Boron-based compound and application thereof in organic electroluminescent device

Abstract

The invention provides a boron-based compound and application thereof in an organic electroluminescent device, the boron-based compound has a structural general formula as shown in formula I. The boron-based compound provided by the invention improves the comprehensive performance of the current blue-light device, i.e., the starting voltage of the blue-light device is reduced, the luminous efficiency is improved, the service life is prolonged and the like; and the commercialized application process of the boron-based device is accelerated.

Description

Technical Field

[0001] The present invention belongs to the field of optoelectronic materials, and in particular relates to a boron-based compound and its application in organic electroluminescent devices. Background Art

[0002] Compared with liquid crystal displays (LCDs), organic light-emitting diodes (OLEDs) have the advantages of self-luminescence, wide viewing angle, high response speed, light weight, low temperature resistance, flexible display and double transparent display, and have bright industrial prospects. In the process of its industrialization, the quality of the luminescent material directly affects the efficiency and life of the device, and has become an important factor affecting the rapid development of OLEDs.

[0003] In recent years, new π-conjugated organic unit materials containing co-embedded boron and nitrogen have become a research hotspot in blue light OLED material systems due to their excellent photophysical and electrochemical properties. However, due to the wide band gap of blue light materials, the carrier transport and energy transfer processes in the electroluminescence process become difficult and unstable. Especially at high current densities, singlet-triplet annihilation (STA), triplet-triplet annihilation (TTA), triplet polaron annihilation (TPQ) and non-radiative attenuation caused by excited state molecular vibrational relaxation will all cause the device efficiency to roll off very seriously. So far, no organic boron semiconductor light-emitting material has the performance to meet the industry needs in the blue light field. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a boron-based compound and its application in organic electroluminescent devices to improve the comprehensive performance of current blue light devices, that is, to reduce the starting voltage of blue light devices, improve the luminous efficiency and life, and accelerate the commercial application process of boron-based devices.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In one aspect, the present invention provides a boron-based compound, the general structural formula of the boron-based compound is shown in Formula 1:

[0007]

[0008] Wherein, X1 and X2 are independently selected from any one of O, S, N(R5) or C(R6)(R7);

[0009] a and b are independently 0 or 1. When a or b is 0, the two aromatic carbon sites bridged by X1 or X2 are directly connected by a single bond; and X2 may not be bridged (i.e., X2 does not exist or there is no connection at the position of X2);

[0010] R1-R4 are one or at least two substituents that satisfy the number of valence bonds of the benzene ring, and are independently selected from hydrogen, fluoro, nitro, cyano, C 1-20 Alkyl, C 1-20 Alkoxy, C 3-20 Cycloalkyl, C 3-20 Heterocycloalkyl, C 6-30 Aryl, C 3-30 Heteroaryl and C 6-30 Any one of the aromatic amine groups;

[0011] R5 is selected from the following: phenyl group substituted or unsubstituted by one substituent, biphenyl group substituted or unsubstituted by one substituent, terphenyl group substituted or unsubstituted by one substituent, and naphthyl group substituted or unsubstituted by one substituent, wherein the substituents are independently selected from any one of fluorine, nitro, cyano, methyl, isopropyl and tert-butyl;

[0012] R6 and R7 are the same as each other and are independently selected from C 1-20 Alkyl, C 3-20 Cycloalkyl, C 3-20 Heterocycloalkyl, C 6-30 Aryl, C 3-30 Heteroaryl and C 6-30 Any one of the aromatic amine groups.

[0013] Preferably, R1-R2 are selected from any one of hydrogen, fluorine, methyl, isopropyl, tert-butyl, methoxy and phenyl.

[0014] Preferably, R3-R4 are selected from one of hydrogen, fluorine, methyl, isopropyl, tert-butyl, methoxy, a group represented by formula A1, a group represented by formula A2, a group represented by formula A3, a group represented by formula A4, and a group represented by formula A5:

[0015]

[0016] Among them R8-R 12 Any one selected from hydrogen, fluoro, methyl, isopropyl, tert-butyl, methoxy and phenyl, each of which is the same or different, * represents the attachment site of the group;

[0017] Furthermore, the boron-based compound is represented by Formula 1-1, Formula 1-2, Formula 1-3, Formula 1-4 or Formula 1-5:

[0018]

[0019]

[0020] The definitions of R1-R4, X1, and X2 are the same as those above.

[0021] Furthermore, the boron-based compound represented by Formula 1 is selected from any one of the following structural formulas:

[0022]

[0023]

[0024]

[0025]

[0026] The second aspect of the present invention provides an organic electroluminescent device, which mainly comprises a cathode, an anode and an organic layer located between the cathode and the anode, wherein the organic layer comprises any of the above-mentioned boron-based compounds.

[0027] Preferably, the organic layer includes a light-emitting layer, the light-emitting layer is composed of a light-emitting host and a light-emitting guest, and the light-emitting guest comprises any of the above-mentioned boron-based compounds.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The boron-based compound provided by the present invention is based on 1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthalene and is bonded to a rigid fused ring macroconjugated main body with a dibenzo hexacyclic group such as carbazole, phenazine or aromatic amine nitrogen. On this basis, the boron group is modified. Due to the weak electron acceptability of the boron-containing material, the compound molecule has a wide band gap. At the same time, the rigidity of the compound molecule becomes stronger, which weakens the non-radiative transition caused by the excited state vibration relaxation. Therefore, the compound exhibits excellent blue light emission. The more rigid structure can also increase the carrier radiation transition rate, improve the luminous efficiency, and provide better thermodynamic stability. Moreover, the present invention replaces the main body with substituents such as phenyl, aromatic amine, and tert-butyl. This short and small spatial configuration can effectively reduce the aggregation of the compound molecules in the solid state, thereby effectively avoiding intermolecular exciton annihilation or quenching, thereby further improving the luminous efficiency. The compound of the present invention is used as a luminescent guest material for an organic electroluminescent device. Compared with other types of organic boron materials in the prior art, the device has significant improvements in starting voltage, luminous efficiency, light color and life. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0031] Synthesis Route 1

[0032]

[0033] Synthesis Example 1: Synthesis of Compound (1)

[0034] In a reaction flask, 6-bromo-1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthalene (74.8 mmol, 20 g), o-chloroaniline (82.3 mmol, 10.5 g), sodium tert-butoxide (89.8 mmol, 8.63 g), and 300 mL of toluene were placed, and the atmosphere was replaced with argon three times. Tris(dibenzylideneacetone)dipalladium (1.5 mmol, 1.3 g) and bis(2-diphenylphosphinophenyl) ether (3.0 mmol, 1.61 g) were then added, and the mixture was heated to reflux for 16 h. The mixture was cooled to room temperature, washed three times with water, extracted once with ethyl acetate, dried over anhydrous sodium sulfate, and the organic phase was concentrated to dryness. Purification by silica gel column chromatography yielded 19.2 g of the compound represented by the following chemical formula (1a) in an 82% yield.

[0035]

[0036] In a reaction flask, the above-mentioned 1a (60.5 mmol, 19 g), potassium carbonate (90.8 mmol, 12.53 g), and 200 mL of xylene (mixed) were placed, and the atmosphere was replaced with argon three times. Subsequently, tris(dibenzylideneacetone)dipalladium (1.2 mmol, 1.1 g) and tri-tert-butylphosphine tetrafluoroborate (2.4 mmol, 0.70 g) were added, and the mixture was heated to reflux for 16 h. The mixture was cooled to room temperature, washed three times with water, extracted once with ethyl acetate, dried over anhydrous sodium sulfate, and the organic phase was concentrated to dryness and purified by silica gel column chromatography to obtain 14.2 g of the compound represented by the following chemical formula (1b) in an 85% yield.

[0037]

[0038] The NMR of the compound represented by chemical formula (1b) was measured, and the data are as follows:

[0039] 1 H-NMR (Bruker, Switzerland, AvanceⅡ400MHz nuclear magnetic resonance spectrometer, CDCl3), δ8.10 (m, 1H), δ8.06 (s, 1H), 7.43 (m, 1H), δ7.37 (s, 1H), δ7.29 (s, 1H), δ7.20~7.17 (m, 2H), δ1.73 (s, 4H), δ0.93 (s, 12H).

[0040] In a reaction flask, 9-hydrocarbazole (71.7 mmol, 12 g), 2,3-dichlorofluorobenzene (86.04 mmol, 14.2 g), cesium carbonate (107 mmol, 35.04 g), and 300 mL of N,N-dimethylformamide were added. The atmosphere was replaced with argon three times and the mixture was heated to reflux for 16 h. The mixture was cooled to room temperature, diluted with ethyl acetate, washed six times with water, and extracted once with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate, concentrated, and purified by silica gel column chromatography to obtain 18.6 g of the compound represented by the following formula (1c) in an 83% yield.

[0041]

[0042] In a reaction flask, 1b (50.4 mmol, 14 g), 1c (55.5 mmol, 17.3 g), 1.0 M lithium bis(trimethylsilylamide) (60.48 mmol, 61 mL), and 300 mL of xylene were placed, and the atmosphere was replaced with argon three times. Tris(dibenzylideneacetone)dipalladium (1.0 mmol, 0.92 g) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (2.0 mmol, 0.95 g) were then added, and the reaction was heated to reflux for 16 h. The mixture was cooled to room temperature, diluted with ethyl acetate, washed six times with water, and extracted once with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate, concentrated, and purified by silica gel column chromatography to obtain 14.2 g of the compound represented by the following formula (1d) in a 51% yield.

[0043]

[0044] In a reaction flask, the above compound 1d (18.1 mmol, 10 g) was dissolved in 300 mL of toluene, and the atmosphere was replaced with argon three times while continuously flowing with argon for protection. The reaction solution was cooled to -50°C, and 34.76 mL of 1.3 M tert-butyl lithium solution in n-pentane was slowly added dropwise. After the addition was completed, the temperature was naturally raised to room temperature and the reaction was carried out for 0.5 h, and then heated to 80°C and reacted for 0.5 h. The reaction solution was cooled to -10°C, and boron tribromide (63.35 mmol, 41.26 g) was added. The reaction solution was raised to room temperature and stirred for 2 h, and then cooled to 0°C, N,N-diisopropylethylamine (81.45 mmol, 10.52 g) was added, and the reaction was heated to reflux. The reaction was monitored by liquid phase monitoring until completion, and the solution was cooled to room temperature. Acetic acid was added to quench the reaction, and the reaction solution was extracted with a mixture of water and dichloromethane. The organic phase was dried over anhydrous magnesium sulfate and concentrated, and purified and separated on a silica gel column using a 1:8 mixed solvent of dichloromethane and petroleum ether to obtain 2.67 g of the compound represented by the following chemical formula (1) with a yield of 28%;

[0045]

[0046] The obtained compound was detected and analyzed, and the results were as follows: LC-MS (m / z+1): 527.26.

[0047] Synthesis Route 2

[0048]

[0049] Synthesis Example 1: Synthesis of Compound (62)

[0050] In a reaction flask, 3-bromo-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene-2-ol (74.8 mmol, 20 g), o-fluoroaniline (82.28 mmol, 9.14 g), sodium tert-butoxide (89.8 mmol, 8.63 g), and 300 mL of toluene were placed, and the atmosphere was replaced with argon three times. Tris(dibenzylideneacetone)dipalladium (1.5 mmol, 1.3 g) and bis(2-diphenylphosphinophenyl) ether (3.0 mmol, 1.61 g) were then added, and the mixture was heated to reflux for 16 h. The mixture was cooled to room temperature, washed three times with water, extracted once with ethyl acetate, dried over anhydrous sodium sulfate, and the organic phase was concentrated to dryness. Purification by silica gel column chromatography yielded 17.8 g of the compound represented by the following formula (62a) in a yield of 76%.

[0051]

[0052] In a reaction flask, the above-mentioned 62a (54.24 mmol, 17 g), potassium carbonate (81.36 mmol, 11.22 g), and 300 mL of dimethyl sulfoxide were added, and the atmosphere was replaced with argon three times. The mixture was heated to reflux for 16 h. The mixture was cooled to room temperature, washed with water six times, extracted once with ethyl acetate, dried over anhydrous sodium sulfate, and the organic phase was concentrated to dryness. Purification by silica gel column chromatography yielded 12.89 g of the compound represented by the following formula (62b) in an 81% yield.

[0053]

[0054] In a reaction flask, 9,9-dimethylacridine (53.7 mmol, 11.24 g), 2,3-dichlorobromobenzene (59.07 mmol, 13.34 g), sodium tert-butoxide (64.44 mmol, 6.18 g), and 250 mL of toluene were placed, and the atmosphere was replaced with argon three times. Tris(dibenzylideneacetone)dipalladium (1.1 mmol, 0.98 g) and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (2.1 mmol, 0.88 g) were then added, and the mixture was heated to reflux for 16 h. The mixture was cooled to room temperature, washed three times with water, extracted once with ethyl acetate, dried over anhydrous sodium sulfate, and the organic phase was concentrated to dryness. Purification by silica gel column chromatography yielded 17.5 g of the compound represented by the following formula (62c) in a 92% yield.

[0055]

[0056] In a reaction flask, 62b (37.49 mmol, 11.0 g), 62c (41.23 mmol, 14.61 g), 1.0 M lithium bistrimethylsilylamide (60.48 mmol, 61 mL), and 250 mL of xylene were placed, and the atmosphere was replaced with argon three times. Tris(dibenzylideneacetone)dipalladium (0.75 mmol, 0.69 g) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (1.5 mmol, 0.71 g) were then added, and the mixture was heated to reflux for 16 h. The mixture was cooled to room temperature, diluted with ethyl acetate, washed three times with water, and extracted once with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate, concentrated, and purified by silica gel column chromatography to obtain 12.1 g of the compound represented by the following formula (62d) in a 53% yield.

[0057]

[0058] In a reaction flask, dissolve compound 62d (16.36 mmol, 10 g) in 300 mL of toluene. The atmosphere was replaced with argon three times, maintaining a continuous argon flow. The reaction mixture was cooled to -50°C and slowly added dropwise with 31.46 mL of a 1.3 M solution of tert-butyl lithium in n-pentane. After addition, the mixture was naturally warmed to room temperature and reacted for 0.5 h. The reaction mixture was then heated to 80°C for 0.5 h. The reaction solution was cooled to -10°C and boron tribromide (57.26 mmol, 14.34 g) was added. The reaction solution was heated to room temperature and stirred for 2 h, then cooled to 0°C and N,N-diisopropylethylamine (73.62 mmol, 9.51 g) was added and heated to reflux for reaction. The reaction was monitored for completion by liquid phase. The solution was cooled to room temperature and quenched by adding acetic acid. The reaction solution was extracted with a mixture of water and dichloromethane. The organic phase was dried over anhydrous magnesium sulfate and concentrated. The product was purified and separated on a silica gel column using a 1:8 mixed solvent of dichloromethane and petroleum ether to obtain 2.87 g of the compound represented by the following chemical formula (62) with a yield of 30%;

[0059]

[0060] The obtained compound was detected and analyzed, and the results were as follows: LC-MS (m / z+1): 585.30.

[0061] Synthesis Example 3: Synthesis of Compound (74)

[0062] The raw material 2,3-dichlorofluorobenzene in reaction 1c of Example 1 was replaced with 3,4-dichloro-5-fluorotoluene. The rest of the synthesis process was the same as that of Example 1 to obtain 1.87 g of the compound represented by the following chemical formula (74) with a yield of 26%.

[0063]

[0064] The obtained compound was detected and analyzed, and the results were as follows: LC-MS (m / z+1): 541.27.

[0065] Synthesis Example 4: Synthesis of Compound (15)

[0066] The raw material 9-hydrocarbazole in reaction 1c of Example 1 was replaced with phenoxazine. The rest of the synthesis process was the same as in Example 1 to obtain 1.96 g of the compound represented by the following chemical formula (15), with a yield of 31%.

[0067]

[0068] The obtained compound was detected and analyzed, and the results were as follows: LC-MS (m / z+1): 559.23.

[0069] Synthesis Example 5: Synthesis of Compound (39)

[0070] The raw material 9-hydrocarbazole in reaction 1c of Example 1 was replaced with di(4-tert-butylphenyl)amine. The rest of the synthesis process was the same as in Example 1 to obtain 2.91 g of the compound represented by the following chemical formula (39) with a yield of 35%.

[0071]

[0072] The obtained compound was detected and analyzed, and the results were as follows: LC-MS (m / z+1): 641.40.

[0073] Synthesis Example 6: Synthesis of Compound (90)

[0074] The raw material 2,3-dichlorofluorobenzene in Example 5 was replaced with 1-bromo-5-(tert-butyl)-2,3-dichlorobenzene. The rest of the synthesis process was the same as in Example 2 to obtain 2.55 g of the compound represented by the following chemical formula (90), with a yield of 31%.

[0075]

[0076] The obtained compound was detected and analyzed, and the results were as follows: LC-MS (m / z+1): 697.46.

[0077] Synthesis Example 7: Synthesis of Compound (64)

[0078] The reaction raw material 9,9-dimethylacridine in Example 2 was replaced with 3,6-di-tert-butylcarbazole. The other synthetic processes were the same as in Example 2 to obtain 1.75 g of the compound represented by the following chemical formula (64), with a yield of 25%.

[0079]

[0080] The obtained compound was detected and analyzed, and the results were as follows: LC-MS (m / z+1): 639.38.

[0081] Synthesis Example 8: Synthesis of Compound (59)

[0082] The reaction raw material 9,9-dimethylacridine in Example 2 was replaced with di(4-tert-butylphenyl)amine. The rest of the synthesis process was the same as Example 2 to obtain 1.99 g of the compound represented by the following chemical formula (59), with a yield of 28%.

[0083]

[0084] The obtained compound was detected and analyzed, and the results were as follows: LC-MS (m / z+1): 641.40.

[0085] Device Example 1

[0086] The glass substrate with a 50nm ITO transparent film was ultrasonically cleaned with acetone, isopropyl alcohol and deionized water for 10 minutes each, vacuum dried at 105°C for 2 hours, and then UV ozone washed for 15 minutes. The ITO glass substrate was then transferred to a vacuum evaporator.

[0087] On the surface where the ITO film is formed, molybdenum trioxide (MoO3) is vacuum evaporated to form a 10nm thick hole injection layer;

[0088] On the hole injection layer, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB) was vacuum-deposited to form a 60 nm thick hole transport layer;

[0089] On the hole transport layer, 4,4',4"-tris(carbazol-9-yl)triphenylamine (TCTA) was vacuum evaporated to form a 10 nm electron blocking layer;

[0090] On the electron blocking layer, 9,10-di(2-naphthyl)anthracene (ADN) (as a light-emitting host material, 95 wt %) and the compound 1 prepared in Synthesis Example 1 (as a light-emitting guest material, 5 wt %) were co-vapor-deposited to form a light-emitting layer with a thickness of 30 nm.

[0091] On the light-emitting layer, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) was vacuum-deposited to form an electron transport layer with a thickness of 30 nm.

[0092] On the electron transport layer, lithium fluoride (LiF) is vacuum evaporated to form an electron injection layer with a thickness of 1 nm;

[0093] Finally, a magnesium-silver alloy (deposition ratio Mg / Ag=1 / 9) was vacuum-deposited on the electron injection layer to form a cathode with a thickness of 100 nm.

[0094] Device Examples 2 to 8

[0095] An organic electroluminescent device was prepared in the same manner as in Device Example 1, except that the compounds synthesized in Synthesis Examples 2 to 8 were used to replace Compound 1 prepared in Synthesis Example 1.

[0096] Device Comparative Example 1 to Device Comparative Example 3

[0097] An organic electroluminescent device was prepared by the same method as in Device Example 1, except that the following compounds A-1, A-2, and A-3 were used to replace the compound 1 prepared in Synthesis Example 1.

[0098]

[0099] The performance tests were conducted on the organic electroluminescent devices prepared from the above device examples and device comparative examples. LT95 refers to the time required for the brightness to drop to 95% of the original brightness while maintaining the current density at an initial brightness of 1000 nit. The test items included the brightness, driving voltage, and current efficiency of the organic electroluminescent device. The driving voltage, current efficiency, and LT95 data were all based on a brightness of 1000 cd / m 2 The relative values ​​(based on the test data of device comparative example 1) are shown in Table 1.

[0100] Table 1

[0101]

[0102] As can be seen from the data in Table 1 above, the present invention provides a compound based on 1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthalene bonded to a rigid fused ring macroconjugated main body with a dibenzo hexacyclic group such as carbazole, phenazine, or an aromatic amine nitrogen, and the main center is modified with a boron group. The rigid macroconjugated main body cooperates with the boron group of the weak acceptor, and the excited state vibration relaxation of the compound molecule is reduced, and the carrier radiation transition rate is increased. In addition, the substitution of the main body with substituents such as phenyl and tert-butyl groups reduces the annihilation or quenching of intermolecular excitons. Therefore, the efficiency roll-off phenomenon of the blue light device prepared using the compound of the present invention as a luminescent guest material is improved, and compared with the device prepared by the existing disclosed compound, it exhibits excellent luminous efficiency and life.

[0103] The applicant states that while the above-described embodiments illustrate the boron-based compounds and their applications in organic electroluminescent devices, the present invention is not limited to these embodiments. This does not necessarily mean that the present invention must rely on these embodiments for implementation. Those skilled in the art will appreciate that any improvements to the present invention, equivalent substitutions for raw materials in the products of the present invention, additions of auxiliary components, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A boron-based compound, characterized in that The general structural formula of the boron-based compound is shown in Formula 1: Wherein, X1 and X2 are independently selected from any one of O, S, N(R5) or C(R6)(R7); a and b are independently 0 or 1. When a or b is 0, the two aromatic carbon sites bridged by X1 or X2 are directly connected by a single bond; and X2 may not be bridged; R1-R4 are one or at least two substituents that satisfy the number of valence bonds of the benzene ring, and are independently selected from hydrogen, fluoro, nitro, cyano, C 1-20 Alkyl, C 1-20 Alkoxy, C 3-20 Cycloalkyl, C 3-20 Heterocycloalkyl, C 6-30 Aryl, C 3-30 Heteroaryl and C 6-30 Any one of the aromatic amine groups; R5 is selected from the following: phenyl group substituted or unsubstituted by one substituent, biphenyl group substituted or unsubstituted by one substituent, terphenyl group substituted or unsubstituted by one substituent, and naphthyl group substituted or unsubstituted by one substituent, wherein the substituents are independently selected from any one of fluorine, nitro, cyano, methyl, isopropyl and tert-butyl; R6 and R7 are the same or different and are independently selected from C 1-20 Alkyl, C 3-20 Cycloalkyl, C 3-20 Heterocycloalkyl, C 6-30 Aryl, C 3-30 Heteroaryl and C 6-30 Any one of the aromatic amine groups.

2. The boron-based compound according to claim 1, characterized in that R1-R2 are selected from any one of hydrogen, fluoro, methyl, isopropyl, tert-butyl, methoxy and phenyl.

3. The boron-based compound according to claim 1, characterized in that R3-R4 is selected from one of hydrogen, fluoro, methyl, isopropyl, tert-butyl, methoxy, a group represented by formula A1, a group represented by formula A2, a group represented by formula A3, a group represented by formula A4, and a group represented by formula A5: Among them R8-R 12 Any one selected from hydrogen, fluoro, methyl, isopropyl, tert-butyl, methoxy and phenyl, each of which is the same or different, and * represents the connection site of the group.

4. The boron-based compound according to any one of claims 1 to 3, characterized in that The boron-based compound is represented by Formula 1-1, Formula 1-2, Formula 1-3, Formula 1-4 or Formula 1-5: The definitions of R1-R4, X1, and X2 are the same as those in claim 1.

5. The boron-based compound according to any one of claims 1 to 4, characterized in that The boron-based compound represented by Formula 1 is selected from any one of the following structural formulas:

6. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises a cathode, an anode, and an organic layer located between the cathode and the anode, wherein the organic layer comprises the boron-based compound according to any one of claims 1 to 5.

7. The organic electroluminescent device according to claim 6, characterized in that: The organic layer includes a light-emitting layer, which is composed of a light-emitting host and a light-emitting guest. The light-emitting guest comprises the boron-based compound according to any one of claims 1 to 5.

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