A boron-containing organic compound and an organic electroluminescent device prepared therefrom

Abstract

The present invention discloses a boron-containing organic compound and an organic electroluminescent device prepared therefrom, belonging to the field of semiconductor technology. The structure of the organic compound of the present invention is shown in general formula (1) or general formula (2). The compound of the present invention has a narrow full width at half maximum, a high fluorescence quantum yield, and a suitable emission color. When used as a doping material in the light-emitting layer material of an OLED light-emitting device, it can be used as a green light doping material for the light-emitting layer of an organic electroluminescent device, thereby improving the color purity and efficiency of the device, and particularly significantly improving the lifespan of the device.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a boron-containing organic compound and an organic electroluminescent device prepared therefrom. Background Art

[0002] Limited by early technologies, traditional fluorescent doping materials can only utilize 25% of singlet excitons formed by electrical excitation for luminescence. The internal quantum efficiency of the device is relatively low (up to 25%), and the external quantum efficiency is generally lower than 5%, showing a large gap compared with the efficiency of phosphorescent devices. Due to the strong spin-orbit coupling of heavy atom centers, phosphorescent materials enhance intersystem crossing, enabling effective utilization of singlet excitons and triplet excitons formed by electrical excitation for luminescence, resulting in an internal quantum efficiency of 100% for the device. However, most phosphorescent materials are expensive, with poor material stability, poor color purity, and serious efficiency roll-off of the device, which limit their application in OLEDs.

[0003] With the advent of the 5G era, higher requirements are put forward for the color rendering standard. In addition to being efficient and stable, luminescent materials also require a narrower full width at half maximum (FWHM) to improve the color purity of device luminescence. Fluorescent doping materials can achieve high fluorescence quantum yield and narrow FWHM through molecular engineering. Breakthroughs have been achieved in blue fluorescent doping materials, and the FWHM of boron-based materials can be reduced to below 30 nm. In the green region, to which the human eye is more sensitive, research mainly focuses on phosphorescent doping materials, but it is difficult to narrow their emission peak shape through simple methods. Therefore, to meet higher color rendering standards, it is of great significance to study highly efficient green fluorescent doping materials with narrow FWHM.

[0004] In addition, the sensitization technology combines a triplet exciton sensitizing material with a fluorescent doping material. Using the triplet exciton sensitizing material as an exciton sensitization medium, it fully utilizes triplet excitons and transfers energy to the fluorescent doping material through energy transfer, also achieving an internal quantum efficiency of 100% for the device. This technology can make up for the deficiency of insufficient exciton utilization rate of fluorescent doping materials and effectively utilize the characteristics of high fluorescence quantum yield, high device stability, high color purity, and low cost of fluorescent doping materials, showing broad prospects in the application of OLEDs.

[0005] Boron compounds with resonance structures are more likely to achieve narrow full-width at half-maximum (FWHM) luminescence. When such materials are applied in sensitization technologies, devices with high efficiency and narrow FWHM emission can be fabricated. For example, in CN 107507921 A and CN 110492006 A, a luminescent layer combination technology is disclosed, which uses a thermally activated delayed fluorescence (TADF) material with the lowest singlet and lowest triplet energy level difference less than or equal to 0.2 eV as the host and a boron-containing material as the dopant; in CN 110492005 A and CN 110492009 A, a luminescent layer combination scheme is disclosed, which uses an exciplex as the host and a boron-containing material as the dopant; both can achieve efficiency comparable to phosphorescence and a relatively narrow FWHM. Therefore, developing sensitization technologies based on narrow FWHM boron-based luminescent materials has unique advantages and strong potential for meeting the BT.2020 display standards.

[0006] In patent CN111377955A, a compound containing two B atoms is introduced. Such materials have high efficiency, but their FWHM is relatively wide, resulting in low color purity. Summary of the Invention

[0007] In view of the above problems existing in the prior art, the present invention provides a boron-containing organic compound and an organic electroluminescent device prepared therefrom. The compound of the present invention has a narrow FWHM and a high fluorescence quantum yield, and can be used as a green light doping material for the luminescent layer of an organic electroluminescent device, thereby improving the color purity and lifespan of the device.

[0008] The technical solution of the present invention is as follows: A boron-containing organic compound, the structure of the boron-containing organic compound is shown in general formula (1) or general formula (2):

[0009]

[0010] In general formula (1) and general formula (2), each occurrence of Z is the same or different and represents C-R1;

[0011] R1 independently represents a hydrogen atom, a deuterium atom, a tritium atom, a halogen atom, a substituted or unsubstituted C1-C 10 alkyl, a substituted or unsubstituted C3-C 10 cycloalkyl, a substituted or unsubstituted C1-C 10 alkoxy, a substituted or unsubstituted C1-C 10 aryloxy, a substituted or unsubstituted arylamino, a substituted or unsubstituted C6-C 30 aryl, a substituted or unsubstituted C2-C 30 heteroaryl;

[0012] M1 represents a substituted or unsubstituted C6-C 30 aryl, a substituted or unsubstituted C2-C30 One of heteroaryls;

[0013] X is represented as N(R2), C(R3)(R4), Si(R5)(R6), O or S;

[0014] R2 is represented as substituted or unsubstituted C1-C 10 alkyl, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C6-C 30 aryl, substituted or unsubstituted C2-C 30 One of heteroaryls;

[0015] R3, R4, R5, R6 are each independently represented as substituted or unsubstituted C1-C 10 alkyl, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 alkoxy, substituted or unsubstituted C1-C 10 aryloxy, substituted or unsubstituted arylamino, substituted or unsubstituted C6-C 30 aryl, substituted or unsubstituted C2-C 30 One of heteroaryls;

[0016] The substituents for the substituted groups are each independently selected from a deuterium atom, a tritium atom, a halogen atom, C1-C 10 alkyl, C3-C 10 cycloalkyl, C6-C 30 aryl, C2-C 30 One or more of heteroaryls.

[0017] In a preferred embodiment, the structure of the organic compound is as shown in General Formula (3) to General Formula (8):

[0018]

[0019] In General Formula (3) - General Formula (8), the meanings of Z and X are as defined above;

[0020] Y1 and Y2 are each independently represented as O or S.

[0021] In a preferred embodiment, the structure of the organic compound is as shown in any one of General Formula (9) to General Formula (18):

[0022]

[0023]

[0024] In General Formula (9) to General Formula (18), the meaning of Z is as defined above;

[0025] Y1 and Y2 each independently represent O or S.

[0026] Preferably, the structure of the organic compound is shown as any one of general formulas (19) to (28):

[0027]

[0028] In general formulas (19) to (28), the meaning of Z is the same as the definition in the above text;

[0029] Y1 and Y2 each independently represent O or S;

[0030] Z1 represents

[0031] Preferably, the structure of the organic compound is shown as any one of general formulas (29) to (35):

[0032]

[0033] In general formulas (29) to (35), each occurrence of Z is the same or different and represents C-R1;

[0034] R1 each independently represents a hydrogen atom, a deuterium atom, a tritium atom, a halogen atom, a substituted or unsubstituted C1-C 10 alkyl group, a substituted or unsubstituted C3-C 10 cycloalkyl group, a substituted or unsubstituted C1-C 10 alkoxy group, a substituted or unsubstituted C1-C 10 aryloxy group, a substituted or unsubstituted arylamino group, a substituted or unsubstituted C6-C 30 aryl group, a substituted or unsubstituted C2-C 30 heteroaryl group;

[0035] Ar represents a substituted or unsubstituted C6-C 30 aryl group, a substituted or unsubstituted C2-C 30 heteroaryl group;

[0036] R a 、R b 、R c 、R d 、R e 、R f each independently represents a hydrogen atom, a deuterium atom, a tritium atom, a halogen atom, a substituted or unsubstituted C1-C 10 alkyl group, a substituted or unsubstituted C3-C 10 cycloalkyl group, a substituted or unsubstituted C1-C 10Alkoxy, substituted or unsubstituted C1-C 10 Aryloxy, substituted or unsubstituted arylamino, substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C2-C 30 Heteroaryl;

[0037] Y1 and Y2 each independently represent O or S;

[0038] The substituents for the substituting groups are each independently selected from a deuterium atom, a tritium atom, a halogen atom, a C1-C 10 alkyl, a C3-C 10 cycloalkyl, a C6-C 30 aryl, a C2-C 30 heteroaryl, or a combination of one or more thereof.

[0039] In a preferred embodiment, Ar is represented by any one of the following structures:

[0040]

[0041] R1, R a , R b , R c , R d , R e , R f are each represented by any one of the following structures:

[0042] In a preferred embodiment, R1, R a , R b , R c , R d , R e , R fIndependently represented as one of a hydrogen atom, a deuterium atom, a tritium atom, a halogen atom, an adamantyl group, a methyl group, a deuterated methyl group, a tritiated methyl group, a trifluoromethyl group, an ethyl group, a deuterated ethyl group, a tritiated ethyl group, an isopropyl group, a deuterated isopropyl group, a tritiated isopropyl group, a tert-butyl group, a deuterated tert-butyl group, a tritiated tert-butyl group, a cyclopentyl group, a deuterated cyclopentyl group, a tritiated cyclopentyl group, a methyl-substituted cyclopentyl group, a cyclohexyl group, a phenyl group, a deuterated phenyl group, a tritiated phenyl group, a biphenyl group, a deuterated biphenyl group, a tritiated biphenyl group, a terphenyl group, a deuterated terphenyl group, a tritiated terphenyl group, a diphenyl ether group, a methyl-substituted diphenyl ether group, a naphthyl group, an anthracenyl group, a phenanthryl group, a pyridyl group, a phenyl-substituted pyridyl group, a quinolinyl group, a furyl group, a thienyl group, a benzofuryl group, a dibenzofuryl group, a dibenzothienyl group, a carbazolyl group, an N-phenylcarbazolyl group, a 9,9-dimethylfluorenyl group, a spirofluorene group, a methyl-substituted phenyl group, an ethyl-substituted phenyl group, an isopropyl-substituted phenyl group, a tert-butyl-substituted phenyl group, a methyl-substituted biphenyl group, an ethyl-substituted biphenyl group, an isopropyl-substituted biphenyl group, a tert-butyl-substituted biphenyl group, a deuterated methyl-substituted phenyl group, a deuterated ethyl-substituted phenyl group, a deuterated isopropyl-substituted phenyl group, a deuterated tert-butyl-substituted phenyl group, a deuterated methyl-substituted biphenyl group, a deuterated ethyl-substituted biphenyl group, a deuterated isopropyl-substituted biphenyl group, a deuterated tert-butyl-substituted biphenyl group, a phenyl-substituted amino group, a tert-butylbenzene-substituted amino group, a tert-butyl-substituted dibenzofuryl group, a phenyl-substituted tert-butyl, an xanthone group, a phenyl-substituted triazine group, a phenyl-substituted borane group, a methoxy group, a tert-butoxy group.

[0043] Ar, R2, R3, R4, R5, and R6 are represented as one of a phenyl group, a deuterated phenyl group, a tritiated phenyl group, a biphenyl group, a deuterated biphenyl group, a tritiated biphenyl group, a terphenyl group, a deuterated terphenyl group, a tritiated terphenyl group, a naphthyl group, an anthracenyl group, a phenanthryl group, a pyridyl group, a phenyl-substituted pyridyl group, a quinolinyl group, a furyl group, a thienyl group, a benzofuryl group, a dibenzofuryl group, a dibenzothienyl group, a carbazolyl group, an N-phenylcarbazolyl group, a 9,9-dimethylfluorenyl group, a spirofluorene group, a methyl-substituted phenyl group, an ethyl-substituted phenyl group, an isopropyl-substituted phenyl group, a tert-butyl-substituted phenyl group, a methyl-substituted biphenyl group, an ethyl-substituted biphenyl group, an isopropyl-substituted biphenyl group, a tert-butyl-substituted biphenyl group, a deuterated methyl-substituted phenyl group, a deuterated ethyl-substituted phenyl group, a deuterated isopropyl-substituted phenyl group, a deuterated tert-butyl-substituted phenyl group, a deuterated methyl-substituted biphenyl group, a deuterated ethyl-substituted biphenyl group, a deuterated isopropyl-substituted biphenyl group, a deuterated tert-butyl-substituted biphenyl group, a phenyl-substituted amino group, a tert-butylbenzene-substituted amino group, a tert-butyl-substituted dibenzofuryl group, a phenyl-substituted tert-butyl, an xanthone group, a phenyl-substituted triazine group.

[0044] In a preferred embodiment, the specific structure of the organic compound is any one of the following structures:

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057] An organic electroluminescent device includes a cathode and an anode, and an organic light-emitting functional layer therebetween. The organic light-emitting functional layer includes a light-emitting layer, and the light-emitting layer contains the boron-containing organic compound.

[0058] In a preferred embodiment, the light-emitting layer contains a host material and a dopant material, and the dopant material contains the boron-containing organic compound.

[0059] In a preferred embodiment, the light-emitting layer contains a first host material, a second host material and a dopant material. At least one of the first host material and the second host material is a TADF material, and the dopant material is the boron-containing organic compound.

[0060] The beneficial technical effect of the present invention lies in:

[0061] The present invention adopts a structure similar to dihydrophenazine with two N para-positions. The compound of the present invention can be used as a dopant material for the light-emitting layer material in an OLED device, and can emit green fluorescence under the action of an electric field. The compound of the present invention as a dopant material has a high fluorescence quantum efficiency, and the fluorescence quantum efficiency of the material is close to 100%, which can significantly reduce the problem of the relatively wide full width at half maximum of the structure in the prior art and has a very high color purity. Description of the Drawings

[0062] Figure 1 It is a schematic structural diagram of the materials listed in the present invention applied to an OLED device;

[0063] Among them, 1 is a transparent substrate layer, 2 is an anode layer, 3 is a hole injection layer, 4 is a hole transport layer, 5 is an electron blocking layer, 6 is a light-emitting layer, 7 is a hole blocking layer, 8 is an electron transport layer, 9 is an electron injection layer, and 10 is a cathode layer. Specific embodiments

[0064] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other. The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but it is not limited to the present invention.

[0065] In the present invention, unless otherwise specified, HOMO means the highest occupied molecular orbital, and LUMO means the lowest unoccupied molecular orbital. In addition, in the present invention, the HOMO and LUMO energy levels are expressed in absolute values, and the comparison between the energy levels is also a comparison of the absolute values. Those skilled in the art know that the larger the absolute value of the energy level, the lower the energy of the energy level.

[0066] In the drawings, for clarity, the dimensions of the layers and regions may be exaggerated. It will also be understood that when a layer or element is referred to as being "on" another layer or substrate, the layer or element may be directly on the other layer or substrate, or there may also be an intermediate layer. In addition, it will also be understood that when a layer is referred to as being "between" two layers, the layer may be the only layer between the two layers, or there may also be one or more intermediate layers. The same reference numerals throughout the text denote the same elements.

[0067] In the present invention, when describing electrodes, organic electroluminescent devices, and other structures, the words indicating directions such as "upper", "lower", "top", and "bottom" are only in the orientation in a specific state and do not mean that the relevant structures can only exist in the described orientation; on the contrary, if the structure can be changed in position, for example, inverted, the orientation of the structure will be changed accordingly. Specifically, in the present invention, the "bottom" and "lower" sides of the electrode refer to the side of the electrode close to the substrate during the preparation process, and the opposite side away from the substrate is the "top" and "upper" sides.

[0068] As the substrate of the organic electroluminescent device of the present invention, any substrate commonly used in organic electroluminescent devices can be used. Examples are transparent substrates such as glass or transparent plastic substrates; opaque substrates such as silicon substrates; flexible PI film substrates. Different substrates have different mechanical strengths, thermal stabilities, transparencies, surface smoothnesses, and water resistances. According to the different properties of the substrates, their usage directions are different. In the present invention, a transparent substrate is preferably used. The thickness of the substrate is not particularly limited.

[0069] A first electrode is formed on a substrate, and the first electrode and the second electrode can face each other. The first electrode can be an anode. The first electrode can be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. When the first electrode is a transmissive electrode, it can be formed using a transparent metal oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium tin zinc oxide (ITZO), etc. When the first electrode is a semi-transmissive electrode or a reflective electrode, it can include Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a metal mixture. The thickness of the first electrode layer depends on the material used and is usually 50 - 500 nm, preferably 70 - 300 nm, and more preferably 100 - 200 nm.

[0070] The organic functional material layer disposed between the first electrode and the second electrode sequentially includes a hole transport region, a light-emitting layer, and an electron transport region from bottom to top.

[0071] In this article, examples of the hole transport region constituting the organic electroluminescent device can include a hole injection layer, a hole transport layer, an electron blocking layer, etc.

[0072] As the materials for the hole injection layer, the hole transport layer, and the electron blocking layer, any material can be selected from known related materials for OLED devices for use.

[0073] Examples of the above materials can be phthalocyanine derivatives, triazole derivatives, triarylmethane derivatives, triarylamine derivatives, oxazole derivatives, oxadiazole derivatives, hydrazone derivatives, stilbene derivatives, pyridinium derivatives, polysilane derivatives, imidazole derivatives, phenylenediamine derivatives, amino-substituted quinone derivatives, styryl anthracene derivatives, styrylamine derivatives, etc., styrene compounds, fluorene derivatives, spirofluorene derivatives, silazane derivatives, aniline copolymers, porphyrin compounds, carbazole derivatives, polyarylalkane derivatives, polyphenylene vinyl and its derivatives, polythiophene and its derivatives, poly-N-vinylcarbazole derivatives, thiophene oligomers, etc., conductive polymer oligomers, aromatic tertiary amine compounds, styrylamine compounds, triamines, tetraamines, benzidine compounds, propynediamine derivatives, p-phenylenediamine derivatives, m-phenylenediamine derivatives, 1,1'-bis(4-diarylaminophenyl)cyclohexane, 4,4'-bis(diarylamino)biphenyls, bis[4-(diarylamino)phenyl]methanes, 4,4'-bis(diarylamino)terphenyls, 4,4'-bis(diarylamino)tetraphenyls, 4,4'-bis(diarylamino)diphenyl ethers, 4,4'-bis(diarylamino)diphenyl sulfides, bis[4-(diarylamino)phenyl]dimethylmethanes, bis[4-(diarylamino)phenyl]-bis(trifluoromethyl)methanes, or 2,2-diphenylethylene compounds, etc.

[0074] Further, according to the device matching requirements, the hole transport film layer between the hole transport auxiliary layer and the hole injection layer that constitutes the organic electroluminescent device can be a single film layer or a stacked structure of multiple hole transport materials. In this article, for the above-mentioned hole carrier conduction film layers with different functions, their film thicknesses are not particularly limited.

[0075] The hole injection layer contains a host organic material that can conduct holes, and also contains a P-type doping material with a deep HOMO energy level (the corresponding LUMO energy level will also be very deep). Based on empirical summaries, in order to achieve smooth injection of holes from the anode to the organic film layer, the HOMO energy level of the host organic material that conducts holes used in the anode interface buffer layer must have certain characteristics with the P-doping material, so as to expect the occurrence of a charge transfer state between the host material and the doping material, achieve ohmic contact between the buffer layer and the anode, and achieve efficient injection from the electrode to hole injection conduction.

[0076] In view of the above empirical summaries, for hole host materials with different HOMO energy levels, different P-doping materials need to be selected to match them in order to achieve ohmic contact at the interface and improve the hole injection effect.

[0077] Therefore, in an embodiment of the present invention, in order to better inject holes, the hole injection layer further contains a charge-conductive P-type doping material selected from the following: quinone derivatives such as tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinodimethane (F4-TCNQ); or hexaazatriphenylene derivatives such as 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN); or cyclopropane derivatives such as 4,4',4”-((1E,1'E,1”E)-cyclopropane-1,2,3-trimethylenetri(cyanomethine))tris(2,3,5,6-tetrafluorobenzyl); or metal oxides such as tungsten oxide and molybdenum oxide, but not limited thereto.

[0078] In the hole injection layer of the present invention, the ratio of the hole transport material to the P-type doping material used is 99:1 - 95:5, preferably 99:1 - 97:3, based on mass.

[0079] The thickness of the hole injection layer of the present invention can be 5 - 100 nm, preferably 5 - 50 nm, and more preferably 5 - 20 nm, but the thickness is not limited to this range.

[0080] The thickness of the hole transport layer of the present invention can be 5 - 200 nm, preferably 10 - 150 nm, and more preferably 20 - 100 nm, but the thickness is not limited to this range.

[0081] The thickness of the electron blocking layer of the present invention can be 1-20 nm, preferably 5-10 nm, but the thickness is not limited to this range.

[0082] After forming the hole injection layer, the hole transport layer and the electron blocking layer, a corresponding light-emitting layer is formed on the electron blocking layer.

[0083] The light-emitting layer may include a host material and a doping material. The host material may use common green host materials in the art, and the doping material uses the boron-containing organic compound represented by the general formula (1) of the present invention.

[0084] In the light-emitting layer of the present invention, the ratio of the host material to the doping material used is 99:1-70:30, preferably 99:1-85:15, and more preferably 97:3-87:13, based on mass.

[0085] The thickness of the light-emitting layer can be adjusted to optimize the light-emitting efficiency and the driving voltage. The preferred thickness range is 5 nm to 50 nm, further preferably 10-50 nm, and more preferably 15-30 nm, but the thickness is not limited to this range.

[0086] In the present invention, the electron transport region may sequentially include, from bottom to top, a hole blocking layer, an electron transport layer, and an electron injection layer provided on the light-emitting layer, but is not limited thereto.

[0087] The hole blocking layer is a layer that blocks holes injected from the anode from passing through the light-emitting layer and entering the cathode, thereby extending the life of the device and improving the efficiency of the device. The hole blocking layer of the present invention can be provided on the light-emitting layer. As the hole blocking layer material of the organic electroluminescent device of the present invention, compounds known in the prior art having a hole blocking effect can be used, for example, phenanthroline derivatives such as bathocuproine (referred to as BCP), metal complexes of hydroxyquinoline derivatives such as aluminum(III) bis(2-methyl-8-quinolinolato)-4-phenylphenolate (BAlq), various rare earth complexes, oxazole derivatives, triazole derivatives, triazine derivatives, pyrimidine derivatives such as 9,9'-(5-(6-([1,1'-biphenyl]-4-yl)-2-phenylpyrimidin-4-yl)-1,3-phenylene)bis(9H-carbazole), etc. The thickness of the hole blocking layer of the present invention can be 2-200 nm, preferably 5-150 nm, and more preferably 10-100 nm, but the thickness is not limited to this range.

[0088] The electron transport layer can be disposed above the light-emitting layer or, if present, the hole blocking layer. The electron transport layer material is a material that can easily receive electrons from the cathode and transfer the received electrons to the light-emitting layer. A material with a high electron mobility is preferably used. As the electron transport layer of the organic electroluminescent device of the present invention, electron transport layer materials known in the prior art for organic electroluminescent devices can be used. For example, metal complexes of hydroxyquinoline derivatives represented by Alq3, BAlq, and Liq, various rare earth metal complexes, triazole derivatives, 2,4-bis(9,9-dimethyl-9H-fluoren-2-yl)-6-(naphthalen-2-yl)-1,3,5-triazine (CAS No.: 1459162-51-6) and other triazine derivatives, 2-(4-(9,10-bis(naphthalen-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole (CAS No.: 561064-11-7, commonly known as LG201) and other imidazole derivatives, oxadiazole derivatives, thiadiazole derivatives, carbodiimide derivatives, quinoxaline derivatives, phenanthroline derivatives, silicon-based compound derivatives, etc. The thickness of the electron transport layer of the present invention can be 10-80 nm, preferably 20-60 nm, and more preferably 25-45 nm, but the thickness is not limited to this range.

[0089] The electron injection layer can be disposed above the electron transport layer. The electron injection layer material is usually preferably a material with a low work function, so that electrons can be easily injected into the organic functional material layer. As the electron injection layer material of the organic electroluminescent device of the present invention, electron injection layer materials known in the prior art for organic electroluminescent devices can be used. For example, lithium; lithium salts such as lithium 8-hydroxyquinoline, lithium fluoride, lithium carbonate, or lithium azide; or cesium salts, cesium fluoride, cesium carbonate, or cesium azide. The thickness of the electron injection layer of the present invention can be 0.1-5 nm, preferably 0.5-3 nm, and more preferably 0.8-1.5 nm, but the thickness is not limited to this range.

[0090] The second electrode can be disposed above the electron transport region. The second electrode can be a cathode. The second electrode can be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. When the second electrode is a transmissive electrode, the second electrode can include, for example, Li, Yb, Ca, LiF / Ca, LiF / Al, Al, Mg, BaF, Ba, Ag, or a compound or mixture thereof; when the second electrode is a semi-transmissive electrode or a reflective electrode, the second electrode can include Ag, Mg, Yb, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture thereof, but is not limited thereto. The thickness of the cathode depends on the material used and is usually 10-50 nm, preferably 15-20 nm.

[0091] The organic electroluminescent device of the present invention may further include a packaging structure. The packaging structure may be a protective structure for preventing external substances such as moisture and oxygen from entering the organic layer of the organic electroluminescent device. The packaging structure may be, for example, a can, such as a glass can or a metal can; or a thin film covering the entire surface of the organic layer.

[0092] A method for preparing the organic electroluminescent device of the present invention includes successively laminating an anode, a hole injection layer, a hole transport layer, an electron blocking layer, an organic film layer, an electron transport layer, an electron injection layer, and a cathode, and optionally a covering layer on a substrate. In this regard, methods such as vacuum deposition, vacuum evaporation, spin coating, casting, LB method, inkjet printing, laser printing, or LITI may be used, but are not limited thereto. In the present invention, vacuum evaporation is preferably used to form each of the layers. Those skilled in the art can conventionally select each process condition in the vacuum evaporation method according to actual needs.

[0093] The raw materials involved in the synthesis examples of the present invention can all be purchased from the market or prepared by conventional preparation methods in the art;

[0094] Synthesis of Compound 56 in Example 1:

[0095]

[0096] Under the protection of nitrogen, 10 mmol of raw material A-1, 10 mmol of NaH, and 10 mL of anhydrous DMF were added to a three-necked flask, stirred at room temperature for 1.5 hours, and then 10 mmol of raw material B-1 was added, and the reaction was carried out at room temperature for 4 hours. After the reaction was completed, 50 ml of deionized water was added, the white precipitate was filtered, the precipitate was dissolved in dichloromethane, dried over anhydrous sodium sulfate, filtered, and concentrated, and the intermediate a-1 was obtained by column chromatography separation. LC-MS: Measured value: 479.11 ([M+H] + ), theoretical value: 478.13.

[0097] Under the protection of nitrogen, 10 mmol of intermediate a-1, 100 mmol of iron powder, and 200 mL of glacial acetic acid were added to a three-necked flask, and the reaction was heated at 60 °C for 12 hours. After the reaction was completed, 200 ml of deionized water was added, the white solid was filtered, dissolved in chloroform, washed with an aqueous solution of anhydrous sodium carbonate, the organic phase was collected and dried over anhydrous sodium sulfate, the organic phase was filtered and concentrated, and the intermediate b-1 was obtained by column chromatography. LC-MS: Measured value: 449.26 ([M+H] + ), theoretical value: 448.15.

[0098] Under nitrogen protection, 10 mmol of intermediate b-1, 15 mmol of sodium tert-butoxide, 0.5 mmol of palladium acetate, 1.5 mmol of tri-tert-butylphosphine and 50 mL of anhydrous toluene were added to a three-necked flask and refluxed for 24 hours. After the reaction, the organic layer was decompressed and concentrated, and then purified by silica gel column chromatography to obtain intermediate c-1. This intermediate is unstable in the air and needs to be protected by nitrogen and stored away from light. LC-MS: Measured value: 369.30 ([M+H] + ), theoretical value: 368.23.

[0099] Under nitrogen protection, 10 mmol of raw material D-1, 10 mmol of NaH, and 10 mL of anhydrous DMF were added to a three-necked flask and stirred at room temperature for 0.5 hours. Then, 10 mmol of raw material C-1 was added and reacted at room temperature for 3 hours. After the reaction, 50 ml of deionized water was added, and the white precipitate was filtered. The precipitate was dissolved with dichloromethane, dried over anhydrous sodium sulfate, filtered, and concentrated. The intermediate d-1 was separated by column chromatography. LC-MS: Measured value: 508.23 ([M+H] + ), theoretical value: 507.19.

[0100] Under nitrogen protection, 10 mmol of intermediate c-1, 10 mmol of NaH, and 10 mL of anhydrous DMF were added to a three-necked flask and stirred at room temperature for 20 minutes. Then, 10 mmol of intermediate d-1 was added and reacted at room temperature for 3 hours. After the reaction, 50 ml of deionized water was added, and the white precipitate was filtered. The precipitate was dissolved in dichloromethane, dried over anhydrous sodium sulfate, filtered, and concentrated. The intermediate e-1 was separated by column chromatography. LC-MS: Measured value: 856.49 ([M+H] + ), theoretical value: 855.41.

[0101] In a sealed pressure-resistant tube, under nitrogen protection, 10 mmol of intermediate e-1 and 5 ml of o-dichlorobenzene were added. 12 mmol of n-butyl lithium in n-hexane solution was added at 0°C, the system was heated to 60°C and reacted for 2 hours, then 15 mmol of boron tribromide was added at 0°C, the reaction was continued at room temperature for 5 hours, then 20 mmol of N,N-diisopropylethylamine was added to the system at 0°C, heated to 200°C and reacted for 18 hours. After the reaction was completed, the organic layer was decompressed and concentrated, and then purified by silica gel column chromatography to obtain compound 56. 1H NMR (400 MHz, deuterated chloroform) δ 8.05 (d, 1H), 7.99-7.92 (m, 3H), 7.58 (dd, 1H), 7.51 (dd, 1H), 7.33 (m, 2H), 7.27 (dd, 1H), 7.16-7.02 (m, 6H), 1.44 (d, 18H), 1.39-1.35 (m, 27H).

[0102] Example 2 Synthesis of Compound 57:

[0103]

[0104] Under nitrogen protection, 10 mmol of raw material A-1, 10 mmol of NaH, and 10 mL of anhydrous DMF were added to a three-necked flask, stirred at room temperature for 1 hour, and then 10 mmol of raw material A-2 was added, and the reaction was carried out at room temperature for 3 hours. After the reaction, 50 ml of deionized water was added, and the white precipitate was filtered. The precipitate was dissolved in dichloromethane, dried over anhydrous sodium sulfate, filtered, and concentrated. The intermediate a-2 was separated by column chromatography. LC-MS: Measured value: 535.22 ([M+H] + ), theoretical value: 534.19.

[0105] Under nitrogen protection, 10 mmol of intermediate a-2, 100 mmol of iron powder, and 200 mL of glacial acetic acid were added to a three-necked flask and heated at 60 degrees Celsius for 15 hours. After the reaction, 200 ml of deionized water was added and filtered to obtain a white solid, which was dissolved in chloroform and washed with anhydrous sodium carbonate aqueous solution. The organic phase was collected and dried with anhydrous sodium sulfate, filtered and concentrated, and separated by column chromatography to obtain intermediate b-2. LC-MS: Measured value: 505.25 ([M+H] + ), theoretical value: 504.21.

[0106] Under nitrogen protection, 10 mmol of intermediate b-2, 15 mmol of sodium tert-butoxide, 0.5 mmol of palladium acetate, 1.5 mmol of tri-tert-butylphosphine and 50 mL of anhydrous toluene were added to a three-necked flask and refluxed for 18 hours. After the reaction, the organic layer was decompressed and concentrated, and then purified by silica gel column chromatography to obtain intermediate c-2. This intermediate is unstable in the air and needs to be protected by nitrogen and stored away from light. LC-MS: Measured value: 425.30 ([M+H] + ), theoretical value: 424.29.

[0107] Under nitrogen protection, 10 mmol of intermediate c-2, 10 mmol of NaH, and 10 mL of anhydrous DMF were added to a three-necked flask, and the mixture was stirred at room temperature for 1.5 hours. Then, 10 mmol of intermediate d-1 was added, and the reaction was carried out at room temperature for 6 hours. After the reaction was completed, 50 ml of deionized water was added, and the white precipitate was filtered. The precipitate was dissolved in dichloromethane, dried over anhydrous sodium sulfate, filtered, and concentrated. Intermediate d-2 was obtained by column chromatography. LC-MS: Measured value: 912.43 ([M+H] + ), theoretical value: 911.48.

[0108] In a sealed pressure-resistant tube, under nitrogen protection, 10 mmol of intermediate d-2 and 5 ml of o-dichlorobenzene were added. A solution of 12 mmol of n-butyllithium in n-hexane was added at 0 °C, and the system was heated to 60 °C and reacted for 2 hours. Then, 15 mmol of boron tribromide was added at 0 °C, and the reaction was continued at room temperature for 4 hours. Then, 20 mmol of N,N-diisopropylethylamine was added to the system at 0 °C, and the temperature was heated to 200 °C and reacted for 20 hours. After the reaction was completed, the organic layer was concentrated under reduced pressure and then purified by silica gel column chromatography to obtain compound 57. 1 1H NMR (400 MHz, chloroform-d) δ 8.05 (d, 1H), 7.91 - 7.79 (m, 2H), 7.63 (dd, 1H), 7.44 - 7.35 (m, 4H), 7.27 - 7.11 (m, 4H), 7.08 (s, 2H), 1.49 - 1.45 (m, 27H), 1.43 - 1.32 (m, 27H).

[0109] Example 3 Synthesis of Compound 58:

[0110]

[0111] Under nitrogen protection, 10 mmol of raw material A-3, 10 mmol of NaH, and 10 mL of anhydrous DMF were added to a three-necked flask, and the mixture was stirred at room temperature for 1.5 hours. Then, 10 mmol of raw material C-1 was added, and the reaction was carried out at room temperature for 5 hours. After the reaction was completed, 50 ml of deionized water was added, and the white precipitate was filtered. The precipitate was dissolved in dichloromethane, dried over anhydrous sodium sulfate, filtered, and concentrated. Intermediate a-3 was obtained by column chromatography. LC-MS: Measured value: 548.19 ([M+H] + ), theoretical value: 547.13.

[0112] Under nitrogen protection, 10 mmol of intermediate c-1, 10 mmol of NaH, and 10 mL of anhydrous DMF were added to a three-necked flask and stirred at room temperature for 0.5 hours. Then, 10 mmol of intermediate a-3 was added and reacted at room temperature for 8 hours. After the reaction, 50 ml of deionized water was added, and the white precipitate was filtered. The precipitate was dissolved with dichloromethane, dried over anhydrous sodium sulfate, filtered, and concentrated. The intermediate b-3 was separated by column chromatography. LC-MS: Measured value: 896.37 ([M+H] + ), theoretical value: 895.35.

[0113] In a sealed pressure-resistant tube, under nitrogen protection, 10 mmol of intermediate b-3 and 5 ml of o-dichlorobenzene were added. 12 mmol of n-butyl lithium in n-hexane solution was added at 0°C, the system was heated to 60°C and reacted for 5 hours, then 15 mmol of boron tribromide was added at 0°C, the reaction was continued at room temperature for 14 hours, then 20 mmol of N,N-diisopropylethylamine was added to the system at 0°C, heated to 200°C and reacted for 21 hours. After the reaction was completed, the organic layer was decompressed and concentrated, and then purified by silica gel column chromatography to obtain compound 58. 1 H NMR (400 MHz, deuterated chloroform) δ 8.40 (d, 1H), 8.23-8.02 (m, 2H), 7.96-7.80 (m, 1H), 7.73-7.62 (m, 2H), 7.55-7.49 (m, 3H), 7.46-7.31 (m, 11H), 7.28-7.22 (m, 3H), 7.19-7.11 (m, 2H), 1.48 (s, 9H), 1.44 (d, 18H).

[0114] Example 4 Synthesis of Compound 128:

[0115]

[0116] Under nitrogen protection, 10 mmol of raw material A-4, 10 mmol of intermediate c-1, 15 mmol of potassium tert-butoxide, 0.5 mmol of Pd2(dba)3, 1.5 mmol of tri-tert-butylphosphine and 20 mL of anhydrous toluene were added to a three-necked flask and refluxed for 22 hours. After the reaction was completed, the organic layer was decompressed and concentrated, and then purified by silica gel column chromatography to obtain intermediate a-4. LC-MS: Measured value: 836.40 ([M+H] + ), theoretical value: 835.33.

[0117] Under nitrogen protection, 10 mmol of intermediate a-4, 10 mmol of raw material B-4, 15 mmol of potassium tert-butoxide, 0.5 mmol of Pd2(dba)3, 1.5 mmol of tri-tert-butylphosphine and 20 mL of anhydrous toluene were added to a three-necked flask and refluxed for 22 hours. After the reaction was completed, the organic layer was concentrated under reduced pressure and then purified by silica gel column chromatography to obtain intermediate b-4. LC-MS: Measured value: 1037.59 ([M+H] + ), theoretical value: 1036.62.

[0118] In a sealed pressure-resistant tube, under nitrogen protection, 10 mmol of intermediate b-4 and 5 ml of o-dichlorobenzene were added. 12 mmol of tert-butyl lithium in n-hexane was added at 0°C, the system was heated to 60°C and reacted for 12 hours, then 15 mmol of boron tribromide was added at 0°C, the reaction was continued at room temperature for 5 hours, then 20 mmol of N,N-diisopropylethylamine was added to the system at 0°C, the reaction was heated to 200°C and reacted for 15 hours. After the reaction was completed, the organic layer was decompressed and concentrated, and then purified by silica gel column chromatography to obtain compound 128. 1 H NMR (400 MHz, deuterated chloroform) δ 8.15-7.98 (m, 2H), 7.62 (dd, 1H), 7.59-7.48 (m, 3H), 7.22 (d, 2H), 7.13-6.99 (m, 15H), 6.97-6.92 (m, 2H), 1.41-1.33 (m, 36H), 1.28 (d, 18H).

[0119] Example 5 Synthesis of Compound 132:

[0120]

[0121] Under nitrogen protection, 10 mmol of intermediate a-4, 10 mmol of raw material A-5, 15 mmol of potassium tert-butoxide, 0.5 mmol of Pd2(dba)3, 1.5 mmol of tri-tert-butylphosphine and 20 mL of anhydrous toluene were added to a three-necked flask and refluxed for 16 hours. After the reaction was completed, the organic layer was concentrated under reduced pressure and then purified by silica gel column chromatography to obtain intermediate a-5. LC-MS: Measured value: 1093.64 ([M+H] + ), theoretical value: 1092.59.

[0122] In a sealed pressure-resistant tube, under nitrogen protection, 10 mmol of intermediate a-5 and 5 ml of o-dichlorobenzene were added. 12 mmol of tert-butyl lithium in n-hexane solution was added at 0°C, the system was heated to 60°C and reacted for 10 hours, then 15 mmol of boron tribromide was added at 0°C, the reaction was continued at room temperature for 5 hours, then 20 mmol of N,N-diisopropylethylamine was added to the system at 0°C, the reaction was heated to 200°C and reacted for 21 hours. After the reaction was completed, the organic layer was concentrated under reduced pressure and then purified by silica gel column chromatography to obtain compound 132. 1 H NMR (400 MHz, deuterated chloroform) δ 8.23-8.07 (m, 2H), 7.86-7.79 (m, 1H), 7.78 (dd, 1H), 7.55 (dd, 1H), 7.44 (dd, 1H), 7.37 (m, 2H), 7.31-7.18 (m, 9H), 7.10-6.94 (m, 6H), 6.89 (dd, 2H), 1.46-1.39 (m, 45H), 1.35 (s, 9H).

[0123] Example 6 Synthesis of Compound 134:

[0124]

[0125] Under nitrogen protection, 22mmol of intermediate c-1, 10mmol of raw material A-4, 30mmol of potassium tert-butoxide, 1.5mmol of Pd2(dba)3, 3mmol of tri-tert-butylphosphine and 40mL of anhydrous toluene were added to a three-necked flask and refluxed for 26 hours. After the reaction, the organic layer was concentrated under reduced pressure and then purified by silica gel column chromatography to obtain intermediate a-6. LC-MS: Measured value: 1124.57 ([M+H] + ), theoretical value: 1123.63.

[0126] In a sealed pressure-resistant tube, under nitrogen protection, 10 mmol of intermediate a-6 and 5 ml of o-dichlorobenzene were added. 12 mmol of tert-butyl lithium in n-hexane was added at 0°C, the system was heated to 60°C and reacted for 11 hours, then 15 mmol of boron tribromide was added at 0°C, the reaction was continued at room temperature for 10 hours, then 20 mmol of N,N-diisopropylethylamine was added to the system at 0°C, the reaction was heated to 200°C and reacted for 24 hours. After the reaction was completed, the organic layer was concentrated under reduced pressure and then purified by silica gel column chromatography to obtain compound 134. 11H NMR (400 MHz, chloroform-d) δ 8.26 (m, 1H), 8.12 - 8.03 (m, 2H), 7.79 (dd, 2H), 7.55 - 7.51 (m, 2H), 7.47 - 7.38 (m, 4H), 7.33 - 7.19 (m, 8H), 7.12 - 6.92 (m, 4H), 6.82 (s, 2H), 1.48 (s, 18H), 1.45 (s, 18H), 1.39 (s, 18H).

[0127] Synthesis of Compound 149 in Example 7:

[0128]

[0129] Under nitrogen protection, 10 mmol of intermediate c-2, 10 mmol of NaH, and 10 mL of anhydrous DMF were added to a three-necked flask, and the mixture was stirred at room temperature for 1.5 hours. Then, 10 mmol of raw material A-7 was added, and the reaction was carried out at room temperature for 5 hours. After the reaction was completed, 50 ml of deionized water was added, and the white precipitate was filtered. The precipitate was dissolved in dichloromethane, dried over anhydrous sodium sulfate, filtered, and concentrated. Column chromatography was used to separate the intermediate a-7. LC-MS: Measured value: 856.44 ([M+H] + ), Theoretical value: 855.41.

[0130] In a sealed pressure-resistant tube, under nitrogen protection, 10 mmol of intermediate a-7 and 5 ml of o-dichlorobenzene were added. At 0 °C, a hexane solution of 12 mmol of n-butyllithium was added, and the reaction system was heated to 60 °C and reacted for 3 hours. Then, at 0 °C, 15 mmol of boron tribromide was added, and the reaction was continued at room temperature for 12 hours. Then, at 0 °C, 20 mmol of N,N-diisopropylethylamine was added to the system, and the temperature was heated to 200 °C and reacted for 12 hours. After the reaction was completed, the organic layer was concentrated under reduced pressure, and then purified by silica gel column chromatography to obtain intermediate b-7. LC-MS: Measured value: 786.51 ([M+H] + ), Theoretical value: 785.49.

[0131] To a single-necked flask, intermediate b-7 (10.0 mmol), bis(pinacolato)diboron (15 mmol), [Ir(COD)(OCH3)]2 (0.06 mmol), and 50 mL of tetrahydrofuran were added in sequence. The reaction was carried out at room temperature for 16 hours under nitrogen protection. Subsequently, the reaction was filtered, the organic phase was concentrated, and the compound was separated by silica gel column to obtain intermediate c-7. This reaction has relatively good selectivity (reference DOI: 10.31635 / ccschem.021.202101033), and the boronic ester at the p-position of B has higher activity and selectivity. LC-MS: Measured value: 912.55 ([M+H] +), theoretical value: 911.57; 1 H NMR (400 MHz, deuterated chloroform) δ 8.54 (d, 1H), 8.21-8.06 (m, 2H), 7.69-7.54 (m, 2H), 7.45-7.25 (m, 3H), 7.23-7.05 (m, 6H), 1.47-1.39 (m, 27H), 1.35 (s, 18H), 1.31 (s, 12H).

[0132] Into a two-necked flask, intermediate c-7 (10.0 mmol), raw material B-7 (10.0 mmol), Pd(PPh3)4 catalyst 0.1 mmol, 50 mL of tetrahydrofuran: water = 10:1 mixed solution, potassium carbonate (20 mmol) were added in sequence, followed by nitrogen protection, stirring at 80 ° C for 24 hours, cooling, separation and collection of the organic phase, drying over anhydrous sodium sulfate, filtering and concentrating the organic phase, separating the compounds by silica gel column to obtain compound 149. 1 H NMR (400 MHz, deuterated chloroform) δ 8.66 (d, 1H), 8.47-8.35 (m, 4H), 8.29-8.15 (m, 2H), 8.03 (d, 1H), 7.61 (dd,, 1H), 7.54-7.36 (m, 10H), 7.30-7.11 (m, 4H), 7.08 (d, 1H), 1.40-1.31 (m, 27H), 1.23 (s, 18H).

[0133] Example 8 Synthesis of Compound 261:

[0134]

[0135] Under nitrogen protection, 10 mmol of intermediate c-2, 10 mmol of raw material A-8, 15 mmol of potassium tert-butoxide, 0.5 mmol of Pd2(dba)3, 1.5 mmol of tri-tert-butylphosphine and 20 mL of anhydrous toluene were added to a three-necked flask and refluxed for 23 hours. After the reaction was completed, the organic layer was concentrated under reduced pressure and then purified by silica gel column chromatography to obtain intermediate a-8. LC-MS: Measured value: 613.17 ([M+H] + ), theoretical value: 612.19.

[0136] Under nitrogen protection, 10 mmol of raw material a-8, 10 mmol of raw material A-8, 15 mmol of potassium carbonate, 0.5 mmol of Pd2(dba)3, 1.5 mmol of 2-bicyclohexylphosphine-2',6'-diisopropoxybiphenyl and 50 mL of anhydrous o-xylene were added to a three-necked flask and refluxed for 19 hours. After the reaction, the organic layer was concentrated under reduced pressure and then purified by silica gel column chromatography to obtain intermediate b-8. LC-MS: Measured value: 890.57 ([M+H] + ), theoretical value: 889.51.

[0137] Under nitrogen protection, 10 mmol of intermediate b-8, 10 mmol of raw material B-8, 15 mmol of potassium tert-butoxide, 0.5 mmol of Pd2(dba)3, 1.5 mmol of tri-tert-butylphosphine and 20 mL of anhydrous toluene were added to a three-necked flask and refluxed for 12 hours. After the reaction, the organic layer was concentrated under reduced pressure and then purified by silica gel column chromatography to obtain intermediate c-8. LC-MS: Measured value: 1078.70 ([M+H] + ), theoretical value: 1077.58.

[0138] In a sealed pressure-resistant tube, under nitrogen protection, 10 mmol of intermediate c-8 and 5 ml of o-dichlorobenzene were added. 15 mmol of tert-butyl lithium in n-hexane was added at 0°C, the system was heated to 60°C and reacted for 10 hours, then 15 mmol of boron tribromide was added at 0°C, the reaction was continued at room temperature for 10 hours, then 20 mmol of N,N-diisopropylethylamine was added to the system at 0°C, the reaction was heated to 200°C and reacted for 36 hours. After the reaction was completed, the organic layer was concentrated under reduced pressure and then purified by silica gel column chromatography to obtain compound 261.

[0139] Example 9 Synthesis of Compound 299:

[0140]

[0141] Under nitrogen protection, 10 mmol of intermediate a-8, 10 mmol of raw material A-9, 15 mmol of potassium tert-butoxide, 0.5 mmol of Pd2(dba)3, 1.5 mmol of tri-tert-butylphosphine and 20 mL of anhydrous toluene were added to a three-necked flask and refluxed for 23 hours. After the reaction was completed, the organic layer was concentrated under reduced pressure and then purified by silica gel column chromatography to obtain intermediate a-9. LC-MS: Measured value: 1055.66 ([M+H] + ), theoretical value: 1054.57.

[0142] In a sealed pressure-resistant tube, under nitrogen protection, 10 mmol of intermediate a-9 and 5 ml of o-dichlorobenzene were added. A solution of 15 mmol of tert-butyllithium in n-hexane was added at 0 °C, and the reaction system was heated to 60 °C and reacted for 6 hours. Then, 15 mmol of boron tribromide was added at 0 °C, and the reaction was continued at room temperature for 12 hours. Subsequently, 20 mmol of N,N-diisopropylethylamine was added to the reaction system at 0 °C, and the mixture was heated to 200 °C and reacted for 23 hours. After the reaction was completed, the organic layer was concentrated under reduced pressure and then purified by silica gel column chromatography to obtain Compound 299.

[0143] The structural characterizations of the compounds obtained in each example are shown in Table 1.

[0144] Table 1

[0145]

[0146] The compounds of the present invention can be used in light-emitting devices and can be used as doping materials for the light-emitting layer. The physical and chemical properties of the compounds prepared in the above examples of the present invention were tested, and the test results are shown in Table 2:

[0147] Table 2

[0148]

[0149] Note: PLQY (fluorescence quantum yield) and FWHM (full width at half maximum) were measured by a Horiba Fluorolog-3 series fluorescence spectrometer in the thin film state.

[0150] From the data in the above table, it can be seen that the compounds of the present invention have a high fluorescence quantum efficiency as doping materials, and the fluorescence quantum efficiency of the materials is close to 100%; at the same time, the spectral FWHM of the materials is narrow, which can effectively improve the color gamut of the device and the light-emitting efficiency of the device;

[0151] Compared with the prior art, the light-emitting efficiency and full width at half maximum of the compounds in the examples of the present invention have been improved to varying degrees;

[0152] Compared with ref-4 (CN111377955A), when the structure of para-double B is replaced with the compound structure type in the present invention, its full width at half maximum is narrowed from 48 nm to less than or equal to 30 nm, and the improvement of this technical effect is unexpected;

[0153] When comparing with the ref-3 structure (CN113045595A) in the prior art, the fluorescence quantum yield of the compounds of the present invention has been significantly improved, and the full width at half maximum has also been narrowed to a certain extent;

[0154] Compared with ref-2 (WO2021075856A1) in the prior art, although the ref-2 structure also has a relatively narrow full-width at half-maximum emission, the light-emitting region of the ref-2 structure is in the blue region, while the emission range of the compound of the embodiment of the present invention is in the green region, and it also has the characteristic of narrow emission;

[0155] The application effects of the OLED materials synthesized by the present invention in devices are described in detail below through Device Examples 1-9 and Device Comparative Examples 1-4. The manufacturing processes of Device Examples 2-9 and Device Comparative Examples 1-4 of the present invention are exactly the same as those of Device Example 1, and the same substrate materials and electrode materials are used, and the film thicknesses of the electrode materials are also kept consistent. The difference is that the light-emitting layer materials in the devices are replaced.

[0156] The layer structures and test results of each device example are shown in Table 3-1 and Table 4 respectively:

[0157] Device Example 1

[0158] As Figure 1 shown, the transparent substrate layer 1 is a transparent PI film. The ITO anode layer 2 (with a film thickness of 150 nm) is washed, that is, washed with a cleaning agent (Semiclean M-L20), pure water, and then dried, and then ultraviolet-ozone washing is carried out to remove organic residues on the surface of the transparent ITO. On the ITO anode layer 2 after the above washing, using a vacuum evaporation device, HT-1 and HI-1 with a film thickness of 10 nm are evaporated as the hole injection layer 3, and the mass ratio of HT-1 and HI-1 is 97:3. Then, HT-1 with a thickness of 60 nm is evaporated as the hole transport layer 4. Subsequently, EB-1 with a thickness of 30 nm is evaporated as the electron blocking layer 5. After the evaporation of the above electron blocking material is completed, the light-emitting layer 6 of the OLED light-emitting device is fabricated. GH-1 and GH-2 are used as host materials, and compound 56 is used as a doping material. The mass ratio of GH-1, GH-2, and compound 56 is 69:30:1, and the film thickness of the light-emitting layer is 30 nm. After the above light-emitting layer 6, HB-1 is continuously vacuum-evaporated with a film thickness of 5 nm, and this layer is the hole blocking layer 7. After the above hole blocking layer 7, ET-1 and Liq are continuously vacuum-evaporated, and the mass ratio of ET-1 and Liq is 1:1, with a film thickness of 30 nm. This layer is the electron transport layer 8. On the electron transport layer 8, a LiF layer with a film thickness of 1 nm is fabricated through a vacuum evaporation device, and this layer is the electron injection layer 9. On the electron injection layer 9, a Mg:Ag electrode layer with a film thickness of 80 nm is fabricated through a vacuum evaporation device, and the mass ratio of Mg and Ag is 1:9. This layer is used as the cathode layer 10.

[0159] The application effects of the synthesized OLED materials of the present invention in devices are described in detail below through Device Examples 10-18 and Device Comparative Examples 5-8. The manufacturing processes of Device Examples 11-18 and Device Comparative Examples 5-8 are exactly the same as those of Device Example 10, and the same substrate materials and electrode materials are used, and the film thicknesses of the electrode materials are also kept consistent. The difference is that the light-emitting layer materials in the devices are replaced. The layer structures and test results of each device example are shown in Tables 3-2 and 4 respectively:

[0160] Device Example 10

[0161] The transparent substrate layer 1 is a transparent PI film. The ITO anode layer 2 (with a film thickness of 150 nm) is washed, that is, washed with a cleaning agent (Semiclean M-L20), pure water, and then dried, and then ultraviolet-ozone washing is carried out to remove organic residues on the surface of the transparent ITO. On the ITO anode layer 2 after the above washing, using a vacuum evaporation device, HT-1 and HI-1 with a film thickness of 10 nm are evaporated as the hole injection layer 3, and the mass ratio of HT-1 and HI-1 is 97:3. Then, HT-1 with a thickness of 60 nm is evaporated as the hole transport layer 4. Subsequently, EB-1 with a thickness of 30 nm is evaporated as the electron blocking layer 5. After the evaporation of the above electron blocking material is completed, the light-emitting layer 6 of the OLED light-emitting device is fabricated. GH-1 and GH-2 are used as the host materials, GD-1 is used as the first doping material, and Compound 56 is used as the second doping material. The mass ratio of GH-1, GH-2, GD-1, and Compound 56 is 66:30:3:1, and the film thickness of the light-emitting layer is 30 nm. After the above light-emitting layer 6, HB-1 is continuously vacuum-evaporated with a film thickness of 5 nm, and this layer is the hole blocking layer 7. After the above hole blocking layer 7, ET-1 and Liq are continuously vacuum-evaporated, and the mass ratio of ET-1 and Liq is 1:1, and the film thickness is 30 nm. This layer is the electron transport layer 8. On the electron transport layer 8, a LiF layer with a film thickness of 1 nm is fabricated through a vacuum evaporation device, and this layer is the electron injection layer 9. On the electron injection layer 9, a Mg:Ag electrode layer with a film thickness of 80 nm is fabricated through a vacuum evaporation device, and the mass ratio of Mg and Ag is 1:9. This layer is used as the cathode layer 10.

[0162] The molecular structural formulas of the related materials are shown as follows:

[0163]

[0164] After completing the OLED light-emitting device as described above, the anode and the cathode are connected by a known driving circuit, and the current efficiency, external quantum efficiency, and lifespan of the device are measured. Device examples and comparative examples prepared by the same method are shown in Tables 3-1 and 3-2; the test results of the current efficiency, external quantum efficiency, and lifespan of the obtained devices are shown in Table 4.

[0165] Table 3-1

[0166]

[0167] Table 3-2

[0168]

[0169] Table 4

[0170]

[0171] Note: Voltage, current efficiency, and emission peak are measured using an IVL (current-voltage-luminance) test system (Suzhou Fosida Scientific Instruments Co., Ltd.); the lifespan test system is the EAS-62C type OLED device lifespan tester of System Technology Research Co., Ltd. in Japan; LT95 refers to the time when the device luminance decays to 95%; all data are tested at 10 mA / cm 2 below.

[0172] From the device data results in Table 4, it can be seen that compared with device comparative examples 1, 2, 3, 5, 6, and 7, both the current efficiency and device lifespan of the organic light-emitting device of the present invention have been significantly improved compared to OLED devices made of known materials;

[0173] while compared with comparative examples 4 and 8, the device efficiency has been improved to a certain extent, and the device lifespan has been significantly improved, showing an unexpectedly improved effect;

[0174] In summary, the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A boron-containing organic compound, characterized in that, The structure of the organic compound is shown as any one of general formula (9) to general formula (18): In general formula (9) to general formula (18), Z represents C-R1 each time it appears, which may be the same or different; R1 independently represents a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted C1-C 10 alkyl group, a substituted or unsubstituted C3-C 10 cycloalkyl group, a substituted or unsubstituted C1-C 10 alkoxy group, a substituted or unsubstituted C6-C 30 aryl group, a substituted or unsubstituted C2-C 30 heteroaryl group, a phenyl-substituted amino group, a tert-butylbenzene-substituted amino group; The substituents for the substituting groups are each independently selected from one or more of a deuterium atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 2 to 30 carbon atoms; Y1 and Y2 each independently represent O or S.

2. A boron-containing organic compound, characterized in that, The structure of the organic compound is shown as any one of general formula (19) to general formula (28): In general formula (19) to general formula (28), Z represents C-R1 each time it appears, which may be the same or different; R1 independently represents a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted C1-C 10 alkyl group, a substituted or unsubstituted C3-C 10 cycloalkyl group, a substituted or unsubstituted C1-C 10 alkoxy group, a substituted or unsubstituted C6-C 30 aryl group, a substituted or unsubstituted C2-C 30 heteroaryl group, a phenyl-substituted amino group, or a tert-butylbenzene-substituted amino group; The substituents for the substituting groups are each independently selected from one or more of a deuterium atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 2 to 30 carbon atoms; Y1 and Y2 each independently represent O or S; Z1 is represented as 3. A boron-containing organic compound, characterized in that, The structure of the organic compound is shown as any one of general formula (29) to general formula (35): In general formula (29) to general formula (35), Z represents C-R1 each time it appears, which may be the same or different; R1 independently represents a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted C1-C 10 alkyl group, a substituted or unsubstituted C3-C 10 cycloalkyl group, a substituted or unsubstituted C1-C 10 alkoxy group, a substituted or unsubstituted C6-C 30 aryl group, a substituted or unsubstituted C2-C 30 heteroaryl group, a phenyl-substituted amino group, a tert-butylbenzene-substituted amino group; Ar represents an aryl group which is substituted or unsubstituted and has 6 to 30 carbon atoms, or a heteroaryl group which is substituted or unsubstituted and has 2 to 30 carbon atoms; R a 、R b 、R c 、R d 、R e 、R f each independently represents a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted C1-C 10 alkyl group, a substituted or unsubstituted C3-C 10 cycloalkyl group, a substituted or unsubstituted C1-C 10 alkoxy group, a substituted or unsubstituted C6-C 30 aryl group, a substituted or unsubstituted C2-C 30 heteroaryl group, a phenyl-substituted amino group, a tert-butylbenzene-substituted amino group; Y1 and Y2 each independently represent O or S; The substituents for the substituting groups are each independently selected from one or more of a deuterium atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 2 to 30 carbon atoms.

4. The boron-containing organic compound according to any one of claims 1-2, characterized in that, The said R1 represents a hydrogen atom, a deuterium atom, a halogen atom, an adamantyl group, a methyl group, a deuterated methyl group, a trifluoromethyl group, an ethyl group, a deuterated ethyl group, an isopropyl group, a deuterated isopropyl group, a tert-butyl group, a deuterated tert-butyl group, a cyclopentyl group, a deuterated cyclopentyl group, a methyl-substituted cyclopentyl group, a cyclohexyl group, a phenyl group, a deuterated phenyl group, a biphenyl group, a deuterated biphenyl group, a terphenyl group, a deuterated terphenyl group, a naphthyl group, an anthracenyl group, a phenanthryl group, a pyridyl group, a phenyl-substituted pyridyl group, a quinolinyl group, a furyl group, a thienyl group, a benzofuryl group, a dibenzofuryl group, a dibenzothienyl group, a carbazolyl group, an N-phenylcarbazolyl group, a 9,9-dimethylfluorenyl group, a spirofluorene group, a methyl-substituted phenyl group, an ethyl-substituted phenyl group, an isopropyl-substituted phenyl group, a tert-butyl-substituted phenyl group, a methyl-substituted biphenyl group, an ethyl-substituted biphenyl group, an isopropyl-substituted biphenyl group, a tert-butyl-substituted biphenyl group, a deuterated methyl-substituted phenyl group, a deuterated ethyl-substituted phenyl group, a deuterated isopropyl-substituted phenyl group, a deuterated tert-butyl-substituted phenyl group, a deuterated methyl-substituted biphenyl group, a deuterated ethyl-substituted biphenyl group, a deuterated isopropyl-substituted biphenyl group, a deuterated tert-butyl-substituted biphenyl group, a phenyl-substituted amino group, a tert-butylbenzene-substituted amino group, a tert-butyl-substituted dibenzofuryl group, a phenyl-substituted tert-butyl group, an oxanthrone group, a phenyl-substituted triazine group, a methoxy group, a tert-butoxy group.

5. The boron-containing organic compound according to claim 3, wherein The R1, R a , R b , R c , R d , R e , R f are each independently represented by a hydrogen atom, a deuterium atom, a halogen atom, an adamantyl group, a methyl group, a deuterated methyl group, a trifluoromethyl group, an ethyl group, a deuterated ethyl group, an isopropyl group, a deuterated isopropyl group, a tert-butyl group, a deuterated tert-butyl group, a cyclopentyl group, a deuterated cyclopentyl group, a methyl-substituted cyclopentyl group, a cyclohexyl group, a phenyl group, a deuterated phenyl group, a biphenyl group, a deuterated biphenyl group, a terphenyl group, a deuterated terphenyl group, a naphthyl group, an anthracenyl group, a phenanthryl group, a pyridyl group, a phenyl-substituted pyridyl group, a quinolinyl group, a furyl group, a thienyl group, a benzofuryl group, a dibenzofuryl group, a dibenzothienyl group, a carbazolyl group, an N-phenylcarbazolyl group, a 9,9-dimethylfluorenyl group, a spirofluorene group, a methyl-substituted phenyl group, an ethyl-substituted phenyl group, an isopropyl-substituted phenyl group, a tert-butyl-substituted phenyl group, a methyl-substituted biphenyl group, an ethyl-substituted biphenyl group, an isopropyl-substituted biphenyl group, a tert-butyl-substituted biphenyl group, a deuterated methyl-substituted phenyl group, a deuterated ethyl-substituted phenyl group, a deuterated isopropyl-substituted phenyl group, a deuterated tert-butyl-substituted phenyl group, a deuterated methyl-substituted biphenyl group, a deuterated ethyl-substituted biphenyl group, a deuterated isopropyl-substituted biphenyl group, a deuterated tert-butyl-substituted biphenyl group, a phenyl-substituted amino group, a tert-butylbenzene-substituted amino group, a tert-butyl-substituted dibenzofuryl group, a phenyl-substituted tert-butyl, an oxanthrone group, a phenyl-substituted triazinyl group, a methoxy group, a tert-butoxy group; Ar is represented by one of phenyl, deuterated phenyl, biphenyl, deuterated biphenyl, terphenyl, deuterated terphenyl, naphthyl, anthryl, phenanthryl, pyridyl, phenyl-substituted pyridyl, quinolinyl, furyl, thienyl, benzofuryl, dibenzofuryl, dibenzothienyl, carbazolyl, N-phenylcarbazolyl, 9,9-dimethylfluorenyl, spirofluorene, methyl-substituted phenyl, ethyl-substituted phenyl, isopropyl-substituted phenyl, tert-butyl-substituted phenyl, methyl-substituted biphenyl, ethyl-substituted biphenyl, isopropyl-substituted biphenyl, tert-butyl-substituted biphenyl, deuterated methyl-substituted phenyl, deuterated ethyl-substituted phenyl, deuterated isopropyl-substituted phenyl, deuterated tert-butyl-substituted phenyl, deuterated methyl-substituted biphenyl, deuterated ethyl-substituted biphenyl, deuterated isopropyl-substituted biphenyl, deuterated tert-butyl-substituted biphenyl, tert-butyl-substituted dibenzofuryl, phenyl-substituted tert-butyl, xanthenone, phenyl-substituted triazinyl.

6. A boron-containing organic compound, characterized in that, The specific structure of the organic compound is any one of the following structures:

7. An organic electroluminescent device, comprising a cathode and an anode, and an organic light-emitting functional layer therebetween, the organic light-emitting functional layer including a light-emitting layer, characterized in that, The light-emitting layer contains the boron-containing organic compound according to any one of claims 1-6.

8. The organic electroluminescent device according to claim 7, characterized in that, The light-emitting layer comprises a host material and a dopant material, and the dopant material contains the boron-containing organic compound according to any one of claims 1-6.

9. The organic electroluminescent device according to claim 7, wherein the light-emitting layer comprises a first host material, a second host material, and a doping material, characterized in that, At least one of the first host material and the second host material is a TADF material, and the dopant material is the boron-containing organic compound according to any one of claims 1-6.

10. The organic electroluminescent device according to claim 7, wherein the light-emitting layer comprises a host material, an exciton sensitizing material, and a doping material, and is characterized in that: The exciton sensitizing material is a metal element-containing complex, and the dopant material is the boron-containing organic compound according to any one of claims 1-6.

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