Boron compound, light-emitting material, and organic electroluminescent device

Abstract

The invention relates to the technical field of organic electroluminescent devices, in particular to a boron compound, a luminescent material and an organic electroluminescent device. The boron compound satisfies any one of the following two conditions: (1) the atomic abundance of 10B of the boron element contained in the boron compound is 25 atom% or more; (2) The abundance of 11B atoms is 83 atom% or more. The light-emitting brightness of the organic light-emitting device prepared subsequently can be effectively improved when the atomic abundance of 10B is limited to be 25 atom% or above, and the service life of the organic light-emitting device can be effectively prolonged when the atomic abundance of 11B is limited to be 85 atom% or above.

Description

[0001] This application is a divisional application of the original application with the filing date of August 26, 2021, the application number of 202110988125.X, and the title of “Boron compound, light-emitting material and organic electroluminescent device”. TECHNICAL FIELD

[0002] The present application relates to the technical field of organic electroluminescent devices, in particular to a boron compound, a light-emitting material and an organic electroluminescent device. BACKGROUND

[0003] In an OLED device, by applying a voltage between a pair of electrodes, holes are injected from the anode and electrons are injected from the cathode into a light-emitting layer containing an organic compound as a light-emitting material. The injected electrons recombine with the holes to form an exciton with light-emitting properties. The excited organic compound emits light. That is, as a self-luminous device, OLEDs have better visibility than liquid crystal devices and can provide clearer display.

[0004] The light-emitting layer of an OLED is composed of a host / dopant in which a light-emitting material is doped. In such a light-emitting layer, excitons can be efficiently generated from the charges injected into the host. Then, the energy of the generated excitons can be transferred to the dopant, and high-efficiency light emission can be obtained from the dopant.

[0005] Researchers have previously conducted various studies on light-emitting layers and are continuing to search for suitable light-emitting materials. For example, in polycyclic aromatic hydrocarbon compounds in which multiple aromatic rings are connected by boron or oxygen, due to the lower aromaticity of the six-membered ring containing a heteroatom, the HOMO-LUMO gap decreases little with the expansion of the conjugated system, and a large band gap Eg can be obtained. It is reported that due to the positioning of SOMO1 and SOMO2 in the triplet excited state (T1), this reduces the exchange interaction between the two orbitals, resulting in a small energy difference between the triplet excited state (T1) and the singlet excited state (S1), and polycyclic aromatic hydrocarbon compounds containing heteroatoms exhibit thermally active delayed fluorescence, thereby improving light-emitting efficiency, but the existing improvements in light-emitting materials are limited, resulting in a small number of types of light-emitting materials, and the light-emitting brightness or service life of the light-emitting material needs to be further improved.

[0006] In view of this, the present application is proposed. SUMMARY

[0007] The purpose of the present application is to provide a boron compound, a light-emitting material and an organic electroluminescent device. The boron compound can effectively improve the light-emitting brightness of the organic electroluminescent device or make the organic electroluminescent device have less decrease in driving light-emitting intensity, i.e., prolong the service life of the organic electroluminescent device, and expand the types of light-emitting materials.

[0008] The present application is achieved in the following manner: In a first aspect, the present application provides a boron compound, which satisfies any one of the following two conditions: (1) the boron element contained in the boron compound has an atomic abundance of B of 25 atom% or more; and (2) the boron element contained in the boron compound has an atomic abundance of B of 83 atom% or more. 10 In a first aspect, the present application provides a boron compound, which satisfies any one of the following two conditions: (1) the boron element contained in the boron compound has an atomic abundance of B of 25 atom% or more; and (2) the boron element contained in the boron compound has an atomic abundance of B of 83 atom% or more. 11 In a first aspect, the present application provides a boron compound, which satisfies any one of the following two conditions: (1) the boron element contained in the boron compound has an atomic abundance of B of 25 atom% or more; and (2) the boron element contained in the boron compound has an atomic abundance of B of 83 atom% or more.

[0009] Generally, a naturally occurring boron compound contains 19.9% of 10 B, the inventors have found that, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. Alternatively, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. Alternatively, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. Alternatively, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. 10 B, the inventors have found that, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. Alternatively, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. Alternatively, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. Alternatively, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. 10 B of 25 atom% or more can effectively improve the luminous brightness of an organic electroluminescent device prepared subsequently. Alternatively, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. Alternatively, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. Alternatively, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. 11 B of 25 atom% or more can effectively improve the luminous brightness of an organic electroluminescent device prepared subsequently. Alternatively, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. Alternatively, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. Alternatively, by increasing the atomic abundance of B, the luminous brightness of an organic electroluminescent device prepared subsequently can be effectively improved. 11 B of 83 atom% or more can make the luminous brightness of an organic electroluminescent device decrease less with driving luminous intensity, i.e. prolong the service life of the organic electroluminescent device.

[0010] In the present application, the atomic abundance refers to the ratio of the number of atoms of a specific isotope to the total number of atoms of the element in an isotope mixture of the element, expressed in atom%.

[0011] In a second aspect, the present application provides a light-emitting material comprising the boron compound according to any one of the preceding embodiments. Preferably, the mass content of the boron compound in the light-emitting material is 0.1-20%. Preferably, the light-emitting material further comprises a host material. Preferably, the light-emitting material is selected from anthracene derivatives. Preferably, the anthracene derivative has the following general structure: wherein Y represents an aromatic or non-aromatic cyclic substituent, and Cy2 represents an aryl group having 6-12 nuclear carbons. Preferably, Cy2 is or .

[0012] In a third aspect, the present application provides an organic electroluminescent device prepared by using the boron compound according to any one of the preceding embodiments or the light-emitting material according to the preceding embodiments.

[0013] In an optional embodiment, the light-emitting layer of the organic electroluminescent device comprises the boron compound or the light-emitting material.

[0014] The present application has the following beneficial effects: the embodiment of the present application can effectively improve the luminous brightness of the organic electroluminescent device prepared subsequently by improving 10 The atomic abundance of B is such that 10 The atomic abundance of B is 25 atom% or more, which can effectively improve the luminous brightness of the organic electroluminescent device prepared subsequently. Or by improving 11 The atomic abundance of B is such that 11 The atomic abundance of B is 83 atom% or more, so that the organic electroluminescent device decreases less with the driving luminous intensity, i.e. prolongs the service life of the organic electroluminescent device. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0016] Figure 1 The structure of the organic electroluminescent device provided by the embodiments of the present application is shown in the schematic diagram.

[0017] Figure legend: 1-anode; 2-hole injection layer; 3-hole transport layer; 4-electron blocking layer; 5-emitting layer; 6-hole blocking layer; 7-electron transport layer; 8-electron injection layer; 9-cathode. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0019] The present application provides a boron compound, which satisfies any one of the following two conditions: (1) the boron element contained in the boron compound has an atomic abundance of B of 25 atom% or more; and (2) the boron element contained in the boron compound has an atomic abundance of B of 83 atom% or more. 10 The atomic abundance of B is 25 atom% or more. For example, 10The atomic abundance of B is any value of 25 atom% or higher, such as 25 atom%, 30 atom%, 35 atom%, 40 atom%, 45 atom%, 50 atom%, 55 atom%, 60 atom%, 65 atom%, 70 atom%, 75 atom%, 80 atom%, 85 atom%, 80 atom%, 95 atom%, and 98 atom%, preferably 50 atom% or higher, more preferably 70 atom% or higher, and more preferably 85 atom% or higher.

[0020] (2) The boron element contained in the boron compound 11 The atomic abundance of B is 83 atom% or higher. Selectable atomic abundances are 83 atom%, 84 atom%, 85 atom%, 86 atom%, 87 atom%, 88 atom%, 89 atom%, 90 atom%, 91 atom%, 92 atom%, 93 atom%, 94 atom%, 95 atom%, 96 atom%, 97 atom%, and 98 atom%, preferably 90 atom% or higher, and more preferably 95 atom% or higher.

[0021] It should be noted that naturally occurring boron compounds typically contain 19.9% ​​boron. 10 B. However, methods such as chromatography using ion exchange resins can be used to... 10 B and 11 B was separated and concentrated to obtain high atomic abundance. 10 B and 11 B. Alternatively, you can directly purchase existing high atomic abundance products. 10 B element, 10 BF3 or 11 BF3, for example, Merck's Sigma-Aldrich trading company, product number 601551, with an atomic abundance of 90 atom%. 10 Element B; catalog number 601357, atomic abundance 95%. 10 BF3, catalog number 610011, atomic abundance ≥95%. 11 BF3; Product code 610038, atomic abundance 98.8%. 11 BF3. Alternatively, it can be prepared using the methods described in existing technologies CN109942005, CN109195910A, or CN103950947. 10 BF3 11 BF3 and 11BCl3, purity can reach 95.5%, 99.95% and 99.999% respectively. Or can use the method described in the prior art CN103950947, CN103950949A to prepare B isotope element and BF3 isotope into BCl3 isotope, BBr3 isotope, such as the method described in CN103950947, CN103950949A.

[0022] Further, the structure of the boron compound is shown as formula (1): Formula (1), wherein Ar is a substituted or unsubstituted 3-20 membered aromatic hetero group or a substituted or unsubstituted 6-40 membered aromatic ring group, for example, Ar is selected from any one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracene, substituted or unsubstituted phenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted fluorene, substituted or unsubstituted pyridine, substituted or unsubstituted pyrimidine, substituted or unsubstituted triazine, substituted or unsubstituted pyrrole, substituted or unsubstituted indole, substituted or unsubstituted carbazole, substituted or unsubstituted furan, substituted or unsubstituted benzofuran, substituted or unsubstituted dibenzofuran, substituted or unsubstituted thiophene, substituted or unsubstituted benzothiophene, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted oxazole, substituted or unsubstituted thiazole, substituted or unsubstituted oxadiazole, substituted or unsubstituted thiadiazole, substituted or unsubstituted triazole, substituted or unsubstituted imidazole, substituted or unsubstituted benzimidazole and substituted or unsubstituted triazole.

[0023] Of course, it can be understood that the above-mentioned groups are only part of the examples of substituted or unsubstituted 3-20 membered aromatic hetero group or substituted or unsubstituted 6-40 membered aromatic ring group, and Ar can also select other substituted or unsubstituted 3-20 membered aromatic hetero group or substituted or unsubstituted 6-40 membered aromatic ring group in the prior art.

[0024] At the same time, the substituent group in the above-mentioned substituted 3-20 membered aromatic hetero group and substituted 6-40 membered aromatic ring can be one or more, that is, one hydrogen in the 3-20 membered aromatic hetero group and 6-40 membered aromatic ring can be substituted to form monosubstitution, or 2, 3, 4 or even more hydrogens can be substituted to form polysubstitution, and in polysubstitution, the hydrogens on the same carbon can be substituted or the hydrogens on different carbons can be substituted.

[0025] Secondly, the substituent group in the substituted 3-20 membered aromatic hetero group and substituted 6-40 membered aromatic ring is selected from any one of cyano, halogen, nitro, carbonyl, substituted or unsubstituted silyl, substituted or unsubstituted amino and substituted or unsubstituted alkyl.

[0026] Further, Ar, in addition to being selected from the aforementioned groups, adjacent Ar can be connected by chemically feasible bonding or fusing to form a ring; for example, any two of the aforementioned specifically defined substituted or unsubstituted 3- to 20-membered aromatic hetero group or substituted or unsubstituted 6- to 40-membered aromatic cyclic group are connected by chemically feasible bonding or fusing to form a ring; and the placement and selection of the substituents in the ring formed by the adjacent Ar are the same as those of the substituents in the aforementioned substituted 3- to 20-membered aromatic hetero group or substituted 6- to 40-membered aromatic cyclic group.

[0027] Further, the boron compound has a structure represented by General Formula (2): General Formula (2), wherein X is absent, that is, X in General Formula (2) can not form a ring with B, but the three Xs in General Formula (2) cannot all be absent at the same time, for example, the structures represented by General Formula (3) and General Formula (4) below. Or X is a single bond, that is, at this time, B and X form a 5-membered ring, not a 6-membered ring; or X is selected from any one of N-Ar, O, S, substituted or unsubstituted methylene, and substituted or unsubstituted silyl; that is, at this time, B and X form a 6-membered ring, and the definition of Ar is the same as that of Ar in the aforementioned General Formula (1).

[0028] R 1- R 11 are each independently any one of hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and substituted or unsubstituted aryloxy, or R 1- R 11 any two of which adjacent to each other are connected by chemically feasible bonding or fusing to form a ring; wherein the aforementioned R 1- R 11 any two of which adjacent to each other form a substituent in the ring selected from any one of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and substituted or unsubstituted aryloxy; As above, the substituent can be a substitution for at least one hydrogen in the ring.

[0029] Further, the substituents in the above-mentioned substituted aryl, substituted heteroaryl, substituted diaryl amino, substituted heteroaryl amino, substituted aryl heteroaryl amino, substituted alkyl, substituted alkoxy and substituted aryloxy are selected from substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or substituted or unsubstituted alkyl. Similarly, the substituents can be the substitution of at least one hydrogen in the above-mentioned aryl, heteroaryl, diaryl amino, heteroaryl amino, aryl heteroaryl amino, alkyl, alkoxy and aryloxy.

[0030] Further, the structure of the boron compound is shown in general formula (3) or general formula (4): General formula (3); General formula (4); wherein, R 1 -R 21 are independently any one of hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diaryl amino, substituted or unsubstituted heteroaryl amino, substituted or unsubstituted aryl heteroaryl amino, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy and substituted or unsubstituted aryloxy, or R 1- R 11 Any two adjacent ones of R Preferably, R 1- R 11 Any two adjacent ones of R Preferably, the substituents in the above-mentioned substituted aryl, substituted heteroaryl, substituted diaryl amino, substituted heteroaryl amino, substituted aryl heteroaryl amino, substituted alkyl, substituted alkoxy and substituted aryloxy are selected from substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or substituted or unsubstituted alkyl.

[0031] Similarly, the above-mentioned substitution refers to the substitution of at least one hydrogen in the corresponding group, and when there are multiple hydrogen substitutions, the hydrogens on different carbons can be substituted.

[0032] Specifically, the boron compound is selected from any one of the compounds shown in the following structural formulae:

[0033]

[0034] .

[0035] In a second aspect, the present application provides a light-emitting material comprising the boron compound described above; the boron compound is used as a dopant. The mass content of the boron compound in the light-emitting material is 0.1-20%.

[0036] The light-emitting material further comprises a host material. Any known material can be used as the host material as long as the host material minimizes the charge injection barrier from the hole transport layer or the electron transport layer, confines the charge in the light-emitting layer, and prevents the quenching of the emitting excitons. However, the inventors have found that the use of an anthracene derivative as the host material in the light-emitting material of the present application can better interact with the boron compound of the present application and improve the performance of the OLED device. The anthracene derivative has the general structure shown below: wherein Y represents an aromatic or non-aromatic cyclic substituent, and the aromatic or non-aromatic cyclic substituent is preferably a phenyl group, a biphenyl group, a naphthyl group, and a diphenyl furan group. Among them, the phenyl group, the 1-biphenyl group, the 1-naphthyl group, and the 2-diphenyl furan group are more preferred.

[0037] Cy2represents an aryl group having 6-12 nuclear carbons; the aryl group having 6-12 nuclear carbons specifically refers to a benzene ring or a naphthalene ring, for example, or that is, the 10-position (or 9-position) of the anthracene structure has a diphenyl furan or a benzofuran naphthalene.

[0038] Specifically, the anthracene derivative is selected from any one of the compounds shown in the following structural formulae: The anthracene derivative shown in the above structural formulae can be used alone or in combination of two or more.

[0039] Further, the mass content of the host material in the light-emitting material is 50-99.9wt%, and more preferably 80-95wt%.

[0040] Further, the present embodiment provides an organic electroluminescent device, which has one or more organic layers between electrodes, for example, the structure of the organic electroluminescent device is "anode 1 / hole injection layer 2 / hole transport layer 3 / emitting layer 5 / electron transport layer 7 / electron injection layer 8 / cathode 9", "anode 1 / hole transport layer 3 / emitting layer 5 / electron transport layer 7 / electron injection layer 8 / cathode 9", "anode 1 / hole injection layer 2 / hole injection layer 2 / emitting layer 5 / electron transport layer 7 / electron injection layer 8 / cathode 9", "anode 1 / hole injection layer 2 / hole transport layer / emitting layer 5 / electron injection layer 8 / cathode 9", "anode 1 / hole injection layer 2 / hole transport layer / emitting layer 5 / electron transport layer 8 / cathode 9", "anode 1 / emitting layer 5 / electron transport layer 7 / electron injection layer 8 / anode 9 transport layer 3 / emitting layer 5 / electron injection layer 8 / cathode 9", "anode 1 / hole transport layer 3 / emitting layer 5 / electron transport layer 7 / cathode 9", "anode 1 / hole injection layer 2 / emitting layer 5 / electron injection layer 8 / cathode 9", "anode 1 / hole injection layer 2 / emitting layer 5 / electron transport layer 7 / cathode 9", and "anode 1 / emitting layer 5 / electron injection layer 8 / cathode 9". In the present embodiment, as shown in Figure 1 the organic electroluminescent device is formed in the order of "anode 1 / hole injection layer 2 / hole transport layer 3 / electron blocking layer 4 / emitting layer 5 / hole blocking layer 6 / electron transport layer 7 / electron injection layer 8 / cathode 9", in which an electron blocking layer 4 and a hole blocking layer 6 are added. The organic layer refers to other layers except the electrodes 1 and 9, i.e., the hole injection layer 2, the hole transport layer 3, the electron blocking layer 4, the emitting layer 5, the hole blocking layer 6, the electron transport layer 7, and the electron injection layer 8.

[0041] The substrate for forming the organic electroluminescent device should be transparent and smooth, with a total light transmittance of at least 70%. Specifically, there are flexible transparent substrates, glass substrates a few microns thick, or special transparent plastics.

[0042] The thin films such as the anode 1, the hole injection layer 2, the hole transport layer 3, the electron blocking layer 4, the emitting layer 5, the hole blocking layer 6, the electron transport layer 7, the electron injection layer 8, and the cathode 9 are formed on the substrate and stacked by vacuum evaporation or plating. The vacuum evaporation is usually performed by heating the evaporation material in a reduced pressure atmosphere, usually less than 10-3Pa. The thickness of each layer depends on the type of layer and the material used, but it is usually about 100 nm for the anode 1 and the cathode 9, and less than 50 nm for other organic layers including the emitting layer 5.

[0043] For the anode 1, a material having a high work function and a total light transmittance of 80% or more is generally used. Specifically, in order to make the light emitted from the anode 1 to be transmitted, transparent conductive ceramics such as indium tin oxide (ITO), zinc oxide (ZnO), polythiophene- polystyrene sulfonic acid (PEDOT-PSS), polyaniline, and other transparent conductive materials are used.

[0044] A hole injection transport layer 2 or a hole transport layer 3 is provided between the anode and the light emitting layer 5, so as to effectively transport the holes from the anode 1 to the light emitting layer.

[0045] The hole injection material forming the hole injection layer 2 includes, for example, (poly (propylene ether ketone) -containing triphenylamine (KLHIP: PPBI), 1, 4, 5, 8, 9, 11-hexaazatriphenylene hexacarbonitrile (HATCN) and PEDOT-PSS, etc. The hole layer 2 made of these materials is also called a polymer buffer layer, which can effectively reduce the driving voltage of the OLED device.

[0046] The hole transport layer 3 is provided between the anode 1 and the light emitting layer 5, so as to effectively transport the holes from the anode 1 to the light emitting layer. The hole transport material has a small ionization potential, that is, the electron is easily excited from the HOMO, and the hole is easily generated. For example, poly (9, 9- dioctylfluorene-alt-N- (4-butylphenyl) diphenylamine) (TFB), 4, 4 '-cyclohexylbis[N, N- bis (4-methylphenyl) aniline] (TAPC), N, N'-diphenyl-N, N'-di (m-toluene) biphenylamine (TPD), N, N'-di (1-naphthyl). N, N'-diphenyl-N, N'-diphenyl biphenylamine (NPD), 4DBFHPB (hexaphenyl derivative), 4, 4', 4''-tri-9-carbazolyltriphenylamine (TCTA) and 4, 4', 4''-tri [phenyl (m-toluene) amino] triphenylamine.

[0047] The light emitting layer 5, like other light emitting layers used in OLED devices, is prepared by the light emitting material provided by the embodiments of the present application.

[0048] An electron blocking layer 4 can be provided between the light emitting layer 5 and the hole transport layer 3. Through the electron blocking layer 4, the electrons can be trapped in the light emitting layer, so as to increase the probability of charge recombination in the light emitting layer, and improve the light emitting efficiency. The electron blocking material forming the electron blocking layer 4 can use monoamine derivatives.

[0049] To efficiently transport electrons from the cathode 9 to the light emitting layer 5, a hole blocking layer 6 and an electron transport layer 7 are provided between the cathode 9 and the light emitting layer 5. Electron transport materials forming the electron transport layer 7 include, for example, 1,4-bis(1,10-phenanthroline-2-yl)benzene (DPB), 8-4,6-bis(3,5-di(pyridine-3-yl)phenyl)-2-hydroxyquinoline (Liq) (Liq), 4,6-bis(3,5-di(pyridine-3-yl)phenyl)-2-methylpyrimidine (B3PymPm), 4,6-bis(3,5-di(pyridine-4)phenyl)-2-phenylpyrimidine (B4PyPm), 2-(4-biphenyl)-5-(p-t-butylphenyl)-1,3,4-oxadiazole (tBPyPm)-1,3-bis[5-(4-t-butylphenyl)-2]oxadiazole (tBu-BD)-oxadiazolyl]benzene (OXD-7), 3-(biphenyl-4-yl)-5-(4-t-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), bathocuproin (BCP), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPPi), (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TFBi), and 3-(4-biphenyl)-4-phenyl-phenyl)-1,2,4-triazole (TAZ), and others. Among them, a mixed layer of DPB and Liq is preferred.

[0050] The hole blocking layer 6 is a layer that restricts holes in the light emitting layer 5 to increase the probability of charge recombination in the light emitting layer 5, thereby improving the light emitting efficiency. DBT-TRZ and other materials are used as a hole blocking material to form the hole blocking layer 6. The thickness of the hole blocking layer 6 and the electron transport layer 7 is generally 3-50 nm, and can be changed according to the desired design.

[0051] The electron injection material forming the electron injection layer 8 includes, for example, lithium fluoride (LiF) and 2-hydroxy-(2,2')-bipyridyl-6-yl-phenolatrichium (Libpp), and the like.

[0052] The cathode 9 is to be made of a material having a low work function (less than 4 eV) and stable chemical properties. Specifically, Al and alloys of alkali metals such as AlLi and AlCa, or MgAg alloy, can be used. These cathode materials can be formed by, for example, resistance heating evaporation, electron beam evaporation, sputtering, or ion plating.

[0053] The features and performance of the present application are further described in detail below with reference to the following examples.

[0054] Example 1 The embodiments of the present invention provide a series of different 10 The structural formula of boron compounds with B atomic abundance is shown below: .

[0055] Its preparation method is as follows: S1: BF3 with abundances of natural values ​​and 95% atom% were purchased from Sigma-Aldrich. 10 BF3 was prepared by adjusting the atomic abundance to 25 atom%, 40 atom%, 60 atom%, and 80 atom, respectively, using existing methods to produce the corresponding BBr3 for later use.

[0056] S2: Different Synthetic Methods 10 5,9-diphenyl-5,9-dihydro-5,9-diaza-13b-boronana[3,2,1-de]anthracene with B atomic abundance; S2.1: See the following synthesis path: ; Specifically, under nitrogen atmosphere and at 80°C, a flask containing diphenylamine (66.0 g), 1-bromo-2,3-dichlorobenzene (40.0 g), Pd-132 (1.3 g), NaOtBu (43.0 g), and xylene (400 ml) was heated and stirred for 2 hours, then the temperature was raised to 120°C and stirred for another 3 hours. After cooling the reaction solution to room temperature, water and ethyl acetate were added, and the precipitated solid was extracted by suction filtration. Purification was performed using silica gel column chromatography. The obtained solid was washed with heptane to remove the solvent by vacuum distillation, thereby obtaining 2-chloro-N 1 N 1 N 3 N 3 -Tetraphenylbenzene-1,3-diamine.

[0057] S2.2: Under nitrogen atmosphere and at -30°C, 2-chloro-N... 1 N 1 N 3 N 3 A 1.7M solution of tert-butyllithium pentane (27.6 ml) was added to a flask containing 20.0 g of tetraphenylbenzene-1,3-diamine and 150 ml of tert-butylbenzene. After the addition was complete, the temperature was raised to 60°C and stirred for 2 hours. The components with boiling points lower than tert-butylbenzene were then distilled off under reduced pressure. The solution was cooled to -30°C, and boron tribromide of different atomic abundances prepared by S1 was added. 10B atoms were 25, 40, 60, 80, and 95 atoms respectively, in a volume of 30 mmol. The mixture was heated to room temperature and stirred for 0.5 hours. Then, it was cooled again to 0°C and N,N-diisopropylethylamine (15.6 ml) was added. The mixture was stirred at room temperature until heating was complete, then heated to 120°C and stirred for 3 hours. The reaction mixture was cooled to room temperature, and sodium acetate aqueous solution cooled in an ice bath and heptane were added sequentially for separation. Subsequently, the mixture was purified using a silica gel short-path column (addition solution: toluene). The obtained solid was dissolved in toluene by vacuum distillation of the solvent, and heptane was added for redeposition to obtain a series of products derived from formula (…). 10 B-2) represents but 10 Boron compounds with varying B abundances.

[0058] Comparative Example 1: Using naturally abundant BCl3 as a raw material, a substance with the same structural formula was synthesized following the same steps as in Example 1.

[0059] Comparative Example 2: Using 11 The abundance of boron atoms is 95%. 11 BCl3, i.e. 10 The abundance of B atoms is 5%. 10 Using BCl3 as a raw material, substances with the same structural formula were synthesized following the same steps as in Example 1.

[0060] Example 2 The embodiments of the present invention provide a series of different 10 The structural formula of boron compounds with B atomic abundance is shown below: .

[0061] Its preparation method is as follows: S1 is the same as S1 in Example 1.

[0062] S2: Different Synthetic Methods 10 N,N,5,9-tetraphenyl-5,9-dihydro-5,9-diaza-13b-boronana[3,2,1-de]anthracene-7-amine with B atomic abundance; In a nitrogen atmosphere, at room temperature, N is added 1 N 1 N 3 N 3 N 5 N 5 In a flask containing hexaphenyl-1,3,5-phenyltriamine (11.6 g, 20 mmol) and o-dichlorobenzene (120 ml), boron tribromide of different atomic abundances provided in the embodiments of the present invention was added. 10After the atomic abundances of B were 25 atom%, 40 atom%, 60 atom%, 80 atom%, and 95 atom% (40 mmol), the mixture was heated and stirred at 170 °C for 48 hours. Subsequently, the reaction solution was distilled off at 60 °C under reduced pressure. The mixture was filtered using a magnesium silicate short-path column, and the solvent was distilled off under reduced pressure to obtain the crude product. The crude product was washed with hexane to obtain a yellow solid of formula (…). 10 The compound represented by B-1).

[0063] Other boron compounds ( 10 B-3 to 10 B-17) Synthesis and the above 10 B-1 and 10 The synthesis method, process and conditions of B-2 are similar, and will not be described in detail in the embodiments of the present invention, but the desired boron compound can be synthesized.

[0064] Example 3 The embodiments of the present invention provide a series of different 11 The structural formula of boron compounds with B atomic abundance is shown below: .

[0065] Its preparation method is as follows: S1: BF3 with abundances of natural values ​​and 95% atom% were purchased from Sigma-Aldrich. 11 BF3, and through proportioning 11 The atomic abundances of B were adjusted to 83, 85, 90, and 93 atoms, respectively. They were then prepared into the corresponding BCl3 or BBr3 using existing techniques for later use.

[0066] S2: Different Synthetic Methods 11 5,9-diphenyl-5,9-dihydro-5,9-diaza-13b-boronana[3,2,1-de]anthracene with B atomic abundance; S2.1: Synthesize 2-chloro-N according to the synthesis method of Example 1. 1 N 1 N 3 N 3 -Tetraphenylbenzene-1,3-diamine.

[0067] S2.2: Under nitrogen atmosphere and at -30°C, 2-chloro-N... 1 N 1 N 3 N 3A 1.7M solution of tert-butyllithium pentane (27.6 ml) was added to a flask containing 20.0 g of tetraphenylbenzene-1,3-diamine and 150 ml of tert-butylbenzene. After the addition was complete, the temperature was raised to 60°C and stirred for 2 hours. The components with boiling points lower than tert-butylbenzene were then distilled off under reduced pressure. The solution was cooled to -30°C, and boron tribromide of different atomic abundances prepared by S1 was added. 11 B, with atomic abundances of 83, 85, 90, 93, and 95 (30 mmol), was heated to room temperature and stirred for 0.5 hours. Then, it was cooled again to 0°C and N,N-diisopropylethylamine (15.6 ml) was added. After heating to room temperature, the mixture was heated to 120°C and stirred for 3 hours. The reaction solution was cooled to room temperature, and sodium acetate aqueous solution cooled in an ice bath and heptane were added sequentially for separation. Subsequently, purification was performed using a silica gel short-path column (addition solution: toluene). The obtained solid was dissolved in toluene by vacuum distillation of the solvent, and heptane was added for redeposition to obtain a series of products derived from formula (…). 11 B-2) represents but 11 Compounds with different B abundances.

[0068] Comparative Example 3: Using 10 The abundance of boron atoms is 50%. 11 BCl3, i.e. 11 The abundance of boron atoms is 50%. 11 Using BCl3 as a raw material, substances with the same structural formula as described above were synthesized following the same steps.

[0069] Example 4 The embodiments of the present invention provide a series of different 11 The structural formula of boron compounds with B atomic abundance is shown below: .

[0070] Its preparation method is as follows: S1 is the same as S1 in Example 3.

[0071] S2: Different Synthetic Methods 11 N,N,5,9-tetraphenyl-5,9-dihydro-5,9-diaza-13b-boronana[3,2,1-de]anthracene-7-amine with B atomic abundance; In a nitrogen atmosphere, at room temperature, N is added 1 N 1 N 3 N 3 N 5 N 5In a flask containing hexaphenyl-1,3,5-phenyltriamine (11.6 g, 20 mmol) and o-dichlorobenzene (120 ml), boron tribromide of different atomic abundances provided in the embodiments of the present invention was added. 11 After the atomic abundances of B were 83, 85, 90, 93, and 95 (in 40 mmol), the mixture was heated and stirred at 170 °C for 48 hours. Subsequently, the reaction solution was distilled off at 60 °C under reduced pressure. The mixture was filtered using a magnesium silicate short-path column, and the solvent was distilled off under reduced pressure to obtain the crude product. The crude product was washed with hexane to obtain a yellow solid of the formula (…). 11 The compound represented by B-1).

[0072] Device Application Examples A 26mm × 28mm × 0.7mm glass substrate (manufactured by Opto Science, Inc.) obtained by sputtering ITO to a thickness of 180nm and polishing it to 150nm was used as a transparent support substrate.

[0073] A transparent support substrate is fixed on the substrate holder of a commercially available vapor deposition apparatus (Showa Vacuum Co., Ltd.), and molybdenum vapor deposition boats containing HIM (hole injection material), HTM (hole transport material), EBL (electron blocking material), BH1 (body), and the present invention embodiment 1 are mounted on the apparatus. 10 Molybdenum evaporation boats containing boron compounds with a boron atom abundance of 25%, molybdenum evaporation boats containing HBL (hole blocking material), molybdenum evaporation boats containing ETL (electron transport material), molybdenum evaporation boats containing LiF, and tungsten evaporation boats containing aluminum are described below. The structural formulas of each of these materials are shown below: .

[0074] The following layers are sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber is depressurized to 5 × 10⁻⁶. -4 First, a vapor deposition boat containing HIM is heated and vapor deposited to a film thickness of 5 nm to form a hole injection layer 2. Next, a vapor deposition boat containing HTM is heated and vapor deposited to a film thickness of 105 nm to form a hole transport layer 3. In addition, a vapor deposition boat containing EBL is heated and vapor deposited to a film thickness of 20 nm to form an electron blocking layer 4.

[0075] Next, the vapor deposition boat containing BH1 and the one containing the material from Example 1 were... 10 A boron compound with a boron atomic abundance of 25% was simultaneously heated and deposited in a vapor deposition boat to a film thickness of 25 nm to form a light-emitting layer 5. The deposition rate was adjusted to make BH1 and the light-emitting layer 5 of Example 1... 10The weight ratio of the boron compound with 25% abundance of B atom is about 80:20. Then, the evaporation boat containing HBL is heated to evaporate to a film thickness of 20 nm to form a hole blocking layer 6. Then, the evaporation boat containing ETL is heated to evaporate to a film thickness of 10 nm to form an electron transport layer 7.

[0076] The evaporation rate of each layer is 0.01-2 nm / sec.

[0077] Then, the evaporation boat containing LiF as the material of the electron injection layer 8 is heated to evaporate at a rate of 0.01-0.1 nm / sec to a film thickness of 1 nm. Then, the evaporation boat containing aluminum is heated to evaporate at a rate of 0.01-2 nm / sec to a film thickness of 100 nm to form a cathode 9, thereby obtaining an OLED device.

[0078] First series of device application examples: different 10 The boron compound with 25% abundance of B atom is used to replace the boron compound with natural abundance in the above Example 1. 10 The boron compound with 25% abundance of B atom is used to replace the boron compound with natural abundance in the above Example 1. 10 The devices prepared by the boron compound with 25 atom%, 40 atom%, 60 atom%, 80 atom% and 95 atom% abundance of B atom in Example 1 of the application are respectively marked as EL-10B-25, EL-10B-40, EL-10B-60, EL-10B-80 and EL-10B-95.

[0079] Second series of device application examples: different 11 The boron compound with 25% abundance of B atom is used to replace the boron compound with natural abundance in the above Example 1. 10 The boron compound with 25% abundance of B atom is used to replace the boron compound with natural abundance in the above Example 1. 11 The devices prepared by the boron compound with 25 atom%, 40 atom%, 60 atom%, 80 atom% and 95 atom% abundance of B atom in Example 1 of the application are respectively marked as EL-10B-25, EL-10B-40, EL-10B-60, EL-10B-80 and EL-10B-95.

[0080] Device comparative example 1: The boron compound with natural abundance is used to replace the boron compound with natural abundance in the above Example 1. 10 The boron compound with 25% abundance of B atom is used to replace the boron compound with natural abundance in the above Example 1. 11 The boron compound with natural abundance is used to replace the boron compound with natural abundance in the above Example 1.

[0081] Device Comparative Example 2: Device Comparative Example 2 was prepared using Comparative Example 2 10 A boron compound having a B atomic abundance of 5% was used instead of the above-mentioned Example 1 10 A boron compound having a B atomic abundance of 25% was used, and then an OLED device was prepared according to the same method and conditions as above. This device is marked as EL-10B-5.

[0082] Device Comparative Example 3: Device Comparative Example 3 was prepared using Comparative Example 3 11 A boron compound having a B atomic abundance of 50% was used instead of the above-mentioned Example 1 10 A boron compound having a B atomic abundance of 25% was used, and then an OLED device was prepared according to the same method and conditions as above. This device is marked as EL-11B-50.

[0083] Test 1: When a DC voltage was applied to the device with an ITO electrode as anode 1 and a LiF / aluminum electrode as cathode 9, blue light emission was obtained. When driven at 10 mA / cm 2 The luminance was measured. The results are shown in Table 1 below. Table 1

[0084] As can be seen from the above table, the organic electroluminescent device prepared using the boron compound of the present application as a blue light dopant material has 10 The higher the B atomic abundance, the higher the blue light luminance of the corresponding device, indicating that the use of 10 B and 10 A B atomic abundance of 25% or more can improve the luminous brightness of a blue organic electroluminescent device.

[0085] Test 2: When a DC voltage was applied to the device with an ITO electrode as anode and a LiF / aluminum electrode as cathode, blue light emission was obtained. When driven at 20 mA / cm2, the time for the initial luminance to decrease by 5% was measured, and the results are shown in Table 2 below. Table 2

[0086] As can be seen from the above table, when the atomic abundance of B in the boron compound is higher than 83%, the lifetime of the OLED prepared using this boron compound is significantly prolonged, and 11 The higher the atomic abundance of B, the more the lifetime is prolonged. 11

[0087] ​The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A boron compound, characterized in that, The boron compound satisfies either of the following two conditions: (1) the atomic abundance of 10B of boron in the boron compound is 25 atom% or more; (2) the atomic abundance of 11B of boron in the boron compound is 83 atom% or more.

2. The boron compound according to claim 1, characterized in that, The boron compound contains boron with an atomic abundance of 10B of 50 atom% or more, preferably 70 atom% or more, and more preferably 85 atom% or more. Preferably, the boron compound contains boron element... 11 The abundance of boron atoms is 90% or higher, preferably 95% or higher.

3. The boron compound according to claim 1 or 2, characterized in that, The structural formula of the boron compound is shown in general formula (1): General formula (1), wherein Ar is a substituted or unsubstituted 3-20 aryl heterogroup or a substituted or unsubstituted 6-40 aryl ring group, or adjacent Ar can be connected by chemically feasible bonding or fusion to form a ring; Preferably, Ar is selected from substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthraquinyl, substituted or unsubstituted phenanthyl, substituted or unsubstituted pyrene, substituted or unsubstituted fluorenyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted triazine, substituted or unsubstituted pyrrole, substituted or unsubstituted indolyl, substituted or unsubstituted carbazole, substituted or unsubstituted furanyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted Any one of dibenzofuranyl, substituted or unsubstituted thiophenyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted oxazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted oxadiazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted triazolyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted benzimidazolyl and substituted or unsubstituted triazolyl, or adjacent Ar is linked by any two of the above groups through a chemically feasible bonding or fusion manner to form a ring; Preferably, the substituents in the substituted 3-20 aryl heterogroup, substituted 6-40 aryl ring, or adjacent Ar ring are selected from any one of cyano, halogen, nitro, carbonyl, substituted or unsubstituted silyl, substituted or unsubstituted amino, and substituted or unsubstituted alkyl.

4. The boron compound according to claim 1 or 2, characterized in that, The structural formula of the boron compound is shown in general formula (2): General formula (2), where R 1- R 11 Each of the following independently constitutes hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and substituted or unsubstituted aryloxy, or R. 1- R 11 Any two adjacent elements are connected by a chemically feasible bonding or fusion method to form a ring; X is absent or is a single bond or is selected from any one of N-Ar, O, S, substituted or unsubstituted methylene and substituted or unsubstituted silyl groups; and the three Xs in general formula (2) are not simultaneously absent; Preferably, R 1- R 11 The substituents in any two adjacent rings are selected from any one of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheterarylamino, substituted or unsubstituted arylheterarylamino, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and substituted or unsubstituted aryloxy. Preferably, the substituents in the substituted aryl, substituted heteroaryl, substituted diarylamino, substituted diarylamino, substituted arylheyrylamino, substituted alkyl, substituted alkoxy, and substituted aryloxy groups are selected from substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, or substituted or unsubstituted alkyl groups.

5. The boron compound according to claim 1 or 2, characterized in that, The structural formula of the boron compound is shown in general formula (3): General formula (3); where R 1 -R 13 Each of the following independently constitutes hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and substituted or unsubstituted aryloxy, or R. 1- R 11 Any two adjacent elements are connected by a chemically feasible bonding or fusion method to form a ring; Preferably, R 1- R 11 The substituents in any two adjacent rings are selected from any one of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheterarylamino, substituted or unsubstituted arylheterarylamino, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and substituted or unsubstituted aryloxy. Preferably, the substituents in the substituted aryl, substituted heteroaryl, substituted diarylamino, substituted diarylamino, substituted arylheyrylamino, substituted alkyl, substituted alkoxy, and substituted aryloxy groups are selected from substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, or substituted or unsubstituted alkyl groups.

6. The boron compound according to claim 1 or 2, characterized in that, The structural formula of the boron compound is shown in general formula (4). General formula (4); where R 1 -R 21 Each of the following independently constitutes hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and substituted or unsubstituted aryloxy, or R. 1- R 11 Any two adjacent elements are connected by a chemically feasible bonding or fusion method to form a ring; Preferably, R 1- R 11 The substituents in any two adjacent rings are selected from any one of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheterarylamino, substituted or unsubstituted arylheterarylamino, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and substituted or unsubstituted aryloxy. Preferably, the substituents in the substituted aryl, substituted heteroaryl, substituted diarylamino, substituted diarylamino, substituted arylheyrylamino, substituted alkyl, substituted alkoxy, and substituted aryloxy groups are selected from substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, or substituted or unsubstituted alkyl groups.

7. The boron compound according to claim 1 or 2, characterized in that, The boron compound is selected from any one of the compounds shown in the following structural formulas: 。 8. A luminescent material, characterized in that, It includes the boron compound as described in any one of claims 1-7; Preferably, the boron compound shown in the luminescent material has a mass content of 0.1-20%; Preferably, the luminescent material further includes a host material; Preferably, the luminescent material is selected from anthracene derivatives; Preferably, the anthracene derivative has the following general structural formula: In this context, Y represents an aromatic or non-aromatic cyclic substituent, and Cy2 represents an aryl group having 6 to 12 nuclear carbons. Preferably, Cy2 is or .

9. An organic electroluminescent device, characterized in that, It is prepared by the boron compound according to any one of claims 1-7 or the luminescent material according to claim 8.

10. The organic electroluminescent device according to claim 9, characterized in that, The light-emitting layer of the organic electroluminescent device includes the boron compound or the light-emitting material.

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