Boron-nitrogen compounds and their use

Abstract

The application provides a boron-nitrogen compound and application thereof. The boron-nitrogen compound of the application is a binuclear BN derivative containing a carbazole skeleton, the effective red shift of the BN derivative spectrum is realized through a binuclear strategy, and the binuclear boron-nitrogen compound containing the carbazole skeleton is used as a narrow-spectrum light-emitting material to prepare a light-emitting layer of an organic electroluminescent device, so that the organic electroluminescent device prepared realizes narrow-spectrum TADF emission.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescence technology and relates to a boron nitrogen compound and its applications. Background Technology

[0002] Organic optoelectronic materials are a class of organic materials that possess properties such as the generation, conversion, and transmission of photons and electrons. Currently, the controllable optoelectronic properties of organic optoelectronic materials have been applied to organic light-emitting diodes (OLEDs), organic photovoltaics (OPVs), organic field-effect transistors (OFETs), and even organic lasers. In recent years, OLEDs have become a very popular new type of flat panel display product both domestically and internationally. OLED displays feature self-emissive characteristics, wide viewing angle, short response time, high luminous efficiency, wide color gamut, low operating voltage, thin panels, the ability to manufacture large-size flexible panels, and low cost, earning them the reputation as the star flat panel display product of the 21st century.

[0003] The history of organic electroluminescence can be traced back to the report by Bernanose et al. in 1953 (see Papkovski D.B. Sens. and Achuators B., 1995, 29, 213). About ten years later, in 1963, Pope et al. at New York University observed the fluorescence emission of anthracene by applying a voltage to anthracene crystals (see M. Pope, H. Kallmann and P. Magnante, J. Chem. Phys., 1963, 38, 2042). In 1987, CWTang et al. of Kodak Corporation in the United States used ultrathin film technology, employing aromatic amines with good hole transport as the hole transport layer, an aluminum complex of 8-hydroxyquinoline as the light-emitting layer, and indium tin oxide (ITO) thin films and metal alloys as the anode and cathode, respectively, to fabricate a light-emitting device. This device achieved a brightness of 1000 cd / m² at a driving voltage of 10V. 2The device emitted green light with an efficiency of 1.5 lm / W (see C.T. Tang and S.A. Van Slyke, Appl. Phys. Lett., 1987, 51, 913). This breakthrough led to the rapid and in-depth development of organic electroluminescence research worldwide. In 1990, Burroughes et al. of Cambridge University proposed the first light-emitting diode based on polymer (PPV). This showed that PPV, in monolayer devices, can serve as a highly fluorescent emitting material with high luminous efficiency (see Burroughes JH, Bradley DDC, Brown A.R., Marks RN, Mackay K., Friend RH, Burns PL, Holmes AB Nature, 1990, 347, 539). In 1998, Baldo, Forrest et al. of Princeton University reported the first phosphorescent device based on electroluminescence, which in principle could have 100% internal quantum yield. (See MA Baldo, DFO' Brinetal., Nature, 1998, 395, 151). However, on the one hand, phosphorescent materials generally use precious metals such as iridium and platinum, which are expensive. On the other hand, deep blue phosphorescent materials still have problems such as chemical instability and large efficiency roll-off of devices at high current densities. Therefore, it is extremely important to develop an OLED device that can achieve high-efficiency light emission using inexpensive and stable small organic molecule materials.

[0004] In 2012, the Adachi research group at Kyushu University reported a highly efficient all-fluorescent OLED device based on the thermally activated delayed fluorescence (TADF) mechanism. (Uoyama H, Goushi K, Shizu K, et al. Highly efficient organic light-emitting diodes from delayed fluorescence[J]. Nature, 2012, 492(7428):234-238.) When the energy difference between the S1 and T1 levels of a molecule is sufficiently small, the triplet exciton can absorb thermal energy, return to the singlet state through a RISC process, and then emit fluorescence. Theoretically, the internal quantum efficiency (IQE) of such devices can reach 100%, and the external quantum efficiency (EQE) can even reach 30%, comparable to the level of phosphorescent devices. As a next-generation luminescent material, research on TADF materials is booming.

[0005] TADF molecules are primarily used as guest materials to dope wide-bandgap host materials, achieving high-efficiency thermally activated delayed fluorescence (see Q. Zhang, J. Li, K. Shizu, S. Huang, S. Hirata, H. Miyazaki, C. Adachi, J. Am. Chem. Soc. 2012, 134, 14706; H. Uoyama, K. Goushi, K. Shizu, H. Nomura, C. Adachi, Nature. 2012, 492, 234; T. Nishimoto, T. Yasuda, SY Lee, R. Kondo, C. Adachi, Mater. Horiz. 2014, 1, 264). Unlike the localized (LE) state emission of traditional fluorescent molecules, TADF emission mainly originates from the transition of ICT states, and is therefore easily affected by the vibrational and rotational motion between the donor and acceptor, resulting in a broad spectrum. While the broad spectrum is beneficial for lighting applications, it cannot meet the high color purity requirements of the display field. Since the primary application of OLEDs is in display, the narrow spectral design of TADF materials (i.e., a smaller half-width at half-maximum, FWHM) is essential. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a boron-nitrogen compound and its applications. The boron-nitrogen compound of the present invention is a binuclear BN derivative containing a carbazole-like skeleton, which aims to solve the defects of TADF luminescent molecules and achieve effective redshift of the BN derivative spectrum by constructing a binuclear strategy. The binuclear boron-nitrogen compound based on the carbazole-like skeleton involved in the present invention is used as a narrow-spectrum green light luminescent material to prepare the luminescent layer of organic electroluminescent devices. The organic electroluminescent devices prepared thereby realize narrow-spectrum TADF emission.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] On one hand, the present invention provides a boron-nitrogen compound having the structure shown in Formula I or Formula II:

[0009]

[0010]

[0011] R1 and R2 are independently H, C1-C16 alkyl, C6-C12 aryl, or C5-C12 heteroaryl.

[0012] R mH, D (deuterium), fluorine, CN, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, C6-C14 aryl substituted with one or more Ra, 5- to 18-membered heteroaryl, substituted with one or more R a Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R a Substituted diphenylamino group, triphenylamino group, or group with one or more R a Substituted triphenylamine group;

[0013] Each occurrence of Ra is independently D (deuterium), fluorine, CN, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, C6-C14 aryl substituted with one or more Rb, 5- to 18-heteroaryl, or substituted with one or more Rb. b Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R b Substituted diphenylamino group, triphenylamino group, or group with one or more R b Substituted triphenylamine group;

[0014] R b Each time it appears independently as D (deuterium), fluorine, CN, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, C6-C14 aryl substituted with one or more Rc, 5- to 18-membered heteroaryl, substituted with one or more Rc c Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R c Substituted diphenylamino group, triphenylamino group, or group with one or more R c Substituted triphenylamine group;

[0015] R c Each time it appears independently as D (deuterium), fluorine, CN, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, C6-C14 aryl substituted with one or more Rd, 5- to 18-membered heteroaryl, substituted with one or more Rd d Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R d Substituted diphenylamino group, triphenylamino group, or group with one or more R d Substituted triphenylamine group;

[0016] R d Each time it appears, it is independently D (deuterium), fluorine, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, or is affected by one or more R groups. e Substituted C6-C14 aryl groups;

[0017] R e Each time it appears, it is independently D (deuterium), fluorine, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, or C6-C14 aryl.

[0018] The alkyl, alkoxy, cycloalkyl, aryl, and heteroaryl groups are optionally substituted with one or more substituents selected from the following: halogen, -CN, C1-C12 alkyl, C1-C12 alkoxy, C1-C12 haloalkyl, C2-C6 alkenyl, C3-C10 cycloalkyl, C6-C14 aryl, and 5- to 18-membered heteroaryl.

[0019] In one implementation, the R m It is H, D (deuterium), fluorine, C1-C12 alkyl, C1~C 12 Alkoxy, C3-C 10 cycloalkyl, C6-C 14 Aryl group, with at least one C1-C 12 Alkyl-substituted C6-C 14 Aryl group, with at least one C1-C 12 Alkoxy-substituted aryl, diphenylamino, triphenylamino, or alkyl ... 12 Alkyl-substituted triphenylamine group, with at least one C1-C 12 Alkyl-substituted diphenylamino group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group.

[0020] In one implementation, the R a Each time it appears, it is independently D (deuterium), fluorine, or C1 to C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, C6-C 14 Aryl group, with at least one C1-C 12 Alkyl-substituted C6-C 14 Aryl group, with at least one C1-C 12 Alkoxy-substituted phenyl, diphenylamino, or alkyl-substituted phenyl group with at least one C1-C 12 Alkyl-substituted diphenylamino group, triphenylamino group, or group with at least one C1-C 12 Alkyl-substituted triphenylamine group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group.

[0021] In one implementation, the R b Each time it appears, it is independently D (deuterium), fluorine, or C1 to C2. 12 Alkyl, C1-C 12Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, diphenylamino, or alkyl-substituted phenyl group with at least one C1-C 12 Alkyl-substituted diphenylamino group, triphenylamino group, or group with at least one C1-C 12 Alkyl-substituted triphenylamine group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group.

[0022] In one implementation, the R c Each time it appears, it is independently D (deuterium), fluorine, or C1 to C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, diphenylamino, or alkyl-substituted phenyl group with at least one C1-C 12 Alkyl-substituted diphenylamino group, triphenylamino group, or group with at least one C1-C 12 Alkyl-substituted triphenylamine group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group.

[0023] In one implementation, the R d Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, C6-C 14 Aryl group, with at least one C1-C 12 Alkyl-substituted C6-C 14 Aryl group, with at least one C1-C 12 Alkoxy-substituted C6-C 14 Aryl.

[0024] In one implementation, the R m The following are compounds: H, D (deuterium), fluorine, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, hexyl, octyl, decyl. Methoxy, ethoxy, butoxy, hexoxy Cyclohexyl, adamantyl, phenyl, 4-methyl-phenyl, 4-ethyl-phenyl, 4-propyl-phenyl, 4-isopropylphenyl, 4-n-butylphenyl The wavy lines represent the connection sites of the functional groups.

[0025] In some preferred embodiments, the R m H, methyl, phenyl, The wavy lines represent the connection sites of the functional groups.

[0026] In one embodiment, R1 and R2 are independently H, methyl, ethyl, phenyl, pyridyl, or...

[0027] In one embodiment of the present invention, the boron nitrogen compound is any one of the following compounds:

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041] The basic synthetic process route of the boron nitrogen compounds involved in this invention is as follows:

[0042]

[0043] in:

[0044]

[0045] Raw material B-1 is Raw material B-II is Where X is a halogen, preferably bromine.

[0046] On the other hand, the present invention provides an organic electroluminescent material, wherein the organic electroluminescent material comprises the boron nitrogen compound as described above.

[0047] On the other hand, the present invention provides an organic electroluminescent device comprising an anode and a cathode and an organic thin film layer disposed between the anode and the cathode, the organic thin film layer comprising a light-emitting layer, an optional hole injection layer, an optional hole transport layer, an optional electron transport layer, and an optional electron injection layer, wherein at least one of the light-emitting layer, the electron injection layer, the electron transport layer, the hole transport layer, and the hole injection layer comprises a boron nitrogen compound as described above.

[0048] In this invention, the boron nitride compound having the structure shown in Formula I or Formula II can be used as a functional material in at least one of the light-emitting layer, electron injection layer, electron transport layer, hole transport layer, and hole injection layer of an organic electroluminescent device.

[0049] In one embodiment, the organic electroluminescent device of the present invention may further include an optional hole blocking layer, an optional electron blocking layer, and an optional capping layer, etc.

[0050] In one embodiment, the organic electroluminescent device has, for example... Figure 1 The structure shown is as follows: 1 is the ITO anode, 2 is the hole injection layer, 3 is the hole transport layer, 4 is the light-emitting layer, 5 is the electron transport layer, 6 is the electron injection layer, and 7 is the metal cathode.

[0051] In one embodiment, the boron nitride compound having the structure shown in Formula I or Formula II is used to prepare the light-emitting layer in an organic electroluminescent device.

[0052] In one embodiment, the organic electroluminescent device further includes a substrate, and an anode layer, an organic light-emitting functional layer, and a cathode layer sequentially formed on the substrate; the organic light-emitting functional layer includes a light-emitting layer containing the boron nitrogen compound as described above, and may also include any one or a combination of multiple of a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

[0053] On the other hand, the present invention provides an organic electroluminescent composition comprising a boron nitride compound of the structure shown in Formula I or Formula II as described above, and a host material, which are used as doping materials;

[0054] Preferably, the host material is a material with electron transport capability and / or hole transport capability, and its triplet excited state energy is higher than or equal to the triplet excited state energy of the doped material.

[0055] In one embodiment of the present invention, the host material in the organic electroluminescent composition is a carbazole derivative and / or a carbline derivative as shown in formulas (H-1) to (H-6).

[0056]

[0057] X1, Y1, and Z1 are CH or N, and at most one of X1, Y1, and Z1 is N.

[0058] Where R 1H and R 2H Independently, it can be any of the following groups:

[0059]

[0060] Where X1, Y1, and Z1 are CH or N, and at most one of X1, Y1, and Z1 is N;

[0061] Where R aH and R bH Independent of H, C1-C 20 Alkyl, C1-C 20 Alkoxy, C6-C 20 Aryl, C1-C 20 Alkyl-substituted C6-C 20 Aryl or C1-C 20 Alkoxy-substituted C6-C 20 Aryl.

[0062] In one embodiment of the present invention, the organic electroluminescent composition preferably contains 0.3-30.0 wt% (by weight) of a boron nitride compound with the structure shown in Formula I or Formula II as described above as a dopant material, and the remaining 99.7-70.0 wt% is a host material composed of one or two compounds of Formula (H-1) to (H-6).

[0063] In one embodiment of the present invention, the main material contains two compounds of formulas (H-1) to (H-6), and the weight ratio of the two compounds is 1:5 to 5:1, for example 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, etc.

[0064] In one embodiment of the present invention, the host material in the organic electroluminescent composition is one or two of compounds H1-1 to H1-427.

[0065] In one embodiment of the present invention, the organic electroluminescent composition contains 0.3-30.0 wt% (by weight) of a boron nitrogen compound with the structure shown in Formula I or Formula II as described above, and the remaining 99.7-70.0 wt% is one or two compounds selected from H1-1 to H1-427.

[0066] In a preferred embodiment of the present invention, the organic electroluminescent composition contains two compounds of formulas H1-1 to H1-427 as main materials, and the weight ratio of the two compounds is 1:5 to 5:1, for example, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, etc.

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087] In one embodiment of the present invention, the doping material in the organic electroluminescent composition is any one of the boron nitride compounds with the structure shown in Formula I or Formula II (content of 0.3wt-30.0wt%); the host material (content of 99.7wt-70.0wt%) is composed of any one of the compounds shown in Formula Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A or Trz6-A and any one of the compounds shown in Formulas H-1 to H-6.

[0088] In a preferred embodiment, the weight ratio of the compounds shown in Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A or Trz6-A to the compounds shown in H-1, H-2, H-3, H-4, H-5 or H-6 in the main material is from 1:5 to 5:1, for example, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, etc.

[0089]

[0090] Where R 1a R 1b R 2a R 2b R 3a and R 3b One or two of them are independent as R Tz The remaining elements are, independently and identically, hydrogen, deuterium, C1-C8 alkyl, C1-C8 alkoxy, or C6-C4. 18 Aryl, C1-C8 alkyl substituted C6-C 18 Aryl or C1-C8 alkoxy-substituted C6-C 18 aryl; R Tz It can be any of the substituents shown in the following formula:

[0091]

[0092]

[0093]

[0094] The asterisk represents the linking site of the functional group.

[0095] In one embodiment of the present invention, the doping material in the organic electroluminescent composition is any one of the boron nitrogen compounds with the structure shown in Formula I or Formula II as described above (content of 0.3wt-30.0wt%); the host material (content of 99.7wt-70.0wt%) is composed of any one of the compounds shown in Formula TRZ-1 to TRZ-76 and any one of the carbazole or carboline derivatives shown in Formula H1-1 to H1-427.

[0096] In a preferred embodiment, the weight ratio of the compound represented by formula TRZ-1 to TRZ-76 in the main material to the carbazole or carboline derivative is 1:5 to 5:1, for example, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, etc.

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] On the other hand, the present invention provides an organic electroluminescent material comprising the organic electroluminescent composition as described above.

[0103] On the other hand, the present invention provides an organic electroluminescent device comprising an anode and a cathode and an organic thin film layer disposed between the anode and the cathode, the organic thin film layer comprising a light-emitting layer, an optional hole injection layer, an optional hole transport layer, an optional electron transport layer, and an optional electron injection layer, wherein at least one of the light-emitting layer, the electron injection layer, the electron transport layer, the hole transport layer, and the hole injection layer comprises the organic electroluminescent composition as described above.

[0104] In this invention, the organic electroluminescent composition can be used as a functional material in at least one of the following layers of an organic electroluminescent device: the light-emitting layer, the electron injection layer, the electron transport layer, the hole transport layer, and the hole injection layer.

[0105] In one embodiment of the present invention, the material of the light-emitting layer in the organic electroluminescent device comprises the organic electroluminescent composition as described above.

[0106] In one embodiment of the present invention, the organic electroluminescent composition is a light-emitting layer, and the light-emitting principle of the light-emitting layer is based on energy transfer from the host material to any compound shown in Formula I or Formula II or carrier capture of the light-emitting material itself.

[0107] In one embodiment of the present invention, the organic electroluminescent composition is a light-emitting layer; the host material in the organic electroluminescent composition may be a carbazole derivative and / or a carbline derivative as shown in formulas (H-1) to (H-6). In a preferred embodiment, the organic electroluminescent composition contains 0.3-30.0 wt% of any compound shown in formula I or formula II, and the remaining 99.7-70.0 wt% is a host composed of 1-2 compounds from formulas (H-1) to (H-6). For example, when the host contains two compounds from formulas (H-1) to (H-6), the weight ratio of the two compounds is 1:5 to 5:1.

[0108] In one embodiment of the present invention, the organic electroluminescent composition is a light-emitting layer; the main material in the composition is one or two compounds selected from H1-1 to H1-427. In a preferred embodiment, the organic electroluminescent composition contains 0.3-30.0 wt% of any compound represented by Formula I or Formula II, and the remaining 99.7-70.0 wt% is one or two compounds selected from H1-1 to H1-427. For example, when the composition contains two compounds selected from H1-1 to H1-427, the weight ratio of the two compounds is 1:5 to 5:1.

[0109] In one embodiment of the present invention, the organic electroluminescent composition is a light-emitting layer; the doping material in the organic electroluminescent composition is any compound of formula I or formula II (content of 0.3wt-30.0wt%); the host material (content of 99.7wt-70.0wt%) is composed of any one of compounds of formula Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A or Trz6-A and any one of compounds of formulas H-1 to H-6. For example, in the host material, the weight ratio between compounds of formula Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A or Trz6-A and compounds of formulas H-1, H-2, H-3, H-4, H-5 or H-6 is 1:5 to 5:1.

[0110] In one embodiment of the present invention, the organic electroluminescent composition is a light-emitting layer; the dopant material in the organic electroluminescent composition is any compound of formula I or formula II (content of 0.3wt-30.0wt%); the host material (content of 99.7wt-70.0wt%) is composed of any one of the 1,3,5-triazine derivatives of formulas TRZ-1 to TRZ-76 and any one of the carbazole or carboline derivatives of formulas H1-1 to H1-427. For example, in the host material, the weight ratio between the 1,3,5-triazine derivative and the carbazole or carboline derivative is 1:5 to 5:1.

[0111] In one embodiment of the present invention, the organic electroluminescent composition is a light-emitting layer; the doping material in the organic electroluminescent composition is any one of the compounds shown in formula BN1 to BN180 (content of 0.3wt-30.0wt%); the host material (content of 99.7wt-70.0wt%) is composed of any one of the compounds of formula Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A, and Trz6-A and any one of the carbazole or carboline derivatives shown in formulas H1-1 to H1-427. For example, in the host material, the weight ratio between the compounds of formula Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A, and Trz6-A and the carbazole or carboline derivatives shown in formulas H1-1 to H1-427 is 1:5 to 5:1.

[0112] In one embodiment of the present invention, the organic electroluminescent device further includes a substrate, and an anode layer, an organic light-emitting functional layer, and a cathode layer sequentially formed on the substrate; the organic light-emitting functional layer includes a light-emitting layer containing the organic electroluminescent composition as described above, and may also include any one or a combination of at least two of a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

[0113] On the other hand, the present invention provides an application of the described organic electroluminescent device in an organic electroluminescent display or an organic electroluminescent lighting source.

[0114] Terminology Explanation

[0115] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0116] As used herein, the terms “containing” or “including (comprise)” can be open-ended, semi-closed, or closed. In other words, the terms also include “consistently made of” or “composed of”.

[0117] Group definition

[0118] In this specification, groups and their substituents may be selected by those skilled in the art to provide stable structural moieties and compounds. When a substituent is described by a conventional chemical formula written from left to right, the substituent also includes chemically equivalent substituents obtained when the structural formula is written from right to left.

[0119] The chapter headings used in this specification are for organizational purposes only and should not be construed as limiting the subject matter. All references or portions thereof cited in this invention, including but not limited to patents, patent applications, articles, books, user manuals, and papers, are incorporated herein by reference in their entirety.

[0120] Unless otherwise specified, all technical and scientific terms used herein have the standard meaning in the field to which the claimed subject matter pertains. Where multiple definitions exist for a term, the definition herein shall prevail.

[0121] It should be understood that the singular forms used in this invention, such as "a," include plural references unless otherwise specified. Furthermore, the term "comprising" is an open-ended limitation, not a closed one; that is, it includes the contents specified in this invention but does not exclude other aspects.

[0122] Unless otherwise stated, this invention employs traditional methods of mass spectrometry and elemental analysis, and the steps and conditions can be referred to conventional operating procedures and conditions in the field.

[0123] Unless otherwise specified, this invention employs standard nomenclature and standard laboratory procedures and techniques of analytical chemistry, organic synthetic chemistry, and optics. In some cases, standard techniques are used for chemical synthesis, chemical analysis, and performance testing of light-emitting devices.

[0124] The compounds of the present invention may contain atomic isotopes in non-natural proportions on one or more atoms constituting the compound. For example, the compounds may be labeled with radioactive isotopes, such as deuterium (₂H). All variations in the isotopic composition of the compounds of the present invention, regardless of radioactivity, are included within the scope of the present invention.

[0125] In this invention, unless otherwise specified, the number of "substitutes" can be one or more; when there are multiples, it means two or more, such as two, three, or four. Furthermore, when there are multiple "substitutes," the "substitutes" can be the same or different. In this invention, unless otherwise specified, the position of the "substitute" can be arbitrary.

[0126] In this invention, as a group or part of other groups (e.g., in halogen-substituted alkyl groups), the term "alkyl" means a saturated aliphatic hydrocarbon group comprising branched and straight chains having a specified number of carbon atoms. For example, C1-C1... 20 Alkyl groups include straight-chain or branched alkyl groups having 1 to 20 carbon atoms. As defined in "C1-C6 alkyl," it includes groups having 1, 2, 3, 4, 5, or 6 carbon atoms in a straight-chain or branched structure. For example, in this invention, each of the C1-C6 alkyl groups is independently methyl, ethyl, propyl, butyl, pentyl, or hexyl; wherein, propyl is a C3 alkyl group (including isomers, such as n-propyl or isopropyl); butyl is a C4 alkyl group (including isomers, such as n-butyl, sec-butyl, isobutyl, or tert-butyl); pentyl is a C5 alkyl group (including isomers, such as n-pentyl, 1-methyl-butyl, 1-ethyl-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, isopentyl, tert-pentyl, or neopentyl); and hexyl is a C6 alkyl group (including isomers, such as n-hexyl or isohexyl).

[0127] As used herein, the term "alkoxy" refers to an alkyl group as defined above, which is connected via an oxygen bond (-O-).

[0128] In this invention, as a group or part of other groups, the term "Cn-m aryl" refers to a monocyclic or polycyclic aromatic group (with only carbon atoms as ring atoms) having n to m ring carbon atoms, possessing at least one carbon ring with a conjugated π-electron system. Examples of the aforementioned aryl unit include phenyl, naphthyl, indene, azulel, fluorenyl, phenanthryl, or anthraceneyl. In one embodiment, the aryl group is preferably a C6-14 aryl group, such as phenyl and naphthyl, more preferably phenyl.

[0129] In this invention, as a group or part of other groups, the term "nm-aryl" refers to an aromatic group whose ring atoms comprise one or more (e.g., 1, 2, 3, and 4) heteroatoms selected from nitrogen, oxygen, and sulfur, having n to m ring atoms. The heteroaryl group is a monocyclic, bicyclic, tricyclic, or tetracyclic system, wherein at least one ring is an aromatic ring. Heteroaryl groups within this definition include, but are not limited to: acridinel, carbazolyl, cyclophosphinyl, quinoxalinyl, pyrazolyl, indolyl, benzotriazolyl, furanyl, thiophene, benzothiophene, benzofuranyl, quinolinyl, isoquinolinyl, oxazolyl, isoxazolyl, pyrazinyl, pyridinyl, pyrimidinel, pyrroleyl, tetrahydroquinoline, imidazolyl, triazolyl, tetrazolyl, thiazolyl, isothiazolyl, furazolyl, thiadiazolyl, etc. Oxadiazole, pyridinyl, pyrazinyl, pyridazinyl, pyrimidinyl, triazinyl, purine, pteridinyl, naphridinyl, quinazolinyl, phthalazinyl, imidazopyridinyl, imidazothiazolyl, imidazooxazinyl, benzothiazolyl, benzooxazinyl, benzoimidazolyl, isoindolyl, indazole, pyrrolopyridinyl, thienopyridinyl, furanolopyridinyl, benzothiadiazole, benzooxadiazole, pyrrolopyrimidinyl, thienofuranyl. In one embodiment, as preferred examples of "5- to 18-membered heteroaryl groups", furanyl, thienoyl, pyrrololyl, imidazolyl, thiazolyl, pyrazolyl, oxazolyl, isoxazolyl, isothiazolyl, pyridinyl, pyrimidinyl, and carbazoleyl are listed, more preferably carbazoleyl.

[0130] As used herein, the term Cn-Cm cycloalkyl refers to a monocyclic or polycyclic alkyl group having n to m carbon atoms, such as 3-C10 cycloalkyl and C3-C6 cycloalkyl. Examples include adamantyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and dicycloheptyl. In one embodiment, the C3-C10 cycloalkyl group is preferably adamantyl or cyclohexyl.

[0131] In this invention, the defined carbon number range of the group refers to any integer number of carbon atoms included within the defined range, such as C1 to C2. 20 This refers to the fact that the number of carbon atoms in the stated group can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, C3-C. 10 This means that the number of carbon atoms in the group can be 3, 4, 5, 6, 7, 8, 9 or 10, and the range of carbon atoms for other groups can be deduced similarly.

[0132] Without violating common sense in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention. All reagents and raw materials used in the present invention are commercially available.

[0133] Compared with the prior art, the present invention has the following beneficial effects:

[0134] The boron-nitrogen compound of the present invention employs a dual-core strategy to achieve an effective redshift of the BN derivative spectrum. The dual-core boron-nitrogen compound containing a carbazole skeleton of the present invention has a narrow spectrum and is used as a narrow-spectrum luminescent material to prepare the luminescent layer of an organic electroluminescent device. The organic electroluminescent device prepared thereby achieves narrow-spectrum TADF emission and makes the external quantum efficiency of electroluminescence of the device as high as 24% or more. Attached Figure Description

[0135] Figure 1 The diagram shows the device structure used in Examples 1-2, where 1 is the ITO anode, 2 is the hole injection layer, 3 is the hole transport layer, 4 is the light-emitting layer, 5 is the electron transport layer, 6 is the electron injection layer, and 7 is the metal cathode.

[0136] Figure 2 Compound BN41 in toluene solution (concentration: 1 x 10⁻⁶) -5 The photoluminescence spectrum of M).

[0137] Figure 3 Compound BN50 in toluene solution (concentration: 1 x 10⁻⁶) -5 The photoluminescence spectrum of M). Detailed Implementation

[0138] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0139] In one embodiment of the present invention, the raw materials used to synthesize the compounds shown in Formulas I and II, except for the substrate 2-bromo-1,3-difluorobenzene, are as follows:

[0140] The specific raw materials used are as follows:

[0141]

[0142]

[0143] Mass spectrometry data (MS) of molecules with relative molecular weights below 1000 were obtained using a Thermo Fisher ITQ1100 ion trap gas chromatograph-mass spectrometer, while MS data of molecules with relative molecular weights above 1000 were obtained using a Bruker Autoflex Speed ​​matrix-assisted laser desorption / ionization time-of-flight mass spectrometer. Elemental analysis of the final products was performed using an Elemental Analysis Flash EA1112 instrument.

[0144] The UV-Vis absorption spectra of the sample films were measured using a PerkinElmer LAMBDA 35 UV-Vis spectrophotometer. Fluorescence spectra were measured using a Shimadzu RF-5301PC fluorometer, with the excitation wavelength being the maximum absorption wavelength.

[0145] Synthesis Examples

[0146] Taking compound BN41 as an example, the specific experimental details of the synthesis examples are explained below:

[0147] In the first step, 60 ml of a 250 ml double-necked round-bottom flask containing 15.2 g of 3,6-bis(4-(tert-butyl)phenyl)-9H-carbazole (35.2 mmol), 10.24 g of cesium carbonate (52.8 mmol), and 3.26 g of 2-bromo-1,3-difluorobenzene (17.0 mmol) was added, followed by 80 ml of anhydrous DMF solution. The reaction mixture was stirred at 160 °C for 24 hours, then cooled to room temperature and poured into ice water (2 L). The white solid was filtered off, dried under vacuum, and then further purified by column chromatography using a mixed eluent of dichloromethane / petroleum ether (1:3) to give 13 g of intermediate 1a as a white solid (79% yield).

[0148] In the second step, under a nitrogen atmosphere, 19.4 mL of a hexane solution of tert-butyllithium (25.2 mmol) was slowly added to a 100 mL tert-butylbenzene solution containing 12.8 g of intermediate 1a (12.6 mmol) (-30 °C). The mixture was slowly heated to 60 °C and stirred for 2 hours. Hexane was then removed under vacuum, and the mixture was cooled to -30 °C. 2.4 mL of boron tribromide (6.3 mmol) was added, and the reaction mixture was stirred at room temperature for 1 hour. Then, 15.6 mL of N,N-diisopropylethylamine (91.1 mmol) was added at 0 °C, and the reaction mixture was heated to 130 °C and stirred for 5 hours, then cooled to room temperature. 5 mL of methanol was added to the reaction mixture to quench any residual BBr3. The reaction mixture was concentrated under vacuum and purified by column chromatography using a dichloromethane / petroleum ether (1:2) mixture as eluent to give 4.2 g of a bright green solid intermediate 1b (34% yield).

[0149] In the third step, at room temperature, 4.1 g of intermediate 1b (6.5 mmol) and 1.7 g of pinacol diborate (13 mmol) were added to tetrahydrofuran (60 mL). The mixture was bubbled under nitrogen for 10 minutes, and then 34.9 mg of 4,4'-di-tert-butyl-2,2'-bipyridine (0.13 mmol) and 43.1 mg of methoxy(cyclooctadiene)iridium dimer (0.065 mmol) were added under high-flow-rate nitrogen. After stirring for 10 minutes, the mixture was heated to reflux and stirred for 24 hours. After the reaction system cooled to room temperature, it was directly concentrated under reduced pressure and purified by column chromatography to obtain 4.17 g of intermediate 1c (yield 85%).

[0150] In the fourth step, 4.5 g of intermediate 1c (6 mmol), 2.0 g of potassium carbonate (15 mmol), and 0.8 g of B1 (2.5 mmol) were added to tetrahydrofuran (35 ml), followed by 8 ml of distilled water. The mixture was bubbled with nitrogen for 5 minutes, and 207.9 mg of tetratriphenylphosphine palladium (0.18 mmol) was added under a high nitrogen flow. The mixture was heated to reflux and stirred for 24 hours. After the system cooled to room temperature, it was concentrated under reduced pressure and purified by column chromatography to obtain 1.5 g of the final product BN41 (yield 40%).

[0151] Other compounds were prepared using the same synthetic method as BN41. The specific raw materials used and the elemental analysis (C, H and N percentages in the compounds), mass spectrometry molecular weights, and synthesis reaction yields of the products are shown in Table 1.

[0152] Table 1

[0153]

[0154]

[0155]

[0156]

[0157]

[0158]

[0159] Examples of electroluminescent devices

[0160] The following are some representative examples of electroluminescent devices. The molecular structures of some materials involved in these device examples are as follows:

[0161]

[0162] The following are examples of electroluminescent devices fabricated using the materials of the present invention, and the specific device fabrication process is as follows:

[0163] (1) Substrate treatment: Transparent ITO glass was used as the substrate material for device fabrication. It was first ultrasonically treated with 5% ITO cleaning solution for 30 minutes, then sequentially ultrasonically washed with distilled water (twice), acetone (twice), and isopropanol (twice). Finally, the ITO glass was stored in isopropanol. Before each use, the surface of the ITO glass was carefully wiped with acetone and isopropanol cotton balls, rinsed with isopropanol, dried, and then plasma-treated for 5 minutes before use. Device fabrication was completed using a combination of spin coating and vacuum evaporation processes.

[0164] (2) Preparation of hole injection layer and hole transport layer: First, a 20 nm thick layer of PEDOT:PSS (poly(3,4-ethylenedioxythiophene):polystyrene sulfonate) was spin-coated on the ITO surface as a hole injection layer. Then, a 50 nm thick layer of Poly-HTL was spin-coated on the hole injection layer as a hole transport layer. Then, the ITO glass with the hole injection layer and the hole transport layer was placed in a glove box under nitrogen protection and annealed at 200 °C for 30 minutes (to allow Poly-HTL to crosslink).

[0165] (3) Preparation of luminescent layer: The main material and the luminescent material are dissolved in xylene at a ratio of 97wt%:3wt% (wt% is the weight percentage concentration) to prepare a solution with a concentration of 2wt%. The luminescent layer is prepared by spin coating using the prepared solution. The thickness of the luminescent layer is 50nm.

[0166] (4) Fabrication of electron transport layer, electron injection layer and metal electrode: The electron transport layer, electron injection layer and metal electrode are fabricated using a vapor deposition process. When the vacuum degree of the vacuum deposition system reaches 5×10 -4 Vapor deposition begins when the pressure is below a certain level (Pa). The deposition rate is measured using a SAINS film thickness gauge. An organic electron transport layer, a LiF electron injection layer, and a metal Al electrode are sequentially deposited on the light-emitting layer using a vacuum evaporation process (see the following effect example for specific device structure). The deposition rate of the organic material is [missing information - likely a specific value]. The deposition rate of LiF is The deposition rate of Al is

[0167] Device Examples A1-A90

[0168] Organic electroluminescent devices (structure as shown in device embodiments A1-A90) Figure 1In the example shown, PEDOT:PSS is used as the hole injection layer, Poly-HTL is used as the hole transport layer, H1-48 is used as the host material in the light-emitting layer, BN-1 to BN-618 are used as doped light-emitting materials (doping concentration of 2wt%), TmPyPB is used as the electron transport material, LiF is used as the electron injection layer, and Al is used as the metal cathode. The structure of the organic electroluminescent device in the example is [ITO / PEDOT:PSS (20nm) / Poly-HTL (50nm) / / H1-33+3wt%BNn / TRZ-8 (50nm) / LiF (1nm) / Al (100nm)].

[0169] The device's current, voltage, luminance, and emission spectrum characteristics were simultaneously tested using a Photo Research PR 655 spectrophotometer and a Keithley K 2400 digital source meter system. Performance testing was conducted at room temperature and under ambient conditions. The external quantum efficiency (EQE) of the device was calculated based on the Lambaugh distribution of emission, using current density, luminance, and electroluminescence spectrum combined with the apparent function.

[0170] The test results are shown in Table 2.

[0171] Table 2

[0172]

[0173]

[0174]

[0175]

[0176] The implementation data of the electroluminescent device listed in Table 2 prove that the luminescent material provided by the present invention can be used to prepare high-efficiency organic electroluminescent devices, and the electroluminescence spectrum has narrow band characteristics, with a half-width of less than 60 nm and an external quantum efficiency of more than 24.4%.

[0177] Device Examples B1-B90

[0178] In the organic electroluminescent devices of device embodiments B1-B90, the organic electroluminescent device of effect embodiment 2 (structure as shown) Figure 1In the example shown, PEDOT:PSS is used as the hole injection layer, Poly-HTL is used as the hole transport layer, a mixture of H1-33 and TRZ-8 is used as the host material in the light-emitting layer (the weight mixing ratio of H1-33 and TRZ-8 is 1:1), BNn is used as the doped light-emitting material (doping concentration is 3wt%), TRZ-8 is used as the electron transport material, LiF is used as the electron injection layer, and Al is used as the metal cathode. The structure of the organic electroluminescent device in the example is [ITO / PEDOT:PSS (20nm) / Poly-HTL (50nm) / H1-33:TRZ-8+3wt%BNn / TRZ-8 (50nm) / LiF (1nm) / Al (100nm)].

[0179] Similarly, the device performance was tested by measuring the peak position and full width at half maximum (FWHM) of its electroluminescence spectrum, as well as the external quantum efficiency of electroluminescence. The test results are shown in Table 3.

[0180] Table 3

[0181]

[0182]

[0183]

[0184]

[0185] The implementation data of the electroluminescent device listed in Table 3 prove that the luminescent material provided by the present invention can be used to prepare high-efficiency organic electroluminescent devices, and the electroluminescence spectrum has narrow band characteristics, with a half-width of less than 60 nm and an external quantum efficiency of more than 26.5%.

[0186] Figure 2 Compound BN41 in toluene solution (concentration: 1 x 10⁻⁶) -5 The photoluminescence spectrum in M) is derived from Figure 2 As can be seen, the emission peak position is 497nm and the full width at half maximum (FWHM) is 22nm.

[0187] Figure 3 Compound BN50 in toluene solution (concentration: 1 x 10⁻⁶) -5 The photoluminescence spectrum in M) is derived from Figure 3 As can be seen, the emission peak position is 490nm and the full width at half maximum (FWHM) is 23nm.

[0188] The applicant declares that the boron-nitrogen compounds and their applications are illustrated through the above embodiments, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A boron-nitrogen compound having the structure shown in Formula I or Formula II: R1 and R2 are independently H, C1-C16 alkyl, C6-C12 aryl, or C5-C12 heteroaryl; R m H, deuterium, fluorine, CN, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, C6-C14 aryl substituted with one or more Ra, 5- to 18-membered heteroaryl, substituted with one or more R a Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R a Substituted diphenylamino group, triphenylamino group, or group with one or more R a Substituted triphenylamine group; Each occurrence of Ra is independently of deuterium, fluorine, CN, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, C6-C14 aryl substituted with one or more Rb, 5- to 18-heteroaryl, or substituted with one or more Rb. b Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R b Substituted diphenylamino group, triphenylamino group, or group with one or more R b Substituted triphenylamine group; R b Each occurrence is independently of deuterium, fluorine, CN, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, C6-C14 aryl substituted with one or more Rc, 5- to 18-membered heteroaryl, or substituted with one or more Rc. c Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R c Substituted diphenylamino group, triphenylamino group, or group with one or more R c Substituted triphenylamine group; R c Each occurrence is independently of deuterium, fluorine, CN, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, and is accompanied by one or more R. d Substituted C6-C14 aryl, 5- to 18-membered heteroaryl, and substituted with one or more R d Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R d Substituted diphenylamino group, triphenylamino group, or group with one or more R d Substituted triphenylamine group; R d Each time it appears, it is independently deuterium, fluorine, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, C6-C14 aryl, or is affected by one or more R groups. e Substituted C6-C14 aryl groups; R e Each time it appears, it is independently deuterium, fluorine, C1-C12 alkyl, C1-C12 alkoxy, C3-C10 cycloalkyl, or C6-C14 aryl; The alkyl, alkoxy, cycloalkyl, aryl, and heteroaryl groups are optionally substituted with one or more substituents selected from the following: halogen, -CN, C1-C12 alkyl, C1-C12 alkoxy, C1-C12 haloalkyl, C2-C6 alkenyl, C3-C10 cycloalkyl, C6-C14 aryl, and 5- to 18-membered heteroaryl.

2. The boron-nitrogen compound according to claim 1, characterized in that, The R m It is H, D (deuterium), fluorine, C1-C12 alkyl, C1~C 12 Alkoxy, C3-C 10 cycloalkyl, C6-C 14 Aryl group, with at least one C1-C 12 Alkyl-substituted C6-C 14 Aryl group, with at least one C1-C 12 Alkoxy-substituted C6-C 14 aryl, diphenylamino, with at least one C1-C 12 Alkyl-substituted diphenylamino group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group.

3. The boron-nitrogen compound according to claim 1, characterized in that, The R a Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, diphenylamino, or alkyl-substituted phenyl group with at least one C1-C 12 Alkyl-substituted diphenylamino group, triphenylamino group, or group with at least one C1-C 12 Alkyl-substituted triphenylamine group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group.

4. The boron-nitrogen compound according to claim 1, characterized in that, The R b Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, diphenylamino, or alkyl-substituted phenyl group with at least one C1-C 12 Alkyl-substituted diphenylamino group, triphenylamino group, or group with at least one C1-C 12 Alkyl-substituted triphenylamine group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group.

5. The boron-nitrogen compound according to claim 1, characterized in that, The R c Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C 12 Alkoxy-substituted phenyl, diphenylamino, or alkyl-substituted phenyl group with at least one C1-C 12 Alkyl-substituted diphenylamino group, triphenylamino group, or group with at least one C1-C 12 Alkyl-substituted triphenylamine group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group.

6. The boron-nitrogen compound according to claim 1, characterized in that, The R d Each occurrence is independent of deuterium, fluorine, and C1-C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, C6-C 14 Aryl group, with at least one C1-C 12 Alkyl-substituted C6-C 14 Aryl group, with at least one C1-C 12 Alkoxy-substituted C6-C 14 Aryl.

7. The boron-nitrogen compound according to claim 1, characterized in that, The R m The compounds are H, deuterium, fluorine, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, hexyl, octyl, decyl. Methoxy, ethoxy, butoxy, hexoxy Cyclohexyl, adamantyl, phenyl, 4-methyl-phenyl, 4-ethyl-phenyl, 4-propyl-phenyl, 4-isopropylphenyl, 4-n-butylphenyl The wavy lines represent the connection sites of the functional groups.

8. The boron-nitrogen compound according to claim 1, characterized in that, The R m H, methyl, phenyl, The wavy lines represent the connection sites of the functional groups.

9. The boron-nitrogen compound according to claim 1, characterized in that, R1 and R2 are independently H, methyl, ethyl, phenyl, pyridyl, or 10. The boron-nitrogen compound according to claim 1, characterized in that, The boron-nitrogen compound is any one of the following compounds:

11. An organic electroluminescent composition, characterized in that, It includes the boron nitride compound as a dopant material as described in any one of claims 1-10 and the host material.

12. The organic electroluminescent composition according to claim 11, characterized in that, The host material is a material with electron transport capability and / or hole transport capability, and its triplet excited state energy is higher than or equal to the triplet excited state energy of the doped material.

13. The organic electroluminescent composition according to claim 11, characterized in that, The host material in the organic electroluminescent composition is a carbazole derivative and / or a carbline derivative as shown in formulas (H-1) to (H-6): Where X1, Y1, and Z1 are CH or N, and at most one of X1, Y1, and Z1 is N; Where R 1H and R 2H Independently, it can be any of the following groups: Where X1, Y1, and Z1 are CH or N, and at most one of X1, Y1, and Z1 is N; Where R aH and R bH Independent of H, C1-C 20 Alkyl, C1-C 20 Alkoxy, C6-C 20 Aryl, C1-C 20 Alkyl-substituted C6-C 20 Aryl or C1-C 20 Alkoxy-substituted C6-C 20 Aryl.

14. The organic electroluminescent composition according to claim 13, characterized in that, The organic electroluminescent composition contains 0.3-30.0 wt% of a boron nitrogen compound as described in any one of claims 1-10 as a dopant material, and the remaining 99.7-70.0 wt% is a host material composed of 1-2 compounds of formula (H-1) to (H-6).

15. The organic electroluminescent composition according to claim 13, characterized in that, The main material contains two compounds of formulas (H-1) to (H-6), with a weight ratio of 1:5 to 5:1 between the two compounds.

16. The organic electroluminescent composition according to claim 11, characterized in that, The host material in the organic electroluminescent composition is one or two of compounds H1-1 to H1-427; 17. The organic electroluminescent composition according to claim 16, characterized in that, The organic electroluminescent composition contains 0.3-30.0 wt% of a boron nitrogen compound as described in any one of claims 1-10, and the remaining 99.7-70.0 wt% is one or two compounds selected from compounds H1-1 to H1-427.

18. The organic electroluminescent composition according to claim 17, characterized in that, The organic electroluminescent composition contains two compounds of formulas H1-1 to H1-427 as main materials, and the weight ratio of the two compounds is 1:5 to 5:

1.

19. The organic electroluminescent composition according to claim 11, characterized in that, The doping material in the organic electroluminescent composition is any one of the boron nitrogen compounds with the structure shown in Formula I or Formula II; the main material is composed of any one of the compounds shown in Formula Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A or Trz6-A and any one of the compounds shown in Formulas H-1 to H-6. Where R 1a R 1b R 2a R 2b R 3a and R 3b One or two of them are independent as R Tz The remaining elements are, independently and identically, hydrogen, deuterium, C1-C8 alkyl, C1-C8 alkoxy, or C6-C4. 18 Aryl, C1-C8 alkyl substituted C6-C 18 Aryl or C1-C8 alkoxy-substituted C6-C 18 aryl; R Tz It can be any of the substituents shown in the following formula: The asterisk represents the linking site of the functional group.

20. The organic electroluminescent composition according to claim 19, characterized in that, The weight ratio of the compounds shown in Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A or Trz6-A to the compounds shown in H-1, H-2, H-3, H-4, H-5 or H-6 in the main material is 1:5 to 5:

1.

21. The organic electroluminescent composition according to claim 11, characterized in that, The doping material in the organic electroluminescent composition is any one of the boron nitrogen compounds with the structure shown in Formula I or Formula II as described above; the host material is composed of any one of the compounds shown in Formula TRZ-1 to TRZ-76 and any one of the carbazole or carbline derivatives shown in Formula H1-1 to H1-427.

22. The organic electroluminescent composition according to claim 21, characterized in that, The weight ratio of the compounds represented by formulas TRZ-1 to TRZ-76 in the main material to the carbazole or carboline derivative is 1:5 to 5:

1.

23. An organic electroluminescent material, characterized in that, The organic electroluminescent material includes any boron nitrogen compound as claimed in any one of claims 1-10 or any organic electroluminescent composition as claimed in any one of claims 11-22.

24. An organic electroluminescent device, characterized in that, The organic electroluminescent device comprises an anode and a cathode, and an organic thin film layer disposed between the anode and the cathode. The organic thin film layer includes a light-emitting layer, an optional hole injection layer, an optional hole transport layer, an optional electron transport layer, and an optional electron injection layer. The light-emitting layer comprises a boron nitrogen compound as described in any one of claims 1-10 or an organic electroluminescent composition as described in any one of claims 11-22.

25. The organic electroluminescent device according to claim 24, characterized in that, The organic electroluminescent device further includes an optional hole blocking layer, an optional electron blocking layer, and an optional capping layer.

26. The application of the organic electroluminescent device according to claim 24 or 25 in an organic electroluminescent display or an organic electroluminescent lighting source.

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