Boron compounds, luminescent materials and organic electroluminescent devices

Abstract

The present invention relates to the technical field of organic electroluminescent devices, and in particular to boron compounds, luminescent materials and organic electroluminescent devices. The boron compound satisfies either of the following two conditions: (1) the boron element contained in the boron compound is 10 The atomic abundance of B is more than 25atom%; (2) 11 The abundance of B atoms is 83atom% or more. 10 The atomic abundance of B is above 25atom%, which can effectively improve the luminous brightness of the organic electroluminescent device prepared subsequently. 11 A B atom abundance of 85 atom % or more can effectively extend the service life of the organic electroluminescent device.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescent devices, in particular to a boron compound, a luminescent material and an organic electroluminescent device. Background Art

[0002] In an OLED device, a voltage is applied between a pair of electrodes, injecting holes from the anode and electrons from the cathode into a light-emitting layer containing an organic compound as the luminescent material. The injected electrons recombine with the holes to form luminescent excitons. The excited organic compound then emits light. As a self-luminous device, OLEDs offer better visibility and clearer displays than LCDs.

[0003] The light-emitting layer of an OLED consists of a host / dopant layer doped with a luminescent material. In this light-emitting layer, excitons are efficiently generated from the charge injected into the host. The energy of the generated excitons is then transferred to the dopant layer, resulting in efficient light emission.

[0004] Researchers have previously conducted various studies on the light-emitting layer 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, since the aromaticity of the six-membered ring containing heteroatoms is low, the decrease in the HOMO-LUMO gap is very small as the conjugated system expands, and a large band gap Eg can be obtained. It is reported that since SOMO1 and SOMO2 are located 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). Polycyclic aromatic hydrocarbon compounds containing heteroatoms exhibit thermally active delayed fluorescence, which in turn improves the luminescence efficiency. However, the existing improvements to luminescent materials are limited, resulting in a small number of luminescent materials, and the luminescence brightness or service life of luminescent materials needs to be further improved.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The present invention aims to provide a boron compound, a luminescent material, and an organic electroluminescent device. When used to prepare an organic electroluminescent device, the boron compound can effectively enhance the luminescence brightness of the organic electroluminescent device or minimize the decrease in luminescence intensity during operation, thereby extending the service life of the organic electroluminescent device and expanding the variety of luminescent materials.

[0007] The present invention is achieved in that:

[0008] In a first aspect, the present invention provides a boron compound, wherein the boron compound satisfies either of the following two conditions: (1) the boron element contained in the boron compound is 10The atomic abundance of B is 25 atom% or more; (2) the boron element contained in the boron compound is 11 The abundance of boron atoms is more than 83 atom%.

[0009] Naturally occurring boron compounds typically contain 19.9% 10 B, the inventor found through research that 10 The atomic abundance of B is such that 10 The atomic abundance of B is 25atom% or more, which can effectively improve the brightness of the organic electroluminescent device prepared later. 11 The abundance of B atoms makes 11 The abundance of B atoms is above 83 atom%, which can reduce the decrease in the luminous intensity of the organic electroluminescent device during driving, that is, extend the service life of the organic electroluminescent device.

[0010] Atomic abundance refers to the ratio of the number of atoms of a particular isotope in a mixture of isotopes of an element to the total number of atoms of the element, expressed as atomic percentage (atom %).

[0011] In a second aspect, the present invention provides a luminescent material comprising the boron compound described in any one of the aforementioned embodiments;

[0012] Preferably, the mass content of the boron compound in the luminescent material is 0.1-20%;

[0013] Preferably, the luminescent material further comprises a host material;

[0014] Preferably, the luminescent material is selected from anthracene derivatives;

[0015] Preferably, the general structural formula of the anthracene derivative is as follows:

[0016] wherein Y represents an aromatic or non-aromatic cyclic substituent, and Cy2 represents an aromatic group having 6 to 12 nuclear carbon atoms;

[0017] Preferably, Cy2 is

[0018] In a third aspect, the present invention provides an organic electroluminescent device, which is prepared by using the boron compound described in any one of the aforementioned embodiments or the luminescent material described in any one of the aforementioned embodiments.

[0019] In an optional embodiment, the light-emitting layer of the organic electroluminescent device includes the boron compound or the light-emitting material.

[0020] The present invention has the following beneficial effects: 10 The atomic abundance of B is such that10 The atomic abundance of B is above 25atom%, which can effectively improve the brightness of the organic electroluminescent device prepared later. 11 The atomic abundance of B is such that 11 The atomic abundance of B is above 83 atom%, so that the luminous intensity of the organic electroluminescent device decreases less as it is driven, that is, the service life of the organic electroluminescent device is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a schematic structural diagram of an organic electroluminescent device provided by an embodiment of the present invention.

[0023] Icon: 1-anode; 2-hole injection layer; 3-hole transport layer; 4-electron blocking layer; 5-light-emitting layer; 6-hole blocking layer; 7-electron transport layer; 8-electron injection layer; 9-cathode. DETAILED DESCRIPTION

[0024] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0025] The embodiment of the present invention provides a boron compound, which satisfies any one of the following two conditions: (1) the boron element contained in the boron compound is 10 The atomic abundance of B is 25atom% or more. For example, 10 The atomic abundance of B is any value above 25 atom%, 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%, and the preferred atomic abundance is above 50 atom%, preferably above 70 atom%, and more preferably above 85 atom%.

[0026] (2) The boron element contained in the boron compound11 The atomic abundance of B is 83 atom% or more. Optional atomic abundances include 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 more, and more preferably 95 atom% or more.

[0027] It should be noted that naturally occurring boron compounds usually contain 19.9% 10 B. However, it is possible to use methods such as chromatography using ion exchange resins to 10 B and 11 B is separated and concentrated to obtain high atomic abundance 10 B and 11 B. Alternatively, you can directly purchase existing high atomic abundance 10 B single substance, 10 BF3 or 11 BF3, for example, available from Sigma-Aldrich, Merck, under the trade name 601551, with an atomic abundance of 90 atom%. 10 B element; item number 601357, atomic abundance 95atom% 10 BF3, product number 610011, atomic abundance ≥95atom% 11 BF3; Product No. 610038, atomic abundance 98.8atom% 11 BF3. Alternatively, it can be prepared by the methods described in the prior art CN109942005, CN109195910A or CN103950947. 10 BF3, 11 BF3 and 11 BCl3, the purity can reach 95.5%, 99.95% and 99.999% respectively. Alternatively, the B isotope element and BF3 isotope can be prepared into BCl3 isotope and BBr3 isotope by the methods described in the prior art CN103950947 and CN103950949A, such as the methods described in CN103950947 and CN103950949A.

[0028] Furthermore, the structural formula of the boron compound is shown in general formula (1):

[0029] 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 substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted pyrenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted triazinyl, substituted or unsubstituted pyrrolyl, substituted or unsubstituted indolyl, Any one of a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted furyl group, a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted thiophenyl group, a substituted or unsubstituted benzothiophenyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted oxazolyl group, a substituted or unsubstituted thiazolyl group, a substituted or unsubstituted oxadiazolyl group, a substituted or unsubstituted thiadiazolyl group, a substituted or unsubstituted triazolyl group, a substituted or unsubstituted imidazolyl group, a substituted or unsubstituted benzimidazolyl group and a substituted or unsubstituted triazolyl group.

[0030] Of course, it is understandable that the above groups are only some examples of substituted or unsubstituted 3-membered to 20-membered aromatic hetero groups or substituted or unsubstituted 6-membered to 40-membered aromatic ring groups, and Ar can also be selected from other substituted or unsubstituted 3-membered to 20-membered aromatic hetero groups or substituted or unsubstituted 6-membered to 40-membered aromatic ring groups in the prior art.

[0031] At the same time, the substituents in the above-mentioned substituted 3-membered to 20-membered aromatic hetero groups and substituted 6-membered to 40-membered aromatic rings may be one or more, that is, one hydrogen in the 3-membered to 20-membered aromatic hetero groups and 6-membered to 40-membered aromatic rings may be replaced to form a single substitution, or two, three, four or even more hydrogens may be replaced to form a multiple substitution, and in the case of multiple substitution, the hydrogens on the same carbon may be replaced, or the hydrogens on different carbons may be replaced.

[0032] Secondly, the substituents in the substituted 3-20 membered aromatic hetero groups and substituted 6-40 membered aromatic rings are selected from any one of cyano, halogen, nitro, carbonyl, substituted or unsubstituted silyl, substituted or unsubstituted amino, and substituted or unsubstituted alkyl.

[0033] Furthermore, in addition to being selected from the above-mentioned groups, adjacent Ar can be connected by chemically feasible bonding or fusion to form a ring; for example, any two of the specific groups in the aforementioned limited substituted or unsubstituted 3-20 membered aromatic hetero groups or substituted or unsubstituted 6-40 membered aromatic ring groups are connected by chemically feasible bonding or fusion to form a ring; and the arrangement and selection of the substituents in the ring formed by adjacent Ar are the same as the substituents in the aforementioned substituted 3-20 membered aromatic hetero groups and substituted 6-40 membered aromatic rings.

[0034] Furthermore, the structural formula of the boron compound is shown in general formula (2):

[0035] Wherein, X is absent, that is, X in general formula (2) may not form a ring with B, but all three Xs in general formula (2) cannot be absent at the same time, for example, the following structural formulas (3) and (4). Alternatively, X is a single bond, that is, in this case, B and X form a 5-membered ring instead of a 6-membered ring; or X is selected from any one of N-Ar, O, S, a substituted or unsubstituted methylene group, and a substituted or unsubstituted silicon group; that is, in this case, 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).

[0036] R 1 -R 11 R is 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 adjacent ones of are connected by chemically feasible bonding or fusion to form a ring;

[0037] Among them, the above R 1 -R 11 The substituents in the ring formed by any two adjacent groups are 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;

[0038] As above, the substituent may be a replacement of at least one hydrogen in the ring.

[0039] Furthermore, the substituents in the aforementioned substituted aryl, substituted heteroaryl, substituted diarylamino, substituted diheteroarylamino, substituted arylheteroarylamino, 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. Similarly, the substituents may replace at least one hydrogen in the aforementioned aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, alkoxy, and aryloxy groups.

[0040] Furthermore, the structural formula of the boron compound is shown in general formula (3) or general formula (4):

[0041]

[0042] Among them, R 1 -R 21R is 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 adjacent ones of are connected by chemically feasible bonding or fusion to form a ring;

[0043] Preferably, R 1 -R 11 The substituents in the ring formed by any two adjacent groups are 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;

[0044] Preferably, the substituents in the substituted aryl, substituted heteroaryl, substituted diarylamino, substituted diheteroarylamino, substituted arylheteroarylamino, substituted alkyl, substituted alkoxy and substituted aryloxy are selected from substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or substituted or unsubstituted alkyl.

[0045] Similarly, the above substitution means that at least one hydrogen in the corresponding group is replaced, and when multiple hydrogens are replaced, the hydrogens on different carbon atoms may be replaced.

[0046] Specifically, the boron compound is selected from any one of the compounds represented by the following structural formulas:

[0047]

[0048]

[0049]

[0050] In a second aspect, an embodiment of the present invention provides a luminescent material comprising the above-mentioned boron compound as a dopant, wherein the boron compound has a mass content of 0.1-20% in the luminescent material.

[0051] The luminescent material also includes a host material, which can be selected from existing host materials. As long as the host material minimizes the barrier to charge injection from the hole transport layer or electron transport layer, confines the charge to the luminescent layer, and prevents quenching of emitted excitons, various known materials can be used as host materials. However, the inventors have found that the use of anthracene derivatives as host materials in the embodiments of the present invention can better interact with the boron compounds of the embodiments of the present invention, thereby improving the performance of OLED devices. The general structural formula of the anthracene derivative is shown below:

[0052] Wherein, Y represents an aromatic or non-aromatic cyclic substituent, and the aromatic or non-aromatic cyclic substituent is preferably phenyl, biphenyl, naphthyl, and diphenylfuranyl. Among them, phenyl, 1-biphenyl, 1-naphthyl, and 2-diphenylfuranyl are more preferred groups.

[0053] Cy2 represents an aromatic group having 6 to 12 carbon atoms; an aromatic group having 6 to 12 carbon atoms specifically refers to a benzene ring or a naphthalene ring, for example That is, the anthracene structure has dibenzofuran or benzonaphthofuran at the 10-position (or 9-position).

[0054] Specifically, the anthracene derivative is selected from any one of the compounds represented by the following structural formulas:

[0055]

[0056] The anthracene derivatives represented by the above structural formula may be used alone or in combination of two or more.

[0057] Furthermore, the mass content of the host material in the luminescent material is 50 to 99.9 wt %, more preferably 80 to 95 wt %.

[0058] Furthermore, an embodiment of the present invention provides an organic electroluminescent device, wherein one or more organic layers are arranged between the electrodes of the organic electroluminescent device. For example, the structure of the organic electroluminescent device is: "anode 1 / hole injection layer 2 / hole transport layer 3 / luminescent layer 5 / electron transport layer 7 / electron injection layer 8 / cathode 9", "anode 1 / hole transport layer 3 / luminescent layer 5 / electron transport layer 7 / electron injection layer 8 / cathode 9", "anode 1 / hole injection layer 2 anode 1 / 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 / light-emitting layer 5 / electron transport layer 7 / electron injection layer 8 / anode 9 transport layer 3 / light-emitting layer 5 / electron injection layer 8 / cathode 9", "anode 1 / hole transport layer 3 / light-emitting layer 5 / electron transport layer 7 / cathode 9", "anode 1 / hole injection layer 2 / light-emitting layer 5 / electron injection layer 8 / cathode 9", "anode 1 / hole injection layer 2 / light-emitting layer 5 / electron transport layer 7 / cathode 9" and "anode 1 / light-emitting layer 5 / electron injection layer 8 / cathode 9".

[0059] In the embodiment of the present invention, Figure 1As shown, the organic electroluminescent device follows the structure of "anode 1 / hole injection layer 2 / hole transport layer 3 / electron blocking layer 4 / luminescent layer 5 / hole blocking layer 6 / electron transport layer 7 / electron injection layer 8 / cathode 9," stacked in this order. Electron blocking layer 4 and hole blocking layer 6 are added to the above structure. The organic layers refer to the layers other than electrodes 1 and 9, namely, hole injection layer 2, hole transport layer 3, electron blocking layer 4, luminescent layer 5, hole blocking layer 6, electron transport layer 7, and electron injection layer 8.

[0060] The substrate 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 several microns thick, or special transparent plastics.

[0061] Thin films such as an anode 1, a hole injection layer 2, a hole transport layer 3, an electron blocking layer 4, a light-emitting layer 5, a hole blocking layer 6, an electron transport layer 7, an electron injection layer 8, and a cathode 9 are formed on a substrate and stacked by vacuum evaporation or coating. Vacuum evaporation is typically performed by heating the deposited material in a reduced pressure atmosphere, typically below 10-3 Pa. The thickness of each layer depends on the type of layer and the material used, but is typically around 100 nm for the anode 1 and cathode 9, and less than 50 nm for the other organic layers, including the light-emitting layer 5.

[0062] Anode 1 typically uses a material with a high work function and a total light transmittance of 80% or higher. Specifically, to allow light emitted from anode 1 to pass through, transparent conductive ceramics such as indium tin oxide (ITO) and zinc oxide (ZnO), polythiophene-polystyrene sulfonate (PEDOT-PSS), polyaniline, and other transparent conductive materials are used.

[0063] There is a hole injection and transport layer 2 or a hole transport layer 3 between the anode and the light-emitting layer 5 to effectively transport holes from the anode 1 to the light-emitting layer.

[0064] The hole injection materials forming the hole injection layer 2 include, for example, poly(propylene ether ketone)-containing triphenylamine (KLHIP:PPBI), 1,4,5,8,9,11-hexaazabenzenehexacarbonitrile (HATCN) and PEDOT-PSS. 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.

[0065] The hole transport layer 3 is disposed between the anode 1 and the light-emitting layer 5 and is used to efficiently transport holes from the anode 1 to the light-emitting layer. Hole transport materials have a low ionization potential, meaning that electrons are easily excited from the HOMO, allowing holes to be easily generated. Examples include 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)benzidine (TPD), N,N'-di(1-naphthyl)-N,N'-diphenyl-N,N'-diphenylbenzidine (NPD), 4DBFHPB (a hexaphenyl derivative), 4,4',4"-tris-9-carbazolyltriphenylamine (TCTA), and 4,4',4"-tris[phenyl(m-toluene)amino]triphenylamine).

[0066] The light-emitting layer 5 is the same as other light-emitting layers used in OLED devices, and the light-emitting layer 5 in the embodiment of the present invention is prepared by using the light-emitting material provided in the embodiment of the present invention.

[0067] An electron blocking layer 4 can be disposed between the light-emitting layer 5 and the hole transport layer 3. Electrons can be trapped within the light-emitting layer by the electron blocking layer 4, thereby increasing the probability of charge recombination within the light-emitting layer and improving luminescence efficiency. The electron blocking material forming the electron blocking layer 4 can be a monoamine derivative.

[0068] In order 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. The electron transport material forming the electron transport layer 7 includes, for example, 1,4-bis(1,10-phenanthroline-2-yl)benzene (DPB), 8-4,6-bis(3,5-di(pyridin-3-yl)phenyl)-2-hydroxyquinoline (Liq)(Liq), 4,6-bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine (B3PymPm), 4,6-bis(3,5-di(pyridin-4)phenyl)-2-phenylpyrimidine (B4PyPm), 2-(4-biphenyl)-5-(p-tert-butylphenyl)-1,3,4-oxadiazole (t BPyPm)-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), 3-(biphenyl-4-yl)-5-triazole (TAZ), basoproline (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, the mixed layer of DPB and Liq is the preferred one.

[0069] Hole-blocking layer 6 is a layer that confines holes in light-emitting layer 5, thereby increasing the probability of charge recombination within light-emitting layer 5 and improving luminescence efficiency. DBT-TRZ and other materials serve as hole-blocking materials to form hole-blocking layer 6. The thickness of hole-blocking layer 6 and electron-transporting layer 7 is typically 3-50 nm and can be varied depending on the desired design.

[0070] 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).

[0071] Cathode 9 should be made of a chemically stable material with a low work function (less than 4 eV). Specifically, alloys of Al, MgAg, or alloys of Al and alkali metals such as AlLi and AlCa can be used. These cathode materials can be formed into films by, for example, resistance heating evaporation, electron beam evaporation, sputtering, or ion plating.

[0072] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0073] Example 1

[0074] The present invention provides a series of different 10 The boron compound with high B atomic abundance has the following structural formula:

[0075]

[0076] The preparation method is as follows:

[0077] S1: BF3 and 95atom% of the abundance of natural value were purchased from Sigma-Aldrich. 10 BF3, and adjust the atomic abundance of respectively to 25atom%, 40atom%, 60atom%, and 80atom% by proportioning, and prepare the corresponding BBr3 by the existing method for standby use.

[0078] S2: Synthesis is different 10 B atomic abundance of 5,9-diphenyl-5,9-dihydro-5,9-diaza-13b-borazinonaphtho[3,2,1-de]anthracene;

[0079] S2.1: See the following synthetic route:

[0080]

[0081] Specifically, under a nitrogen environment, 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 at 80° C. for 2 hours, then the temperature was raised to 120° C. and further heated and stirred for 3 hours. After the reaction solution was cooled to room temperature, water and ethyl acetate were added, and the precipitated solid was extracted by suction filtration. Silica gel column chromatography was used for purification. The solid obtained by decompressing the solvent was washed with heptane to obtain 2-chloro-N 1 ,N 1 ,N 3 ,N 3 -Tetraphenylbenzene-1,3-diamine.

[0082] S2.2: Under nitrogen atmosphere, 2-chloro-N 1 ,N 1 ,N 3 ,N 3-tetraphenylbenzene-1,3-diamine (20.0g) and tert-butylbenzene (150ml) were added to a flask with 1.7M tert-butyllithium pentane solution (27.6ml). After the addition was completed, the temperature was raised to 60°C and stirred for 2 hours. The components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -30°C and the boron tribromide ( 10 B has an atomic abundance of 25atom%, 40atom%, 60atom%, 80atom%, and 95atom%, respectively (the amount is 30mmol), and the temperature is raised to room temperature and stirred for 0.5 hours. Thereafter, it is cooled to 0°C again and N,N-diisopropylethylamine (15.6ml) is added, and the mixture is stirred at room temperature until the heating ends, and the temperature is raised to 120°C and heated with stirring for 3 hours. The reaction solution is cooled to room temperature, and sodium acetate aqueous solution and heptane cooled by ice bath are added in sequence for liquid separation. Subsequently, after purification using a silica gel short-range column (additive liquid: toluene), the solid obtained by decompressing the solvent is dissolved in toluene, and heptane is added for reprecipitation to obtain a series of products represented by the formula ( 10 B-2) indicates that 10 B Boron compounds with different abundances.

[0083] Comparative Example 1: Using naturally abundant BCl3 as a raw material, the same steps as in Example 1 were followed to synthesize a substance with the same structural formula.

[0084] Comparative Example 2: Use 11 The abundance of B atoms is 95%. 11 BCl3, that is 10 The abundance of B atoms is 5%. 10 Using BCl3 as a raw material, the same steps as in Example 1 were followed to synthesize a substance with the same structural formula.

[0085] Example 2

[0086] The present invention provides a series of different 10 The boron compound with high abundance of B atoms has the following structural formula:

[0087]

[0088] The preparation method is as follows:

[0089] S1 is the same as S1 in Example 1.

[0090] S2: Synthesis is different 10 B atomic abundance of N,N,5,9-tetraphenyl-5,9-dihydro-5,9-diaza-13b-borazinonaphtho[3,2,1-de]anthracen-7-amine;

[0091] Under nitrogen atmosphere, and at room temperature, 1 ,N 1 ,N 3 ,N 3 ,N 5 ,N 5 -hexaphenyl-1,3,5-phenyltriamine (11.6 g, 20 mmol) and o-dichlorobenzene (120 ml) were added to a flask containing boron tribromide ( 10 The atomic abundance of B was 25atom%, 40atom%, 60atom%, 80atom%, and 95atom%, respectively (the amount was 40 mmol), and the mixture was heated and stirred at 170°C for 48 hours. Thereafter, the reaction solution was distilled off at 60°C under reduced pressure. Filtration was performed using a magnesium silicate short-path column, and the solvent was distilled off under reduced pressure to obtain a crude product. The crude product was washed with hexane to obtain a yellow solid of the formula ( 10 B-1) The compound represented by.

[0092] Other boron compounds ( 10 B-3 to 10 B-17) Synthesis and 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 present embodiment, but the desired boron compound can be synthesized.

[0093] Example 3

[0094] The present invention provides a series of different 11 The boron compound with high abundance of B atoms has the following structural formula:

[0095]

[0096] The preparation method is as follows:

[0097] S1: BF3 and 95atom% of the abundance of natural value were purchased from Sigma-Aldrich. 11 BF3, and through the ratio 11 The atomic abundance of B is adjusted to 83 atom%, 85 atom%, 90 atom%, and 93 atom%, respectively, and the corresponding BCl3 or BBr3 is prepared by the existing method for later use.

[0098] S2: Synthesis is different 11 B atomic abundance of 5,9-diphenyl-5,9-dihydro-5,9-diaza-13b-borazinonaphtho[3,2,1-de]anthracene;

[0099] 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.

[0100] S2.2: Under nitrogen atmosphere, 2-chloro-N 1 ,N 1 ,N 3 ,N 3 -tetraphenylbenzene-1,3-diamine (20.0g) and tert-butylbenzene (150ml) were added to a flask with 1.7M tert-butyllithium pentane solution (27.6ml). After the addition was completed, the temperature was raised to 60°C and stirred for 2 hours. The components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -30°C and the boron tribromide ( 11 B has an atomic abundance of 83atom%, 85atom%, 90atom%, 93atom%, and 95atom%, respectively (the amount is 30mmol), and the temperature is raised to room temperature and stirred for 0.5 hours. Thereafter, the mixture is cooled to 0°C again and N,N-diisopropylethylamine (15.6ml) is added, and the mixture is stirred at room temperature until the heating ends, and the temperature is raised to 120°C and heated with stirring for 3 hours. The reaction solution is cooled to room temperature, and an aqueous sodium acetate solution and heptane cooled with an ice bath are added in sequence for liquid separation. Subsequently, the solution is purified using a silica gel short-range column (additive: toluene), and the solid obtained by decompressing the solvent is dissolved in toluene, and heptane is added for reprecipitation to obtain a series of products represented by the formula ( 11 B-2) indicates that 11 B Compounds with different abundances.

[0101] Comparative Example 3: Use 10 The abundance of B atoms is 50%. 11 BCl3, that is 11 The abundance of B atoms is 50%. 11 Using BCl3 as the raw material, the same steps were followed to synthesize substances with the same structural formula as above.

[0102] Example 4

[0103] The present invention provides a series of different 11 The boron compound with high B atomic abundance has the following structural formula:

[0104]

[0105] The preparation method is as follows:

[0106] S1 is the same as S1 in Example 3.

[0107] S2: Synthesis is different 11 B atomic abundance of N,N,5,9-tetraphenyl-5,9-dihydro-5,9-diaza-13b-borazinonaphtho[3,2,1-de]anthracen-7-amine;

[0108] Under nitrogen atmosphere, and at room temperature, 1 ,N 1 ,N 3 ,N 3 ,N 5 ,N 5 -hexaphenyl-1,3,5-phenyltriamine (11.6 g, 20 mmol) and o-dichlorobenzene (120 ml) were added to a flask containing boron tribromide ( 11 The atomic abundance of B was 83atom%, 85atom%, 90atom%, 93atom%, and 95atom%, respectively (using an amount of 40 mmol), and then heated and stirred at 170°C for 48 hours. Thereafter, the reaction solution was distilled off at 60°C under reduced pressure. Filtration was performed using a magnesium silicate short-path column, and the solvent was distilled off under reduced pressure to obtain a crude product. The crude product was washed with hexane to obtain a yellow solid of the formula ( 11 B-1) The compound represented by.

[0109] Device Application Examples

[0110] A 26 mm×28 mm×0.7 mm glass substrate (manufactured by Opto Science, Inc.) obtained by polishing ITO formed to a thickness of 180 nm by sputtering to 150 nm was used as a transparent supporting substrate.

[0111] The transparent supporting substrate was fixed on the substrate holder of a commercially available evaporation device (Showa Vacuum Co., Ltd.), and a molybdenum evaporation boat containing HIM (hole injection material), a molybdenum evaporation boat containing HTM (hole transport material), a molybdenum evaporation boat containing EBL (electron blocking material), a molybdenum evaporation boat containing BH1 (main body), a molybdenum evaporation boat containing Example 1 of the present invention, ... BH1 (main body) were installed. 10 A molybdenum evaporation boat containing a boron compound with a boron atomic abundance of 25%, a molybdenum evaporation boat containing an HBL (hole blocking material), a molybdenum evaporation boat containing an ETL (electron transport material), a molybdenum evaporation boat containing LiF, and a tungsten evaporation boat containing aluminum. The structural formulas of each of the above materials are shown below:

[0112]

[0113] The following layers were formed in sequence on the ITO film of the transparent supporting substrate. The vacuum chamber was decompressed to 5×10-4 Pa, first heated the evaporation boat containing the HIM and evaporated it to a film thickness of 5 nm to form the hole injection layer 2. Next, heated the evaporation boat containing the HTM and evaporated it to a film thickness of 105 nm to form the hole transport layer 3. In addition, heated the evaporation boat containing the EBL and evaporated it to a film thickness of 20 nm to form the electron blocking layer 4.

[0114] Next, the evaporation boat containing BH1 and the evaporation boat containing Example 1 were placed. 10 The evaporation boat of boron compound with 25% boron atomic abundance was heated and evaporated to a thickness of 25 nm to form the light-emitting layer 5. The evaporation rate was adjusted so that BH1 and Example 1 10 The weight ratio of the boron compound with a boron atomic abundance of 25% was approximately 80:20. Next, the HBL was heated and deposited in the deposition boat to a thickness of 20 nm, forming the hole-blocking layer 6. Next, the ETL was heated and deposited in the deposition boat to a thickness of 10 nm, forming the electron-transporting layer 7.

[0115] The evaporation rate of each layer is 0.01 to 2 nm / second.

[0116] Next, a vapor deposition boat containing LiF, the material for the electron injection layer 8, was heated and vapor-deposited at a rate of 0.01 to 0.1 nm / sec to a film thickness of 1 nm. Subsequently, a vapor deposition boat containing aluminum was heated and vapor-deposited at a rate of 0.01 to 2 nm / sec to a thickness of 100 nm to form the cathode 9, thereby completing the OLED device.

[0117] The first series of device application examples: the different 10 The boron compounds with high B atomic abundance replace the boron compounds in Example 1 above. 10 A series of OLED devices were obtained using the same conditions as above using a boron compound having a boron atomic abundance of 25%. 10 The devices prepared from the boron compound of Example 1 of the present invention with the atomic abundance of B being 25 atom%, 40 atom%, 60 atom%, 80 atom% and 95 atom% are marked as EL-10B-25, EL-10B-40, EL-10B-60, EL-10B-80 and EL-10B-95 respectively.

[0118] The second series of device application examples: the different 11 The boron compounds with high B atomic abundance replace the boron compounds in Example 1 above. 10 A series of OLED devices were obtained using the same conditions as above using a boron compound having a boron atomic abundance of 25%. 11The devices prepared from the boron compound of Example 3 of the present invention with the atomic abundance of B being 83 atom%, 85 atom%, 90 atom%, 93 atom% and 95 atom% are marked as EL-11B-83, EL-11B-85, EL-11B-90, EL-11B-93 and EL-11B-95 respectively.

[0119] Device Comparison Example 1:

[0120] The boron compound of natural abundance was prepared by using Comparative Example 1 instead of the boron compound of Example 1. 10 The boron compound with a boron atomic abundance of 25% was then used to prepare an OLED device according to the same method and conditions as above. The device was labeled EL-10B-nature. 11 B OLED devices prepared from naturally abundant boron compounds.

[0121] Device Comparison Example 2:

[0122] Prepared using Comparative Example 2 10 The boron compound with a boron atomic abundance of 5% replaces the 10 A boron compound with a boron atomic abundance of 25% was prepared, and an OLED device was prepared according to the same method and conditions as above. The device was labeled EL-10B-5.

[0123] Device Comparison Example 3:

[0124] Prepared using Comparative Example 3 11 The boron compound with a boron atomic abundance of 50% replaces the boron in Example 1. 10 A boron compound with a boron atomic abundance of 25% was prepared, and an OLED device was prepared according to the same method and conditions as above. The device was labeled EL-11B-50.

[0125] Test 1:

[0126] When a DC voltage is applied to the device with an ITO electrode as the anode 1 and a LiF / aluminum electrode as the cathode 9, blue light emission is obtained. 2 When driving, measure the brightness. The results are shown in Table 1:

[0127] Table 1

[0128]

[0129] According to the above table, the organic electroluminescent device prepared by using the boron compound of the present invention as a blue light doping material, wherein 10 The higher the abundance of B atoms, the higher the blue light brightness of the corresponding device, indicating that the 10 B and 10A boron atom abundance of more than 25% can enhance the luminescence brightness of blue organic electroluminescent devices.

[0130] Test 2:

[0131] When a DC voltage was applied with the ITO electrode as the anode and the LiF / aluminum electrode as the cathode, blue light was emitted. When driven at 20 mA / cm2, the time until the initial brightness dropped by 5% was measured, as shown in Table 2:

[0132] Table 2

[0133]

[0134] According to the above table, boron compounds 11 When the atomic abundance of B is higher than 83%, the life of the OLED prepared by the boron compound is significantly prolonged. 11 As the atomic abundance of B increases, the lifetime is extended even further.

[0135] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A boron compound, characterized in that The boron compound is selected from any one of the compounds represented by the following structural formulas: ； The boron compound satisfies any one of the following two conditions: (1) the boron element contained in the boron compound is 10 The atomic abundance of B is 25atom% or more; (2) the boron element contained in the boron compound is 11 The abundance of boron atoms is more than 83 atom%.

2. The boron compound according to claim 1, characterized in that The boron element contained in the boron compound 10 The atomic abundance of B is 50 atom % or more.

3. The boron compound according to claim 1, characterized in that The boron element contained in the boron compound 10 The atomic abundance of B is more than 70 atom%.

4. The boron compound according to claim 1, characterized in that The boron element contained in the boron compound 10 The atomic abundance of B is more than 85 atom%.

5. The boron compound according to claim 1, characterized in that The boron element contained in the boron compound 11 The abundance of B atoms is over 90%.

6. The boron compound according to claim 1, characterized in that The boron element contained in the boron compound 11 The abundance of B atoms is above 95%.

7. A luminescent material, characterized in that: It comprises the boron compound according to any one of claims 1 to 6.

8. The luminescent material according to claim 7, characterized in that The mass content of the boron compound in the luminescent material is 0.1-20%.

9. The luminescent material according to claim 7, characterized in that The luminescent material further includes a host material.

10. The luminescent material according to claim 9, characterized in that The host material is selected from anthracene derivatives; The general structural formula of the anthracene derivative is shown below: , where Y represents an aromatic or non-aromatic cyclic substituent, Cy 2 represents an aromatic group having 6 to 12 nuclear carbon atoms.

11. The luminescent material according to claim 10, characterized in that Cy 2 for or .

12. The luminescent material according to claim 10, characterized in that The anthracene derivative is selected from any one of the compounds represented by the following structural formulas: ； The anthracene derivatives represented by the above structural formula may be used alone or in combination of two or more.

13. An organic electroluminescent device, characterized in that: It is prepared by the luminescent material according to claim 7; the luminescent layer of the organic electroluminescent device comprises the luminescent material.

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