Host compound, organic electroluminescent material containing double hosts and organic electroluminescent device

Abstract

The invention belongs to the technical field of organic photoelectric materials, and discloses a host compound, an organic electroluminescent material containing double hosts and an organic electroluminescent device. The organic electroluminescent material containing the double hosts comprises a first host compound and a second host compound, the first host compound is a compound with a structure shown in a formula I, and the second host compound is a compound with a structure shown in a formula II. The organic electroluminescent material containing the double hosts is applied to the organic electroluminescent device, and has the advantages of low driving voltage, high luminous efficiency and long service life.

Description

TECHNICAL FIELD

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

[0002] Since the discovery of organic electroluminescence (OLED) technology, it has developed rapidly in the past few decades due to its unique advantages in the field of display and lighting, such as high contrast, wide viewing angle, lightness, flexibility and other characteristics brought by self-luminescence.

[0003] An organic electroluminescent device is usually composed of a multi-layer structure, including a substrate, an anode, a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), an electron injection layer (EIL) and a cathode. When a voltage is applied to the anode and the cathode, an electric field is generated between the two electrodes. Under the action of the electric field, electrons on the cathode side move to the electroluminescent layer, and holes on the anode side also move to the electroluminescent layer. Electrons and holes combine in the electroluminescent layer to form excitons. The excitons in the excited state release energy outward, and then the electroluminescent layer emits light. Among them, the host material in the emission layer has a great influence on the performance of the device. The traditional single host material needs to complete the functions of electron transport and hole transport at the same time. The single host material is difficult to meet the high performance requirements in efficiency and service life, and the double host material is thus born.

[0004] However, the energy matching and charge transfer process between different hosts and guests of the double host luminescent material are not perfect. In some cases, there may be incomplete energy transfer or accumulation of charges in the host material, which leads to the problem that part of the excitons cannot be effectively converted into photons, thereby reducing the overall light-emitting efficiency and limiting the further improvement of the light-emitting efficiency and service life of the double host material.

[0005] The organic electroluminescent double host material still faces many challenges in current research and application, and more double host materials are urgently needed to solve the problems existing in the prior art and promote the further development of OLED technology in the field of display and lighting. SUMMARY

[0006] Therefore, the application discloses a host compound, an organic electroluminescent material containing double hosts and an organic electroluminescent device. The organic electroluminescent material containing double hosts of the application has low driving voltage, high light-emitting efficiency and long service life when applied to an organic electroluminescent device.

[0007] In order to achieve the above-mentioned purpose, the following technical solutions are adopted:

[0008] In one aspect, the application provides a host compound, which has a structure shown in Formula I:

[0009]

[0010] wherein ring A is selected from dibenzofuran, benzonaphthofuran, dibenzothiophene or benzonaphthothiophene;

[0011] Ra is selected from any one of substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C6-C18 heteroaryl, substituted or unsubstituted C10-C18 fused ring group; n is selected from 1, 2, 3, 4, 5, 6, 7, 8 or 9;

[0012] R is selected from any one of substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C6-C30 heteroaryl, substituted or unsubstituted C10-C30 fused ring group, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C10-C42 arylamine group;

[0013] L is selected from any one of a bond, substituted or unsubstituted C6-C30 arylene, substituted or unsubstituted C6-C30 heteroarylene, substituted or unsubstituted C10-C42 arylamine group.

[0014] In the present application, the "substitution" means that the hydrogen atom bonded to the carbon atom of the compound is changed into another substituent, and the position of substitution is not limited as long as it is the position where the hydrogen atom is substituted, i.e., the position where the substituent can be substituted, and when two or more substituents are substituted, the two or more substituents can be the same as or different from each other.

[0015] In the present application, the heteroaryl is a monocyclic aromatic group containing at least one heteroatom and / or a polycyclic aromatic ring group containing at least one heteroatom, and the heteroatom is O, S, N, P or B. The fused ring group includes a fused aromatic ring sharing at least two carbon atoms, and also includes two fused aromatic rings connected by a single bond.

[0016] All hydrogens in the above formula I can be independently substituted with deuterium or unsubstituted.

[0017] Further, formula I has the following structures of formula I-A to formula I-H:

[0018]

[0019] Further preferably, L is selected from a bond, phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiophenyl, phenanthryl, phenyl-substituted naphthyl, phenyl-substituted dibenzofuranyl, phenyl-substituted dibenzothiophenyl, which are all substituted with deuterium, partially substituted with deuterium or unsubstituted.

[0020]

[0021] R is selected from the group consisting of phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiophenyl, phenyl-substituted naphthyl, phenyl-substituted dibenzofuranyl, phenyl-substituted dibenzothiophenyl, which are fully substituted with deuterium or partially substituted with deuterium or unsubstituted,

[0022] wherein, is a group attachment site;

[0023] Ra is selected from the group consisting of phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiophenyl, phenyl-substituted naphthyl, phenyl-substituted dibenzofuranyl, phenyl-substituted dibenzothiophenyl, which are fully substituted with deuterium or partially substituted with deuterium or unsubstituted.

[0024] The number of carbon atoms of aryl group, heteroaryl group, fused ring group, arylene group, heteroarylene group and cycloalkyl group in the terms "substituted or unsubstituted C6-C42 aryl group", "substituted or unsubstituted C6-C30 heteroaryl group", "substituted or unsubstituted C10-C30 fused ring group", "substituted or unsubstituted C3-C30 cycloalkyl group", "substituted or unsubstituted C6-C30 arylene group", "substituted or unsubstituted C6-C30 heteroarylene group" indicates the number of carbon atoms constituting unsubstituted aryl group, unsubstituted alkyl group or the total number of heteroatoms and carbon atoms constituting heteroaryl group, without considering the number of carbon atoms in substituents.

[0025] The term "substituted" means substituted with one, two or more substituents selected from the group consisting of cyano group, methyl group, ethyl group, propyl group, butyl group, tert-butyl group, cyclopentane group, cyclohexane group, phenyl group, biphenyl group, naphthyl group, fluorenyl group, dimethylfluorenyl group, phenanthryl group, triphenylenyl group, furanyl group, thiophenyl group, pyrrolyl group, pyridyl group, benzofuranyl group, benzothiophenyl group, isobenzofuranyl group, dibenzofuranyl group or dibenzothiophenyl group, or substituted with substituents selected from the group consisting of at least two substituents selected from the group consisting of cyano group, methyl group, ethyl group, propyl group, butyl group, tert-butyl group, cyclopentane group, cyclohexane group, phenyl group, biphenyl group, naphthyl group, fluorenyl group, dimethylfluorenyl group, phenanthryl group, triphenylenyl group, furanyl group, thiophenyl group, pyrrolyl group, pyridyl group, benzofuranyl group, benzothiophenyl group, isobenzofuranyl group, dibenzofuranyl group or dibenzothiophenyl group, which are connected to each other.

[0026] In the present application, the host compound is any one of the compounds represented by the following formulae H1-1 to H1-432, but is not limited thereto:

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045] In a second aspect, the present invention also provides an organic electroluminescent material containing two main bodies, wherein the organic electroluminescent material containing two main bodies includes a first main body compound and a second main body compound, wherein the first main body compound is the main body compound as described above.

[0046] The second host compound has the structure shown in Formula II:

[0047]

[0048] L1 and L2 are each independently selected from any one of the following: the linking bond, substituted or unsubstituted C6-C42 arylene, and substituted or unsubstituted C6-C42 heteroarylene;

[0049] 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 C10-C42 fused cyclic, substituted or unsubstituted phosphoxy, substituted or unsubstituted silyl, and substituted or unsubstituted germanyl.

[0050] R1 is selected from any one of substituted or unsubstituted C6-C42 aryl or substituted or unsubstituted C3-C42 heteroaryl;

[0051] 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;

[0052] The substituents include deuterium, fluorine, cyano, or C1-C6 straight-chain or branched alkyl groups, cyclohexane, and phenyl.

[0053] Furthermore, L1 and L2 are each independently selected from any one of the following: a linking bond, a substituted or unsubstituted C6-C18 aryl group, or a substituted or unsubstituted C6-C18 heteroaryl group; Ar1 ​​and Ar2 are each independently selected from any one of the following: a substituted or unsubstituted C6-C18 aryl group, a substituted or unsubstituted C6-C18 heteroaryl group, a substituted or unsubstituted C10-C18 fused ring group, a substituted or unsubstituted phosphoxy group, a substituted or unsubstituted silyl group, or a substituted or unsubstituted germanyl group; R1 is selected from any one of the following: a substituted or unsubstituted C6-C18 aryl group, or a substituted or unsubstituted C3-C18 heteroaryl group.

[0054] Furthermore, L1 and L2 are each independently selected from any one of the following: linking bond, phenylene, naphthylene, thiopheneyl, and furanylene;

[0055] Ar1 and Ar2 are each independently selected from phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, anthracene, biphenyl, thiophene, chromyl, furanyl, phenyl-benzofuranyl, furanyl-deuterated phenyl, naphthiophene, phenanthiophene, triphenyl-benzofuranyl, pyrene-benzofuranyl, phenanthiophene, tert-butylphenyl, benzoxazine, phenyl-benzothiophene, fluorenyl, diphenyl-benzofluorenyl, dibenzo-carbazoyl, naphthiobenzo-carbazoyl, phenanthiobenzo-carbazoyl, phenylbenzoxazole, phenylnaphthiazole, phenylphenanthiazole, phenylcarbazo-oxazole, phenylnaphthiazole, phenyl dibenzofuran-oxazole, phenyl trzoxazole, phenyl dibenzofluoren-oxazole, phenyl triphenyl-benzoxazole, phenyl benzothiazole, phenylnaphthiazole, phenyl phenanthiazole, fluoranyl The group consisting of phenylene, pyrene, naphthobenzofluorenyl, perylene, naphthothianyl, triphenylene, phenylnaphthyl, dibenzofuranyl, dibenzothiopheneyl, cyanophenyl, benzophenanthryl, tetraphenylgermanyl, benzonaphthoselenophenolyl, or any one of the following groups:

[0056]

[0057] in This is the group linkage site.

[0058] 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:

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076] 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.

[0077] In this invention, the defined carbon number range of the 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, and the defined carbon number range of other groups is analogous.

[0078] Thirdly, the present invention also provides a method for preparing a host compound having the structure shown in Formula I.

[0079] The reaction route for compound I is as follows:

[0080]

[0081] Wherein, rings A, L, R, Ra, and n 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] Specific preparation method of compound formula I:

[0083] 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 (0.02-0.05 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℃, 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.

[0084] Under nitrogen protection, raw materials A3 (1 eq), 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 (0.02-0.05 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℃, 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.

[0085] Under nitrogen protection, intermediate compound I-1 (1 eq), intermediate compound I-2 (1-1.1 eq), and sodium tert-butoxide (1.5-2 eq) were added to the reaction system, along with toluene, catalyst tris(dibenzylacetone) dipalladium (0.02-0.04 eq), and ligand 50% tritert-butylphosphine (0.04-0.08 eq). The reaction was refluxed at 110-120 °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 intermediate compound I-3 as shown.

[0086] Under nitrogen protection, raw materials A5 (1 eq), 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 (0.02-0.05 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℃, 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-4 shown.

[0087] Under nitrogen protection, intermediate compounds I-3 (1 eq), I-4 (1-1.1 eq), and sodium tert-butoxide (1.5-2 eq) were added to the reaction system, along with toluene, the catalyst tris(dibenzylacetone)dipalladium (0.02-0.04 eq), and the ligand 50% tri-tert-butylphosphine (0.04-0.08 eq). The reaction was refluxed at 110-120 °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 the main compound with the structure shown in Formula I.

[0088] Fourthly, the present invention also provides a method for preparing a host compound having the structure shown in Formula II.

[0089] 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:

[0090]

[0091] Among them, L1, L2, Ar1, Ar2, and R1 are each independently selected from the same range as Equation II.

[0092] Specific preparation methods include:

[0093] (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.

[0094] (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.

[0095] (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.

[0096] Fifthly, the present invention also provides an organic electroluminescent material, the organic electroluminescent material comprising the aforementioned organic electroluminescent material containing a dual host.

[0097] Preferably, the organic electroluminescent material further includes a dopant material.

[0098] Preferably, the mass ratio of the dual host material to the doped 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, etc., more preferably (5-100):1, and even more preferably (5-15):1.

[0099] In a sixth aspect, the present invention also provides an organic electroluminescent device, the organic electroluminescent device comprising the dual host material or the organic electroluminescent material.

[0100] In this 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 or the organic electroluminescent material.

[0101] 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.

[0102] In this invention, the first electrode is the anode.

[0103] In this invention, the anode material is preferably a material with a high work function, which is used to facilitate the injection of holes into the organic layer. 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.

[0104] In this invention, the anode is an ITO anode.

[0105] In this invention, 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. The material of the hole injection layer includes metalloporphyrins, oligothiophenes, arylamine-based organic materials, benzonitrile-based organic materials, quinacridone-based organic materials, and conductive polymers based on polyaniline or polythiophene.

[0106] In this invention, the hole transport layer is made of a material capable of receiving holes from the anode or hole injection layer and transporting them to the light-emitting layer, and possessing a high hole mobility. The material of the hole transport layer includes, but is not limited to, arylamine-based organic materials, conductive polymers, and block copolymers having both conjugated and non-conjugated portions.

[0107] In this invention, the electron transport layer facilitates electron transport. The material of the electron transport layer is a material with high electron mobility, used to receive electrons from the cathode and transport them to the light-emitting layer. The material of the electron transport layer includes an Al complex of 8-hydroxyquinoline and an organic free radical compound.

[0108] 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, and 50 nm. The electron transport layer not only prevents a decrease in electron transport characteristics but also prevents an increase in driving voltage due to an excessively thick electron transport layer.

[0109] In this invention, the electron injection layer promotes electron injection, and the material of the electron injection layer preferably has the ability to transport electrons, exhibiting an electron injection effect from the cathode, and providing excellent electron injection effect to the light-emitting layer or light-emitting material. This prevents excitons generated in the light-emitting layer from migrating to the hole injection layer, and further, it possesses excellent thin film forming ability. 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.

[0110] In this invention, the second electrode is a cathode.

[0111] In this invention, the cathode material is preferably a material with a low work function to facilitate the injection of electrons into the organic layer. The cathode material includes: metals, such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, lead, or their alloys; multilayer materials, such as LiF / Al or LiO2 / Al; but is not limited thereto. In some embodiments of this 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] As can be seen from the above technical solution, 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 can be used as the emitting layer material for organic electroluminescent devices. This balances hole and electron mobility, increasing excitons in the emitting layer and improving not only the luminous efficiency and lifespan of the device but also reducing the driving voltage. Attached Figure Description

[0116] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0117] Figure 1 This is the nuclear magnetic resonance image of the first host compound H1-270 prepared in Example 1 of the present invention. Detailed Implementation

[0118] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments and related drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0119] 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.

[0120] Unless otherwise stated, the raw materials and reagents used in the following examples are all commercially available products.

[0121] The following are common knowledge references:

[0122] 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.

[0123] Organic Chemistry and Optoelectronic Materials Experiment Tutorial, Chen Runfeng, Publisher: Southeast University Press, Publication Date: 2019-11-00, ISBN: 9787564184230, Page 174.

[0124] This invention specifically discloses a host compound, an organic electroluminescent material containing two hosts, and an organic electroluminescent device.

[0125] The features and performance of the present invention will be further described in detail below with reference to specific embodiments.

[0126] Example 1

[0127] Preparation of the first host compound H1-270

[0128] Under nitrogen protection, raw materials 270-1 (1 eq), 270-2 (1 eq), and sodium tert-butoxide (1.5 eq) were added to the reaction system, along with toluene, the catalyst tris(dibenzylacetone)dipalladium (0.02 eq), and the ligand 50% tri-tert-butylphosphine (0.04 eq). The reaction was refluxed at 110 °C for 18 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 270-1.

[0129] Under nitrogen protection, raw materials 270-3 (1 eq), 270-4 (1 eq), and potassium carbonate (3 eq) were added to the reaction system, along with toluene, ethanol, water, and catalyst tetra(triphenylphosphine)palladium (0.02 eq). The reaction was refluxed at 90°C for 20 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 270-2.

[0130] Under nitrogen protection, intermediates 270-1 (1 eq), 270-2 (1 eq), and sodium tert-butoxide (1.5 eq) were added to the reaction system, along with toluene, tris(dibenzylacetone) dipalladium catalyst (0.02 eq), and 50% tri-tert-butylphosphine ligand (0.04 eq). The mixture was refluxed at 120 °C for 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 (13.33 g, yield 61.50%, HPLC > 99%, mass spectrometry value 715.41). The reaction route is shown below:

[0131]

[0132] The proton NMR spectrum of H1-270 is shown below. Figure 1 .

[0133] Example 2

[0134] Preparation of the second host compound H2-154

[0135] Under nitrogen protection, reactants 154-1 (1 eq), 154-2 (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 H2-154 (15.67 g, yield 66.30%, HPLC > 99%, mass spectrometry value: 511.40). The reaction route is shown below:

[0136]

[0137] In addition, it should be noted that other compounds of the present invention can be obtained by referring to the preparation methods of the examples listed above, so they will not be listed one by one here.

[0138] Examples 1-44, Comparative Examples 1-43

[0139] Examples 1-44 and Comparative Examples 1-43 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-6 are shown below:

[0140]

[0141] The fabrication method of organic electroluminescent devices includes the following steps:

[0142] (1) The thickness is The ITO (indium tin oxide) glass substrate was cleaned twice with distilled water, ultrasonically washed for 30 minutes, then repeatedly cleaned twice with distilled water, ultrasonically washed for 10 minutes. After washing, it was ultrasonically washed sequentially with methanol, acetone, and isopropanol (5 minutes each time), dried, and then transferred to a plasma cleaner for 5 minutes to obtain the ITO anode.

[0143] (2) In the vapor deposition machine, HIL is vacuum vapor deposited on the ITO anode surface obtained in step (1), with a thickness of [missing information]. A hole injection layer was obtained.

[0144] (3) Vacuum vapor deposition of HTL is performed on the surface of the hole injection layer obtained in step (2), with a thickness of [missing information]. The hole transport layer is obtained.

[0145] (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 [missing information]. A light-emitting layer is obtained; the material of the light-emitting layer includes a dual host material and a dopant 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 dopant material is 10:1, and the dual host materials are the host materials provided in Examples 1 to 44 and Comparative Examples 1 to 43, respectively.

[0146] (5) Evaporate BAlq onto the surface of the light-emitting layer obtained in step (4), with a thickness of A cavity barrier layer is formed.

[0147] (6) Vacuum vapor deposition of ETL is performed on the surface of the hole blocking layer obtained in step (5), with a thickness of [missing information]. An electron transport layer was obtained.

[0148] (7) Liq is vacuum-deposited onto the surface of the electron transport layer obtained in step (6), with a thickness of [missing information]. An electron-injected layer was obtained.

[0149] (8) Evaporation on the surface of the electron injection layer obtained in step (7) Al is used to form a cathode, thus obtaining the organic electroluminescent device.

[0150] The structure of the material used in the above preparation method is as follows:

[0151]

[0152] 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.

[0153] Table 1

[0154]

[0155]

[0156]

[0157] 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.

[0158] As can be seen from the comparison between Examples 1-44 and Comparative Examples 1-43, 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.

[0159] As can be seen from Examples 1-44 and Comparative Examples 7-18, the luminous efficiency of Comparative Examples 7-18 is 30.2-31.4 cd / A, the driving voltage is 3.51-3.63 V, and the lifetime is 329-341 h. In contrast, the luminous efficiency of Examples 1-44 of the present invention is 37.5-43.4 cd / A, which is significantly higher than that of Comparative Examples 7-18. The driving voltage of Examples 1-44 of the present invention is 3.25-3.39 V, which is significantly lower than that of Comparative Examples 7-18. The lifetime of Examples 1-44 of the present invention is 461-496 h, which is much higher than that of Comparative Examples 7-18. This is because the first host compound with a specific structure provided by the present invention has specific aryl or heteroaryl groups attached to dibenzofuran, dibenzothiophene, naphthofuran, and naphthothiophene. This gives the first host compound better planarity and stability, and can further reduce molecular symmetry, which is more conducive to improving charge mobility. At the same time, the spatial structure is more compact, the film stacking morphology is better, the film formation is better, which is more conducive to extending the device life. The second host compound has a faster electron mobility. By compounding the first host compound and the second host compound with specific structures, it can be used as the light-emitting layer material of organic electroluminescent devices. It can balance the 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] Furthermore, the test results of Comparative Examples 1-6 and Comparative Examples 19-43, which consist of devices with only a single host material, show that the performance of devices with the light-emitting layer material including the first host compound with the specific structure provided by the present invention is slightly higher than that of single host compounds in the prior art. Therefore, the host material provided by the present invention has superior performance.

[0162] The applicant declares that the present invention is illustrated through the above embodiments to demonstrate the main compound, the organic electroluminescent material containing two main components, and the light-emitting 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.

[0163] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A host compound, characterized in that, The host compound has the structure shown in Formula I: Wherein, ring A is selected from dibenzofuran, benzonaphthofuran, dibenzothiophene, or benzonaphthothiophene; Ra is selected from any one of substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C6-C18 heteroaryl, or substituted or unsubstituted C10-C18 fused ring group; n is selected from 1, 2, 3, 4, 5, 6, 7, 8, or 9. R is selected from any one of the following: substituted or unsubstituted C6-C42 aryl, substituted or unsubstituted C6-C30 heteroaryl, substituted or unsubstituted C10-C30 fused cyclic group, substituted or unsubstituted C3-C30 cycloalkyl, and substituted or unsubstituted C10-C42 aromatic amino group; L is 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-C42 arylamino. 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 or B; The substituents are selected from 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, All hydrogen atoms in Formula I can be independently substituted with or not substituted with deuterium; Formula I has the following structure: Formulas IA to IH 3. The main compound according to claim 1 or 2, characterized in that, L is selected from the following groups that are completely or partially substituted with deuterium or are unsubstituted, forming a linking bond: phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiophene, phenanthryl, benzene-substituted naphthyl, benzene-substituted dibenzofuranyl, and benzene-substituted dibenzothiophene. R is selected from the following groups that are completely substituted with deuterium, partially substituted with deuterium, or unsubstituted: phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiophene, phenanthryl, naphthylbenzofuranyl, naphthylbenzothiophene, benzene-substituted naphthyl, benzene-substituted dibenzofuranyl, benzene-substituted dibenzothiophene. in, For group linkage sites; Ra is selected from the following groups that are fully or partially substituted with deuterium or are unsubstituted: phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiophene, phenanthryl, benzene-substituted naphthyl, benzene-substituted dibenzofuranyl, and benzene-substituted dibenzothiophene.

4. 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 H1-432, but is not limited to this:

5. An organic electroluminescent material containing two main components, characterized in that, The organic electroluminescent material containing two main components includes a first main compound and a second main compound, wherein the first main compound has a structure shown in Formula I; and the second main compound has a structure shown in Formula II. L1 and L2 are each independently selected from any one of the following: the linking bond, substituted or unsubstituted C6-C42 arylene, and substituted or unsubstituted C6-C42 heteroarylene; 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 C10-C42 fused cyclic, substituted or unsubstituted phosphoxy, substituted or unsubstituted silyl, and substituted or unsubstituted germanyl. R1 is selected from any one of substituted or unsubstituted C6-C42 aryl or substituted or unsubstituted C3-C42 heteroaryl; 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, cyclohexane, and phenyl.

6. The organic electroluminescent material containing two main bodies according to claim 5, characterized in that, L1 and L2 are each independently selected from any one of the following: a linking bond, a substituted or unsubstituted C6-C18 aryl group, or a substituted or unsubstituted C6-C18 heteroaryl group; Ar1 ​​and Ar2 are each independently selected from any one of the following: a substituted or unsubstituted C6-C18 aryl group, a substituted or unsubstituted C6-C18 heteroaryl group, a substituted or unsubstituted C10-C18 fused ring group, a substituted or unsubstituted phosphoxy group, a substituted or unsubstituted silyl group, or a substituted or unsubstituted germanyl group; R1 is selected from any one of the following: a substituted or unsubstituted C6-C18 aryl group, or a substituted or unsubstituted C3-C18 heteroaryl group.

7. The organic electroluminescent material containing two main bodies according to claim 6, characterized in that, L1 and L2 are each independently selected from any one of the following: linking bond, phenylene, naphthylene, thiopheneyl, and furanylene; Ar1 and Ar2 are each independently selected from phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, anthracene, biphenyl, thiophene, chromyl, furanyl, phenyl-benzofuranyl, furanyl-deuterated phenyl, naphthiophene, phenanthiophene, tri-benzofuranyl, pyrene-benzofuranyl, phenanthiophene, tert-butylphenyl, benzoxazine, phenyl-benzothiophene, fluorenyl, diphenyl-benzofluorenyl, dibenzo-carbazoyl, naphthiobenzo-carbazoyl, phenanthiobenzo-carbazoyl, phenylbenzoxazole, phenylnaphthoxazole, phenylphenanthoxazole, phenylcarbazoxazole, phenylnaphthoxazole, phenyl dibenzofuranoxazole, phenyl trzoxazole, phenyl dibenzofluorenoxazole, phenyl tri-benzoxazole, phenyl benzothiazole, phenylnaphthothiazole, phenyl phenanthiazole, fluoranyl The group consisting of phenylene, pyrene, naphthobenzofluorenyl, perylene, naphthothianyl, triphenylene, phenylnaphthyl, dibenzofuranyl, dibenzothiopheneyl, cyanophenyl, benzophenanthryl, tetraphenylgermanyl, benzonaphthoselenophenolyl, or any one of the following groups: in This is the group linkage site.

8. The organic electroluminescent material containing two main bodies according to claim 5, characterized in that, The second host compound is any one of the compounds shown in formula H2-1 to formula H2-408, but is not limited to this:

9. An organic electroluminescent device, characterized in that, The organic electroluminescent device comprises the organic electroluminescent material containing a dual host as described in claim 5.

10. The organic electroluminescent device according to claim 9, characterized in that, The organic electroluminescent device includes a first electrode, an organic electroluminescent material layer, and a second electrode; the organic electroluminescent material layer includes a light-emitting layer, which includes a doped material and an organic electroluminescent material containing two main bodies; the mass ratio of the organic electroluminescent material containing two main bodies to the doped material is (5-199):1.

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