CN115724865A - Boron compound, luminescent material and organic electroluminescent device - Google Patents

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 either of the following two conditions: (1) Of boron contained in boron compounds ¹⁰ The atomic abundance of B is more than 25 atom%; (2) ¹¹ The abundance ratio of B atoms is more than 83 atom%. Define the limit ¹⁰ The atomic abundance of B is more than 25atom percent, so that the luminous brightness of the organic electroluminescent device obtained by subsequent preparation can be effectively improved, and the limitation is realized ¹¹ The abundance of the B atoms is more than 85atom percent, so that the service life of the organic electroluminescent device can be effectively prolonged.

Description

Boron compound, luminescent material and organic electroluminescent device

Technical Field

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.

Background

In the OLED device, by applying a voltage between a pair of electrodes, holes are injected from an anode, and electrons are injected from a cathode into a light-emitting layer containing an organic compound as a light-emitting material. The injected electrons are recombined with the holes to form excitons having a light-emitting property. The excited organic compound emits light. That is, the OLED is more visible than a liquid crystal device as a self-light emitting device and can provide clearer display.

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

Researchers have previously conducted various studies on light emitting layers, and are continuing to search for suitable light emitting materials. For example, in a polycyclic aromatic hydrocarbon compound in which a plurality of aromatic rings are bonded to each other by boron or oxygen, since the aromatic degree of a six-membered ring containing a heteroatom is low, the reduction of the HOMO-LUMO gap is small as the conjugated system is enlarged, 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), which reduces the exchange between the two orbitals, resulting in a small energy difference between the triplet excited state (T1) and the singlet excited state (S1), the polycyclic aromatic hydrocarbon compound containing a heteroatom exhibits thermally-activated delayed fluorescence, and thus, the light emitting efficiency is improved, but the existing improvement on the light emitting material is limited, so that the variety of the light emitting material is small, and the light emitting luminance of the light emitting material or the service life thereof needs to be further improved.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

The invention aims to provide a boron compound, a luminescent material and an organic electroluminescent device. When the boron compound is used for preparing the organic electroluminescent device, the luminous brightness of the organic electroluminescent device can be effectively improved or the luminous intensity of the organic electroluminescent device is reduced less along with the driving, namely the service life of the organic electroluminescent device is prolonged, and the types of luminescent materials are expanded.

The invention is realized by the following steps:

in a first aspect, the present invention provides a boron compound satisfying either of the following two conditions: (1) Of boron element contained in said boron compound ¹⁰ The atomic abundance of B is more than 25 atom%; (2) Of boron element contained in said boron compound ¹¹ The abundance ratio of B atoms is more than 83 atom%.

The naturally occurring boron compound generally contains 19.9% of ¹⁰ B, the inventor finds and promotes ¹⁰ Atomic abundance of B such that ¹⁰ The atomic abundance of B is more than 25atom%, so that the luminous brightness of the organic electroluminescent device prepared subsequently can be effectively improved. Or to lift ¹¹ Abundance of B atom such that ¹¹ The abundance of the B atoms is more than 83atom%, so that the light-emitting intensity of the organic electroluminescent device is reduced less along with the driving, namely the service life of the organic electroluminescent device is prolonged.

Wherein, the atomic abundance refers to the ratio of the number of atoms of a specific isotope to the total number of atoms of an element in an isotopic mixture of the element, and is expressed as atomic percent (atom%).

In a second aspect, the present invention provides a luminescent material comprising a boron compound shown in any one of the preceding embodiments;

preferably, the mass content of the boron compound in the luminescent material is 0.1-20%;

preferably, the luminescent material further comprises a host material;

preferably, the light emitting material is selected from anthracene derivatives;

preferably, the structural formula of the anthracene derivative is as follows:

wherein Y represents an aromatic or non-aromatic cyclic substituent, and Cy2 represents an aryl group having 6 to 12 nuclear carbons;

preferably, cy2 is

In a third aspect, the present invention provides an organic electroluminescent device prepared from the boron compound according to any one of the preceding embodiments or the luminescent material according to the preceding embodiments.

In an alternative embodiment, the light emitting layer of the organic electroluminescent device includes the boron compound or the light emitting material.

The invention has the following beneficial effects: the embodiment of the invention promotes ¹⁰ The atomic abundance of B is such that ¹⁰ The atomic abundance of B is more than 25atom%, and the luminous brightness of the organic electroluminescent device prepared subsequently can be effectively improved. Or by lifting ¹¹ The atomic abundance of B is such that ¹¹ The atomic abundance of B is more than 83atom percent, so that the luminous intensity of the organic electroluminescent device is reduced less along with the driving, namely the service life of the organic electroluminescent device is prolonged.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of an organic electroluminescent device according to an embodiment of the present invention.

Icon: 1-an anode; 2-a hole injection layer; 3-a hole transport layer; 4-an electron blocking layer; 5-a light-emitting layer; 6-a hole blocking layer; 7-an electron transport layer; 8-electron injection layer; 9-cathode.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are conventional products which are not indicated by manufacturers and are commercially available.

The embodiment of the invention provides a boron compound, which meets any one of the following two conditions: (1) Of boron element contained in said boron compound ¹⁰ The atomic abundance of B is more than 25 atom%. For example, ¹⁰ the atomic abundance of B is any of 25atom% or more, such as 25atom%, 30atom%, 35atom%, 40atom%, 45atom%, 50atom%, 55atom%, 60atom%, 65atom%, 70atom%, 75atom%, 80atom%, 85atom%, 80atom%, 95atom%, and 98atom%, preferably 50atom% or more, preferably 70atom% or more, and more preferably 85atom% or more.

(2) Of boron element contained in said boron compound ¹¹ The abundance ratio of B atoms is more than 83 atom%. The optional atomic abundance is 83atom%, 84atom%, 85atom%, 86atom%, 87atom%, 88atom%, 89atom%, 90atom%, 91atom%, 92atom%, 93atom%, 94atom%, 95atom%, 96atom%, 97atom%, 98atom%, preferably 90atom% or more, more preferably 95atom% or more.

It should be noted that: normally the naturally occurring boron compound contains 19.9% of ¹⁰ B. However, the resin can be prepared by a method such as chromatography using an ion exchange resin ¹⁰ B and B ¹¹ B is separated and respectively concentrated to obtain the product with high atomic abundance ¹⁰ B and ¹¹ B. or can purchase existing high atomic abundance directly ¹⁰ B simple substance, ¹⁰ BF ₃ Or ¹¹ BF ₃ For example, merck Sigma-aldrich trade company, cat # 601551, with an atomic abundance of 90atom% ¹⁰ B simple substance; the cargo number is 601357, atomengDegree of 95atom% ¹⁰ BF ₃ The cargo number is 610011, and the atomic abundance is more than or equal to 95atom percent ¹¹ BF ₃ (ii) a The cargo number is 610038, and the atomic abundance is 98.8atom% ¹¹ BF ₃ . Or can be prepared by the method described in prior arts CN109942005, CN109195910A or CN103950947 ¹⁰ BF ₃ 、 ¹¹ BF ₃ And ¹¹ BCl ₃ the purity can reach 95.5%, 99.95% and 99.999% respectively. Alternatively, the isotope B and BF can be prepared by the method described in prior arts CN103950947 and CN103950949A ₃ Isotope preparation to BCl ₃ Isotope, BBr ₃ Examples of the isotope include methods described in CN103950947 and CN 103950949A.

Further, the boron compound has a structural formula shown in general formula (1):

wherein Ar is a substituted or unsubstituted 3-to 20-membered heteroaromatic group or a substituted or unsubstituted 6-to 40-membered aromatic ring group, for example, ar is selected from any one of a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted pyrrolyl group, a substituted or unsubstituted indolyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted furyl group, a substituted or unsubstituted benzofuryl group, a substituted or unsubstituted dibenzofuryl group, a substituted or unsubstituted thienyl group, a substituted or unsubstituted benzothienyl 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.

It will of course be appreciated that the above groups are merely exemplary of some of the substituted or unsubstituted 3-to 20-membered heteroaromatic groups or substituted or unsubstituted 6-to 40-membered aromatic ring groups, and that Ar may also be selected from other substituted or unsubstituted 3-to 20-membered heteroaromatic groups or substituted or unsubstituted 6-to 40-membered aromatic ring groups known in the art.

Meanwhile, the substituent in the substituted 3-20-membered heteroaromatic group and the substituted 6-40-membered aromatic ring can be 1 or more, that is, one hydrogen in the 3-20-membered heteroaromatic group and the 6-40-membered aromatic ring can be substituted to form a single substituent, or 2,3, 4 or even more hydrogens can be substituted to form multiple substituents, and when multiple substituents are substituted, the hydrogens on the same carbon can be substituted, or the hydrogens on different carbons can be substituted.

And secondly, the substituted 3-20-membered aromatic heterocyclic group and the substituted 6-40-membered aromatic ring are selected from any one of cyano, halogen, nitro, carbonyl, substituted or unsubstituted silyl, substituted or unsubstituted amino and substituted or unsubstituted alkyl.

Further, ar may be, in addition to being selected from the above groups, adjacent Ar may be connected to form a ring using a chemically feasible junction or fusion means; for example, any two of the specific groups in the aforementioned defined substituted or unsubstituted 3-to 20-membered heteroaromatic group or substituted or unsubstituted 6-to 40-membered aromatic ring group are joined by chemically feasible joining or fusing to form a ring; and the arrangement and selection of the substituent groups in the adjacent Ar forming rings are the same as those of the substituent groups in the substituted 3-to 20-membered aromatic heterocyclic group and the substituted 6-to 40-membered aromatic ring.

Further, the structural formula of the boron compound is shown as the general formula (2):

wherein X is absent, that is, X in the general formula (2) may not form a ring with B, but 3X in the general formula (2) may not be present at the same time, for example, the following formulae of the general formulae (3) and (4). Or X is a single bond, i.e., when B forms a 5-membered ring with X, but 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 silicon; that is to sayIn this case, B and X form a 6-membered ring, and Ar is defined as the same as that of Ar in the aforementioned general formula (1).

R ¹ -R ¹¹ Each independently is 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 of them are connected by a chemically feasible joining or fusing means to form a ring;

wherein R is as defined above ¹ -R ¹¹ Any adjacent two of them form a ring, and a substituent is 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 may be a substitution of at least one hydrogen in the ring.

Further, the substituents in the above-mentioned 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. Similarly, the substituent may be a substitution of at least one hydrogen of the above-mentioned aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, alkoxy, and aryloxy groups.

Further, the structural formula of the boron compound is shown as a general formula (3) or a general formula (4):

wherein R is ¹ -R ²¹ Each independently is 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 are linked by chemically feasible joining or fusing to form a ring;

preferably, R ¹ -R ¹¹ Any adjacent two of them form a ring, and a substituent is 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;

preferably, the substituents in the 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 above substitution means that at least 1 hydrogen in the corresponding group is substituted, and when a plurality of hydrogens are substituted, hydrogens on different carbons may be substituted.

Specifically, the boron compound is selected from any one of the compounds represented by the following structural formula:

in a second aspect, embodiments of the present invention provide a luminescent material, which includes the above boron compound; the boron compound is used as a doping material. And the mass content of the boron compound in the luminescent material is 0.1-20%.

The light emitting material further includes a host material, which may be selected from those in the prior art, and various known materials may be used as the host material as long as the host material minimizes a charge injection barrier from the hole transport layer or the electron transport layer, confines charges to the light emitting layer, and prevents quenching of emitted excitons. However, the inventor finds that the anthracene derivative used as the main material in the embodiment of the invention can better react with the boron compound in the embodiment of the invention, and the performance of the OLED device is improved. The structural general formula of the anthracene derivative is shown as follows:

wherein Y represents an aromatic or non-aromatic cyclic substituent, and the aromatic or non-aromatic cyclic substituent is preferably a phenyl group, biphenyl group, naphthyl group, or dibenzofuranyl group. Among them, phenyl, 1-biphenyl and 1-naphthyl, and 2-diphenylfuryl and the like are more preferable groups.

Cy2 represents an aryl group having 6 to 12 nuclear carbons; aryl having 6 to 12 nuclear carbons is in particular a phenyl ring or a naphthyl ring, for example

That is, the 10-position (or 9-position) of the anthracene structure has dibenzofuran or benzonapran.

Specifically, the anthracene derivative is selected from any one of the compounds represented by the following structural formula:

the anthracene derivative represented by the structural formula may be used alone or in combination of two or more.

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

Further, an embodiment of the present invention provides an organic electroluminescent device, where one or more organic layers are disposed between electrodes of the organic electroluminescent device, for example, the organic electroluminescent device has a structure that: "anode 1/hole injection layer 2/hole transport layer 3/light-emitting layer 5/electron transport layer 7/electron injection layer 8/cathode 9", "anode 1/hole injection layer 2/emission layer 5/electron transport layer 7/electron injection layer 8/cathode 9", "anode 1/hole injection layer 2/hole transport layer/emission 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 injection layer 2/hole transport layer 3/light-emitting layer 5/electron transport layer 7/cathode 9", "anode 1/hole injection layer 2/electron injection layer 5/electron injection layer 8/cathode 9", "1/electron injection layer 7/cathode 9", "anode 1/electron injection layer 2/hole transport layer 7/cathode 9" and "cathode injection layer 8/cathode 9".

In the embodiment of the present invention, as shown in fig. 1, the organic electroluminescent device is formed by stacking the structures of "anode 1/hole injection layer 2/hole transport layer 3/electron blocking layer 4/light emitting layer 5/hole blocking layer 6/electron transport layer 7/electron injection layer 8/cathode 9" in this order, and the electron blocking layer 4 and the hole blocking layer 6 are added to the above structure. The organic layer means layers other than the electrodes 1 and 9, i.e., 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, and an electron injection layer 8.

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 of several micrometers thickness or special transparent plastics.

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 are stacked by vacuum evaporation or plating. Vacuum deposition is generally carried out by heating the deposition material in a reduced pressure atmosphere, usually less than 10-3 Pa. The thickness of each layer depends on the type of layer and the material used, but is typically around 100nm for the anode 1 and cathode 9, and less than 50nm for other organic layers including the light-emitting layer 5.

For the anode 1, a material having a high work function and a total light transmittance of 80% or more is generally used. Specifically, transparent conductive ceramics such as Indium Tin Oxide (ITO) and zinc oxide (ZnO), transparent conductive ceramics such as polythiophene-polystyrene sulfonic acid (PEDOT-PSS) and polyaniline, and other transparent conductive materials are used to transmit light emitted from the anode 1.

Between the anode and the light-emitting layer 5 there is a hole injection transport layer 2 or a hole transport layer 3 to efficiently transport holes from the anode 1 to the light-emitting layer.

Hole injection materials forming the hole injection layer 2 include, for example, (poly (propylene ether ketone) -triphenylamine-containing (KLHIP: PPBI), 1,4,5,8,9, 11-hexaazabenzene hexacyano-nitrile (HATCN), PEDOT-PSS, etc. the hole layer 2 made of these materials is also referred to as a polymer buffer layer, and can effectively reduce the driving voltage of the OLED device.

The hole transport layer 3 is provided between the anode 1 and the light emitting layer 5 for efficiently transporting holes from the anode 1 to the light emitting layer. Hole transport materials have a small ionization potential, i.e., electrons are easily excited from the HOMO and holes are easily generated. For example, poly (9, 9-dioctylfluorene-alt-N- (4-butylphenyl) diphenylamine) (TFB), 4 '-cyclohexylbis [ N, N-bis (4-methylphenyl) aniline ] (TAPC), N' -diphenyl-N, N '-di (m-toluene) benzidine (TPD), N' -di (1-naphthyl) ], N '-diphenyl-N, N' -diphenyl benzidine (NPD), 4DBFHPB (hexa-biphenyl derivative), 4',4 "-tris 9-carboxylic acid" -tri-9-carbozolylphenylamine (TCTA) and 4,4',4 "-tris [ phenyl (m-toluene) amino ] triphenylamine), and the like.

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

An electron blocking layer 4 may be provided between the light-emitting layer 5 and the hole transport layer 3. Through the electron blocking layer 4, electrons can be trapped in the light emitting layer to increase the probability of charge recombination in the light emitting layer, thereby improving the light emitting efficiency. As the electron blocking material forming the electron blocking layer 4, a monoamine derivative may be used.

In order to transport electrons from the cathode 9 to the light-emitting layer 5 efficiently, 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-bis (pyridin-3-yl) phenyl) -2-hydroxyquinoline (Liq), 4, 6-bis (3, 5-bis (pyridin-3-yl) phenyl) -2-methylpyrimidine (B3 PymPm), 4, 6-bis (3, 5-bis (pyridin-4) phenyl) -2-phenylpyrimidine (B4 PyPm), 2- (4-biphenyl) -5- (p-tert-butylphenyl) -1,3, 4-oxadiazole (tbpm) -1, 3-bis [5- (4-t-butylphenyl) -2] oxadiazolyl (tBu-BD) -oxadiazolyl ] benzene (OXD-7), 3- (biphenyl-4-yl) -5- (4-t-butyrylphenyl) -4-triazolyl ] benzene (OXD-7), 3- (biphenyl-4-yl) -5- (4-t-butyrylphenyl) -4-triazolyl (tpyl), tris (tpp-phenyl) -1,3, 5-bis (tppypm), 3-benzophenonyl) benzene (tpy-1, 3, 4-bis (tpy-phenyl) benzene (tpy-1, 4-phenyl) and 1, 4-bis (tpy) phenyl) benzene. (1, 3, 5-tris (1-phenyl-1H-benzimidazol-2-yl) benzene (TFBi) and 3- (4-biphenyl) -4-phenyl) -1,2,4-Triazole (TAZ) and others. Among them, a mixed layer of DPB and Liq is preferred.

The hole blocking layer 6 is a layer that limits holes in the light emitting layer 5 to increase the probability of charge recombination in the light emitting layer 5 and improve light emitting efficiency. DBT-TRZ and other materials as hole blocking materials, forming the hole blocking layer 6. The thickness of the hole blocking layer 6 and the electron transport layer 7 is typically 3 to 50nm and may vary depending on the desired design.

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

The cathode 9 is made of a chemically stable material having a low work function (less than 4 eV). Specifically, an alloy of Al and an alkali metal such as Al, mgAg alloy, or AlLi and AlCa may be used. These cathode materials can be formed into a film by, for example, resistance heating evaporation, electron beam evaporation, sputtering, or ion plating.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

The embodiments of the present invention provide a series of differences ¹⁰ The B-atom abundance boron compound has the following structural formula:

the preparation method comprises the following steps:

s1: BF was purchased from Sigma-aldrich, respectively, as a natural value ₃ 95atom% of ¹⁰ BF ₃ And the abundance ratio of atoms is adjusted to 25atom%, 40atom%, 60atom% and 80atom% respectively. It was prepared by a method of the prior art into the corresponding BBr ₃ And then standby.

S2: different in synthesis ¹⁰ 5, 9-Diphenyl-5, 9-dihydro-5, 9-diaza-13B-boranonaphtho [3,2,1-de ] of B atom abundance]Anthracene;

s2.1: see the following synthetic pathway:

specifically, 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 ℃ for 2 hours under a nitrogen atmosphere, then heated to 120 ℃ and further heated and stirred for 3 hours. After the reaction mixture was cooled to room temperature, water and ethyl acetate were added, and the precipitated solid was extracted by suction filtration. Purification was performed by silica gel column chromatography. Washing the solid obtained by distilling off the solvent under reduced pressure with heptane, therebyObtaining 2-chloro-N ¹ ,N ¹ ,N ³ ,N ³ Tetraphenylbenzene-1, 3-diamine.

S2.2 adding 2-chloro-N in nitrogen atmosphere at-30 deg.C ¹ ,N ¹ ,N ³ ,N ³ A flask containing (20.0 g) of (E) -tetraphenylbenzene-1, 3-diamine and (150 ml) of tert-butylbenzene was charged with a 1.7M solution of tert-butyllithium pentane (27.6 ml). After the completion of the dropwise addition, the temperature was raised to 60 ℃ and the mixture was stirred for 2 hours, and then a component having a boiling point lower than that of tert-butylbenzene was distilled off under reduced pressure. Cooling to-30 deg.C, and adding boron tribromide (B) with different atomic abundances prepared by S1 ¹⁰ The atomic abundance of B was 25atom%, 40atom%, 60atom%, 80atom%, 95atom%, and the amount was 30 mmol), and the mixture was stirred for 0.5 hour after the temperature was raised to room temperature. Thereafter, the mixture was cooled again to 0 ℃ and N, N-diisopropylethylamine (15.6 ml) was added thereto, and the mixture was stirred at room temperature until heat generation was completed, and then heated to 120 ℃ and stirred for 3 hours. The reaction solution was cooled to room temperature, and an aqueous sodium acetate solution cooled with an ice bath and heptane were added in this order to separate the reaction solution. Then, a silica gel short-path column (addition liquid: toluene), the solvent was distilled off under reduced pressure, and the obtained solid was dissolved in toluene, and heptane was added thereto for reprecipitation, to obtain a series of the following compounds represented by the formula (a) ¹⁰ B-2) is represented by ¹⁰ Boron compounds with different B abundance.

Comparative example 1: BCl using natural abundance ₃ As a starting material, a substance having the same structural formula was synthesized in the same manner as in example 1.

Comparative example 2: use of ¹¹ The abundance of B atoms is 95% ¹¹ BCl ₃ I.e. by ¹⁰ The abundance of B atoms is 5% ¹⁰ BCl ₃ As a starting material, a substance having the same structural formula was synthesized in the same manner as in example 1.

Example 2

The embodiments of the present invention provide a series of differences ¹⁰ The B atom abundance boron compound has the following structural formula:

the preparation method comprises the following steps:

s1 is the same as S1 of example 1.

S2: different in synthesis ¹⁰ N, N,5, 9-tetraphenyl-5, 9-dihydro-5, 9-diaza-13B-bora-naphtho [3,2,1-de ] of B atomic abundance]Anthracen-7-amine;

under nitrogen atmosphere, adding N at room temperature ¹ ,N ¹ ,N ³ ,N ³ ,N ⁵ ,N ⁵ In a flask of hexaphenyl-1, 3, 5-benzenetriamine (11.6 g, 20mmol) and o-dichlorobenzene (120 ml), boron tribromide (B) in various atomic abundances provided in the example of the present invention was added ¹⁰ The atomic abundances of B are 25atom%, 40atom%, 60atom%, 80atom%, 95atom%, and 40 mmol), respectively, and then the mixture was stirred at 170 ℃ for 48 hours. Thereafter, the reaction solution was distilled off at 60 ℃ under reduced pressure. Filtration was carried out using a magnesium silicate short path column, and the solvent was distilled off under reduced pressure to obtain a crude product. Washing the crude biomass with hexane, thereby obtaining a crude biomass of formula (a) as a yellow solid ¹⁰ A compound represented by B-1).

Of other boron compounds (C) ¹⁰ B-3 to ¹⁰ B-17) Synthesis and above ¹⁰ B-1 and ¹⁰ the synthesis method, process and conditions of B-2 are similar, and the embodiment of the present invention will not be described in detail, but the desired boron compound can be synthesized.

Example 3

The embodiments of the present invention provide a series of differences ¹¹ The B-atom abundance boron compound has the following structural formula:

the preparation method comprises the following steps:

s1: BF is obtained from Sigma-Aldrich company and has natural abundance ₃ And 95atom% ¹¹ BF ₃ And by proportioning ¹¹ The atomic abundance of B was adjusted to 83atom%, 85atom%, 90atom%, and 93atom%, respectively. By means of prior artThe method prepares the BCl into corresponding BCl ₃ Or BBr ₃ And then standby.

S2: different in synthesis ¹¹ 5, 9-Diphenyl-5, 9-dihydro-5, 9-diaza-13B-boranaphtho [3,2,1-de ] rich in B atom]Anthracene;

s2.1: synthesis of 2-chloro-N according to the Synthesis method of example 1 ¹ ,N ¹ ,N ³ ,N ³ Tetraphenylphenyl-1, 3-diamine.

S2.2 adding 2-chloro-N in nitrogen atmosphere at-30 deg.C ¹ ,N ¹ ,N ³ ,N ³ A flask containing tetraphenylphenyl-1, 3-diamine (20.0 g) and tert-butylbenzene (150 ml) was charged with 1.7M tert-butyllithium pentane solution (27.6 ml). After the completion of the dropwise addition, the temperature was raised to 60 ℃ and the mixture was stirred for 2 hours, and then a component having a boiling point lower than that of tert-butylbenzene was distilled off under reduced pressure. Cooling to-30 ℃, and adding boron tribromide (B) with different atomic abundances prepared by S1 ¹¹ The atomic abundance of B was 83atom%, 85atom%, 90atom%, 93atom%, 95atom%, and the amount was 30 mmol), and the mixture was stirred for 0.5 hour after the temperature was raised to room temperature. Thereafter, the mixture was cooled again to 0 ℃ and N, N-diisopropylethylamine (15.6 ml) was added thereto, and the mixture was stirred at room temperature until the heat generation was completed, and then the mixture was heated to 120 ℃ and stirred for 3 hours. The reaction solution was cooled to room temperature, and an aqueous sodium acetate solution cooled by an ice bath and heptane were sequentially added thereto for liquid separation. Then, a silica gel short-path column (addition liquid: toluene), the solvent was distilled off under reduced pressure, and the obtained solid was dissolved in toluene, and heptane was added thereto for reprecipitation, to obtain a series of the following compounds represented by the formula (a) ¹¹ B-2) is represented by ¹¹ Compounds with different abundance of B.

Comparative example 3: use of ¹⁰ The abundance of B atoms is 50% ¹¹ BCl ₃ I.e. by ¹¹ With an abundance of B atoms of 50% ¹¹ BCl ₃ As a raw material, a substance having the same structural formula as described above was synthesized in accordance with the same procedure.

Example 4

The embodiments of the present invention provide a series of differences ¹¹ The B atom abundance boron compound has the following structural formula:

the preparation method comprises the following steps:

s1 is the same as S1 of example 3.

S2: different in synthesis ¹¹ N, N,5, 9-tetraphenyl-5, 9-dihydro-5, 9-diaza-13B-bora-naphtho [3,2,1-de ] of B atomic abundance]Anthracen-7-amine;

under nitrogen atmosphere, adding N at room temperature ¹ ,N ¹ ,N ³ ,N ³ ,N ⁵ ,N ⁵ Flask of (11.6 g, 20mmol) of (hexaphenyl) -1,3, 5-benzenetriamine and (120 ml) of o-dichlorobenzene boron tribromide (B) with different atomic abundances provided by the embodiment of the invention is added ¹¹ The atomic abundance of B was 83atom%, 85atom%, 90atom%, 93atom%, 95atom%, using 40 mmol), and then the mixture was stirred at 170 ℃ for 48 hours. Thereafter, the reaction solution was distilled off at 60 ℃ under reduced pressure. Filtration was carried out using a magnesium silicate short-path column, and the solvent was distilled off under reduced pressure to obtain a crude product. The crude biomass was washed with hexane, thus obtaining as a yellow solid a compound of the formula (A) ¹¹ A compound represented by B-1).

Device application example

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

A transparent support substrate was fixed to a substrate holder of a commercially available vapor deposition apparatus (Showa Vacuum co., ltd.), and a molybdenum vapor deposition boat containing HIM (hole injection material), a molybdenum vapor deposition boat containing HTM (hole transport material), a molybdenum vapor deposition boat containing EBL (electron blocking material), a molybdenum vapor deposition boat containing BH1 (body), and a substrate holder containing example 1 of the present invention were loaded ¹⁰ A molybdenum evaporation boat of a boron compound having a B atomic abundance of 25%, a molybdenum evaporation boat containing HBL (hole blocking material), a molybdenum evaporation boat containing ETL (electron transport material), a molybdenum evaporation boat containing LiF, and a tungsten evaporation boat containing aluminum. Wherein, the structural formula of each material is as follows:

the following layers are sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was depressurized to 5X 10 ^-4 Pa, the hole injection layer 2 was formed by heating and evaporating an evaporation boat containing HIM to a film thickness of 5 nm. Next, an evaporation boat containing an HTM was heated and evaporated to a film thickness of 105nm, thereby forming a hole transport layer 3. Further, an evaporation boat containing EBL was heated and evaporated to a film thickness of 20nm to form the electron blocking layer 4.

Next, a vapor deposition boat containing BH1 and a vapor deposition boat containing example 1 were used ¹⁰ A boron compound vapor deposition boat having a B atomic abundance of 25% was simultaneously heated and vapor-deposited to a film thickness of 25nm to form the light-emitting layer 5. The evaporation rate was adjusted so that BH1 was identical to that of example 1 ¹⁰ The weight ratio of boron compound with 25% B atomic abundance is about 80. Subsequently, the evaporation boat containing HBL was heated and evaporated to a film thickness of 20nm to form the hole-blocking layer 6. Next, an evaporation boat containing ETL was heated and evaporated to a film thickness of 10nm to form an electron transport layer 7.

Wherein the evaporation rate of each layer is 0.01 to 2 nm/sec.

Then, a deposition boat containing LiF as a material of the electron injection layer 8 was heated and deposited at a deposition rate of 0.01 to 0.1nm/sec to a film thickness of 1 nm. Then, the evaporation boat containing aluminum was heated and evaporated to 100nm at an evaporation rate of 0.01 to 2nm/sec to form a cathode 9, thereby obtaining an OLED device.

First series of device application examples: differences of example 1 of the present invention ¹⁰ Boron compounds with B atom abundance substituted for those of the above example 1 ¹⁰ And (3) obtaining a series of OLED devices by using the boron compound with the B atomic abundance of 25% according to the conditions of the same method. ¹⁰ The devices made from the boron compound of example 1 of the present invention in which the atomic abundances of B are 25atom%, 40atom%, 60atom%, 80atom%, 95atom% are respectively labeled as EL-10B-25, EL-10B-40, EL-10B-60, EL-10B-80, EL-10B-95.

Second series of device application examples: differences of example 3 of the invention ¹¹ Boron compounds with B atom abundance substituted for those of the above example 1 ¹⁰ And (3) obtaining a series of OLED devices by using the boron compound with the B atomic abundance of 25% according to the conditions of the same method. ¹¹ The devices made from the boron compound of example 3 of the present invention having an atomic abundance of B of 83atom%, 85atom%, 90atom%, 93atom%, 95atom% are labeled as EL-11B-83, EL-11B-85, EL-11B-90, EL-11B-93, EL-11B-95, respectively.

Device comparative example 1:

preparation of boron Compound of Natural abundance Using comparative example 1 instead of that of example 1 ¹⁰ Boron compound with 25% abundance of B atom, and then preparing OLED device according to the same method and conditions as above. The device is labeled EL-10B-nature. At this time, it is also ¹¹ B boron compound with natural abundance is used for preparing the OLED device.

Device comparative example 2:

preparation with comparative example 2 ¹⁰ Boron compound with 5% abundance of B atom in place of the boron compound of the above example 1 ¹⁰ Boron compound with 25% abundance of B atom, and then preparing OLED device according to the same method and conditions as above. The device is labeled EL-10B-5.

Device comparative example 3:

preparation by comparative example 3 ¹¹ Boron compound having 50% abundance of B atom in place of that of example 1 ¹⁰ Boron compound with 25% abundance of B atom, and then preparing OLED device according to the same method and conditions as above. The device is labeled EL-11B-50.

Detection 1:

when a DC voltage is applied to the device with an ITO electrode as anode 1 and a LiF/aluminum electrode as cathode 9, blue light emission is obtained. When the current is 10mA/cm ² When driving, the brightness is measured. The results are given in table 1 below:

TABLE 1

As can be seen from the above table, the boron compounds of the present invention are used as blue light dopesAn organic electroluminescent device prepared from the hetero material, wherein ¹⁰ The higher the abundance of B atoms, the higher the blue light brightness of the corresponding device, which indicates that the use of ¹⁰ B and ¹⁰ the abundance of the B atoms is more than 25%, so that the luminous brightness of the blue organic electroluminescent device can be improved.

And (3) detection 2:

when a DC voltage was applied to the anode electrode made of ITO and the cathode electrode made of LiF/aluminum, blue light emission was obtained. When the current is at 20mA/cm ₂ When driving, the time until the initial luminance was decreased by 5% was measured, and the results are shown in table 2 below:

TABLE 2

As can be seen from the above table, among the boron compounds ¹¹ When the atomic abundance of B is higher than 83 percent, the service life of the OLED prepared by the boron compound is obviously prolonged, and the service life of the OLED is prolonged along with the increase of the atomic abundance of B ¹¹ The atomic abundance of B is increased, and the service life is prolonged for more time.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A boron compound, characterized in that the boron compound satisfies any one of the following two conditions: (1) Of boron element contained in said boron compound ¹⁰ The atomic abundance of B is more than 25 atom%; (2) Of boron element contained in said boron compound ¹¹ The abundance ratio of B atoms is more than 83 atom%.

2. The boron compound according to claim 1, wherein the boron compound contains boron element ¹⁰ The atomic abundance of B is 50atom% or more, preferably 70atom% or more, and more preferably 85atom% or more;

preferably, the boron element contained in the boron compound ¹¹ The abundance ratio of B atoms is 90% or more, preferably 95% or more.

3. The boron compound according to claim 1 or 2, wherein the structural formula of the boron compound is represented by general formula (1):

wherein Ar is a substituted or unsubstituted 3-to 20-membered heteroaromatic group or a substituted or unsubstituted 6-to 40-membered aromatic ring group, or adjacent Ar's may be linked to form a ring by a chemically feasible junction or fusion;

preferably, 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 anthracenyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted pyrenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidyl, substituted or unsubstituted triazinyl, substituted or unsubstituted pyrrolyl, substituted or unsubstituted indolyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted furyl, substituted or unsubstituted benzofuryl, substituted or unsubstituted dibenzofuryl, substituted or unsubstituted thienyl, substituted or unsubstituted benzothienyl, substituted or unsubstituted dibenzothienyl, substituted or unsubstituted oxazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted oxadiazolyl, substituted or unsubstituted thiadiazolyl, substituted or unsubstituted triazolyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted benzimidazolyl, and substituted or unsubstituted triazolyl, or adjacent Ar are connected by chemically feasible joining or fusing using any two of the above groups to form a ring;

preferably, the substituent of the substituted 3-to 20-membered heteroaromatic group, the substituted 6-to 40-membered aromatic ring or the adjacent Ar forming ring is selected from any one of cyano, halogen, nitro, carbonyl, substituted or unsubstituted silyl, substituted or unsubstituted amino, substituted or unsubstituted alkyl.

4. The boron compound according to claim 1 or 2, wherein the structural formula of the boron compound is represented by general formula (2):

wherein R is ¹ -R ¹¹ Each independently is 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 are linked by chemically feasible joining or fusing 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 silicon; and three X in the general formula (2) are not selected to be absent at the same time;

preferably, R ¹ -R ¹¹ Any adjacent two of them form a ring, and a substituent is 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;

preferably, the substituents in the 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.

5. The boron compound according to claim 1 or 2, wherein the structural formula of the boron compound is represented by general formula (3):

wherein R is ¹ -R ¹³ Each independently is 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 are linked by chemically feasible joining or fusing to form a ring;

preferably, R ¹ -R ¹¹ Any adjacent two of them form a ring, and a substituent is 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;

preferably, the substituents in the 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.

6. The boron compound according to claim 1 or 2, characterized in that the structural formula of the boron compound is represented by the general formula (4),

wherein R is ¹ -R ²¹ Each independently 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 arylaminoAny one of oxy or R ¹ -R ¹¹ Any two adjacent of them are connected by a chemically feasible joining or fusing means to form a ring;

preferably, R ¹ -R ¹¹ Any two of which are adjacent to each other to form a ring is 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;

preferably, the substituents in the 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.

7. The boron compound according to claim 1 or 2, wherein the boron compound is selected from any one of the compounds represented by the following structural formula:

8. a luminescent material, characterized in that it comprises a boron compound according to any one of claims 1 to 7;

preferably, the mass content of the boron compound in the luminescent material is 0.1-20%;

preferably, the luminescent material further comprises a host material;

preferably, the light emitting material is selected from anthracene derivatives;

preferably, the structural formula of the anthracene derivative is as follows:

wherein Y represents an aromatic or non-aromatic cyclic substituent, and Cy2 represents an aryl group having 6 to 12 nuclear carbons;

preferably, cy2 is

9. An organic electroluminescent device prepared from the boron compound according to any one of claims 1 to 7 or the luminescent material according to claim 8.

10. The organic electroluminescent device according to claim 9, wherein a light-emitting layer of the organic electroluminescent device comprises the boron compound or the light-emitting material.

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