A boron-nitrogen compound, a preparation method and application thereof

Abstract

The present application provides a kind of boron-nitrogen compound and its preparation method and application, the boron-nitrogen compound is the binuclear boron-nitrogen derivative containing carbazole skeleton, with narrow spectrum, the present application realizes the effective red shift of BN derivative spectrum by constructing binuclear strategy, the binuclear boron-nitrogen compound containing carbazole skeleton of the present application is used as narrow spectrum luminescent material for preparing the light-emitting layer of organic electroluminescence device, and the organic electroluminescence device prepared thereby realizes narrow spectrum TADF emission.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescence technology, specifically relating to a boron nitrogen compound, its preparation method, and its application. 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 its device can reach 100%, and the external quantum efficiency (EQE) can even reach 30%, comparable to the level of phosphorescent devices. As a next-generation light-emitting 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, its preparation method, and its applications. The boron-nitrogen compound is a binuclear boron-nitrogen derivative containing a carbazole-like skeleton, exhibiting a narrow spectrum. This invention aims to overcome the defects of TADF luminescent molecules and achieves an effective redshift of the BN derivative spectrum through a binuclear construction strategy. The carbazole-like binuclear boron-nitrogen compound of the present invention is used as a narrow-spectrum green, yellow, and orange-red luminescent material to prepare the luminescent layer of organic electroluminescent devices. The organic electroluminescent devices prepared thereby achieve 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:

[0009]

[0010] Among them, R m1 and R m2 Each occurrence is independent of H, D (deuterium), fluorine, and C1-C. 20 Alkyl, C1-C 20 Alkoxy, C3-C 10 cycloalkyl, C6-C 14 aryl, with one or more R a Replacement of C6~C 14aryl, 5- to 18-membered heteroaryl, with one or more R a Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R a Substituted diphenylamine group, triphenylamine group, or group with one or more R a Substituted triphenylamine group;

[0011] 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, with one or more R b Replacement of C6~C 14 aryl, 5- to 18-membered heteroaryl, with one or more R b Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R b Substituted diphenylamine group, triphenylamine group, or group with one or more R b Substituted triphenylamine group;

[0012] R b 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, with one or more R c Replacement of C6~C 14 aryl, 5- to 18-membered heteroaryl, with one or more R c Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R c Substituted diphenylamine group, triphenylamine group, or group with one or more R c Substituted triphenylamine group;

[0013] 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, C6-C 14 aryl, with one or more R d Replacement of C6~C 14 aryl, 5- to 18-membered heteroaryl, with one or more R d Substituted 5- to 18-membered heteroaryl, diphenylamino, or substituted with one or more R d Substituted diphenylamine group, triphenylamine group, or group with one or more R dSubstituted triphenylamine group;

[0014] R d 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 or aryl group with one or more R groups e Replacement of C6~C 14 Aryl;

[0015] R e Each time it appears, it is independently D (deuterium), fluorine, or C1 to C2. 12 Alkyl, C1-C 12 Alkoxy, C3-C 10 cycloalkyl, or C6-C 14 Aryl;

[0016] The alkyl, alkoxy, cycloalkyl, aryl, or heteroaryl groups may optionally be substituted with one or more substituents selected from the following: halogen, -CN, C1-C. 12 Alkyl, C1-C 12 Alkoxy, C1-C 12 Haloalkyl, C2-C6 alkenyl, C3-C 10 cycloalkyl, C6-C 14 Aryl and 5- to 18-membered heteroaryl.

[0017] In one implementation, the R m1 and R m2 Each occurrence is independently of H, D (deuterium), fluorine, C1-C12 alkyl, or C1-C2 alkyl. 12 Alkoxy, C3-C 10 cycloalkyl, phenyl, with at least one C1-C 12 Alkyl-substituted aryl group, with at least one C1-C 12 Alkoxy-substituted aryl, diphenylamine, or alkyl groups with at least one C1-C substituted group 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.

[0018] 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, with at least one C1-C 12 Alkyl-substituted phenyl, with at least one C1-C12 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.

[0019] In one implementation, the R b 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, carbazole, triphenylamino, or compounds with at least one C1-C group 12 Alkyl-substituted triphenylamine group, with at least one C1-C 12 Alkyl-substituted carbazole group.

[0020] 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.

[0021] In one implementation, the R d 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 12Alkyl-substituted triphenylamine group, carbazole group, or group with at least one C1-C 12 Alkyl-substituted carbazole group.

[0022] In one implementation, the R m1 and R m2 Each time it appears independently, it is 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.

[0023] In one embodiment of the present invention, the boron nitrogen compound is any one of the following compounds:

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] On the other hand, the present invention provides a method for preparing the boron nitrogen compound as described above, the method comprising the following steps:

[0032] Compound 1c reacts in toluene under weakly basic conditions in the presence of iodobenzene and palladium dichloride bis(triphenylphosphine) catalysts under nitrogen protection to give the boron-nitrogen compound shown in Formula I, as follows:

[0033]

[0034] In the preparation method of boron nitrogen compounds described in this invention, the addition of the catalyst iodobenzene has a significant impact on the reaction effect. For the same reaction, without the catalyst iodobenzene, the yield is only 12-15%. However, the use of the catalyst iodobenzene can ensure a significant increase in the synthesis yield of the compounds involved in this invention.

[0035] Preferably, the amount of the catalyst iodobenzene is 2%-20% of the amount of compound 1c;

[0036] Preferably, the amount of the bis(triphenylphosphine)palladium dichloride is 5%-25% of the amount of compound 1c.

[0037] Preferably, the weakly alkaline condition is a weakly alkaline environment in the presence of potassium carbonate;

[0038] Preferably, the molar ratio of compound 1c to potassium carbonate is 1:1-2;

[0039] Preferably, the potassium carbonate is provided by an aqueous solution of potassium carbonate, the concentration of which is 1-3 mol / L;

[0040] Preferably, distilled water is added to the reaction, and the volume ratio of distilled water to toluene is 1:1-4;

[0041] Preferably, the reaction is carried out under reflux and the reaction time is 8-48 hours.

[0042] Compound 1c used in this invention can be prepared by conventional chemical synthesis methods in the art, and the steps and conditions can be referred to the steps and conditions of similar reactions in the art.

[0043] For example, the basic synthetic process route of compound 1c involved in this invention is as follows:

[0044]

[0045] in:

[0046]

[0047] 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.

[0048] 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.

[0049] In this invention, the boron-nitrogen compound having the structure shown in formula (I) 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.

[0050] 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.

[0051] 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.

[0052] In one embodiment, the boron nitride compound having the structure shown in formula (I) is used to prepare the light-emitting layer in an organic electroluminescent device.

[0053] 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.

[0054] The present invention provides an organic electroluminescent composition comprising a boron nitride compound of the structure shown in Formula I as described above, which serves as a dopant material, and a host material.

[0055] 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.

[0056] 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).

[0057]

[0058] X1, Y1, and Z1 are CH or N, and at most one of X1, Y1, and Z1 is N.

[0059] Where R 1H and R 2H Independently, it can be any of the following groups:

[0060]

[0061] Where X1, Y1, and Z1 are CH or N, and at most one of X1, Y1, and Z1 is N;

[0062] Where R aH and RbH 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.

[0063] 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 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 formulas (H-1) to (H-6).

[0064] 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.

[0065] 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.

[0066] 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 as described above, and the remaining 99.7-70.0 wt% is one or two compounds selected from H1-1 to H1-427.

[0067] 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.

[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-nitrogen compounds of Formula I (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 or Trz6-A and any one of the compounds of 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 R2a 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 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] The present invention provides an application of the organic electroluminescent composition as described above as an organic electroluminescent material.

[0102] In one embodiment of the present invention, the organic electroluminescent composition is used to prepare the light-emitting layer in an organic electroluminescent device.

[0103] The present invention also provides an organic electroluminescent device comprising an anode, an emissive layer, an optional hole injection layer, an optional hole transport layer, an optional electron transport layer, an optional electron injection layer, and a cathode, wherein at least one of the emissive 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 a preferred embodiment, the light-emitting layer of the organic electroluminescent device comprises the organic electroluminescent composition as described above.

[0105] In one embodiment of the present invention, the organic electroluminescent composition is used as the material of the light-emitting layer of an organic electroluminescent device. The light-emitting principle of the light-emitting layer is based on energy transfer from the host material to any boron nitride compound shown in Formula I or carrier capture of the light-emitting material itself.

[0106] In one embodiment of the present invention, the organic electroluminescent composition is used as a material for the light-emitting layer of an organic electroluminescent device; 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 a boron nitride compound with the structure shown in formula I as described above as a dopant material, and the remaining 99.7-70.0 wt% is a host material composed of 1-2 compounds from formulas (H-1) to (H-6). For example, when the host material contains two compounds from formulas (H-1) to (H-6), the weight ratio of the two compounds is 1:5 to 5:1.

[0107] 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), 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.

[0108] In one embodiment of the present invention, the organic electroluminescent composition is used as the material of the light-emitting layer of an organic electroluminescent device; the doping material in the organic electroluminescent composition is a boron nitride compound with the structure shown in Formula I as described above (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 the compounds of Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A or Trz6-A and the compounds of H-1, H-2, H-3, H-4, H-5 or H-6 is 1:5 to 5:1.

[0109] In one embodiment of the present invention, the organic electroluminescent composition is used as the material of the light-emitting layer of an organic electroluminescent device; the doping material in the organic electroluminescent composition is a boron-nitrogen compound with the structure shown in Formula I 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 1,3,5-triazine derivatives shown in Formulas TRZ-1 to TRZ-76 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 1,3,5-triazine derivative and the carbazole or carboline derivative is 1:5 to 5:1.

[0110] In one embodiment of the present invention, the organic electroluminescent composition is used as the material of the light-emitting layer of an organic electroluminescent device; the doping material in the organic electroluminescent composition is any compound of formula I (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, and Trz6-A and any one of carbazole or carboline derivatives of formulas H1-1 to H1-427. For example, in the host material, the weight ratio between compounds of formula Trz1-A, Trz2-A, Trz3-A, Trz4-A, Trz5-A, and Trz6-A and carbazole or carboline derivatives of formulas H1-1 to H1-427 is 1:5 to 5:1.

[0111] 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.

[0112] This invention provides an application of the described organic electroluminescent device in an organic electroluminescent display or an organic electroluminescent lighting source.

[0113] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[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, for example, two, three, or four. Furthermore, when there are multiple "substitutes," the "substitutes" can be the same or different. In this disclosure, the position of the "substitute" can be arbitrary unless otherwise specified.

[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 disclosure, as part of a group or other group, the term "Cn-m aryl" refers to a monocyclic or polycyclic aromatic group (where the ring atoms are only carbon atoms) having n to m ring carbon atoms, and having at least one carbon ring with a conjugated π-electron system. Examples of the aforementioned aryl unit include phenyl, naphthyl, indenyl, 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 This is a schematic diagram of the structure of the electroluminescent device of the present invention, wherein 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 BN7 in toluene solution (concentration: 1×10⁻⁶) -5 The photoluminescence spectrum of M). Detailed Implementation

[0137] 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.

[0138] For experimental methods in the following examples where specific conditions are not specified, follow conventional methods and conditions, or select according to the product instructions.

[0139] 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.

[0140] Fluorescence spectra were measured using an RF-5301PC fluorometer from Shimadzu Corporation, Japan. The excitation wavelength selected during the test was the maximum absorption wavelength.

[0141] The following raw materials were used to synthesize the compound shown in Formula I, excluding the substrates 2-bromo-1,3-difluorobenzene and 1,3-dibromo-5-iodobenzene:

[0142]

[0143]

[0144]

[0145]

[0146] This involves C n H 2n+1 The groups represented are all straight-chain alkyl groups, for example, C4H9 represents n-butyl.

[0147] Synthesis Examples

[0148] The specific preparation method of the compound is as follows:

[0149] In the first step, 35.2 mmol of the starting material (carbazole derivatives C-1 to C-100), 10.24 g of cesium carbonate (52.8 mmol), and 3.26 g of 2-bromo-1,3-difluorobenzene (17.0 mmol) were added to a 250 mL double-necked round-bottom flask, 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 to obtain intermediate 1a, which was a white solid.

[0150] 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 12.6 mmol of intermediate 1a (at -30°C). The mixture was slowly heated to 60°C and stirred for 2 hours, then cooled to -30°C, and 2.4 mL of boron tribromide (6.3 mmol) was added. 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 system was concentrated under vacuum and purified by column chromatography using a dichloromethane / petroleum ether mixture as eluent to obtain intermediate 1b.

[0151] In the third step, at room temperature, 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 intermediate 1c.

[0152] In the fourth step, intermediate 1 (6 mmol), catalyst iodobenzene (0.6 mmol), and potassium carbonate (15 mmol) were added to toluene (35 ml), followed by 8 ml of distilled water. The mixture was bubbled under nitrogen for 5 minutes, and then 126.18 mg of bis(triphenylphosphine)palladium dichloride (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 the final product BNn (n = 1-100). The yield of this step was between 26-37%. Data on the obtained target compounds are shown in Table 1.

[0153] Taking compound BN7 as an example, the specific experimental details of the synthesis examples are explained below:

[0154] 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 further purified by column chromatography using a dichloromethane / petroleum ether (1:3) eluent to give 13 g of intermediate 1a as a white solid (yield 79%).

[0155] 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).

[0156] 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%).

[0157] In the fourth step, 4.5 g of intermediate 1c (6 mmol), iodobenzene catalyst (0.6 mmol), and 2.0 g of potassium carbonate (15 mmol) were added to toluene (35 ml), followed by 8 ml of distilled water. The mixture was bubbled with nitrogen for 5 minutes, and 126.18 mg of bis(triphenylphosphine)palladium dichloride (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 1.33 g of the final product BN7 (yield 35%).

[0158] Other compounds were prepared using the same synthetic method as described above. The specific raw materials used and the elemental analysis (C, H and N percentages in the compounds), mass spectrometry molecular weight, and synthesis reaction yield data of the products are shown in Table 1.

[0159] Table 1

[0160]

[0161]

[0162]

[0163] Examples of electroluminescent devices

[0164] The molecular structures of some materials involved in the device embodiments are as follows:

[0165]

[0166] The following are examples of electroluminescent devices fabricated using the materials of the present invention, and the specific device fabrication process is as follows:

[0167] (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.

[0168] (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).

[0169] (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.

[0170] (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

[0171] Device Examples A1-A100

[0172] Organic electroluminescent devices (structure as shown in device embodiments A1-A100) Figure 1 In 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, BNn is used as the doped light-emitting material (doping concentration is 2wt%), 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 device embodiment is [ITO / PEDOT:PSS (20nm) / Poly-HTL (50nm) / H1-33+3wt%BNn / TRZ-8 (50nm) / LiF (1nm) / Al (100nm)].

[0173] 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.

[0174] The test results are shown in Table 2.

[0175] Table 2

[0176]

[0177]

[0178]

[0179] The data from the electroluminescent device examples listed in Table 2 demonstrate that the luminescent material provided by this invention can be used to prepare high-efficiency organic electroluminescent devices. Moreover, the electroluminescence spectrum has narrow band characteristics, with a full width at half maximum (FWHM) of less than 60 nm and an external quantum efficiency of over 24%.

[0180] Furthermore, compound BN7 in toluene solution (concentration: 1×10⁻⁶) -5 The photoluminescence spectrum (i.e., fluorescence spectrum) in M) is as follows: Figure 2 As shown, by Figure 2 As can be seen, the emission peak position is 501nm and the full width at half maximum (FWHM) is 35nm.

[0181] Device Examples B1-B100

[0182] In the organic electroluminescent devices of device embodiments B1-B100, the structure is as follows: Figure 1 As 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-1 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)].

[0183] 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.

[0184] Table 3

[0185]

[0186]

[0187]

[0188] The electroluminescent device performance data listed in Table 3 proves that the luminescent material provided by this invention can be used to prepare high-efficiency organic electroluminescent devices. Moreover, the electroluminescence spectrum has narrow band characteristics, with a full width at half maximum (FWHM) of less than 60 nm and an external quantum efficiency of over 26%.

[0189] The applicant declares that the boron nitrogen compound, its preparation method, and its application are illustrated by 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, characterized in that, The boron-nitrogen compound has the structure shown in Formula I: ； Among them, R m1 and R m2 Each occurrence is independent of H, deuterium, fluorine, and C1~C. 20 Alkyl, C1~C 20 Alkoxy, C3-C 10 cycloalkyl, C6~C 14 aryl, with one or more R a Replacement of C6~C 14 aryl, diphenylamino, or with one or more R a Substituted diphenylamine group, triphenylamine group, or group with one or more R a Substituted triphenylamine group, carbazole group, or group with one or more R a Substituted carbazoyl group; R a Each occurrence is independent of deuterium, fluorine, and C1~C. 12 Alkyl, C1~C 12 Alkoxy, C3-C 10 cycloalkyl, C6~C 14 aryl, with one or more R b Replacement of C6~C 14 aryl, diphenylamino, or with one or more R b Substituted diphenylamine group, triphenylamine group, or group with one or more R b Substituted triphenylamine group, carbazole group, or group with one or more R b Substituted carbazoyl group; R b Each occurrence is independent of deuterium, fluorine, and C1~C. 12 Alkyl, C1~C 12 Alkoxy, C3-C 10 cycloalkyl, C6~C 14 aryl, with one or more R c Replacement of C6~C 14 aryl, diphenylamino, or with one or more R c Substituted diphenylamine group, triphenylamine group, or group with one or more R c Substituted triphenylamine group, carbazole group, or group with one or more R c Substituted carbazoyl group; R c Each occurrence is independent of deuterium, fluorine, and C1~C. 12 Alkyl, C1~C 12 Alkoxy, C3-C 10 cycloalkyl, C6~C 14 aryl, with one or more R d Replacement of C6~C 14 aryl, diphenylamino, or with one or more R d Substituted diphenylamine group, triphenylamine group, or group with one or more R d Substituted triphenylamine group, carbazole group, or group with one or more R d Substituted carbazoyl group; R d Each occurrence is independent of deuterium, fluorine, and C1~C. 12 Alkyl, C1~C 12 Alkoxy, C3-C 10 cycloalkyl, C6~C 14 aryl or aryl group with one or more R groups e Replacement of C6~C 14 Aryl; R e Each occurrence is independent of deuterium, fluorine, and C1~C. 12 Alkyl, C1~C 12 Alkoxy, C3-C 10 cycloalkyl, or C6~C 14 Aryl; The alkyl, alkoxy, or cycloalkyl groups may optionally be substituted with one or more substituents selected from the following: halogen, -CN, C1-C. 12 Alkyl, C1-C 12 Alkoxy, C1-C 12 Haloalkyl, C2-C6 alkenyl, C3-C 10 cycloalkyl, C6-C 14 Aryl.

2. The boron-nitrogen compound according to claim 1, characterized in that, The R m1 and R m2 Each occurrence is independently of H, deuterium, fluorine, C1-C12 alkyl, C1~C 12 Alkoxy, C3-C 10 cycloalkyl, phenyl, with at least one C1-C 12 Alkyl-substituted aryl group, with at least one C1-C 12 Alkoxy-substituted aryl, diphenylamino, triphenylamino, or alkyl-substituted aryl, di ... 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.

3. The boron-nitrogen compound according to claim 1, characterized in that, The R a Each occurrence is independent of deuterium, fluorine, and C1~C. 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~C. 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~C. 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~C. 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 or 2, characterized in that, The R m1 and R m2 Each time it appears independently, it is 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 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , or .

8. The boron-nitrogen compound according to claim 1, characterized in that, The boron-nitrogen compound is any one of the following compounds: 。 9. The method for preparing the boron-nitrogen compound according to any one of claims 1-8, characterized in that, The preparation method includes the following steps: Compound 1c reacts in toluene under weakly basic conditions in the presence of iodobenzene and palladium dichloride bis(triphenylphosphine) catalysts under nitrogen protection to give the boron-nitrogen compound shown in Formula I, as follows: 。 10. The preparation method according to claim 9, characterized in that, The amount of the catalyst iodobenzene is 2%-20% of the amount of compound 1c.

11. The preparation method according to claim 9, characterized in that, The amount of bis(triphenylphosphine)palladium dichloride is 5%-25% of the amount of compound 1c.

12. The preparation method according to claim 9, characterized in that, The weakly alkaline condition refers to a weakly alkaline environment in the presence of potassium carbonate.

13. The preparation method according to claim 9, characterized in that, The molar ratio of compound 1c to potassium carbonate is 1:1-2.

14. The preparation method according to claim 12, characterized in that, The potassium carbonate is provided by an aqueous solution of potassium carbonate, the concentration of which is 1-3 mol / L.

15. The preparation method according to claim 9, characterized in that, Distilled water is added to the reaction, and the volume ratio of the distilled water to toluene is 1:1-4.

16. The preparation method according to claim 9, characterized in that, The reaction is carried out under reflux for 8-48 hours.

17. An organic electroluminescent composition, characterized in that, It includes the boron nitride compound as a dopant material as described in any one of claims 1-8 and the host material.

18. The organic electroluminescent composition according to claim 17, 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.

19. The organic electroluminescent composition according to claim 17, characterized in that, The main material is a carbazole derivative and / or 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 group, the asterisk represents the linking site of the group.

20. The organic electroluminescent composition according to claim 19, 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 1-8 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).

21. The organic electroluminescent composition according to claim 20, 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.

22. The organic electroluminescent composition according to claim 19, characterized in that, The host material in the organic electroluminescent composition is one or two of compounds H1-1 to H1-427; 。 23. The organic electroluminescent composition according to claim 22, characterized in that, The organic electroluminescent composition contains 0.3-30.0 wt% of the boron nitrogen compound as described in any one of claims 1-8, and the remaining 99.7-70.0 wt% is one or two compounds selected from compounds H1-1 to H1-427.

24. The organic electroluminescent composition according to claim 23, characterized in that, The organic electroluminescent composition contains two compounds of formulas H1-1 to H1-427 as host materials, with a weight ratio of 1:5 to 5:1 between the two compounds.

25. The organic electroluminescent composition according to claim 17, characterized in that, The doping material in the organic electroluminescent composition is any one of the boron-nitrogen compounds according to any one of claims 1-8; the host 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.

26. The organic electroluminescent composition according to claim 25, characterized in that, The doping material in the organic electroluminescent composition is any one of the boron nitrogen compounds according to any one of claims 1-8, with a content of 0.3-30.0 wt%; the main material is composed of any one of the compounds shown in formulas TRZ-1 to TRZ-76 and any one of the carbazole or carboline derivatives shown in formulas H1-1 to H1-427, with a content of 99.7-70.0 wt%. 。 27. The organic electroluminescent composition according to claim 26, 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 carbline derivative is 1:5 to 5:

1.

28. An organic electroluminescent material, characterized in that, The organic electroluminescent material includes any boron nitrogen compound as claimed in any one of claims 1-8 or any organic electroluminescent composition as claimed in any one of claims 17-27.

29. 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 1-8 or an organic electroluminescent composition as described in any one of claims 17-27.

30. The organic electroluminescent device according to claim 29, characterized in that, The organic electroluminescent device further includes an optional hole blocking layer, an optional electron blocking layer, and an optional capping layer.

31. The application of the organic electroluminescent device according to claim 29 or 30 in an organic electroluminescent display or an organic electroluminescent lighting source.

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