or more of fluorenone, anthraquinone dimethane, biphenylquinone, thiamethane dioxide, imidazole, perylenetetracarboxylic acid, fluorenemethane, anthrone, and their derivatives, metal complexes, and nitrogen-containing five-membered ring derivatives.

[0109] In this invention, the second electrode is a cathode.

[0110] As a cathode material, a material with a low work function is generally preferred in order to facilitate the injection of electrons into the organic layer.

[0111] In one embodiment of the present invention, the cathode material includes: a metal, such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, lead, or alloys thereof; a multilayer structure material, such as LiF / Al or LiO2 / Al; but is not limited thereto. In some embodiments of the present invention, the cathode material is Al.

[0112] In this invention, the organic electroluminescent device can be a top-emitting type, a bottom-emitting type, or a dual-sided emitting type.

[0113] 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.

[0114] Compared with the prior art, the present invention has the following beneficial effects:

[0115] The dual-host material provided by this invention comprises a first host compound and a second host compound with specific structures. The first host compound exhibits a faster hole mobility, while the second host compound exhibits a faster electron mobility. This dual-host material combines two host compounds with different properties. By compounding the first and second host compounds with specific structures, it serves as the emitting layer material for organic electroluminescent devices. This balances hole and electron mobility, allowing the dual-host material to increase excitons in the emitting layer, thereby improving not only the luminous efficiency and lifespan of the device but also reducing the driving voltage. Attached Figure Description

[0116] Figure 1 The image shows the nuclear magnetic resonance (NMR) spectrum of the first host compound H1-93 prepared in Example 1. Detailed Implementation

[0117] 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.

[0118] Additionally, it should be noted that the values ​​given in the following embodiments are as accurate as possible. However, those skilled in the art will understand that due to unavoidable measurement errors and experimental issues, each number should be understood as an approximation rather than an absolutely accurate value.

[0119] Unless otherwise stated, the raw materials and reagents used in the following examples are all commercially available products.

[0120] The following are common knowledge references:

[0121] Organometallic Chemistry (6th Edition), Robert H. Crabtree, published by East China University of Science and Technology Press, Shanghai, September 00, 2017, ISBN: 978-7-5628-5111-0, page 388.

[0122] Organic Chemistry and Optoelectronic Materials Experiment Tutorial, Chen Runfeng, Publisher: Southeast University Press, Publication Date: 2019-11-00, ISBN: 9787564184230, Page 174.

[0123] The features and performance of the present invention will be further described in detail below with reference to specific preparation examples.

[0124] Preparation Example 1

[0125] Preparation of the first host compound H1-93

[0126] Under nitrogen protection, raw material 93-1 (1 eq), raw material 93-2 (1.0 eq), and potassium carbonate (2 eq) were added to the reaction system, along with tetrakis(triphenylphosphine)palladium (0.02 eq), toluene, ethanol, and water. The mixture was heated to 90°C and refluxed for 20 hours. After the reaction was completed, purified water and dichloromethane were added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain the intermediate compound 93-1.

[0127] Under nitrogen protection, intermediate compound 93-1 (1 eq), starting material 93-3 (1 eq), and potassium acetate (2.5 eq) were added to the reaction system, along with 1,4-dioxane, catalyst tris(dibenzylacetone)dipalladium (0.01 eq), and ligand x-phos (2-bicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, 0.08 eq). The mixture was heated to 100°C and refluxed for 24 hours. After the reaction was completed, the temperature was lowered to 25°C, purified water was added, and the mixture was stirred and allowed to stand for separation. After separation and purification by column chromatography, intermediate compound 93-2 was obtained.

[0128] Under nitrogen protection, intermediate 93-2 (1 eq), starting material 93-4 (1.0 eq), and potassium carbonate (2 eq) were added to the reaction system, along with tetrakis(triphenylphosphine)palladium (0.02 eq), toluene, ethanol, and water. The mixture was heated to 90°C and refluxed for 20 hours. After the reaction was completed, purified water and dichloromethane were added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain intermediate compound 93-3.

[0129] Under nitrogen protection, intermediate compound 93-3 (1 eq), (methoxymethyl)triphenylphosphine chloride (1.3 eq), and THF were added to the reaction system 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, the solvent was removed by rotary evaporation, and the mixture was purified by column chromatography to obtain intermediate compound 93-4.

[0130] Under nitrogen protection, intermediate compound 93-4, boron trifluoride ether, and dichloromethane were added to the reaction system and stirred for 3 hours. After the reaction was completed, the organic layer was extracted with dichloromethane and water, then dried with sodium sulfate, the solvent was removed by rotary evaporator, and then purified by column chromatography to obtain intermediate compound 93-5.

[0131] Under nitrogen protection, intermediate 93-5 (1 eq), starting material 93-5 (1 eq), and sodium tert-butoxide (1.5 eq) were added to the reaction system, along with toluene, catalyst tris(dibenzylacetone)dipalladium (0.02 eq), and ligand 50% tri-tert-butylphosphine (0.04 eq). The reaction was refluxed at 120 °C for 18–24 h. After the reaction was completed, the temperature was lowered to 25 °C, purified water was added, and the mixture was stirred and allowed to stand for separation. After separation, the mixture was purified by column chromatography to obtain compound H1-270 (17.20 g, yield 63.50%, HPLC > 99%, mass spectrometry value 652.40, elemental analysis values ​​C: 86.46; H: 4.30; N: 4.30). The reaction route is shown below.

[0132]

[0133] The proton NMR spectrum of H1-93 is shown below. Figure 1 .

[0134] Preparation Example 2

[0135] Preparation of the second host compound H2-199

[0136] Under nitrogen protection, reactants 199-1 (1 eq), 199-2 (1 eq), and potassium carbonate (2.5 eq) were weighed and added to the reaction system. Toluene, ethanol, water, and tetrakis(triphenylphosphine)palladium catalyst (0.04 eq) were added. The mixture was refluxed at 90 °C for 24 h under nitrogen protection, then cooled to 25 °C, filtered, and subjected to solid column chromatography to obtain compound H2-199 (13.40 g, yield 67.30%, HPLC > 99%, mass spectrometry value: 549.35). The reaction route is shown below.

[0137]

[0138] In addition, it should be noted that other compounds of the present invention can be obtained by referring to the synthesis methods of the preparation examples listed above, so they will not be listed one by one here.

[0139] Examples 1-110, Comparative Examples 1-57

[0140] Examples 1-110 and Comparative Examples 1-57 each provide a host material, the formulation of which is shown in Table 1. For schemes with a dual host material comprising a first host compound and a second host compound, the mass ratio of the first host compound to the second host compound is 60:40. In Table 1, "-" indicates that the host material does not contain that compound; the structures of D-1 to D-8 are shown below.

[0141] .

[0142] The fabrication method of organic electroluminescent devices includes the following steps:

[0143] (1) The ITO (indium tin oxide) glass substrate with a thickness of 1500 Å 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.

[0144] (2) In the vapor deposition machine, HIL is vacuum vapor deposited on the ITO anode surface obtained in step (1) with a thickness of 200 Å to obtain a hole injection layer.

[0145] (3) A hole transport layer is obtained by vacuum evaporation of HTL on the surface of the hole injection layer obtained in step (2) with a thickness of 400 Å.

[0146] (4) Evaporate the light-emitting layer material on the surface of the hole transport layer and perform linear gradient co-evaporation using a multi-source co-evaporation method to obtain a thickness of 300 Å 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 is 60:40, the mass ratio of the dual host material and the doped material is 10:1, and the dual host materials are the host materials provided in Examples 1 to 110 and Comparative Examples 1 to 57, respectively.

[0147] (5) A hole blocking layer is formed by vapor deposition of BAlq on the surface of the light-emitting layer obtained in step (4) with a thickness of 100 Å.

[0148] (6) Vacuum vapor deposition of ETL on the surface of the hole blocking layer obtained in step (5) with a thickness of 400 Å is obtained to obtain the electron transport layer.

[0149] (7) A Liq layer with a thickness of 15 Å is vacuum-deposited on the surface of the electron transport layer obtained in step (6); an electron injection layer is obtained.

[0150] (8) 1500 Å 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.

[0151] The structure of the material used in the above preparation method is as follows:

[0152]

[0153] The driving voltage, luminous efficiency, and time (lifetime; T95) of the organic electroluminescent device at a brightness of 5000 nits were tested. The test results are shown in Table 1.

[0154] Table 1

[0155]

[0156] As shown in Table 1, the dual-host material provided by the present invention, which employs a first host compound and a second host compound with specific structures, can reduce the driving voltage of the device, improve the luminous efficiency of the device, and extend the service life of the device.

[0157] As can be seen from the comparison between Examples 1-110 and Comparative Examples 1-57, the main material of the light-emitting layer is a combination of the first main compound and the second main compound, which can greatly improve the luminous efficiency and lifespan. If only one of them is selected, the luminous efficiency of the device will be greatly reduced, the lifespan will be significantly shortened, and the voltage will increase.

[0158] As can be seen from Examples 1-110 and Comparative Examples 9-24, the luminous efficiency of Comparative Examples 9-24 is 32.1-33.6 cd / A, the driving voltage is 3.50-3.62 V, and the lifetime is 321-343 h. In contrast, the luminous efficiency of Examples 1-110 of the present invention is 37.5-46.3 cd / A, which is significantly higher than that of Comparative Examples 9-24. The driving voltage of Examples 1-110 of the present invention is 3.21-3.36 V, which is significantly lower than that of Comparative Examples 9-24. The lifetime of Examples 1-110 of the present invention is 461-554 h, which is much higher than that of Comparative Examples 9-24.

[0159] This is because the first host compound with a specific structure provided by this invention has a CN group attached to the furan ring or thiophene ring. This results in a lower LOMO in the first host compound, causing a redshift of the emission spectrum to the deep red band, which is more conducive to improving luminous efficiency and charge mobility. Fused rings such as phenanthrene and anthracene, combined with the CN group, form a rigid molecular structure, resulting in a more compact spatial structure, better film stacking morphology, and greater benefits for extending device lifetime, especially in terms of… The structure, with the parent nucleus formed by the furan ring or thiophene ring at positions 3 and 4 of the phenanthrene, has a larger conjugated system. Linking it with aromatic amine hole transport fragments can enhance intermolecular forces and significantly improve the hole mobility of the compound. The second host compound has a faster electron mobility. By compounding the first and second host compounds with specific structures, it can be used as the light-emitting layer material of organic electroluminescent devices, which can balance hole and electron mobility. The dual host material can not only improve the luminous efficiency and lifespan of the device by adding excitons in the light-emitting layer, but also reduce the driving voltage.

[0160] Therefore, it can be seen that when the main material of the light-emitting layer is a combination of the first main compound with a specific structure and the second main compound with a specific structure of the present invention, the luminous efficiency and service life can be greatly improved.

[0161] As can be seen from the test results of Comparative Examples 1-8 and Comparative Examples 25-57, which are devices with only a single host material, the performance of devices including the first host compound with a specific structure provided by the present invention is slightly higher than that of single host compounds in the prior art. The host material provided by the present invention has better performance.

[0162] The applicant declares that the present invention is illustrated through the above embodiments to demonstrate the main compound, dual-subject material, and organic electroluminescent device of the present invention. However, the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in 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. A host compound, characterized in that, The host compound has the structure shown in Formula I: ； Wherein, ring A is selected from substituted or unsubstituted phenanthrene, substituted or unsubstituted anthracene; Ring B and ring C are each independently selected from substituted or unsubstituted C6~C42 aryl, substituted or unsubstituted C6~C30 heteroaryl, substituted or unsubstituted C10~C30 fused ring, or substituted or unsubstituted C10~C42 aromatic amino; and at least one of ring B and ring C is selected from substituted or unsubstituted C10~C42 aromatic amino. Z is selected from O or S; m is selected from 0 or 1; L1 and L2 are each independently selected from any one of the following: a linking bond, a substituted or unsubstituted C6-C30 arylene, a substituted or unsubstituted C6-C30 heteroarylene, a substituted or unsubstituted C10-C30 fused ring, or a substituted or unsubstituted C10-C42 arylamino. In Formula I, all hydrogen atoms are either unsubstituted by deuterium, partially substituted by deuterium, or completely substituted by deuterium. "Substitution" means substitution by one, two or more substituents selected from the following, or by at least two substituents linked together: cyano, methyl, ethyl, propyl, butyl, tert-butyl, cyclopentane, cyclohexane, phenyl, biphenyl, naphthyl, fluorenyl, dimethylfluorenyl, phenanthrene, triphenylene, furanyl, thiophene, pyrrole, pyridyl, benzofuranyl, benzothiophene, isobenzofuranyl, dibenzofuranyl or dibenzothiophene.

2. The main compound according to claim 1, characterized in that, Ring B and ring C are each independently selected from substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C6-C18 heteroaryl, substituted or unsubstituted C10-C18 fused ring, or substituted or unsubstituted C10-C42 arylamino; and at least one of ring B and ring C is selected from substituted or unsubstituted C10-C42 arylamino. L1 and L2 are each independently selected from any one of the following: a linking bond, a substituted or unsubstituted C6-C18 arylene, a substituted or unsubstituted C6-C18 heteroarylene, a substituted or unsubstituted C10-C18 fused ring, or a substituted or unsubstituted C10-C30 arylamine.

3. The host compound according to claim 1, characterized in that, The host compound has a structure shown in any one of formulas IA-IJ: ； Wherein, ring B and ring C are each independently selected from the following groups that are completely substituted with deuterium, partially substituted with deuterium, or unsubstituted: phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiophene, phenanthryl, benzene-substituted naphthyl, benzene-substituted dibenzofuranyl, benzene-substituted dibenzothiophene, or the following groups: ； ； L1 and L2 are each independently selected from the linking bond and are either completely or partially substituted by deuterium, or unsubstituted, of the following groups: phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiophene, phenanthryl, benzene-substituted naphthyl, benzene-substituted dibenzofuranyl, benzene-substituted dibenzothiophene, or the following groups: ； in This is the group linkage site, where D represents deuterium.

4. The host compound according to claim 3, characterized in that, The host compound has a structure shown in any one of formulas IH-1 to IH-8: 。 5. The host compound according to claim 1, characterized in that, The host compound is any one of the compounds shown in formula H1-1 to formula H1-528: ； Where D represents deuterium.

6. A dual-body material, characterized in that, The dual-host material comprises a first host compound and a second host compound, wherein the first host compound is the host compound according to any one of claims 1-5; The second host compound has the structure shown in Formula II: ； L3 and L4 are each independently selected from any one of the following: a linking bond, a substituted or unsubstituted C6-C30 arylene, a substituted or unsubstituted C6-C30 heteroarylene, or a substituted or unsubstituted C10-C30 fused ring group; Ar1 and Ar2 are each independently selected from any one of the following: substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C6-C42 heteroaryl, substituted or unsubstituted phosphoxy, substituted or unsubstituted silyl, and substituted or unsubstituted C10-C42 fused cyclic groups; Ar3 is selected from substituted or unsubstituted C6-C42 aryl and substituted or unsubstituted C3-C42 heteroaryl groups; The heteroaryl group is a monocyclic aromatic group containing at least one heteroatom and / or a polycyclic aromatic ring group containing at least one heteroatom, wherein the heteroatom is O, S, N, P, B or Si; The substituents include deuterium, fluorine, cyano, or C1-C6 straight-chain or branched alkyl groups and phenyl groups.

7. The dual-body material according to claim 6, characterized in that, L3 and L4 are each independently selected from any one of the following: linking bond, substituted or unsubstituted C6~C18 arylene, substituted or unsubstituted C6~C18 heteroarylene, and substituted or unsubstituted C10~C18 fused ring group; Ar1 and Ar2 are each independently selected from any one of the following: substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C6-C18 heteroaryl, substituted or unsubstituted phosphoxy, substituted or unsubstituted silyl, and substituted or unsubstituted C10-C18 fused cyclic groups; Ar3 is selected from substituted or unsubstituted C6-C18 aryl groups and substituted or unsubstituted C3-C18 heteroaryl groups.

8. The dual-body material according to claim 6, characterized in that, L3 and L4 are each independently selected from any one of the following: linking bond, phenylene, naphthylene, thiopheneyl, and furanylene; Ar1 and Ar2 are independently selected from phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, anthracene, biphenyl, thiophene, chromyl, furanyl, phenyl-furanyl, furanyl-deuterated phenyl, naphthiophene, phenanthiophene, tri-benzofuranyl, pyrene-furanyl, phenanthiophene, tert-butylphenyl, benzoxazine, phenyl-thiophene, fluorenyl, diphenyl-fluorenyl, dibenzocarbazoyl, naphthiobenzocarbazoyl, phenanthiobenzocarbazoyl, phenylbenzoxazole, phenylnaphthoxazole, and benzene, respectively. The following groups are included: phenanthrene-1, phenylcarbazo-1, phenylnaphtho-1, phenyldibenzofuran-1, phenyldrozo-1, phenyldibenzofluoren-1, phenyltriphenyl-1, phenylbenzothiazole, phenylnaphthothiazole, phenylphenanthrene-1, fluoranyl, phenylyl, pyrene, naphthobenzofluorenyl, peryl, naphthothianyl, triphenylene, phenylnaphthyl, dibenzofuranyl, dibenzothiopheneyl, cyanophenyl, benzophenanthryl, tetraphenylgermanyl, benzonaphthoselenophenolyl, or any one of the following groups: ； in This is the group linkage site.

9. The dual-body material according to claim 6, characterized in that, The second host compound is any one of the compounds shown in formula H2-1 to formula H2-408: ； Where D represents deuterium; The mass ratio of the first main compound to the second main compound is (10~90):(90~10).

10. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode, the organic layer including a light-emitting layer, the light-emitting layer including the dual-body material according to any one of claims 6-9; The organic layer further includes any one or a combination of at least two of the following: a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

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