Boron-nitrogen-containing polycyclic compound based on indolocarbazole structure as well as preparation method and application of boron-nitrogen-containing polycyclic compound

Abstract

The invention relates to the technical field of organic photoelectric materials, in particular to a boron-nitrogen-containing polycyclic compound based on an indolocarbazole structure and a preparation method and application of the boron-nitrogen-containing polycyclic compound. The invention discloses a boron-nitrogen-containing polycyclic aromatic hydrocarbon organic photoelectric functional material based on an indolocarbazole structure, and aims to solve the problems of insufficient color purity, low luminous efficiency and poor stability of the existing red luminescent material. A rigid near-plane structure is constructed by fusing a 11, 12-dihydroindolo [2, 3-a] carbazole (ICz) donor and a 1, 4-azaboryl BN-heteroarene (BNCz) core through an intramolecular covalent bond, so that orbits are maximized to be overlapped, an intramolecular charge transfer effect is enhanced, and red light emission is realized. In addition, the thermal decomposition temperature of the material reaches 400 DEG C or above while the molecular weight is reduced to realize red light emission, and the material is suitable for a vacuum thermal evaporation process.

Description

Technical Field

[0001] The present invention relates to the technical field of organic optoelectronic materials, and particularly relates to a boron and nitrogen-containing polycyclic compound based on an indolocarbazole structure, a preparation method thereof, and applications thereof. Background Art

[0002] Organic optoelectronic materials are a class of organic functional materials that combine the functions of photon and electron generation, conversion, and transmission. With their excellent adjustable optoelectronic properties, such materials have been widely used in multiple emerging device fields, including organic light-emitting diodes (OLEDs), organic solar cells (OPVs), organic field-effect transistors (OFETs), and organic lasers. Among them, OLED technology has become a research and development hotspot in the international display industry in recent years and is widely regarded as one of the core solutions for the next generation of flat panel displays.

[0003] OLED displays have a series of remarkable advantages, such as high contrast and wide viewing angles brought by the self-luminous characteristics, extremely short response times, high luminous efficiency, wide color gamut, low driving voltage, and structural advantages such as being able to achieve thin, flexible, and large-area fabrication, showing comprehensive performance superior to that of traditional liquid crystal displays (LCDs). Therefore, they are hailed as the "star display technology of the 21st century". With the rapid development of ultra-high-definition display technology, OLED devices have put forward higher performance standards for red light-emitting materials, especially in terms of color purity, luminous efficiency, and device stability, and the requirements are becoming increasingly stringent. Traditional red fluorescent materials are difficult to meet the high-efficiency requirements due to low exciton utilization efficiency; although phosphorescent materials can achieve high-efficiency light emission, they usually rely on rare noble metal elements (such as iridium and platinum), and the emission bandwidth is relatively wide, resulting in low color purity and difficulty in meeting high-specification display standards such as the international ultra-high-definition display standard BT.2020. In recent years, thermally activated delayed fluorescence (TADF) materials that have emerged, although theoretically capable of achieving 100% exciton utilization efficiency and having good efficiency potential, usually have a relatively wide emission band, resulting in a deviation of the color coordinates from the target value, and there is still a large room for optimization in the maximum external quantum efficiency (EQE) and stability of the device.

[0004] In contrast, due to the excited-state localization and precise control of electron distribution brought by the rigid molecular skeleton of multi-resonant boron-nitrogen polycyclic compounds, narrow-band high-color-purity emission can be achieved, making it an important research direction for the next generation of high-performance red light materials. However, the existing red multi-resonant boron-nitrogen polycyclic compounds have relatively limited design strategies, and generally have problems such as large molecular size, complex synthesis routes, and poor process compatibility, making it difficult to meet the comprehensive requirements of high efficiency, easy synthesis, and processability in industrial applications.

[0005] To overcome the above technical bottlenecks, the present invention aims to introduce a rigid near-planar skeleton structure into the molecular structure, and use 11,12-dihydroindolo[2,3-a]carbazole and its derivatives (Indolo[2,3-a]carbazole, ICz) as fused donor units to effectively increase the intramolecular charge transfer excited state, thereby achieving a significant red shift of the emission wavelength and compression of the emission band. In addition, the enhancement of molecular rigidity is conducive to restricting the non-radiative transition process, while improving the spectral stability, significantly improving the luminescence efficiency and device lifetime of the material. Finally, a red boron-nitrogen polycyclic compound with high efficiency, high color purity, and excellent luminescence stability is realized, providing a high-performance solution with application potential for OLED devices for ultra-high definition displays. Summary of the Invention

[0006] The present invention provides a boron-nitrogen polycyclic compound based on an indolocarbazole structure, its preparation method and application, aiming to solve the problems of insufficient color purity, low luminescence efficiency, and poor stability of existing red light-emitting materials. By fusing the 11,12-dihydroindolo[2,3-a]carbazole (ICz) and its derivative donors with the 1,4-aza-boryl BN-heteroarene and its derivative (BNCz) cores through intramolecular donor fusion, a rigid near-planar structure is constructed, significantly enhancing the intramolecular charge transfer effect and achieving a large red shift of the spectrum. In addition, while reducing the molecular weight to achieve red light emission, the thermal decomposition temperature of the materials all reaches above 400 °C, which is suitable for vacuum thermal evaporation process.

[0007] To solve the above technical problems, the technical solutions of the present invention are specifically as follows:

[0008] A boron-nitrogen polycyclic compound based on an indolocarbazole structure, the structure of the compound is shown in general formula I:

[0009]

[0010] Wherein, X 1 represents one of none, direct bond, O, S, Se, NR9 or C(R 10 )(R 11 );

[0011] The Ar1 ring and the Ar2 ring are each independently selected from substituted or unsubstituted C6-C 60 aryl rings, C5-C 60 heteroaryl rings. When there are substituents, the number of substituents is selected from 1 to the maximum number of substituents allowed for the ring, and two adjacent substituents can be connected by a single bond to form a ring. The substituents are each independently selected from deuterium, halogen, cyano, C1-C 36 linear alkyl groups, C1-C 36 linear alkenyl groups, C1-C 36 linear alkynyl groups, C3-C 36 cycloalkyl groups, C4-C 36 cycloalkenyl groups, C4-C 36 cycloalkynyl groups, C1-C 30 alkoxy groups, C1-C 30 thioalkoxy groups, carbonyl, carboxyl, nitro, silyl, amino, C6-C 30 arylamino groups, C3-C 30 heteroarylamino groups, C6-C 60 monocyclic aryl groups, C 8- C 60 fused-ring aryl groups, C6-C 60 aryloxy groups, C2-C 60 monocyclic heteroaryl groups, C4-C 60 fused-ring heteroaryl groups;

[0012] R1 to R6 are the same or different and are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, mercapto, cyano, nitro, amidino, nitrile, hydrazone, carboxylic acid group, carboxylate group, sulfonic acid group, sulfonate group, phosphoric acid group, phosphate group, unsubstituted or R7-substituted C1-C 30 alkyl groups, C2-C 10 alkenyl groups, C2-C 10 alkynyl groups, C1-C 10 alkoxy groups, C1-C 10 alkylthio groups, C3-C 10 cycloalkyl groups, C1-C 10 heterocycloalkyl groups, C3-C 10 cycloalkenyl groups, C2-C 10 heterocycloalkenyl groups, C6-C 30 aryl groups, C7-C 30 aralkyl groups, C6-C 30 aryloxy groups, C6-C 30 arylthio groups, C2-C 30 heteroaryl groups, C3-C 30 heteroaralkyl groups, C2-C 30 heteroaryloxy groups, C2-C 30Heteroarylthio, -N(Q1)(Q2), -Si(Q3)(Q4)(Q5), -B(Q6)(Q7) or -P(=O)(Q8)(Q9);

[0013] R9 is selected from unsubstituted or R7-substituted C1-C 10 alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl, C1-C 10 alkoxy, C1-C 10 alkylthio, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C2-C 10 heterocycloalkenyl, C6-C 30 aryl, C6-C 30 aralkyl, C6-C 30 aryloxy, C6-C 30 arylthio, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy, C2-C 30 heteroarylthio;

[0014] R 10 、R 11 are each independently selected from unsubstituted or R7-substituted C1-C 10 alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl, C1-C 10 alkoxy, C1-C 10 alkylthio, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C2-C 10 heterocycloalkenyl, C6-C 30 aryl, C7-C 30 aralkyl, C6-C 30 aryloxy, C6-C 30 arylthio, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy, C2-C 30 heteroarylthio;

[0015] R7 is the same or different and is selected from hydrogen, deuterium, -F, -Cl, -Br, -I, -CD3, -CD2H, -CDH2, -CF3, -CF2H, -CFH2, hydroxy, mercapto, cyano, nitro, amidino, nitrile, hydrazone, carboxylic acid group, carboxylate group, sulfonic acid group, sulfonate group, phosphoric acid group, phosphate group, C1-C 10 alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl, C1-C 10 alkoxy, C1-C 10 alkylthio, C3-C 10 cycloalkyl, C2-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C2-C 10 heterocycloalkenyl, C6-C 30 aryl, C6-C 30 aralkyl, C6-C 30 aryloxy, C6-C 30 arylthio, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy, C2-C 30 heteroarylthio, -N(Q 11 )(Q 12 )、-Si(Q 13 )(Q 14 )(Q 15 )、-B(Q 16 )(Q 17 ) or -P(=O)(Q 18 )(Q 19 );

[0016] R8 is the same or different and is selected from hydrogen, deuterium, -F, -Cl, -Br, -I, -CD3, -CD2H, -CDH2, -CF3, -CF2H, -CFH2, hydroxy, mercapto, cyano, nitro, amidino, nitrile, hydrazone, carboxylic acid group, carboxylate group, sulfonic acid group, sulfonate group, phosphoric acid group, phosphate group, C1-C 10 alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl, C1-C 10 alkoxy, C1-C 10 alkylthio, C3-C 10 cycloalkyl, C2-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C2-C 10 heterocycloalkenyl, C6-C 30 aryl, C7-C30 Arylalkyl, C6-C 30 Aryloxy, C6-C 30 Arylthio, C2-C 30 Heteroaryl, C3-C 30 Heteroarylalkyl, C2-C 30 Heteroaryloxy, C2-C 30 Heteroarylthio;

[0017] Q1-Q9, Q 11 -Q 19 Same or different, each independently selected from hydrogen, deuterium, C1-C 10 Alkyl, C2-C 10 Alkenyl, C2-C 10 Alkynyl, C1-C 10 Alkoxy, C1-C 10 Alkylthio, C3-C 10 Cycloalkyl, C2-C 10 Heterocycloalkyl, C3-C 10 Cycloalkenyl, C2-C 10 Heterocycloalkenyl, C6-C 30 Aryl, C7-C 30 Arylalkyl, C6-C 30 Aryloxy, C6-C 30 Arylthio, C2-C 30 Heteroaryl, C3-C 30 Heteroarylalkyl, C2-C 30 Heteroaryloxy, C2-C 30 Heteroarylthio;

[0018] Wherein, the heteroatom is one or more of N, O, S, Si.

[0019] As a preference of the present invention, when there are substituent groups on the Ar1 ring and the Ar2 ring, the substituent groups are each independently selected from deuterium, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, 2,2-dicyano vinyl, phenyl, naphthyl, anthracenyl, benzanthracenyl, phenanthryl, benzophenanthryl, pyrenyl, perylenyl, fluoranthenyl, tetraphenyl, pentaphenyl, benzopyrenyl, biphenyl, terphenyl, quaterphenyl, fluorenyl, spirobifluorenyl, dihydrophenanthryl, dihydropyrenyl, tetrahydropyrenyl, cis- or trans-indeno[1,2-b]fluorene, trimeric indene, isomeric trimeric indene, spirotrimeric indene, spiroisomeric trimeric indene, furyl, benzofuryl, isobenzofuryl, dibenzofuryl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, pyrrolyl, isoindolyl, carbazolyl, indeno[1,2-b]carbazolyl, pyridyl, quinolinyl, isoquinolinyl, acridinyl, phenanthridinyl, benzo[5,6]quinolinyl, benzo[6,7]quinolinyl, benzo[7,8]quinolinyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthimidazolyl, phenanthrimidazolyl, pyridinimidazolyl, pyrazinimidazolyl, quinoxalinimidazolyl, oxazolyl, benzoxazolyl, naphthoxazolyl, anthraoxazolyl, phenanthroxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthracenyl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4,5-diazapyrenyl, 4,5,9,10-tetraazaperopyrenyl, pyrazinyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbazolyl, phenanthroline, 1,2,3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetrazinyl, 1,2,3,4-tetrazinyl, 1,2,3,5-tetrazinyl, purinyl, pteridinyl, indolizinyl, benzothiadiazolyl, 9,9-dimethylacridinyl, diarylamino, adamantyl, fluorophenyl, methylphenyl, trimethylphenyl, cyanophenyl, pyrrolidine, piperidine, methoxy, silyl, cyano, fluorine, chlorine;

[0020] R1 to R6 are the same or different and are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxy, mercapto, cyano, nitro, unsubstituted or R7-substituted C1-C 20Alkyl, C3-C 10 Cycloalkyl, C6-C 30 Aryl, C7-C 30 Aralkyl, C6-C 30 Aryloxy, C2-C 30 Heteroaryl, C3-C 30 Heteroaralkyl, C2-C 30 Heteroaryloxy, -N(Q1)(Q2), -Si(Q3)(Q4)(Q5), -B(Q6)(Q7);

[0021] R9, R 10 , R 11 are each independently selected from unsubstituted or R7-substituted C1-C 10 alkyl, C6-C 30 aryl;

[0022] R7 are the same or different and are selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, mercapto, cyano, nitro, unsubstituted or R8-substituted C1-C 10 alkyl, C3-C 10 cycloalkyl, C6-C 30 aryl, C7-C 30 aralkyl, C6-C 30 aryloxy, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy, -N(Q 11 )(Q 12 ), -Si(Q 13 )(Q 14 )(Q 15 ), -B(Q 16 )(Q 17 );

[0023] R8 are the same or different and are selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, mercapto, cyano, nitro, C1-C 10 alkyl, C3-C 10 cycloalkyl, C6-C 30 aryl, C7-C 30 aralkyl, C6-C 30 aryloxy, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy;

[0024] Q1-Q9, Q 11 -Q 19 are the same or different and each independently selected from hydrogen, deuterium, C1-C 10Alkyl, C3-C 10 Cycloalkyl, C6-C 30 Aryl, C7-C 30 Aralkyl, C6-C 30 Aryloxy, C2-C 30 Heteroaryl, C3-C 30 Heteroaralkyl, C2-C 30 Heteroaryloxy.

[0025] As a preference of the present invention, X 1 is represented as none or a direct bond, and the general formula I is represented by the following general formula I-1 or general formula I-2:

[0026]

[0027] The Ar1 ring and the Ar2 ring are each independently selected from substituted or unsubstituted C6-C 20 aryl rings;

[0028] R1 to R6 are the same or different and are each independently selected from hydrogen, D, fluorine, hydroxyl, mercapto, unsubstituted or R7-substituted C1-C 20 alkyl, C6-C 20 aryl, C7-C 20 aralkyl, C6-C 20 aryloxy, C2-C 20 heteroaryl, C3-C 20 heteroaralkyl, C2-C 20 heteroaryloxy, -N(Q1)(Q2), -Si(Q3)(Q4)(Q5), -B(Q6)(Q7);

[0029] R9, R 10 、R 11 are each independently selected from unsubstituted or R7-substituted C1-C 10 alkyl, C6-C 20 aryl;

[0030] R7 are the same or different and are selected from hydrogen, hydroxyl, mercapto, unsubstituted or R8-substituted C1-C4 alkyl, C6-C 20 aryl, C7-C 20 aralkyl, C6-C 20 aryloxy, C2-C 20 heteroaryl, C3-C 20 heteroaralkyl, C2-C 20 heteroaryloxy, -N(Q 11 )(Q 12 ), -Si(Q 13 )(Q 14 )(Q 15 )、-B(Q 16 )(Q17 ));

[0031] R8 is the same or different and is selected from hydrogen, methyl, isopropyl, tert-butyl, C6-C 20 aryl, C7-C 20 aralkyl, C6-C 20 aryloxy, C2-C 20 heteroaryl, C3-C 20 heteroaralkyl, C2-C 20 heteroaryloxy;

[0032] Q1-Q9, Q 11 -Q 19 are the same or different and each independently is selected from hydrogen, C1-C4 alkyl, C6-C 20 aryl, C7-C 20 aralkyl, C6-C 20 aryloxy, C2-C 20 heteroaryl, C3-C 20 heteroaralkyl, C2-C 20 heteroaryloxy.

[0033] 4. A boron and nitrogen-containing polycyclic compound based on an indolocarbazole structure according to claim 1, wherein R1 to R6 are the same or different and each independently is selected from H, D, fluorine, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, hexyl, octyl, decyl, methoxy, ethoxy, butoxy, hexyloxy, cyclohexyl, adamantyl, phenyl, 4-methyl-phenyl, 4-ethyl-phenyl, 4-propyl-phenyl, 4-isopropylphenyl, 4-n-butylphenyl,

[0034] wherein the wavy line represents the connection site.

[0035] As a preference of the present invention, the compound is selected from the following structures:

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054] The second object of the present invention is to provide a preparation method of a boron and nitrogen-containing polycyclic compound based on an indolocarbazole structure, comprising the following steps:

[0055] (1) Under nitrogen protection and catalyzed by strong alkaline conditions, compound A and compound B with a molar ratio of 1:0.8 to 2 are placed in an organic solvent and heated for reaction for 20 to 30 hours to obtain compound C. The reaction formula is as follows:

[0056]

[0057] (2) Under nitrogen protection and catalyzed by strong alkaline conditions, compound C and compound D with a molar ratio of 1:1.5 to 3 are placed in an organic solvent and heated for reaction for 40 to 50 hours to obtain compound E. The reaction formula is as follows:

[0058]

[0059] (3) Under nitrogen protection, butyllithium (BuLi) is added to a solution of compound E in tert-butylbenzene (t-BuPh) for lithiation reaction for 4 to 12 hours. The molar ratio of compound E to butyllithium is 1:1.5 to 3. Subsequently, boron tribromide (BBr3) is added for boronation reaction for 0.5 to

[0060]

[0061] Preferably in the present invention, R5 and R6 in Compound A are the same or different and are selected from the following structures:

[0062]

[0063] The structural formula of the said Compound B is one of the following structures:

[0064]

[0065] The structural formula of the said Compound D is one of the following structures:

[0066]

[0067] X and X 1 are the same.

[0068] Preferably in the present invention, the general reaction formula of this preparation method is as follows:

[0069]

[0070] Synthesis of Compound C:

[0071] Under nitrogen protection, in a 500 mL two-necked flask, successively add Compound A (1.0 equivalent), Compound B (1.2 equivalents), strongly basic cesium carbonate (Cs2CO3, 4.0 equivalents) and N,N-dimethylformamide (DMF, 300 mL), heat under reflux in an oil bath at 160 °C for 24 hours. After the reaction is completed, cool to room temperature, slowly pour the reaction solution into 1000 mL of distilled water, stir to precipitate a solid, vacuum filter to obtain a white filter cake, then extract and concentrate with dichloromethane / water, and perform column chromatography separation using dichloromethane and petroleum ether with a volume ratio of 2:1 as the eluent to obtain a white solid, which is Compound C;

[0072] Synthesis of Compound E:

[0073] Under nitrogen protection, in a 250 mL two-necked flask, successively add Compound C (1.0 equivalent), Compound D (2.0 equivalents), strongly basic cesium carbonate (Cs2CO3, 5.0 equivalents) and N,N-dimethylformamide (DMF, 150 mL), heat under reflux in an oil bath at 160 °C for 48 hours. After the reaction is completed, cool to room temperature, slowly pour the reaction solution into 1000 mL of distilled water, stir to precipitate a solid, vacuum filter to obtain a white filter cake, then extract and concentrate with dichloromethane / water, and perform column chromatography separation using dichloromethane and petroleum ether with a volume ratio of 1:10 as the eluent to obtain a white solid, which is Compound E.

[0074] Synthesis of the target compound F:

[0075] Under nitrogen protection and in an ice-water bath, in a 100 mL dry two-necked flask, dissolve compound E (1.0 equivalent) in tert-butylbenzene (t-BuPh, 40 mL), stir and cool down to 0 °C. Subsequently, slowly add n-butyllithium (nBuLi, 2.5 M pentane solution, 3.0 equivalents) to the reaction system, control the dropping rate to keep the reaction temperature between 0 and 5 °C. After the addition is complete, raise the temperature to 50 °C and continue stirring for 5 hours. After the reaction is completed, remove the organic solvent under reduced pressure; cool the reaction system to -30 °C again, add boron tribromide (BBr3, 3.0 equivalents) and stir for 1 hour. After the reaction warms back to room temperature, slowly add N,N-diisopropylethylamine (DIEA, 5.0 equivalents) at 0 °C, heat the system to 140 °C, continue stirring for 12 hours, cool to room temperature, add 2 mL of methanol to quench the residual BBr3, stir for 10 minutes, then transfer the mixture to a separatory funnel, add an equal volume of water and dichloromethane, perform extraction three times, combine the organic phases, dry with anhydrous sodium sulfate, filter and concentrate. The obtained crude product is purified by column chromatography, collect the target fraction and concentrate. Finally, place the purified product in a vacuum sublimation device and perform gradient sublimation starting from 120 °C and rising to above 350 °C to obtain the target compound F.

[0076] The third object of the present invention is to provide an organic electroluminescent device, including a first electrode, a second electrode and an organic material layer disposed therebetween. The organic material layer includes a light-emitting layer, and the light-emitting layer includes a host material and a doping material. The doping material contains the above-mentioned boron and nitrogen-containing polycyclic compound based on the indolo[2,3-a]carbazole structure.

[0077] Preferably, the organic electroluminescent device of the present invention is applied in a display device, and the display device is a mobile phone display screen, a computer display screen, a television display screen, a smart watch display screen, a smart car display panel, a VR or AR helmet display screen, or a display of various smart devices.

[0078] Advantages of the present invention:

[0079] The boron and nitrogen-containing polycyclic aromatic hydrocarbon organic optoelectronic functional material of the present invention based on the indolo[2,3-a]carbazole structure aims to solve the problems of insufficient color purity, low luminous efficiency and poor stability of existing red light-emitting materials. By fusing the 11,12-dihydroindolo[2,3-a]carbazole (ICz) donor and the 1,4-aza-borabenzene (BNCz) core through an intramolecular covalent bond to construct a rigid near-planar structure, maximizing the orbital overlap of the orbitals, enhancing the intramolecular charge transfer effect, and realizing red light emission. In addition, while reducing the molecular weight to achieve red light emission, the thermal decomposition temperature of the materials all reaches above 400 °C, which is suitable for the vacuum thermal evaporation process. Brief Description of the Drawings

[0080] The drawings described herein are provided to further understand the present invention and form a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0081] Figure 1 is the photoluminescence spectrum of Compound 3 in toluene solution (concentration: 1×10 -5 M);

[0082] Figure 2 is the electroluminescence spectrum diagram of Compound 3. Detailed Description of the Embodiments

[0083] The present invention will be further described in detail below with reference to specific embodiments and drawings, but the embodiments of the present invention are not limited thereto. The experimental methods without specific conditions noted in the following embodiments are carried out according to conventional methods and conditions, or selected according to the product specifications. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0084] Preparation Examples

[0085] Taking Compounds 3, 13, 21, 24, 37, 46, 53, 58, 69, 71, 88, 93, 106, 115, 122, 137, 149, 151, 164, 178, 183, 196, 205, 212, 227, 234, 241, 258, 263, 270, 325, 333, 336, 357, 360 as examples to illustrate the specific details of the preparation example experiments:

[0086] Example 1:

[0087] [[ID=……]]

[0088] Add (2.11 g, 10.00 mmol), (3.08 g, 12.00 mmol), cesium carbonate (13.04 g, 40.00 mmol) and 300 mL of N,N-dimethylformamide into a 500 mL two-necked flask. Under nitrogen protection, heat at 160 °C in an oil bath for 24 hours to stop the reaction. Pour the reaction mixture into distilled water to precipitate, and vacuum filter to obtain a white filter cake. Then dissolve the filter cake in dichloromethane, extract with dichloromethane / water and rotary evaporate. After concentration, column chromatography separation is carried out with dichloromethane and petroleum ether (the volume ratio of dichloromethane to petroleum ether is 2:1) as the eluent to obtain white intermediate 1-A (3.59 g, yield 84%);

[0089] Add intermediate 1-A (2.14 g, 5.00 mmol) to a 250 mL two-necked flask, (2.79 g, 10.00 mmol), cesium carbonate (8.15 g, 25.00 mmol) and 150 mL of N,N-dimethylformamide. Under nitrogen protection, heat at 160 °C in an oil bath for 48 hours to stop the reaction. Pour the reaction mixture into distilled water to precipitate, and obtain a white filter cake by vacuum filtration. Subsequently, dissolve the filter cake in dichloromethane, extract with dichloromethane / water and rotary evaporate to dryness. After concentration, separate by column chromatography with dichloromethane and petroleum ether (volume ratio 1:10) as the eluent to obtain white intermediate 1-B (3.30 g, yield 96%);

[0090] Under nitrogen protection and in an ice-water bath, slowly add n-butyllithium solution (5.24 mL, 13.11 mmol) dropwise to a solution of intermediate 1-B (3.00 g, 4.37 mmol) in tert-butylbenzene (40.00 mL). Then heat to 50 °C and stir for 5 hours, and remove n-pentane in vacuo. Then add boron tribromide (1.3 mL, 13.11 mmol) at -30 °C, and stir the reaction system at room temperature for 1 hour. Finally, add N,N-diisopropylethylamine (4.99 mL, 21.85 mmol) at 0 °C, stir the reaction system at 140 °C for 12 hours, and then cool to room temperature. Add 2 mL of methanol to the reaction system to quench the residual boron tribromide. Extract the mixture with 40 mL of water and 40 mL of dichloromethane, combine the organic layers, concentrate in vacuo, purify by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:20), and then obtain a red-violet solid compound 3 (0.73 g, yield 27%) by vacuum gradient sublimation. MS: 615.59, elemental analysis (%): C, 82.71; H, 3.79; N, 6.81; O, 3.87.

[0091] Example 2:

[0092] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with through nucleophilic substitution reaction to obtain an intermediate, and finally obtaining a purple-red solid compound 13 with a yield of 29%. MS: 533.45, elemental analysis (%): C, 85.55; H, 4.52; N, 7.87.

[0093] Example 3:

[0094] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, a purple-red solid compound 21 was finally prepared with a yield of 25%, MS: 657.57, elemental analysis (%) : C, 87.66; H, 4.28; N, 6.37.

[0095] Example 4:

[0096] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, a purple-red solid compound 24 was finally prepared with a yield of 26%, MS: 922.01, elemental analysis (%) : C, 88.59; H, 5.70; N, 4.55.

[0097] Example 5:

[0098] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, a purple-red solid compound 37 was finally prepared with a yield of 28%, MS: 530.41, elemental analysis (%) : C, 83.77; H, 4.20; N, 7.30; O, 2.78.

[0099] Example 6:

[0100] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, a purple-red solid compound 46 was finally prepared with a yield of 30%, MS: 507.25, elemental analysis (%) : C, 73.54; H, 3.48; N, 5.76.

[0101] Example 7:

[0102] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, a purple-red solid compound 53 was finally prepared with a yield of 29%, MS: 639.35, elemental analysis (%) : C, 71.14; H, 2.48; N, 6.29.

[0103] Example 8:

[0104] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, a purple-red solid compound 58 was finally prepared with a yield of 27%, MS: 565.43, elemental analysis (%) : C, 80.55; H, 4.28; N, 7.15; O, 5.48.

[0105] Example 9:

[0106] Similar to the preparation reaction of Compound 3, using as the raw material, successively reacting with through nucleophilic substitution reaction to obtain an intermediate, and finally preparing a purple-red solid Compound 69 with a yield of 25%, MS: 587.52, elemental analysis (%) : C, 85.95; H, 5.17; N, 6.98.

[0107] Example 10:

[0108] Similar to the preparation reaction of Compound 3, using as the raw material, successively reacting with through nucleophilic substitution reaction to obtain an intermediate, and finally preparing a purple-red solid Compound 71 with a yield of 31%, MS: 671.68, elemental analysis (%) : C, 85.89; H, 6.49; N, 5.96.

[0109] Example 11:

[0110] Similar to the preparation reaction of Compound 3, using as the raw material, successively reacting with through nucleophilic substitution reaction to obtain an intermediate, and finally preparing a purple-red solid Compound 88 with a yield of 31%, MS: 1102.17, elemental analysis (%) : C, 87.36; H, 5.61; N, 6.26.

[0111] Example 12:

[0112] Similar to the preparation reaction of Compound 3, using as the raw material, successively reacting with through nucleophilic substitution reaction to obtain an intermediate, and finally preparing a purple-red solid Compound 93 with a yield of 31%, MS: 531.40, elemental analysis (%) : C, 85.80; H, 4.20; N, 7.85.

[0113] Example 13:

[0114] Similar to the preparation reaction of Compound 3, using as the raw material, successively reacting with through nucleophilic substitution reaction to obtain an intermediate, and finally preparing a purple-red solid Compound 106 with a yield of 25%, MS: 587.52, elemental analysis (%) : C, 85.62; H, 4.90; N, 7.36.

[0115] Example 14:

[0116] Similar to the preparation reaction of Compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, a purple-red solid compound 115 was finally prepared with a yield of 28%, MS: 617.59, elemental analysis (%) : C, 85.56; H, 5.87; N, 6.79.

[0117] Example 15:

[0118] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, a purple-red solid compound 122 was finally prepared with a yield of 29%, MS: 825.90, elemental analysis (%) : C, 87.25; H, 6.34; N, 5.10.

[0119] Example 16:

[0120] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, a purple-red solid compound 137 was finally prepared with a yield of 29%, MS: 617.61, elemental analysis (%) : C, 85.57; H, 5.87; N, 6.79.

[0121] Example 17:

[0122] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, a purple-red solid compound 149 was finally prepared with a yield of 26%, MS: 837.79, elemental analysis (%) : C, 85.88; H, 4.58; N, 8.54.

[0123] Example 18:

[0124] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, a purple-red solid compound 151 was finally prepared with a yield of 30%, MS: 950.01, elemental analysis (%) : C, 86.12; H, 5.60; N, 7.28.

[0125] Example 19:

[0126] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, the purple-red solid compound 164 was finally prepared with a yield of 30%, MS: 711.67, elemental analysis (%) : C, 88.04; H, 4.53; N, 6.04.

[0127] Example 20:

[0128] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, the purple-red solid compound 178 was finally prepared with a yield of 27%, MS: 671.69, elemental analysis (%) : C, 85.79; H, 6.13; N, 6.37.

[0129] Example 21:

[0130] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, the purple-red solid compound 183 was finally prepared with a yield of 30%, MS: 767.78, elemental analysis (%) : C, 87.82; H, 5.36; N, 5.44.

[0131] Example 22:

[0132] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, the purple-red solid compound 196 was finally prepared with a yield of 27%, MS: 825.91, elemental analysis (%) : C, 87.10; H, 6.09; N, 5.38.

[0133] Example 23:

[0134] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, the purple-red solid compound 205 was finally prepared with a yield of 24%, MS: 561.45, elemental analysis (%) : C, 85.56; H, 5.02; N, 7.45.

[0135] Example 24:

[0136] Similar to the preparation reaction of compound 3, using as the raw material, successively reacting with After the nucleophilic substitution reaction to obtain the intermediate, the purple-red solid compound 212 was finally prepared with a yield of 26%, MS: 932.04, elemental analysis (%) : C, 85.04; H, 5.83; N, 4.48.

[0137] Example 25:

[0138] Similar to the preparation reaction of compound 3, As raw materials, After the intermediate was obtained by nucleophilic substitution reaction, purple solid compound 227 was finally prepared with a yield of 28%, MS: 755.72, elemental analysis (%): C, 85.83; H, 5.06; N, 5.55; O, 2.10.

[0139] Example 26:

[0140] Similar to the preparation reaction of compound 3, As raw materials, and After the intermediate was obtained by nucleophilic substitution reaction, purple solid compound 234 was finally prepared with a yield of 27%, MS: 829.84, elemental analysis (%): C, 88.30; H, 5.33; N, 5.07.

[0141] Example 27:

[0142] Similar to the preparation reaction of compound 3, As raw materials, After the intermediate was obtained by nucleophilic substitution reaction, purple solid compound 241 was finally prepared with a yield of 25%, MS: 1008.05, elemental analysis (%): C, 86.97; H, 4.99; N, 6.94.

[0143] Example 28:

[0144] Similar to the preparation reaction of compound 3, As raw materials, After the intermediate was obtained by nucleophilic substitution reaction, purple solid compound 258 was finally prepared with a yield of 25%, MS: 683.61, elemental analysis (%): C, 87.84; H, 4.41; N, 6.14.

[0145] Example 29:

[0146] Similar to the preparation reaction of compound 3, As raw materials, After the intermediate was obtained by nucleophilic substitution reaction, purple solid compound 263 was finally prepared with a yield of 29%, MS: 771.73, elemental analysis (%): C, 88.82; H, 4.34; N, 5.56.

[0147] Example 30:

[0148] Similar to the preparation reaction of compound 3, as raw materials, successively react with After obtaining the intermediate through nucleophilic substitution reaction, a purple-red solid compound 270 was finally prepared with a yield of 28%, MS: 949.92, elemental analysis (%) : C, 87.22; H, 4.50; N, 7.58.

[0149] Example 31:

[0150] Similar to the preparation reaction of Compound 3, using as raw materials, successively react with After obtaining the intermediate through nucleophilic substitution reaction, a purple-red solid compound 325 was finally prepared with a yield of 27%, MS: 819.75, elemental analysis (%) : C, 89.36; H, 4.16; N, 5.12.

[0151] Example 32:

[0152] Similar to the preparation reaction of Compound 3, using as raw materials, successively react with After obtaining the intermediate through nucleophilic substitution reaction, a purple-red solid compound 333 was finally prepared with a yield of 24%, MS: 819.76, elemental analysis (%) : C, 89.35; H, 4.15; N, 5.14.

[0153] Example 33:

[0154] Similar to the preparation reaction of Compound 3, using as raw materials, successively react with After obtaining the intermediate through nucleophilic substitution reaction, a purple-red solid compound 336 was finally prepared with a yield of 29%, MS: 817.75, elemental analysis (%) : C, 89.58; H, 3.96; N, 5.12.

[0155] Example 34:

[0156] Similar to the preparation reaction of Compound 3, using as raw materials, successively react with After obtaining the intermediate through nucleophilic substitution reaction, a purple-red solid compound 357 was finally prepared with a yield of 25%, MS: 744.67, elemental analysis (%) : C, 87.11; H, 3.91; N, 7.48.

[0157] Example 35:

[0158] Similar to the preparation reaction of Compound 3, using as raw materials, successively react with After the intermediate was obtained by nucleophilic substitution reaction, purple solid compound 360 was finally prepared with a yield of 28%, MS: 746.67, elemental analysis (%): C, 86.85; H, 4.17; N, 7.50.

[0159] Device Examples

[0160] In order to evaluate the luminescent properties of the compounds of the present invention in organic electroluminescent devices, a series of OLED devices based on multilayer organic thin film structures were designed and constructed. The specific preparation process is as follows:

[0161] (1) Substrate pretreatment

[0162] The substrate used is a conductive glass plate pre-coated with indium tin oxide (ITO). Its surface resistivity is approximately 15Ω / sq, which combines good electrical conductivity with visible light transmittance. Before device fabrication, it must be thoroughly cleaned to remove residual impurities and increase surface energy. The specific steps are as follows:

[0163] First, immerse the ITO glass in a commercial glass cleaner (such as 2% Elma EC or equivalent) and perform ultrasonic treatment for 20 to 30 minutes; then rinse thoroughly with deionized water to remove the residual cleaning agent; then place the substrate in a mixed solvent of acetone and ethanol for ultrasonic cleaning, treating each solvent twice for 10 minutes each time to further remove oil and organic impurities; the cleaned substrate is placed in a clean oven and heat-dried at about 100°C for at least 30 minutes to ensure that the surface moisture is completely removed; after cooling to room temperature, it is treated with a UV / ozone cleaning system for 10 minutes to further improve the hydrophilicity and hole injection ability of the ITO surface; finally, to further enhance the adhesion and interface quality of the organic layer, the substrate surface is bombarded with a low-energy ion beam (such as argon ions) to form a cleaner and more activated surface for subsequent organic layer deposition.

[0164] (2) Construction of hole injection layer (HIL)

[0165] The treated ITO substrate is placed in a vacuum evaporation chamber. After the system reaches high vacuum, the hole injection layer is first deposited. This layer uses a co-evaporation combination of HT and HI (mass ratio 97:3, w / w). The two materials are placed in different evaporation sources, and precise proportional control is achieved by adjusting the evaporation rate. The deposition rate is set to 0.1nm / s, and a uniform film of approximately 10nm is finally formed. This doping system is designed to improve the energy level matching between the anode and the organic layer and reduce the hole injection barrier.

[0166] (3) Deposition of hole transport layer (HTL) and electron blocking layer (EBL)

[0167] On top of the HIL, a hole transport layer (HTL) is continuously deposited. The material used is an HT series aromatic amine derivative, and the film thickness is controlled to be 60 nm. The evaporation rate is also set to 0.1 nm / s. The main function of this layer is to efficiently transport holes and suppress electron back-injection, maintaining good charge balance in the device. Subsequently, an electron blocking layer (EBL) with a thickness of 5 nm is deposited, still using HT-based materials, aiming to limit the penetration of electrons into the HTL region, thereby effectively enhancing the binding ability and recombination efficiency of excitons in the light-emitting region.

[0168] (4) Construction of the emission layer (EML)

[0169] The emission layer adopts a multi-source co-evaporation process. The host and guest materials are placed in independent evaporation sources respectively, and a co-doped composite emission film is formed by controlling the evaporation rate ratio at 100:3 (w / w). The main material is a TH-based host material, and the guest material is the red-light emitting material synthesized in this invention. The co-evaporation thickness is controlled to be 30 nm, and the evaporation rate is stably controlled within 0.1 nm / s.

[0170] (5) Construction of the electron transport region (HBL + ETL + EIL)

[0171] After the deposition of the emission layer, a 5-nm-thick hole blocking layer (HBL) is first deposited on it. The material is selected from the ET series, which is used to block the escape of holes to the electron region and enhance the electron injection interface simultaneously.

[0172] Subsequently, a 30-nm-thick electron transport layer (ETL) is deposited on the HBL, adopting a doping system of ET and LiQ (mass ratio 50:50, w / w). This combination helps to improve the electron transport rate and interface injection efficiency. The evaporation rate of the ETL is controlled at 0.1 nm / s. As the electron injection layer (EIL), a 0.5-nm-thick LiF is further deposited on the top of the ETL. Its excellent insulation and extremely low work function help to form an interface dipole and improve the electron injection efficiency from the Al cathode to the ETL.

[0173] (6) Deposition of the metal electrode (cathode)

[0174] Finally, an aluminum metal electrode with a thickness of about 150 nm is deposited on the EIL by thermal evaporation. The evaporation rate is set to 1.0 nm / s to form the cathode of the device. The evaporation processes of the entire organic layer and the cathode are completed in a continuous vacuum to avoid interface oxidation or contamination.

[0175] After the device is fabricated, it can be directly packaged or transferred to the testing process.

[0176] The structure of the organic light-emitting device constructed in this embodiment is as follows:

[0177] ITO / HIL (HT-4:HI-3 = 97:3, w / w, 10 nm) / HTL (HT-4, 30 nm) / EBL (HT-14, 10 nm) / EML (TH-5:MR-TADF = 100:3, w / w, 30 nm) / HBL (ET-13, 10 nm) / ETL (ET-14:LiQ = 50:50, w / w, 30 nm) / EIL (LiF, 0.5 nm) / Al (150 nm)

[0178] The descriptions of each functional layer are as follows:

[0179] ITO (Indium Tin Oxide): As the anode, it provides a hole injection channel and has good light transmittance;

[0180] HIL (Hole Injection Layer): Co-evaporated by HT-4 and HI-3 (mass ratio 97:3), with a thickness of about 10 nm, used to reduce the hole injection barrier;

[0181] HTL (Hole Transport Layer): Constructed with HT-4 material, with a thickness of 30 nm, providing an efficient hole transport channel;

[0182] EBL (Electron Blocking Layer): Set with HT-!4, with a thickness of 10 nm, effectively blocking electron penetration and promoting carrier recombination;

[0183] EML (Emitting Layer): Co-evaporated by the host material TH-5 and the red light guest material synthesized in this invention, with a mass ratio of 100:3 and a total thickness of 30 nm, achieving high-efficiency red light emission;

[0184] HBL (Hole Blocking Layer): Using ET-13 material, with a thickness of 10 nm, preventing hole leakage to the cathode side;

[0185] ETL (Electron Transport Layer): Co-evaporated by ET-14 and LiQ (mass ratio 50:50), with a thickness of 30 nm, used to improve electron injection and migration efficiency;

[0186] EIL (Electron Injection Layer): A 0.5 nm thick LiF layer, which can effectively reduce the work function difference between the metal and the organic layer;

[0187] Al (Aluminum Electrode): As the cathode, with a thickness of 150 nm, completing electron collection.

[0188] The compound structures used in the device are as follows:

[0189]

[0190] Device Examples D1 - D20

[0191] The device embodiments D1 - D20 of the present invention are obtained by selecting the organic optoelectronic functional material compounds 3, 13, 21, 24, 37, 46, 53, 58, 69, 71, 88, 93, 106, 115, 122, 137, 149, 151, 164, 178 as the host materials of the light - emitting layer.

[0192] The following performance measurements were carried out on the organic electroluminescent devices prepared by the above - mentioned process: At the same brightness, a digital source meter and a luminance meter were used to measure the turn - on voltage and the full - width at half - maximum (FWHM) of the organic electroluminescent devices prepared in Application Examples D1 - D20. Specifically, the voltage was increased at a rate of 0.1 V per second, and the voltage when the brightness of the organic electroluminescent device reached lcd / m 2 was measured as the turn - on voltage; when it was 10 cd / m 2 the maximum emission peak wavelength, the full - width at half - maximum, and the corresponding CIE color coordinates were obtained; the external quantum efficiency (EQE) of the device was calculated by combining the current density, luminance, and electroluminescence spectrum with the visibility function under the condition that the emission was Lambertian distribution. The electroluminescent performance of the comparative examples and the application example devices is shown in Table 1.

[0193] Table 1 Performance table of organic electroluminescent devices

[0194]

[0195] Among them, the photoluminescence spectrum of Compound 3 in a toluene solution (concentration: 1×10 - 5 M) is as Figure 1 As can be seen from Figure 1 , the emission peak position is 615 nm, and the full - width at half - maximum is 44 nm.

[0196] Figure 2 is the electroluminescence spectrum of Compound 3. As can be seen from Figure 2 , its emission peak position is 624 nm, and the CIE coordinates are (0.67, 0.33), meeting the NTSC standard.

[0197] The above experimental data show that the present invention realizes red light emission by constructing a rigid near - planar structure through the donor - fusion strategy, enhancing the intramolecular charge - transfer effect. In addition, while achieving red light emission by reducing the molecular weight, the thermal decomposition temperature of the materials all reaches above 400 °C, which is suitable for the vacuum thermal evaporation process.

[0198] The above - mentioned embodiments only list the effect data of the devices made of a part of the structural formulas. This is a representative sampling test. Judging from the experimental data, the overall data do not differ much and can represent the effects of other unlisted structures.

[0199] The applicant declares that the organic electroluminescent material and the organic electroluminescent device of the present invention 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 improvement to the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc. all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A boron and nitrogen-containing polycyclic compound based on an indolocarbazole structure, characterized in that, The structure of the compound is shown in General Formula I: wherein, X 1 is represented as one of none, direct bonding, O, S, Se, NR9 or C(R 10 )(R 11 ); The Ar1 ring and the Ar2 ring are each independently selected from substituted or unsubstituted C6-C 60 aryl rings, C5-C 60 heteroaryl rings. When there are substituent groups, the number of substituent groups is selected from 1 to the maximum number of substituent groups allowed for the ring, and two adjacent substituent groups can be connected into a ring through a single bond. The substituent groups are each independently selected from deuterium, halogen, cyano, C1-C 36 linear alkyl groups, C1-C 36 linear alkenyl groups, C1-C 36 linear alkynyl groups, C3-C 36 cycloalkyl groups, C4-C 36 cycloalkenyl groups, C4-C 36 cycloalkynyl groups, C1-C 30 alkoxy groups, C1-C 30 thioalkoxy groups, carbonyl groups, carboxyl groups, nitro groups, silyl groups, amino groups, C6-C 30 arylamino groups, C3-C 30 heteroarylamino groups, C6-C 60 monocyclic aryl groups, C 8- C 60 fused polycyclic aryl groups, C6-C 60 aryloxy groups, C2-C 60 monocyclic heteroaryl groups, C4-C 60 fused polycyclic heteroaryl groups; R1 to R6 are the same or different and each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, mercapto, cyano, nitro, amidino, nitrile, hydrazone, carboxylic acid group, carboxylate group, sulfonic acid group, sulfonate group, phosphoric acid group, phosphate group, unsubstituted or R7-substituted C1-C 30 alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl, C1-C 10 alkoxy, C1-C 10 alkylthio, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C2-C 10 heterocycloalkenyl, C6-C 30 aryl, C7-C 30 aralkyl, C6-C 30 aryloxy, C6-C 30 arylthio, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy, C2-C 30 heteroarylthio, -N(Q1)(Q2), -Si(Q3)(Q4)(Q5), -B(Q6)(Q7) or -P(=O)(Q8)(Q9); R9 is selected from unsubstituted or R7-substituted C1-C 10 alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl, C1-C 10 alkoxy, C1-C 10 alkylthio, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C2-C 10 heterocycloalkenyl, C6-C 30 aryl, C7-C 30 aralkyl, C6-C 30 aryloxy, C6-C 30 arylthio, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy, C2-C 30 heteroarylthio; R 10 and R 11 are each independently selected from unsubstituted or R7-substituted C1-C 10 alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl, C1-C 10 alkoxy, C1-C 10 alkylthio, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C2-C 10 heterocycloalkenyl, C6-C 30 aryl, C7-C 30 aralkyl, C6-C 30 aryloxy, C6-C 30 arylthio, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy, C2-C 30 heteroarylthio; R7 is the same or different and is selected from hydrogen, deuterium, -F, -Cl, -Br, -I, -CD3, -CD2H, -CDH2, -CF3, -CF2H, -CFH2, hydroxyl, mercapto, cyano, nitro, amidino, nitrile, hydrazone, carboxylic acid group, carboxylate group, sulfonic acid group, sulfonate group, phosphoric acid group, phosphate group, unsubstituted or R8-substituted C1-C 10 alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl, C1-C 10 alkoxy, C1-C 10 alkylthio, C3-C 10 cycloalkyl, C2-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C2-C 10 heterocycloalkenyl, C6-C 30 aryl, C6-C 30 aralkyl, C6-C 30 aryloxy, C6-C 30 arylthio, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy, C2-C 30 heteroarylthio, -N(Q 11 )(Q 12 )、-Si(Q 13 )(Q 14 )(Q 15 )、-B(Q 16 )(Q 17 ) or -P(=O)(Q 18 )(Q 19 ); R8 is the same or different and is selected from hydrogen, deuterium, -F, -Cl, -Br, -I, -CD3, -CD2H, -CDH2, -CF3, -CF2H, -CFH2, hydroxyl, mercapto, cyano, nitro, amidino, nitrile, hydrazone, carboxylic acid group, carboxylate group, sulfonic acid group, sulfonate group, phosphoric acid group, phosphate group, C1-C 10 alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl, C1-C 10 alkoxy, C1-C 10 alkylthio, C3-C 10 cycloalkyl, C2-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C2-C 10 heterocycloalkenyl, C6-C 30 aryl, C7-C 30 aralkyl, C6-C 30 aryloxy, C6-C 30 arylthio, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy, C2-C 30 heteroarylthio; Q1-Q9, Q 11 -Q 19 are the same or different and each independently selected from hydrogen, deuterium, C1-C 10 alkyl, C2-C 10 alkenyl, C2-C 10 alkynyl, C1-C 10 alkoxy, C1-C 10 alkylthio, C3-C 10 cycloalkyl, C2-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C2-C 10 heterocycloalkenyl, C6-C 30 aryl, C7-C 30 aralkyl, C6-C 30 aryloxy, C6-C 30 arylthio, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy, C2-C 30 heteroarylthio; Wherein, the heteroatom is one or more of N, O, S, and Si.

2. The boron and nitrogen-containing polycyclic compound based on an indolocarbazole structure according to claim 1, wherein When there are substituent groups on the Ar1 ring and the Ar2 ring, the substituent groups are independently selected from deuterium, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, 2,2-dicyano vinyl, phenyl, naphthyl, anthracenyl, benzanthracenyl, phenanthryl, benzophenanthryl, pyrenyl, perylenyl, fluoranthenyl, tetraphenyl, pentaphenyl, benzopyrenyl, biphenyl, terphenyl, quaterphenyl, fluorenyl, spirobifluorenyl, dihydrophenanthryl, dihydropyrenyl, tetrahydropyrenyl, cis- or trans-indeno[1,2-b]fluorene, trimeric indene, isomeric trimeric indene, spirotrimeric indene, spiroisomeric trimeric indene, furyl, benzofuryl, isobenzofuryl, dibenzofuryl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, pyrrolyl, isoindolyl, carbazolyl, indeno[1,2-c]carbazolyl, pyridyl, quinolinyl, isoquinolinyl, acridinyl, phenanthridinyl, benzo[5,6]quinolinyl, benzo[6,7]quinolinyl, benzo[7,8]quinolinyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthimidazolyl, phenanthrimidazolyl, pyridinimidazolyl, pyrazinimidazolyl, quinoxalinimidazolyl, oxazolyl, benzoxazolyl, naphthoxazolyl, anthraoxazolyl, phenanthrooxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthracenyl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4,5-diazapyrenyl, 4,5,9,10-tetraazaperylene, pyrazinyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbazolyl, phenanthroline, 1,2,3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetrazinyl, 1,2,3,4-tetrazinyl, 1,2,3,5-tetrazinyl, purinyl, pteridinyl, indolizinyl, benzothiadiazolyl, 9,9-dimethylacridinyl, diarylamino, adamantyl, fluorophenyl, methylphenyl, trimethylphenyl, cyanophenyl, pyrrolidine, piperidine, methoxy, silyl, cyano, fluorine, chlorine; R1 to R6 are the same or different and each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, mercapto, cyano, nitro, unsubstituted or R7-substituted C1-C 20 alkyl, C3-C 10 cycloalkyl, C6-C 30 aryl, C7-C 30 aralkyl, C6-C 30 aryloxy, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy, -N(Q1)(Q2), -Si(Q3)(Q4)(Q5), -B(Q6)(Q7); R9, R 10 , R 11 are each independently selected from unsubstituted or R7-substituted C1-C 10 alkyl, C6-C 30 aryl; R7 is the same or different and is selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxy, mercapto, cyano, nitro, unsubstituted or R8-substituted C1-C 10 alkyl, C3-C 10 cycloalkyl, C6-C 30 aryl, C7-C 30 aralkyl, C6-C 30 aryloxy, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy, -N(Q 11 )(Q 12 )、-Si(Q 13 )(Q 14 )(Q 15 )、-B(Q 16 )(Q 17 ); R8 is the same or different and is selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxy, mercapto, cyano, nitro, C1-C 10 alkyl, C3-C 10 cycloalkyl, C6-C 30 aryl, C7-C 30 aralkyl, C6-C 30 aryloxy, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy; Q1-Q9, Q 11 -Q 19 are the same or different and each independently selected from hydrogen, deuterium, C1-C 10 alkyl, C3-C 10 cycloalkyl, C6-C 30 aryl, C7-C 30 aralkyl, C6-C 30 aryloxy, C2-C 30 heteroaryl, C3-C 30 heteroaralkyl, C2-C 30 heteroaryloxy.

3. The boron and nitrogen-containing polycyclic compound based on indolocarbazole structure according to claim 1, characterized in that, X 1 Represented as none or directly linked, general formula I is represented by the following general formula I-1 or general formula I-2: The Ar1 ring and the Ar2 ring are each independently selected from substituted or unsubstituted C6-C 20 aryl rings; R1 to R6 are the same or different and each independently selected from hydrogen, D, fluorine, hydroxyl, mercapto, unsubstituted or R7-substituted C1-C 20 alkyl, C6-C 20 aryl, C7-C 20 aralkyl, C6-C 20 aryloxy, C2-C 20 heteroaryl, C3-C 20 heteroaralkyl, C2-C 20 heteroaryloxy, -N(Q1)(Q2), -Si(Q3)(Q4)(Q5), -B(Q6)(Q7); R9, R 10 , R 11 are each independently selected from unsubstituted or R7-substituted C1-C 10 alkyl, C6-C 20 aryl; R7 is the same or different and is selected from hydrogen, hydroxy, mercapto, unsubstituted or R8-substituted C1-C4 alkyl, C6-C 20 aryl, C7-C 20 aralkyl, C6-C 20 aryloxy, C2-C 20 heteroaryl, C3-C 20 heteroaralkyl, C2-C 20 heteroaryloxy, -N(Q 11 )(Q 12 )、-Si(Q 13 )(Q 14 )(Q 15 )、-B(Q 16 )(Q 17 ); R8 is the same or different and is selected from hydrogen, methyl, isopropyl, tert-butyl, C6-C 20 aryl, C7-C 20 aralkyl, C6-C 20 aryloxy, C2-C 20 heteroaryl, C3-C 20 heteroaralkyl, C2-C 20 heteroaryloxy; Q1-Q9, Q 11 -Q 19 are the same or different and each independently selected from hydrogen, C1-C4 alkyl, C6-C 20 aryl, C7-C 20 aralkyl, C6-C 20 aryloxy, C2-C 20 heteroaryl, C3-C 20 heteroaralkyl, C2-C 20 heteroaryloxy.

4. A boron and nitrogen-containing polycyclic compound based on an indolocarbazole structure according to claim 1, characterized in that, R1 to R6 are the same or different and each independently selected from H, D, fluorine, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, hexyl, octyl, decyl, methoxy, ethoxy, butoxy, hexyloxy, cyclohexyl, adamantyl, phenyl, 4-methyl-phenyl, 4-ethyl-phenyl, 4-propyl-phenyl, 4-isopropylphenyl, 4-n-butylphenyl, Wherein the wavy line represents the connection site.

5. A boron and nitrogen-containing polycyclic compound based on an indolocarbazole structure according to claim 1, characterized in that, The compound is selected from the following structures:

6. The preparation method of any one of the boron-nitrogen polycyclic compounds based on indolocarbazole structure according to claims 1 to 5, characterized in that, Including the following steps: (1) Under nitrogen protection and catalyzed under strongly basic conditions, compound A and compound B with a molar ratio of 1:0.8 - 2 are placed in an organic solvent and heated for reaction for 20 - 30 hours to obtain compound C. The reaction formula is as follows: (2) Under nitrogen protection and catalyzed under strongly basic conditions, compound C and compound D with a molar ratio of 1:1.5 - 3 are placed in an organic solvent and heated for reaction for 40 - 50 hours to obtain compound E. The reaction formula is as follows: (3) Under nitrogen protection, butyllithium is added to the tert - butylbenzene solution of compound E for lithiation reaction for 4 - 12 hours. The molar ratio of compound E to butyllithium is 1:1.5 - 3. Subsequently, boron tribromide is added for boronation reaction for 0.5 - 3 hours, and then N,N - diisopropylethylamine is added for cyclization reaction under reflux for 10 - 15 hours to obtain the target compound F, that is, a boron - and nitrogen - containing polycyclic compound based on the indolocarbazole structure. The reaction formula is as follows:

7. The preparation method of a boron and nitrogen-containing polycyclic compound based on an indolocarbazole structure according to claim 6, characterized in that, R5 and R6 in compound A are the same or different and are selected from the following structures: The structural formula of the said compound B is one of the following structures: The structural formula of the said compound D is one of the following structures:

8. The preparation method of a boron and nitrogen-containing polycyclic compound based on an indolocarbazole structure according to claim 6, characterized in that, The general reaction formula of this preparation method is as follows: Synthesis of compound C: Under nitrogen protection, in a 500 mL two - necked flask, compound A (1.0 equivalent), compound B (1.2 equivalents), strongly basic cesium carbonate (Cs2CO3, 4.0 equivalents) and N,N - dimethylformamide (DMF, 300 mL) are added successively, and heated under reflux in an oil bath at 160 °C for 24 hours. After the reaction is completed, it is cooled to room temperature. The reaction solution is slowly poured into 1000 mL of distilled water, stirred to precipitate, vacuum - filtered to obtain a white filter cake, then extracted and dried by dichloromethane / water, and column - chromatographically separated using dichloromethane and petroleum ether with a volume ratio of 2:1 as the eluent to obtain a white solid, which is compound C; Synthesis of compound E: Under nitrogen protection, in a 250 mL two - necked flask, compound C (1.0 equivalent), compound D (2.0 equivalents), strongly basic cesium carbonate (Cs2CO3, 5.0 equivalents) and N,N - dimethylformamide (DMF, 150 mL) are added successively, and heated under reflux in an oil bath at 160 °C for 48 hours. After the reaction is completed, it is cooled to room temperature. The reaction solution is slowly poured into 1000 mL of distilled water, stirred to precipitate, vacuum - filtered to obtain a white filter cake, then extracted and dried by dichloromethane / water, and column - chromatographically separated using dichloromethane and petroleum ether with a volume ratio of 1:10 as the eluent to obtain a white solid, which is compound E. Synthesis of the target compound F: Under nitrogen protection and an ice-water bath, in a 100 mL dry two-necked flask, compound E (1.0 equivalent) was dissolved in tert-butylbenzene (t-BuPh, 40 mL). The mixture was stirred and cooled to 0 °C. Subsequently, n-butyllithium (nBuLi, 2.5 M pentane solution, 3.0 equivalents) was slowly added dropwise to the reaction system, and the dropping rate was controlled to keep the reaction temperature between 0 and 5 °C. After the addition was complete, the temperature was raised to 50 °C, and stirring was continued for 5 hours. After the reaction was completed, the organic solvent was removed under reduced pressure; the reaction system was cooled to -30 °C again, boron tribromide (BBr3, 3.0 equivalents) was added and stirred for 1 hour. After the reaction warmed to room temperature, N,N-diisopropylethylamine (DIEA, 5.0 equivalents) was slowly added at 0 °C. The system was heated to 140 °C and stirred for another 12 hours. After cooling to room temperature, 2 mL of methanol was added to quench the residual BBr3. After stirring for 10 minutes, the mixture was transferred to a separatory funnel, and an equal volume of water and dichloromethane were added for extraction three times. The organic phases were combined, dried over anhydrous sodium sulfate, filtered and concentrated. The obtained crude product was purified by column chromatography, the target fractions were collected and concentrated. Finally, the purified product was placed in a vacuum sublimation device for gradient sublimation with an initial temperature of 120 °C and raised to above 350 °C to obtain the target compound F.

9. An organic electroluminescent device, comprising a first electrode, a second electrode, and an organic material layer disposed therebetween, characterized in that, The organic material layer includes a light-emitting layer, the light-emitting layer includes a host material and a doping material, and the doping material contains the boron and nitrogen polycyclic compound based on the indolocarbazole structure according to any one of claims 1 to 5.

10. The organic electroluminescent device according to claim 9, wherein The organic electroluminescent device is applied in a display device, and the display device is a mobile phone display screen, a computer display screen, a television display screen, a smart watch display screen, a smart car display panel, a VR or AR helmet display screen, and the display of various smart devices.

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