Boron-nitrogen compound and application thereof

Abstract

The invention discloses a boron-nitrogen compound and application thereof, the structural general formula is as shown in formula (I), in the formula (I), ring m and ring n are respectively and independently selected from substituted or unsubstituted C6-C50 aryl, substituted or unsubstituted C2-C50 heteroaryl and a combination thereof, L is O, S, S = O, SO2, Se, GeR3R4, SiR3R4, C = O, CR3R4 or NAr2; x1 and X2 each independently represent N or CR5, or X1 and X2 represent a group represented by formula (II) or formula (III); y is O, S, Se or NAr4; r1, R2, R3, R4, R5, R6, R7 and R8 are selected from a group consisting of hydrogen, deuterium, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C50 aryl, substituted or unsubstituted C3-C30 cycloalkyl and the like; ar1, Ar2, Ar3 and Ar4 are respectively and independently selected from a group consisting of substituted or unsubstituted C6-C50 aryl groups, substituted or unsubstituted C6-C50 fused aryl groups and the like. According to the invention, a compound with a double boron-nitrogen unit as a parent nucleus is used as a light-emitting unit, so that not only can a TADF effect be realized, but also a narrower half-peak width can be realized; .

Description

Technical Field

[0001] This invention relates to the field of electroluminescence technology. Specifically, it relates to a boron-nitrogen compound and its applications. Background Technology

[0002] In traditional fluorescent materials, the ratio of singlet excitons (S1) to triplet excitons (T1) generated during electroluminescence is 1:3, and triplet excitons cannot emit light directly but are deactivated through nonradiative transitions. Consequently, the theoretical limit of quantum efficiency within the device is 25%.

[0003] Existing research has developed fluorescent materials with the thermally activated delayed effect (TADF), utilizing the reverse system crossing (RISC) process to convert triplet excitons (T1) into singlet excitons (S1), effectively improving the exciton utilization efficiency of fluorescent materials. TADF materials need to simultaneously possess a small singlet-triplet energy level difference and high fluorescence quantum efficiency. Current techniques mainly achieve this by introducing acceptor and donor groups into the molecule, thus spatially separating the lowest empty orbital and the highest occupied orbital, thereby achieving a small singlet-triplet energy level difference. However, this method has the following drawbacks: the donor-acceptor structure of the fluorescent molecule exhibits vibrational relaxation in the excited state, resulting in a significant redshift in its fluorescence spectrum compared to the corresponding absorption spectrum; furthermore, the fluorescent materials with donor-acceptor structures have broad emission spectra, with a full width at half maximum (FWHM) of 70-100 nm, leading to poor color purity and limiting their application in light-emitting devices.

[0004] Therefore, it is necessary to scientifically design and improve the molecular structure of existing fluorescent materials in order to overcome the aforementioned defects of existing fluorescent materials. Summary of the Invention

[0005] Therefore, the technical problem to be solved by this invention is to provide a boron-nitrogen compound with high color purity that possesses both the TADF effect and narrow spectral characteristics, thereby addressing the technical problems of existing luminescent materials, such as broad emission spectra and poor color purity. This invention also provides an application of the boron-nitrogen compound, as well as organic electroluminescent materials and organic electroluminescent elements.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A boron-nitrogen compound with the general structural formula shown in formula (I):

[0008] ;

[0009] In formula (I), ring m and ring n are each independently selected from substituted or unsubstituted C6~C50 aromatics, substituted or unsubstituted C2~C50 heteroaryl groups and combinations thereof;

[0010] L represents O, S, S=O, SO2, Se, and GeR. 3 R 4 SiR 3 R 4 C=O, CR 3 R 4 or NAr 2 ;

[0011] X 1 and X 2 Each independently represents N or CR 5 , or X 1 and X 2 The group represented by formula (II) or formula (III);

[0012] , ;

[0013] In equations (II) and (III), Z independently represents CR. 6 Or N; two adjacent "^" represent adjacent groups X in formula (I). 1 and X 2 ;G is O, S, S=O, SO2, Se, GeR 7 R 8 SiR 7 R 8 C=O, CR 7 R 8 or NAr 3 ;

[0014] Y is O, S, Se, or NAr 4 ;

[0015] In equations (I), (II), and (III), R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 They may be the same or different from each other, and each is independently selected from hydrogen, deuterium, substituted or unsubstituted C1~C. 30 Alkyl, substituted or unsubstituted C6~C 50 aryl, substituted or unsubstituted C3~C 30 Cycloalkyl, substituted or unsubstituted C2~C 50 heteroaryl, substituted or unsubstituted C1~C 30 Alkoxy, substituted or unsubstituted C6~C 50 aryloxy group, substituted or unsubstituted C1~C 30Alkyl thio, substituted or unsubstituted C5~C 50 aryl thio, substituted or unsubstituted C1~C 30 Alkylamine, substituted or unsubstituted C5~C 50 arylamine, substituted or unsubstituted C1~C 30 Alkylsilyl, substituted or unsubstituted C5~C 50 The group consisting of arylsilyl, nitro, cyano, or halogen atoms; any two or more adjacent R groups 1 ~R 8 They can be arbitrarily joined or fused to form substituted or unsubstituted rings, which may or may not contain heteroatoms N, O, S, P, B, Si or Se.

[0016] In equations (I), (II), and (III), Ar 1 Ar 2 Ar 3 and Ar 4 Each is independently selected from substituted or unsubstituted C6~C. 50 aryl, substituted or unsubstituted C6~C 50 Floated aryl, substituted or unsubstituted C2~C 50 heteroaryl, substituted or unsubstituted C6~C 50 A group consisting of arylamine groups; any two or more adjacent Ar groups 1 ~Ar 4 They can be arbitrarily joined or fused to form substituted or unsubstituted rings, which may or may not contain heteroatoms N, O, S, P, B, Si or Se.

[0017] The above boron-nitrogen compounds, of formula (I), have any one of the following structures:

[0018]

[0019]

[0020]

[0021] In the above formula, M is R 5 or R 6 In the above boron-nitrogen compounds, in formula (I), Y is O, S, or NAr. 4 L represents O, S, Se, CR 3 R 4 or NAr 2 X 1 and X 2 All are CR 5 ;

[0022] In equations (II) and (III), G represents O, S, Se, and CR. 7 R 8 or NAr 3 ;

[0023] In equations (I), (II), and (III), R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 They may be the same as or different from each other, and are independently selected from hydrogen, deuterium, fluorine, cyano, methyl, methoxy, ethyl, ethoxy, propyl, propoxy, isopropyl, isopropoxy, butyl, butyloxy, isobutyl, isobutyloxy, tert-butyl, tert-butyloxy, trifluoromethyl, trifluoromethyloxy, pentafluoroethyl, pentafluoroethoxy, trimethylsilyl, substituted or unsubstituted phenyl dimethylsilyl, cyclobutyl, cyclopentyl, cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted diphenyl, substituted or unsubstituted triphenyl, substituted or unsubstituted tetraphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted The group consisting of phenanthrene, substituted or unsubstituted triphenylene, substituted or unsubstituted anthraquinone, substituted or unsubstituted benzo[anthraquinone], substituted or unsubstituted pyrene, substituted or unsubstituted hydroxyl, substituted or unsubstituted perylene, substituted or unsubstituted fluoranthraquinone, substituted or unsubstituted carbazolyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted indolyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzothiophene, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, and substituted or unsubstituted triazineyl.

[0024] Ar 1 Ar 2 Ar 3 and Ar 4 Each of the following is independently selected from the group consisting of substituted or unsubstituted phenyl, substituted or unsubstituted diphenyl, substituted or unsubstituted triphenyl, substituted or unsubstituted tetraphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthyl, substituted or unsubstituted triphenylene, substituted or unsubstituted anthraxyl, substituted or unsubstituted benzo[anthraxyl], substituted or unsubstituted pyrene, substituted or unsubstituted hydroxyl, substituted or unsubstituted peryl, substituted or unsubstituted fluoranthyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted indolyl, substituted or unsubstituted benzo[furan], substituted or unsubstituted benzo[thiophene], substituted or unsubstituted dibenzo[furan], and substituted or unsubstituted dibenzo[thiophene].

[0025] In this invention, the heteroaryl group contains 2 to 50 carbon atoms and at least one heteroatom, provided that the sum of the carbon atoms and the heteroatom is at least 5; the heteroatom is preferably selected from N, O or S. As non-limiting examples of aryl and heteroaryl groups, particularly those selected from the following groups: phenyl, naphthyl, anthracene, benzo[a]anthrayl, phenanthryl, pyrene, phenyl, peryl, fluoranyl, tetraphenyl, pentaphenyl, benzo[a]pyrene, biphenyl, amphyl, terphenyl, triphenyl, tetraphenyl, fluorenyl, spirodifluorenyl, dihydrophenanthryl, triphenylene, dihydropyrene, tetrahydropyrene, cis or trans indo[a]fluorenyl, cis or trans indo[a]carbazolyl, indol[a]carbazolyl, benzo[a]furan[a]carbazolyl, benzo[a]thiophen[a]carbazolyl, benzo[a]carbazolyl, dibenzo[a]carbazolyl, azadibenzo[g,Id]naphtho[2,1,8-cde]azine, tri-indo[a] , isotri-indene, spirotri-indene, spiroisotri-indene, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thiopheneyl, benzothiopheneyl, isobenzothiopheneyl, dibenzothiopheneyl, pyrroleyl, indoleyl, isoindoleyl, carbazoyl, pyridyl, quinolinyl, isoquinolinyl, acridineyl, phenanthridineyl, benzo[5,6]quinolinyl, benzo[6,7]quinolinyl, benzo[7,8]quinolinyl, phenothiazinyl, phenotoxazinyl, pyrazolyl, indazoleyl, imidazoyl, benzoimidazoyl, naphthizoyl, phenanthrenezoyl, pyridiniumimidazoyl, pyraziniumimidazoyl, quinoxoliniumimidazoyl, oxazolyl, benzoxoxazolyl, naphthizoyl Oxazolyl, anthrazoxazolyl, phenanthoxazolyl, isoxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, hexaazabenzophenanthryl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthryl, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazaperyl, pyrazinyl, phenazinyl, phenoxazinyl, phenthiazinyl, fluoresceinyl, naphridinyl, azacarbazolyl, benzocarbaolinyl, carbaolinyl, phenanthrolinel, 1,2,3-triazolyl, 1,2, A group consisting of the group consisting of 4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetraazinyl, 1,2,3,4-tetraazinyl, 1,2,3,5-tetraazinyl, purine, pteridine, inazinyl, quinazolinyl, benzothiadiazolyl, or a combination thereof.

[0026] In this invention, fused aryl refers to a monovalent functional group obtained by removing one hydrogen atom from an aromatic hydrocarbon with 6 to 50 carbon atoms that has two or more rings. In this case, the two or more rings can be simply attached to each other or attached in a condensed form. Non-limiting examples include phenanthrene, anthracene, fluoranthracene, pyrene, triphenylene, peryl, and alkyl.

[0027] Aromatic amines refer to amines substituted with aryl groups having 6 to 50 carbon atoms. Non-limiting examples of aromatic amines include diphenylamine, N-phenyl-1-naphthylamine, and N-(1-naphthyl)-2-naphthylamine. Heteroaromatic amines refer to amines substituted with aryl groups having 6 to 50 carbon atoms or heteroaromatic groups having 2 to 50 carbon atoms. Non-limiting examples of heteroaromatic amines include N-phenylpyridin-3-amine, N-([1,1'-biphenyl]-4-yl)dibenzo[b,d]furan-2-amine, and N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-9H-fluorene-2-amine.

[0028] For the alkyl group in the sense of this invention, which contains 1 to 30 carbon atoms and in which a single hydrogen atom or -CH2- group can be replaced by the above-mentioned groups, it is preferably considered to refer to the following groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, neopentyl, cyclopentyl, n-hexyl, neohexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl or cyclooctenyl.

[0029] The alkoxy group preferably has 1 to 30 carbon atoms, and is considered to be alkoxy, trifluoromethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, sec-pentoxy, 2-methylbutoxy, n-hexoxy, cyclohexoxy, n-heptoxy, cycloheptoxy, n-octoxy, cyclooctoxy, 2-ethylhexoxy, pentafluoroethoxy, and 2,2,2-trifluoroethoxy.

[0030] Heteroalkyl groups are preferably alkyl groups having 1 to 30 carbon atoms, referring to groups in which a single hydrogen atom or -CH2- group can be replaced by an oxygen, sulfur, or halogen atom. These are considered to be alkoxy, alkathio, fluorinated alkoxy, fluorinated alkathio, particularly methyl thio, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, methylthio, ethyl thio, n-propylthio, isopropylthio, n-butylthio, isobutylthio, sec-butylthio, tert-butylthio, trifluoromethylthio. Trifluoromethoxy, pentafluoroethoxy, pentafluoroethylthio, 2,2,2-trifluoroethoxy, 2,2,2-trifluoroethylthio, ethyleneoxy, ethylenethio, propyleneoxy, propylenethio, butenthio, butenoxy, penenoxy, penenthio, cyclopentenoxy, cyclopententhio, hexenoxy, hexenthio, cyclohexenoxy, cyclohexenthio, acetylenoxy, acetylenthio, propylenoxy, propylenthio, butylenoxy, butylenthio, penylenoxy, penylenthio, hexylenoxy, hexylenthio.

[0031] Generally, the cycloalkyl group in this invention can be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptyl, or cycloheptenyl, wherein one or more -CH2- groups can be replaced by the above groups; in addition, one or more hydrogen atoms can be replaced by deuterium atoms, halogen atoms, or nitrile groups.

[0032] The alkylamine group used in this invention refers to an amine that is substituted with an alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 3 to 30 carbon atoms. Non-limiting examples of alkylamine groups include dimethylamine, diethylamine, dipropylamine, diisopropylamine, etc.

[0033] The alkenyl or alkynyl group in this invention has 2 to 30 carbon atoms, and the alkenyl or alkynyl group in which a single hydrogen atom can be replaced by the above-mentioned group R is preferably vinyl, propenyl, butenyl, isobutenyl, styryl, stilbene, acetyl, propynyl, butynyl, or phenylacetyl; in addition, one or more hydrogen atoms may be replaced by deuterium atoms, halogen atoms or nitrile groups.

[0034] The aryloxy group used in this invention refers to the monovalent functional group represented by R'O-, where R' is an aryl group with 6 to 50 carbon atoms. Non-limiting examples of such aryloxy groups include phenoxy, naphthoxy, and biphenyloxy groups.

[0035] The aryl thio group used in this invention refers to the monovalent functional group represented by R'S-, where R' is an aryl group with 6 to 50 carbon atoms. Non-limiting examples of such aryl thio groups include phenylthio, naphthio, and biphenylthio.

[0036] The alkylsilyl group used in this invention refers to a silyl group substituted with an alkyl group having 1 to 30 carbon atoms, and the alkylsilyl group has at least 3 carbon atoms. Non-limiting examples of alkylsilyl groups include trimethylsilyl and triethylsilyl. Arylsilyl refers to a silyl group substituted with an aryl group having 6 to 50 carbon atoms.

[0037] The arylphospho group used in this invention refers to a diarylphospho group substituted with an aryl group having 6 to 50 carbon atoms. Non-limiting examples of arylphospho groups include diphenylphospho and di(4-trimethylsilylphenyl)phospho. Aryloxophospho is formed when the phosphorus atom of a diarylphospho group is oxidized to its highest valence state.

[0038] The arylboryl group used in this invention refers to a diarylboryl group substituted with an aryl group having 6 to 50 carbon atoms. Non-limiting examples of arylboryl groups include diphenylboryl and di(2,4,6-trimethylphenyl)boryl. Alkylboryl groups refer to dialkylboryl groups substituted with an alkyl group having 1 to 30 carbon atoms. Non-limiting examples of alkylboryl groups include di-tert-butylboryl and diisobutylboryl.

[0039] In this invention, the terms "halogen", "halogen", "halogen atom", and "halogen group" are used interchangeably and refer to fluorine, chlorine, bromine, or iodine.

[0040] As used herein, “combination” or “group” means that one or more members of the applicable list are combined to form a known or chemically stable arrangement that can be conceived by one of ordinary skill in the art from the applicable list. For example, alkyl and deuterium can be combined to form partially or fully deuterated alkyl groups; halogen and alkyl groups can be combined to form haloalkyl substituents, such as trifluoromethyl; and halogen, alkyl and aryl groups can be combined to form haloaralkyl groups.

[0041] As used herein, the term "substituted or unsubstituted" means substituted or unsubstituted by one or more substituents selected from hydrogen, deuterium, halogen, hydroxyl, nitrile, nitro, amino, amido, hydrazine, hydrazone, carboxyl or its carboxylate, sulfonic acid or its sulfonate, phosphate or its phosphate, C1-C30 alkyl, C2-C30 alkenyl, C2-C30 alkynyl, C1-C30 alkoxy, C3-C30 cycloalkyl, C3-C30 cycloalkenyl, C6-C50 aryl, C6-C50 aryloxy, C6-C50 arylsulfide, and C2-C50 heterocyclic aryl, or substituted or unsubstituted by two or more substituents linked together from the substituents exemplified above.

[0042] In one instance, the term substitution includes a combination of two to four listed groups.

[0043] In another example, the term substitution comprises a combination of two or three groups. In yet another example, the term substitution comprises a combination of two groups. Preferred combinations of substituents are combinations containing up to fifty atoms that are not hydrogen or deuterium, or combinations containing up to forty atoms that are not hydrogen or deuterium, or combinations containing up to thirty atoms that are not hydrogen or deuterium. In many cases, preferred combinations of substituents will comprise up to twenty atoms that are not hydrogen or deuterium.

[0044] In the substituted or unsubstituted rings formed by the combination of adjacent groups in this invention, "ring" refers to a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle.

[0045] The above-mentioned boron-nitrogen compounds, wherein the compound of formula (I) is any one of the compounds shown in formulas YJ001 to YJ144;

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054] Alternatively, the compound of formula (I) is any one of the compounds in which some or all of the hydrogen atoms in the compounds shown in formulas YJ001 to YJ144 are replaced with deuterium.

[0055] An application of a boron-nitrogen compound, wherein the aforementioned boron-nitrogen compound is used in organic electroluminescent materials or organic electroluminescent elements.

[0056] An organic electroluminescent material comprising the aforementioned boron-nitrogen compound. The organic electroluminescent material of this invention may consist solely of the boron-nitrogen compound of this invention, or may contain other compounds simultaneously.

[0057] An organic electroluminescent element includes a first electrode, a second electrode, and at least one organic layer disposed between the first electrode and the second electrode, the organic layer comprising the aforementioned boron-nitrogen compound.

[0058] The aforementioned organic electroluminescent element comprises an organic layer consisting of at least one light-emitting layer; or the organic layer consists of at least one light-emitting layer and at least one other layer, the other layer including one or more combinations of electron injection layer, electron transport layer, hole injection layer, hole transport layer, hole blocking layer, electron blocking layer and charge generation layer, each layer being one or more; at least one of the light-emitting layers contains the aforementioned boron-nitrogen compound.

[0059] The aforementioned organic electroluminescent element further includes a host material and a dopant material in the light-emitting layer; the host material comprises compounds composed of the following chemical groups: triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenene, azitrimethylene, azicarbazole, azidibenzothiophene, azidibenzofuran, azidibenzoselenene, triazine, benzothiophene, benzofuran, and indole; the dopant material comprises the aforementioned boron-nitrogen compounds.

[0060] Any substituent in the host material may be independently selected from non-fused substituents of the group consisting of the following groups: C n H 2n+1 OC n H 2n+1 OAr 8 、N(C n H 2n+1 2. N(Ar) 8 (Ar) 9 CH=CH-C n H 2n+1 C≡CC n H 2n+1 Ar 8 Ar 8 -Ar 9 C n H 2n -Ar 8 Or without substituents, where n is an integer from 1 to 10; and where Ar 8 with Ar 9 Independently selected from the group consisting of: phenyl, biphenyl, naphthyl, triphenylene, carbazolyl and its heteroaromatic analogs.

[0061] Furthermore, the main material is selected from one or more compounds represented by formulas KJ01 to KJ90:

[0062]

[0063]

[0064]

[0065]

[0066]

[0067] In the above-mentioned organic electroluminescent element, the mass ratio of the doped material to the host material is 1:99 to 50:50.

[0068] The present invention also includes an organic electroluminescent element comprising a cathode, an anode, and at least one emitting layer. In addition to these layers, it may also comprise other layers, such as, in each case, one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers, electron blocking layers, and / or charge generation layers. An intermediate layer having, for example, exciton blocking functionality may also be introduced between two emitting layers. However, it should be noted that each of these layers is not necessarily required. The organic electroluminescent element described herein may comprise one emitting layer, or it may comprise multiple emitting layers. That is, a variety of luminescent compounds capable of emitting light are used in the emitting layers. A system having three emitting layers is particularly preferred, wherein the three layers may exhibit blue, green, and red light emission. If more than one emitting layer is present, according to the present invention, at least one of these layers comprises a compound of the present invention.

[0069] Furthermore, the organic electroluminescent element according to the present invention does not contain a separate hole injection layer and / or hole transport layer and / or hole blocking layer and / or electron transport layer, that is, the light-emitting layer is directly adjacent to the hole injection layer or the anode, and / or the light-emitting layer is directly adjacent to the electron transport layer or the electron injection layer or the cathode.

[0070] In the other layers of the organic electroluminescent element according to the invention, particularly in the hole injection and hole transport layers and in the electron injection and electron transport layers, all materials can be used in accordance with the manner commonly used in the prior art. Those skilled in the art will therefore be able to combine all materials known about organic electroluminescent elements in the light-emitting layers according to the invention without inventive effort.

[0071] Furthermore, the following organic electroluminescent element is preferred, wherein one or more layers are applied to the element by means of a sublimation method, wherein in a vacuum sublimation apparatus at a temperature below 10 -5 Pa, preferably below 10 -6 The material is applied by vapor deposition at an initial pressure of Pa. However, the initial pressure may be even lower, for example, below 10 Pa. -7 Pa.

[0072] The organic electroluminescent element, preferably as described below, can be applied with one or more layers by means of organic vapor deposition or by means of carrier gas sublimation, wherein, in 10 -5The material is applied at a pressure between Pa and 1 Pa. A particular example of this method is the organic vapor jet printing method, in which the material is applied directly through a nozzle and is therefore structured.

[0073] Furthermore, the following organic electroluminescent elements are preferred, which produce one or more layers from solution, for example by spin coating, or by any desired printing method such as screen printing, flexographic printing, offset printing, photoinitiated thermal imaging, thermal transfer, inkjet printing, or nozzle printing. Soluble compounds, for example, obtained by appropriate substitution modification of the boron-nitrogen compound. These methods are also particularly suitable for oligomers, dendritic macromolecules, and polymers. Additionally, a mixing method is feasible, in which one or more layers are applied from solution and one or more additional layers are applied by vapor deposition.

[0074] These methods are generally known to those skilled in the art, and they can be applied to organic electroluminescent elements containing the boron-nitrogen compounds of the present invention without any inventive effort.

[0075] Therefore, the present invention also relates to a method for manufacturing an organic electroluminescent element according to the invention, wherein at least one layer may be applied by means of a sublimation method, and / or by means of an organic vapor deposition method or by means of carrier gas sublimation, and / or by means of spin coating or printing from a solution.

[0076] Furthermore, the present invention relates to a boron-nitrogen compound comprising at least one of the boron-nitrogen compounds of the present invention as described above. The same preferred embodiments as noted above regarding organic electroluminescent elements apply to the boron-nitrogen compounds of the present invention. In particular, the boron-nitrogen compounds may also preferably comprise other compounds. Processing the boron-nitrogen compounds of the present invention from the liquid phase, for example by spin coating or printing methods, requires formulations for processing the compounds of the present invention. These formulations may be, for example, solutions, dispersions, or emulsions. For this purpose, mixtures of two or more solvents are preferably used. Suitable and preferred solvents include, for example, toluene, anisole, o-xylene, m-xylene or p-xylene, methyl benzoate, mesitylene, naphthalene, o-dimethoxybenzene, tetrahydrofuran, methyltetrahydrofuran, tetrahydropyran, chlorobenzene, dioxane, phenoxytoluene, especially 3-phenoxytoluene, (-)-fenone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidone, 3-methyl anisole, 4-methyl anisole, 3,4-dimethyl anisole, 3,5-dimethyl anisole, acetophenone, α-terpenes. The solvents are benzothiazole, butyl benzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decahydronaphthalene, dodecylbenzene, ethyl benzoate, indane, methyl benzoate, 1-methylpyrrolidone, p-methylisopropylbenzene, phenethyl ether, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentabenzene, hexene, heptene, octene, 1,1-bis(3,4-dimethylphenyl)ethane, or mixtures of these solvents.

[0077] The technical solution of the present invention achieves the following beneficial technical effects:

[0078] The boron-nitrogen compound of this invention uses a diboron-nitrogen unit as its core. Through the resonance effect of the diboron-polynitrogen structure, the lowest empty orbital and the highest occupied orbital are spatially separated, resulting in a smaller singlet-triplet energy level difference. Furthermore, the hybrid units of boron and nitrogen atoms in this boron-nitrogen compound structure, along with large planar conjugated groups, form a rigid framework structure. This rigid framework structure significantly reduces the relaxation degree of the excited state structure, effectively avoiding the problem of large Stokes shifts and achieving a narrower emission spectrum (half-width at half maximum of 20 nm-80 nm), thus improving color purity. By introducing different substituents onto the rigid framework, this invention can further adjust the delayed fluorescence lifetime and half-width at half maximum of the fluorescent material. When used as a luminescent material, the boron-nitrogen compound of this invention emits deep blue to blue light with high luminous efficiency and high color purity. Attached Figure Description

[0079] Figure 1 A schematic diagram of the structure of the organic electroluminescent element 100 in this embodiment of the invention;

[0080] Figure 2 A schematic diagram of the structure of the organic electroluminescent element 200 in this embodiment of the invention;

[0081] The reference numerals in the figures are as follows: 100 - Organic electroluminescent element in Example 5; 101 - Substrate layer; 102 - Anode layer; 103 - Hole injection layer; 104 - Hole transport layer; 105 - Electron blocking layer; 106 - Light emitting layer; 107 - Electron transport layer; 108 - Electron injection layer; 109 - Cathode layer; 110 - Capping layer (CPL);

[0082] 200 - Other forms of organic electroluminescent elements; 201 - Substrate layer; 202 - Anode layer; 203 - First hole injection layer; 204 - First hole transport layer; 205 - First light-emitting layer; 206 - First electron transport layer; 207 - Charge generation layer; 208 - Second hole injection layer; 209 - Second hole transport layer; 210 - Second light-emitting layer; 211 - Second electron transport layer; 212 - Electron injection layer; 213 - Cathode layer. Detailed Implementation

[0083] Figure 1 and Figure 2 The simple layered structures described herein are provided as non-limiting examples, and it should be understood that embodiments of the invention can be used in combination with a wide variety of other structures. The specific materials and structures described are exemplary in nature, and other materials and structures can be used. A functional OLED can be realized by combining the described layers in different ways based on design, performance, and cost factors, or several layers can be omitted entirely. Other layers not specifically described may also be included. Materials different from those specifically described may be used. Although many examples provided herein describe various layers as comprising a single material, it will be understood that combinations of materials, such as mixtures of matrix and dopant, or more generally, mixtures, can be used. Furthermore, the layers may have various sublayers. The names given to the various layers herein are not intended to be strictly limiting. For example, in element 200, hole transport layer 204 transports holes and injects holes into light-emitting layer 205, and can be described as a hole transport layer or an electron blocking layer. In one embodiment, the OLED can be described as having an organic layer disposed between a cathode and an anode. This organic layer may comprise a single layer or may further comprise, as exemplified... Figure 1 and Figure 2 Multiple layers of different organic materials are described.

[0084] Structures and materials not specifically described can also be used, such as PLEDs containing polymer materials. As another example, OLEDs with a single organic layer or multiple stacks can be used. OLED structures can be detached from... Figure 1 and Figure 2 The simple layered structure is illustrated in the diagram. For example, the substrate may include angled reflective surfaces to improve optical coupling.

[0085] Unless otherwise specified, any of the layers in the various embodiments can be deposited by any suitable method. For organic layers, preferred methods include thermal evaporation, organic vapor deposition methods, or applying one or more layers by means of carrier gas sublimation, wherein, in 10 -5 The material is applied at a pressure between millibar and 1 bar. A particular example of this method is an organic vapor jet printing method, in which the material is applied directly through a nozzle and is therefore structured. Other suitable deposition methods include producing one or more layers, for example by spin coating, or by means of any desired printing method such as screen printing, flexographic printing, offset printing, photoinitiated thermal imaging, thermal transfer, inkjet printing, or nozzle printing. Soluble compounds, for example, are obtained through appropriate substitution. These methods are also particularly suitable for oligomers, dendritic macromolecules, and polymers. Furthermore, mixing methods are feasible, in which one or more layers are applied, for example, from a solution and one or more additional layers are applied by vapor phase deposition.

[0086] The element manufactured according to embodiments of the present invention may optionally further include a barrier layer. One use of the barrier layer is to protect the electrodes and organic layers from damage caused by exposure to harmful substances in the environment, including moisture, vapors, and / or gases. The barrier layer may be deposited on, under, or beside a substrate or electrode, or on any other part of the element, including edges. The barrier layer may comprise a single layer or multiple layers. The barrier layer can be formed using various known chemical vapor deposition techniques and may comprise compositions having a single phase as well as compositions having multiple phases. Any suitable material or combination of materials may be used for the barrier layer. The barrier layer may incorporate inorganic or organic compounds, or both. Preferably, the barrier layer comprises a mixture of polymeric and non-polymeric materials. For it to be considered a mixture, the aforementioned polymeric and non-polymeric materials constituting the barrier layer should be deposited under the same conditions and / or simultaneously. The weight ratio of polymeric material to non-polymeric material may be in the range of 95 / 5 to 5 / 95. In one example, the mixture of polymeric and non-polymeric materials is essentially composed of polymeric silicon and inorganic silicon.

[0087] In any of the compounds mentioned above used in each layer of the OLED element described above, hydrogen atoms may be partially or fully deuterated. Therefore, any specifically listed substituents, such as (but not limited to) methyl, phenyl, pyridyl, etc., may be in their undeuterated, partially deuterated, and fully deuterated forms. Similarly, substituent classes (e.g., (but not limited to) alkyl, aryl, cycloalkyl, heteroaryl, etc.) may also be in their undeuterated, partially deuterated, and fully deuterated forms.

[0088] The materials and structures described herein can be applied to components other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors can use the materials and structures described herein.

[0089] Furthermore, organic devices, such as organic transistors, can utilize the aforementioned materials and structures.

[0090] In the following embodiments of the present invention, conventional preparation methods are used unless otherwise specified. All raw materials used are commercially available unless otherwise specified, and all percentages are by mass unless otherwise specified.

[0091] Example 1

[0092] The structural formula of the boron-nitrogen compound in this embodiment is shown in YJ023:

[0093]

[0094] YJ023

[0095] The preparation method of compound YJ023 is as follows:

[0096] Step (1), Preparation of intermediate ZJT-1-1:

[0097]

[0098] Under nitrogen protection, 20.0 mmol of 2-chloro-1,3-difluoro-4-nitrobenzene (CAS: 3847-58-3), 20.0 mmol of p-tert-butylaniline, and 40.0 mmol of anhydrous potassium carbonate were added to 50 mL of DMSO and mixed thoroughly. The mixture was then heated to 90 °C and stirred for 2 h. After the reaction was completed, the mixture was cooled to room temperature, poured into 150 mL of water, stirred thoroughly, and filtered. The filter cake was washed again with water. The washed solid product was recrystallized from anhydrous ethanol to obtain compound ZJT-1-1. Compound ZJT-1-1 is a yellow solid, and the yield of ZJT-1-1 is 75%.

[0099] Step (2), Preparation of intermediate ZJT-1-2:

[0100]

[0101] Under nitrogen protection, 22.0 mmol of Rea-2 (CAS: 2648147-42-4), 20.0 mmol of ZJT-1-1, and 40.0 mmol of anhydrous potassium carbonate were added to 50 mL of DMSO and mixed thoroughly. The mixture was then heated to 110 °C and stirred for 5 h. After the reaction was completed, the mixture was cooled to room temperature, poured into 150 mL of water, stirred thoroughly, and filtered. The filter cake was washed again with water. The washed solid product was recrystallized from anhydrous ethanol to obtain intermediate ZJT-1-2. Intermediate ZJT-1-2 was a yellow solid, and the yield of ZJT-1-2 was 83%.

[0102] Step (3), Preparation of intermediate ZJT-1-3:

[0103]

[0104] Under nitrogen protection, 25.0 mmol of ZJT-1-2 was added to 60 mL of methanol and 40 mL of water and mixed thoroughly. Then, 110.0 mmol of sodium dithionite (Sodium hydrosulfite) was added in portions, and the mixture was stirred for 10 h. After the reaction was completed, 50 mL of water was added to the resulting mixture, and the methanol was removed by concentration under reduced pressure. The remaining aqueous phase was extracted with ethyl acetate. The extracted organic phase was concentrated and dried under reduced pressure. The dried product was passed through a short alkaline alumina column, and the eluent was recrystallized in anhydrous ethanol to obtain intermediate ZJT-1-3. Intermediate ZJT-1-3 was a yellow solid, and the yield of ZJT-1-3 was 85%.

[0105] Step (4): Preparation of intermediate ZJT-1-4:

[0106]

[0107] Under nitrogen protection, 20.0 mmol of compound ZJT-1-3 was dissolved in 80 mL of toluene and mixed thoroughly. Then, 20.0 mmol of 4-tert-butylbromobenzene, 30.0 mmol of sodium tert-butoxide, 0.1 mmol of Pd2(dba)3 (CAS: 51364-51-3) and 0.2 mmol of Xantphos (CAS: 161265-03-8) were added, and the mixture was heated to 100 °C and stirred for 15 h. After the reaction was completed, the mixture was cooled to room temperature, and 50 mL of water was added to the resulting mixture for dilution. After separation, the organic phase was separated, and the aqueous phase was extracted with ethyl acetate. The organic phase obtained by ethyl acetate extraction was dried, filtered, and the filtrate was concentrated and dried under reduced pressure. The filtrate was rinsed with a short alkaline alumina column, and the eluent was recrystallized from toluene / ethanol to obtain intermediate ZJT-1-4. Intermediate ZJT-1-4 was a yellow solid, and the yield of ZJT-1-4 was 82%.

[0108] Step (5): Preparation of intermediate ZJT-1-5:

[0109]

[0110] Under nitrogen protection, 20.0 mmol of compound ZJT-1-4 was dissolved in 80 mL of dry toluene, followed by the addition of 40.0 mmol of Rea-3 (CAS: 854952-58-2), 20.0 mmol of p-toluenesulfonic acid, and 10 g of 4 Å molecular sieve. The mixture was heated to reflux and stirred for 15 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the resulting filter cake was washed with dichloromethane. The washings and filtrate were combined, concentrated under reduced pressure, and dried. The dried product was purified by silica gel column chromatography to obtain intermediate ZJT-1-5. Intermediate ZJT-1-5 was a yellow solid, and the yield of ZJT-1-5 was 76%.

[0111] Step (6): Preparation of compound YJ023:

[0112]

[0113] Under nitrogen protection, 10.0 mmol of ZJT-1-5 was dissolved in 40 mL of dry DMF, and 12.0 mmol of pinacol diborate (CAS: 73183-34-3), 15.0 mmol of anhydrous potassium acetate, 0.1 mmol of palladium acetate, and 0.2 mmol of XPhos (CAS: 564483-18-7) were added. After thorough mixing, the mixture was heated to 110 °C and stirred for 15 h under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature. 150 mL of water was added to the resulting mixture for dilution and filtration. The filter cake was washed with water and purified by silica gel column chromatography to obtain the pinacol diborate intermediate.

[0114] Under nitrogen protection, 5.0 mmol of the prepared pinacol borate intermediate, 5.0 g of anhydrous aluminum trichloride, and 20 mL of dry o-dichlorobenzene were mixed, followed by the addition of 10 mL of dry N,N-diisopropylethylamine. The mixture was then heated to 120 °C and stirred for 5 h, followed by a further increase to 150 °C and stirring for another 1 h. After the reaction was completed, the mixture was cooled to room temperature and poured into 200 mL of ice water. After standing and separating the layers, the organic phase was separated, and the remaining aqueous phase was extracted with dichloromethane. The extracted organic phase was dried, filtered, and the filtrate was concentrated under reduced pressure and purified by silica gel column chromatography to obtain compound YJ023. Compound YJ023 was a yellow solid with a yield of 43%.

[0115] The prepared compound YJ023 was analyzed by mass spectrometry (MS (TOF) m / z): 967.5052 [M+H]. Elemental analysis: theoretical values ​​(%): C, 81.98; H, 6.67; B, 2.24; N, 5.79; S, 3.32; experimental values ​​(%): C, 81.74; H, 6.95; B, 2.19; N, 5.84; S, 3.28.

[0116] 1HNMR (δ, CDCl3): 8.29 (1H, s); 8.15~8.12 (1H, m); 7.97 (1H, s); 7.87~7.85 (1H, d); 7.52~7.45 (6H, m); 7.37~7.29 (6H, m); 7.27~7.22 (4H, m); 7.17~7.15 (1H, d); 7.10~7.05 (4H, m); 7.02~6.98 (2H, m); 6.79~6.77 (1H, d); 1.41 (9H, s); 1.35 (9H, s); 1.33 (18H, s).

[0117] Example 2

[0118] The structural formula of the boron-nitrogen compound in this embodiment is shown in YJ088:

[0119]

[0120] YJ088

[0121] The preparation method of compound YJ088 is as follows:

[0122] Step (1), Preparation of intermediate ZJT-2-1:

[0123]

[0124] Under nitrogen protection, 20.0 mmol of 2-chloro-1,3-difluoro-4-nitrobenzene (CAS: 3847-58-3), 22.0 mmol of 5-tert-butylbenzo[b]thiophene-3-amine hydrochloride, 10 mL of pyridine, and 50 mL of DMSO were mixed thoroughly and heated to 90 °C with stirring for 2 h. After the reaction was completed, the mixture was cooled to room temperature, poured into 150 mL of water, stirred thoroughly, and filtered. The filter cake was washed again with water. The washed solid product was recrystallized from anhydrous ethanol to give compound ZJT-2-1. Compound ZJT-2-1 is a yellow solid, and the yield of ZJT-2-1 is 91%.

[0125] Step (2), Preparation of intermediate ZJT-2-2:

[0126]

[0127] Under nitrogen protection, 22.0 mmol of ZJT-2-1, 20.0 mmol of p-tert-butylphenol, 40.0 mmol of anhydrous potassium carbonate, and 50 mL of DMF were mixed and heated to 120 °C with stirring for 5 h. The mixture was then cooled to room temperature, poured into 150 mL of water, stirred until homogeneous, and filtered. The filter cake was washed again with water. The washed solid product was recrystallized from anhydrous methanol to obtain intermediate ZJT-2-2. Intermediate ZJT-2-2 was a yellow solid, and the yield of ZJT-2-2 was 84%.

[0128] Step (3), Preparation of intermediate ZJT-2-3:

[0129]

[0130] 20.0 mmol of ZJT-2-2, 72.0 mmol of neopentyl glycol diboronate, 0.4 mmol of 4,4'-bipyridine, and 80 mL of acetonitrile were mixed and heated to reflux with stirring for 15 h. After the reaction was completed, the mixture was cooled to room temperature, and 80 mL of 3M dilute hydrochloric acid aqueous solution was added to the resulting mixture. The mixture was stirred for 30 min. Then, sodium carbonate solid was added in batches to neutralize the mixture to alkaline conditions. The mixture was then extracted with ethyl acetate. The extracted organic phase was dried, filtered through a short alkaline alumina column, eluted with ethyl acetate, and the filtrate was concentrated under reduced pressure to dryness to obtain intermediate ZJT-2-3. Intermediate ZJT-2-3 was a yellow solid, and the yield of intermediate ZJT-2-3 was 82%.

[0131] Step (4): Preparation of intermediate ZJT-2-4:

[0132]

[0133] Referring to the synthesis method of step (4) in Example 1, ZJT-1-3 in step (4) of Example 1 was replaced with ZJT-2-3 and 4-tert-butylbromobenzene was replaced with 4-bromobiphenyl to prepare intermediate ZJT-2-4; intermediate ZJT-2-4 is a yellow solid and the yield of ZJT-2-4 is 83%.

[0134] Step (5): Preparation of intermediate ZJT-2-5:

[0135]

[0136] Referring to the synthesis method of step (5) in Example 1, ZJT-1-4 in step (5) of Example 1 was replaced with ZJT-2-4 and Rea-3 was replaced with 4-biphenylboronic acid to prepare intermediate ZJT-2-5; intermediate ZJT-2-5 is a yellow solid and the yield of ZJT-2-5 is 78%.

[0137] Step (6): Preparation of compound YJ088:

[0138]

[0139] Under nitrogen protection, 20.0 mmol of ZJT-2-5 was dissolved in 80 mL of dry diphenyl ether and cooled to 0 °C. Then, 24.0 mmol of 1.6 M tert-butyllithium solution was added, and the mixture was heated to room temperature and stirred for 1 h. The mixture was then cooled to 0 °C, and 30.0 mmol of boron tribromide was added dropwise. The mixture was then heated to room temperature and stirred for 1 h. Next, 0.1 mol of N,N-diisopropylethylamine was added, and the mixture was heated to 160–165 °C and stirred for 5 h. After the reaction was completed, the mixture was cooled to room temperature, and 50 mL of saturated sodium acetate aqueous solution and 150 mL of n-heptane were added. The mixture was stirred for 30 min and then filtered. The filter cake was washed successively with water and anhydrous ethanol. The washed filter cake was purified by silica gel column chromatography to obtain compound YJ088. Compound YJ088 was a light yellow solid, and the yield of compound YJ088 was 38%.

[0140] The prepared compound YJ088 was analyzed by mass spectrometry (MS (TOF) m / z: 767.3374 [M+H]. Elemental analysis showed theoretical values ​​(%): C, 81.47; H, 5.79; B, 2.82; N, 3.65; S, 4.18, and experimental values ​​(%): C, 81.33; H, 5.96; B, 2.72; N, 3.84; S, 4.06.

[0141] 1HNMR (δ, CDCl3): 8.06 (1H, s); 7.79 (1H, s); 7.74~7.72 (1H, d); 7.62~7.58 (6H, m); 7.50~7.42 (8H, m); 7.38~7.35 (3H, m); 7.29~7.27 (1H, dd); 7.18~7.15 (2H, m); 7.02~7.01 (1H, d); 6.86~6.84 (1H, d); 6.65~6.64 (1H, d); 1.42 (9H, s); 1.34 (9H, s).

[0142] Example 3

[0143] The structural formula of the boron-nitrogen compound in this embodiment is shown in YJ102:

[0144]

[0145] YJ102

[0146] The preparation method of compound YJ102 is as follows:

[0147] Step (1), Preparation of intermediate ZJT-3-1:

[0148]

[0149] Referring to the synthesis method of step (2) in Example 1, only ZJT-1-1 in step (2) of Example 1 was replaced with ZJT-2-1 prepared in step (1) of Example 2 to obtain intermediate ZJT-3-1; intermediate ZJT-3-1 is a yellow solid and the yield of ZJT-3-1 is 85%.

[0150] Step (2), Preparation of intermediate ZJT-3-2:

[0151]

[0152] Referring to the synthesis method of step (3) in Example 1, only ZJT-1-2 in step (3) of Example 1 was replaced with ZJT-3-1 to prepare intermediate ZJT-3-2; intermediate ZJT-3-2 is a yellow solid and the yield of ZJT-3-2 is 88%.

[0153] Step (3), Preparation of intermediate ZJT-3-3:

[0154]

[0155] Referring to the synthesis method of step (4) in Example 1, only ZJT-1-3 in step (4) of Example 1 was replaced with ZJT-3-2 to prepare intermediate ZJT-3-3; intermediate ZJT-3-3 is a yellow solid and the yield of ZJT-3-3 is 84%.

[0156] Step (4): Preparation of intermediate ZJT-3-4:

[0157]

[0158] Referring to the synthesis method of step (5) in Example 1, ZJT-1-4 in step (5) of Example 1 was replaced with ZJT-3-3 and Rea-3 was replaced with 4-biphenylboronic acid to prepare intermediate ZJT-3-4; intermediate ZJT-3-4 is a yellow solid and the yield of ZJT-3-4 is 77%.

[0159] Step (5), Preparation of compound YJ102

[0160]

[0161] Following the synthesis method of step (6) in Example 2, only ZJT-2-5 in step (6) of Example 2 was replaced with ZJT-3-4 to prepare compound YJ102; compound YJ102 is a yellow solid with a yield of 44%.

[0162] The prepared compound YJ102 was analyzed by mass spectrometry (MS (TOF) m / z: 934.4507 [M+H]. Elemental analysis showed the following theoretical values ​​(%): C, 79.74; H, 6.58; B, 2.31; N, 4.50; S, 6.87, and experimental values ​​(%): C, 79.58; H, 6.72; B, 2.26; N, 4.74; S, 6.70.

[0163] 1HNMR (δ, CDCl3): 7.84 (1H, s); 7.79 (1H, s); 7.75~7.73 (2H, dd); 7.61~7.58 (4H, m); 7.48~7.43 (4H, m); 7.40~7.35 (3H, m); 7.28~7.26 (2H, dd); 7.20~7.18 (2H, dd); 7.04~7.01 (3H, m); 6.96~6.94 (2H, m); 6.78~6.77 (1H, d); 1.42~1.41 (18H, d); 1.32 (18H, s).

[0164] Example 4

[0165] The structural formula of the boron-nitrogen compound in this embodiment is shown in YJ135:

[0166]

[0167] YJ135

[0168] The preparation method of compound YJ135 is as follows:

[0169] Step (1), Preparation of intermediate ZJT-4-1:

[0170]

[0171] Under nitrogen protection, 20.0 mmol of ZJT-2-1 (synthesized using the same method as in Example 2), 22.0 mmol of 3,6-di-tert-butylcarbazole, 40.0 mmol of anhydrous cesium carbonate, and 50 mL of DMSO were mixed, and the mixture was heated to 110 °C and stirred for 5 h. After the reaction was completed, the mixture was cooled to room temperature, and the resulting reaction solution was poured into 150 mL of water, stirred, and filtered. The resulting filter cake was washed successively with water and anhydrous ethanol. The washed filter cake was purified by silica gel column chromatography to obtain intermediate ZJT-4-1. Intermediate ZJT-4-1 was a yellow solid, and the yield of intermediate ZJT-4-1 was 75%.

[0172] Step (2), Preparation of intermediate ZJT-4-2:

[0173]

[0174] Referring to the synthesis method of step (3) in Example 1, only ZJT-1-2 in step (3) of Example 1 was replaced with ZJT-4-1 to prepare intermediate ZJT-4-2; intermediate ZJT-4-2 is a yellow solid and the yield of ZJT-4-2 is 86%.

[0175] Step (3), Preparation of intermediate ZJT-4-3:

[0176]

[0177] Under nitrogen protection, 20.0 mmol of compound ZJT-4-2 was dissolved in 80 mL of toluene, followed by the addition of 20.0 mmol of 3-bromo-9-phenylcarbazole, 30.0 mmol of sodium tert-butoxide, 0.1 mmol of Pd2(dba)3 (CAS: 51364-51-3), and 0.2 mmol of Xantphos (CAS: 161265-03-8). The mixture was then heated to 90 °C and stirred for 15 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. 50 mL of water was added to the resulting mixture to dilute it, and the organic phase was separated by standing. The aqueous phase was extracted with ethyl acetate, and the extracted organic phase was dried, filtered, concentrated under reduced pressure, dried, and rinsed with a short alkaline alumina column. The solution was then recrystallized from toluene / ethanol to give intermediate ZJT-4-3. Intermediate ZJT-4-3 was a yellow solid, and the yield of ZJT-4-3 was 86%.

[0178] Step (4): Preparation of intermediate ZJT-4-4:

[0179]

[0180] Referring to the synthesis method of step (5) in Example 1, ZJT-1-4 in step (5) of Example 1 was replaced with ZJT-4-3 and Rea-3 was replaced with 4-tert-butylphenylboronic acid to prepare intermediate ZJT-4-4. ZJT-4-4 is a yellow solid and the yield of ZJT-4-4 is 74%.

[0181] Step (5), Preparation of compound YJ135:

[0182]

[0183] Following the synthesis method of step (6) in Example 1, only ZJT-1-5 in step (6) of Example 1 was replaced with ZJT-4-4 to prepare compound YJ135; compound YJ135 is a yellow solid with a yield of 54%.

[0184] The prepared compound YJ135 was analyzed by mass spectrometry (MS (TOF) m / z: 965.4892 [M+H]. Elemental analysis showed the following theoretical values ​​(%): C, 82.15; H, 6.48; B, 2.24; N, 5.81; S, 3.32, and experimental values ​​(%): C, 82.47; H, 6.39; B, 2.18; N, 5.72; S, 3.24.

[0185] 1HNMR (δ, CDCl3): 8.74 (1H, s); 8.12~8.09 (2H, m); 7.79 (1H, s); 7.75~7.73 (1H, d); 7.66~7.63 (1H, m); 7.59~7.56 (2H, m); 7.53~7.45 (5H, m); 7.42~7.39 (3H, m); 7.37~7.29 (5H, m); 7.21~7.16 (4H, m); 7.14~7.13 (1H, d); 1.42 (9H, s); 1.39~1.38 (18H, d); 1.32 (9H, s).

[0186] Other compounds in compounds YJ001-YJ144, excluding YJ023, YJ088, YJ102 and YJ135, were prepared using methods similar to those in Examples 1 to 5. The specific preparation processes are not listed here.

[0187] Example 5

[0188] like Figure 1 As shown, the organic electroluminescent element in this embodiment has a substrate 101, an anode layer 102, a hole injection layer 103, a hole transport layer 104, an electron blocking layer 105, a light-emitting layer 106, an electron transport layer 107, an electron injection layer 108, a cathode layer 109, and a capping layer (CPL) 110.

[0189] The method for preparing the organic electroluminescent element in this embodiment is as follows:

[0190] (1) The glass substrate coated with an ITO (indium tin oxide) conductive layer was ultrasonically treated in a cleaning agent for 30 min, then rinsed with deionized water; then ultrasonically treated in an acetone / ethanol mixed solvent for 30 min; then baked in a clean environment until completely dry, irradiated with a UV cleaner for 10 min, and bombarded with a low-energy cation beam. The treated ITO glass substrate was placed in a vacuum chamber and evacuated to a vacuum level less than 1 × 10⁻⁶. -5 Pa, metallic silver is deposited on the above ITO film with a film thickness of 1500 Å to obtain the anode layer 102.

[0191] (2) On the above-mentioned anode layer film, the compound DNTPD is further deposited as a hole injection layer 103 with a film thickness of 2100 Å; HTM is further deposited as a hole transport layer 104 on the above-mentioned hole injection layer film with a film thickness of 1500 Å.

[0192] (3) A layer of compound HT100 is deposited on the hole transport layer as an electron blocking layer, with a thickness of 100 Å.

[0193] (4) A layer of boron-nitrogen compound YJ023 and KJ78 prepared in Example 1 is deposited on the electron blocking layer film as the light-emitting layer 106, wherein KJ78 is the host material and YJ023 is the dopant material, the mass concentration of YJ023 in KJ78 is 10wt%, and the thickness of the deposited film is 300Å.

[0194] (5) A layer of compounds LiQ and ET205 is deposited on the above-mentioned light-emitting layer film as the electron transport layer 107 of the device, wherein the mass ratio of LiQ and ET205 is 1:1 and the thickness of the deposited film is 200 Å.

[0195] (6) A compound LiF is deposited on the above electron transport layer film as an electron injection layer 108 of the element, and the thickness of the deposited film is 10 Å.

[0196] (7) A cathode layer 109 of magnesium and silver as elements is deposited on the electron injection layer film, wherein the mass ratio of magnesium to silver is 10:1 and the thickness of the deposited film is 1100 Å.

[0197] (8) The compound HT038 is deposited on the above cathode layer as CPL layer 110, and the thickness of the deposited film is 600 Å.

[0198] The structural formulas of the compounds DNTPD, HTM, HT100, ET205, LiQ, and HT038 used in this embodiment are shown below:

[0199] , ,

[0200] , , .

[0201] In other embodiments, the structure of the organic electroluminescent element 200 may also be as follows: Figure 2As shown, the device includes a substrate 201, an anode layer 202, a first hole injection layer 203, a first hole transport layer 204, a first light-emitting layer 205, a first electron transport layer 206, a charge generation layer 207, a second hole injection layer 208, a second hole transport layer 209, a second light-emitting layer 210, a second electron transport layer 211, an electron injection layer 212, and a cathode layer 213. It can use materials similar to those described for the organic electroluminescent element 100 of this embodiment, and the manufacturing method is the same. Most common OLED devices have one light-emitting layer, while element 200 has a first light-emitting layer and a second light-emitting layer. The emission peaks of the first and second light-emitting layers can be overlapping, cross-overlapping, or non-overlapping.

[0202] Organic electroluminescent elements were prepared by using the exact same preparation method as in this embodiment, replacing compound YJ023 in step (4) with compounds YJ001-YJ144. The specific preparation methods will not be listed here.

[0203] Comparative Example

[0204] Organic electroluminescent elements were prepared using the same method as in Example 5, with compound DZ01 replacing compound YJ023 in step (4) of Example 5.

[0205]

[0206] DZ01.

[0207] The organic electroluminescent elements prepared above were subjected to performance tests. Chromaticity coordinates: measured using a PhotoResearch PR-715 spectral scanner; Current-voltage: measured using a Keithley 2420 digital source meter; Power efficiency: measured using a NEWPORT 1931-C; Luminance: measured using a Minolta Cs-1000A luminance meter.

[0208] The performance testing method is as follows: the voltage is increased at a rate of 0.1V per second, and the brightness of the organic electroluminescent element is measured when it reaches 1000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is measured simultaneously; the ratio of brightness to current density is the current efficiency; the LT95% lifespan test is as follows: using a luminance meter at 1000 cd / m² 2 At a constant current under ideal brightness conditions, the brightness decay of the organic electroluminescent element was measured to be 950 cd / m². 2The time is in hours. The data listed in Table 1 are relative to the comparative data. The performance test results are shown in Table 1. In Table 1, the measured values ​​of driving voltage, current efficiency and LT95% of DZ01 material are 3.96V, 14.58 cd / A and 4.5 cd / A, respectively.

[0209] Table 1

[0210]

[0211]

[0212]

[0213]

[0214] As shown in Table 1, the organic electroluminescent elements prepared using compounds YJ001-YJ144 as luminescent materials exhibit lower driving voltage, higher current efficiency, and higher LT95% lifetime compared to the luminescent elements prepared in the comparative example. This indicates that the boron-nitrogen compounds designed in this invention, as organic luminescent materials, simultaneously possess a small singlet-triplet energy level difference and high fluorescence quantum efficiency, satisfying the conditions for thermal activation delay effect in TADF materials. The organic electroluminescent materials prepared using these boron-nitrogen compounds demonstrate superior luminescence performance compared to the existing material DZ01. This is because the boron-nitrogen compounds of this invention, through the resonance effect of diboron-polynitrogen, enable spatial separation of the lowest empty orbital and the highest occupied orbital, thereby achieving a smaller singlet-triplet energy level difference. Furthermore, the hybrid units of boron and nitrogen atoms in the structure of these boron-nitrogen compounds, along with the large planar conjugated groups, form a rigid framework structure. This rigid framework structure significantly reduces the relaxation degree of the excited state structure, effectively avoiding the problem of large Stokes shift, achieving a narrower emission spectrum, and improving color purity.

[0215] The boron-nitrogen compound of the present invention can be used as a blue light material in blue light organic electroluminescent elements. This element can be used in sign lights, display panels or blue light sources, such as wall-mounted TVs, flat panel displays, lighting and other planar light sources, copiers, printers, backlights of liquid crystal displays or light sources of measuring instruments.

[0216] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A boron-nitrogen compound characterized in that, The structural general formula is shown as formula (I): ； In formula (I), ring m and ring n are each independently selected from a substituted or unsubstituted C6-C50 aryl, a substituted or unsubstituted C2-C50 heteroaryl, and a combination thereof; L is O, S, S=0, S02, Se, GeR 3 R 4 , SiR 3 R 4 , C=0, CR 3 R 4 or NAr 2 ; X 1 and X 2 each independently represents N or CR 5 , or X 1 and X 2 represent a group of formula (II) or formula (III); In formula (II) and formula (III), Z each independently represents CR 6 or N; two adjacent "^" represent adjacent groups X in formula (I) 1 and X 2 ; G is O, S, S=O, SO2, Se, GeR 7 R 8 , SiR 7 R 8 , C=O, CR 7 R 8 or NAr 3 ; Y is O, S, Se or NAr 4 ; In equations (I), (II), and (III), R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 They may be the same or different from each other, and each is independently chosen from hydrogen, deuterium, substituted or unsubstituted C1~C. 30 Alkyl, substituted or unsubstituted C6~C 50 aryl, substituted or unsubstituted C3~C 30 Cycloalkyl, substituted or unsubstituted C2~C 50 heteroaryl, substituted or unsubstituted C1~C 30 Alkoxy, substituted or unsubstituted C6~C 50 aryloxy group, substituted or unsubstituted C1~C 30 Alkyl thio, substituted or unsubstituted C5~C 50 aryl thio, substituted or unsubstituted C1~C 30 Alkylamine, substituted or unsubstituted C5~C 50 arylamine, substituted or unsubstituted C1~C 30 Alkyl silyl, substituted or unsubstituted C5~C 50 The group consisting of arylsilyl, nitro, cyano, or halogen atoms; any two or more adjacent R groups 1 ~R 8 They can be arbitrarily joined or fused to form substituted or unsubstituted rings, which may or may not contain heteroatoms N, O, S, P, B, Si or Se. In equations (I), (II), and (III), Ar 1 Ar 2 Ar 3 and Ar 4 Each is independently selected from substituted or unsubstituted C6~C. 50 aryl, substituted or unsubstituted C6~C 50 Floated aryl, substituted or unsubstituted C2~C 50 heteroaryl, substituted or unsubstituted C6~C 50 A group consisting of arylamine groups; any two or more adjacent Ar groups 1 ~Ar 4 They can be arbitrarily joined or fused to form substituted or unsubstituted rings, which may or may not contain heteroatoms N, O, S, P, B, Si or Se.

2. The boron-nitrogen compound according to claim 1, characterized in that, The compound of formula (I) is any one of the following structures: ； ； ； In the above formula, M is R 5 or R 6 .

3. The boron-nitrogen compound according to claim 1, characterized in that, In formula (I), Y is O, S or NAr 4 , L is O, S, Se, CR 3 R 4 or NAr 2 , X 1 and X 2 are each CR 5 ; In formula (II) and formula (III), G is O, S, Se, CR 7 R 8 or NAr 3 ; In equations (I), (II), and (III), R 1 R 2 R 3 R 4 R 5 R 6 R 7 and R 8 They may be the same as or different from each other, and are independently selected from hydrogen, deuterium, fluorine, cyano, methyl, methoxy, ethyl, ethoxy, propyl, propoxy, isopropyl, isopropoxy, butyl, butyloxy, isobutyl, isobutyloxy, tert-butyl, tert-butyloxy, trifluoromethyl, trifluoromethyloxy, pentafluoroethyl, pentafluoroethoxy, trimethylsilyl, substituted or unsubstituted phenyl dimethylsilyl, cyclobutyl, cyclopentyl, cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted diphenyl, substituted or unsubstituted triphenyl, substituted or unsubstituted tetraphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted The group consisting of phenanthrene, substituted or unsubstituted triphenylene, substituted or unsubstituted anthraquinone, substituted or unsubstituted benzo[anthraquinone], substituted or unsubstituted pyrene, substituted or unsubstituted hydroxyl, substituted or unsubstituted perylene, substituted or unsubstituted fluoranthraquinone, substituted or unsubstituted carbazolyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted indolyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzothiophene, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, and substituted or unsubstituted triazineyl. Ar 1 , Ar 2 , Ar 3 , and Ar 4 are each independently selected from the group consisting of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted quaterphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted triphenylenyl, substituted or unsubstituted anthryl, substituted or unsubstituted benzanthryl, substituted or unsubstituted pyrenyl, substituted or unsubstituted chrysenyl, substituted or unsubstituted perylenyl, substituted or unsubstituted fluoranthenyl, substituted or unsubstituted carbazoyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted indolyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzothienyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothienyl.

4. The boron-nitrogen compound of claim 1, wherein, The compound of formula (I) is any one of the compounds shown in formulas YJ001-YJ144. ； ； ； ； ； ； #imgpt12# #imgpt13# Alternatively, the compound of formula (I) is any one of the compounds obtained by replacing part or all of the hydrogens in the compounds shown in formulas YJ001-YJ144 with deuterium.

5. Use of a boron-nitrogen compound, characterized in that The boron-nitrogen compound according to any one of claims 1-4 is used in an organic electroluminescent material or an organic electroluminescent element.

6. An organic electroluminescent material, characterized by The organic electroluminescent material comprises the boron-nitrogen compound according to any one of claims 1-4.

7. An organic electroluminescent element comprising a first electrode, a second electrode, and at least one organic layer interposed between the first electrode and the second electrode, characterized by The organic layer comprises the boron-nitrogen compound according to any one of claims 1-4.

8. The organic electroluminescent element according to claim 7, wherein The organic layer is composed of at least one light-emitting layer; or the organic layer is composed of at least one light-emitting layer and at least one other layer, the other layer comprising one or two or a combination of two or more of an electron injection layer, an electron transport layer, a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, and a charge generation layer, each layer being one or several in number; at least one of the light-emitting layers comprises the boron-nitrogen compound according to any one of claims 1-4.

9. The organic electroluminescence element according to claim 8, wherein The light-emitting layer further comprises a host material and a dopant material; the host material comprises a compound consisting of a triphenylene group, a carbazolyl group, a dithiophenyl group, a dibenzofuranyl group, a dibenzoselenophenyl group, an azatriphenylene group, an azacarbazolyl group, an azadithiophenyl group, an azadibenzofuranyl group, an azadibenzoselenophenyl group, a triazinyl group, a benzothiophenyl group, a benzofuranyl group, and an indolyl group; and the dopant material comprises the boron-nitrogen compound according to any one of claims 1-4.

10. The organic electroluminescent element according to claim 9, wherein The mass ratio of the dopant material to the host material is 1:99-50:50.

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