Fusion donor-based boron-nitrogen heterocyclic derivatives, their preparation and use

Abstract

The application belongs to the technical field of organic optoelectronic material preparation and application, and discloses a boron-nitrogen heterocyclic derivative based on a fusion donor, preparation and application thereof.The organic material takes a boron-nitrogen heterocyclic ring containing different numbers of ring-forming boron atoms as a core, and is obtained by extending the molecular skeleton through the conjugation and ring of the peripheral chemical groups of the fusion donor.The boron-nitrogen heterocyclic derivative based on the fusion donor has excellent light and thermal stability, good electrochemical stability, and excellent electroluminescent performance, and can be applied to an organic electroluminescent device as a host material or a sensitizing agent material or a luminescent material, so that higher device efficiency, stability and color purity can be obtained.

Description

Technical Field

[0001] This invention belongs to the field of organic optoelectronic material preparation and application technology, and more specifically, relates to a boron-nitrogen heterocyclic derivative based on a fusion donor, its preparation and application. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are a type of current-driven organic light-emitting device that achieves electroluminescence through carrier injection and recombination. OLED devices can be classified into four types based on their structure: single-layer, double-layer, triple-layer, and multi-layer structures. Currently, multi-layer structures are commonly used, including positive and negative electrode layers and various organic functional layers sandwiched between the electrode layers. Compared to traditional LED devices, OLED devices offer advantages such as thinness, high brightness, low power consumption, fast response, high resolution, good flexibility, and high luminous efficiency, meeting consumers' evolving demands for display technology. OLED technology has made significant progress in the display field. Furthermore, OLED technology has enormous application potential in lighting, smart wearables, medical devices, transportation, and industrial control.

[0003] With the continuous development of OLED technology, the requirements for various performance indicators of OLED luminescent materials are also constantly increasing. Traditional fluorescent materials have an internal quantum efficiency of only 25% and a low external quantum efficiency. Phosphorescent materials and traditional thermo-delayed fluorescence luminescent materials can achieve an internal quantum efficiency of 100%, and the external quantum efficiency of devices can currently reach or even exceed 30%. However, due to the structural relaxation of the excited state of molecules and strong intramolecular charge transfer, the full width at half maximum (FWHM) of organic electroluminescence spectra is usually above 70 nm. Today, the OLED display industry has placed higher demands on resolution, color purity, device power consumption, and device lifetime. Existing traditional thermo-delayed fluorescence and phosphorescent materials, without the addition of external optical technologies, are clearly unable to meet the needs of future display products. Recently, multiple resonance thermo-delayed fluorescence materials (MR-TADF) have attracted widespread attention from the scientific research and industry communities due to their narrower spectral FWHM. However, the reported MR-TADF molecules all use a single group and a single boron atom to construct the resonance core, resulting in a relatively weak molecular structure and a tendency towards planarity. This leads to severe intermolecular stacking between luminescent materials, which easily causes exciton quenching, resulting in a low fluorescence quantum yield (PLQY). Consequently, this has an adverse effect on the low brightness, efficiency, efficiency roll-off, and lifetime of electroluminescent devices (Advanced Materials, 2016, 28(14):2777-2781, Adv Funct Mater, 2020, 30:1908677). On the other hand, due to the influence of the single-boron resonance core framework, MR-TADF molecules are mostly concentrated in the blue and visible light regions, limiting the application of this type of material in the field of organic high-resolution displays. Summary of the Invention

[0004] To address the pressing problems in existing technologies, this invention aims to provide a boron-nitrogen heterocyclic derivative based on a fusion donor strategy, its preparation, and applications. This involves fusing different types of single donor groups with themselves or other groups to form novel fusion donors with large volume, high steric hindrance, and strong rigidity. These fusion donors are then introduced into the resonance core of MR-TADF luminescent molecules, thereby obtaining novel boron-nitrogen heterocyclic derivatives based on fusion donors. Furthermore, the material system of such luminescent molecules is greatly expanded by introducing different numbers of boron atoms. This series of compounds possesses the characteristics of boron-nitrogen multiple induced resonance effects, resulting in narrow-band emission peaks with a full width at half maximum (FWHM) generally below 40 nm. Simultaneously, based on the different electron-donating capabilities of the fusion donors and the varying numbers of boron atoms, a wide range of emission wavelength modulation can be achieved. Applying these organic luminescent molecules as luminescent materials, host materials, or sensitizers in the emissive layer structure of OLED devices can achieve high device efficiency and color purity. In addition, the introduction of fusion donors enhances molecular rigidity and significantly improves the thermodynamic stability of the materials, which is beneficial for improving the stability of electroluminescent devices.

[0005] To achieve the above objectives, according to one aspect of the present invention, a boron-nitrogen heterocyclic derivative based on a fusion donor is provided, the general structural formula of which is shown in formula a, b, or c:

[0006]

[0007] Wherein: R1 is an aromatic amine group with 12-31 carbon atoms or an aromatic amine heterocyclic group with 12-31 carbon atoms; R2 is an aromatic amine group with 12-31 carbon atoms, an aromatic amine heterocyclic group with 12-31 carbon atoms or an aromatic fluorene group with 13-38 carbon atoms; the fusion site of R1 and R2 is a benzene ring group;

[0008] The carbon atom bonded to the boron atom is either the carbon atom at position 1 of the benzene ring at the fusion site of R1 and R2, or the carbon atom at position 1 of the benzene ring at the unfused site of the R1 group.

[0009] Preferably, the aromatic amine group is diphenylamine, carbazole, 9,10-dihydroacridinyl, 9,10-dihydrophenazinyl, 9,9-diphenylacridinyl, 9,9-dimethylacridinyl, diphenylamine derivative, carbazole derivative, 9,10-dihydroacridinyl derivative, 9,10-dihydrophenazinyl derivative, 9,9-diphenylacridinyl derivative, or 9,9-dimethylacridinyl derivative.

[0010] Preferably, the aromatic amine heterocyclic group is phenoxazinyl, phenthiazinyl, phenoxazinyl derivative or phenthiazinyl derivative.

[0011] Preferably, the aromatic fluorene group is 9,9-diphenylfluorenyl, 9,9-dimethylfluorenyl, a 9,9-diphenylfluorenyl derivative or a 9,9-dimethylfluorenyl derivative.

[0012] According to another aspect of the present invention, a method for preparing any of the boron-nitrogen heterocyclic derivatives based on fusion donors is provided, comprising the following steps:

[0013] (1) Using the fusion donor shown in Formula 1 and the meta-trihalobenzene shown in Formula 2 as raw materials, where X in Formula 2 is fluorine, chlorine, bromine or iodine, the boron nitrogen resonance derivative intermediate based on the fusion donor shown in Formula 3 is obtained through CN coupling reaction.

[0014] The reaction formula is:

[0015]

[0016] (2) The boron-nitrogen resonance derivative intermediate based on the fusion donor obtained in step (1) is subjected to a boron-fried-Krawtz reaction using boron trihalide, wherein the halogen in the boron trihalide is the same as the halogen shown in X in step (1), thereby obtaining the boron-nitrogen resonance derivative based on the fusion donor.

[0017] The reaction formula is:

[0018]

[0019] Preferably, the specific process of step (1) is as follows: adding bromine or iodine-containing meta-trihalobenzene, the fusion donor shown in Formula 1, palladium catalyst, ligand, base and solvent into the reaction apparatus, then using nitrogen to purge the air, and then heating to reflux under nitrogen protection conditions. After the reaction is complete, cooling to room temperature for purification and post-processing, the boron-nitrogen resonance derivative intermediate based on the fusion donor shown in Formula 3 is obtained.

[0020] Preferably, the palladium catalyst is tridibenzylacetone dipalladium or palladium acetate;

[0021] Preferably, the ligand is tri-tert-butylphosphine tetrafluoroborate, tri-tert-butylphosphine, or 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl.

[0022] Preferably, the specific process of step (2) is as follows: dissolve the boron-nitrogen resonance derivative intermediate based on the fusion donor shown in Formula 3 into o-dichlorobenzene, then add boron tribromide dropwise, or add a mixture of boron tribromide and triphenylboron dropwise; then heat to 150℃-250℃, react for 20-48 hours, cool to room temperature, put the system in an ice bath, then add NN-diisopropylethylamine, react for 1-5 hours, remove the solvent by vacuum distillation, and then separate and purify by column chromatography to obtain the boron-nitrogen resonance derivative based on the fusion donor;

[0023] Wherein, if the ratio of the amount of boron-nitrogen resonance derivative intermediate based on fusion donor, the volume of o-dichlorobenzene, the amount of boron tribromide, and the amount of N-diisopropylethylamine is 1 mmol: 10-30 ml: 1.5-8 mmol: 12-18 mmol, the boron-nitrogen resonance derivative based on fusion donor shown in formula a is obtained.

[0024] If the ratio of the amount of boron-nitrogen resonance derivative intermediate based on the fusion donor, the volume of o-dichlorobenzene, the amount of boron tribromide, and the amount of N-diisopropylethylamine is 1 mmol:10-30 ml:12-28 mmol:12-18 mmol, then the boron-nitrogen resonance derivative based on the fusion donor shown in formula b is obtained.

[0025] If the ratio of the amount of boron-nitrogen resonance derivative intermediate based on the fusion donor, the volume of o-dichlorobenzene, the amount of boron tribromide, the amount of triphenylboron, and the amount of N-diisopropylethylamine is 1 mmol: 10-30 ml: 2-10 mmol: 1-5 mmol: 12-18 mmol, then the boron-nitrogen resonance derivative based on the fusion donor shown in formula c is obtained.

[0026] According to another aspect of the present invention, the application of any of the boron-nitrogen heterocyclic derivatives based on fusion donors in organic electroluminescent devices is provided;

[0027] Preferably, the boron-nitrogen heterocyclic derivative based on the fusion donor is used as the light-emitting layer material in the organic electroluminescent device.

[0028] According to another aspect of the present invention, an organic electroluminescent device is provided, comprising, from bottom to top, an anode, a hole injection layer, a hole transport layer, an emitting layer, an electron transport layer, an electron injection layer, and a cathode; wherein the material of the emitting layer is any of the boron-nitrogen heterocyclic derivatives based on fusion donors described above.

[0029] Preferably, an electron blocking layer is further included between the hole transport layer and the light-emitting layer, and a hole blocking layer is further included between the light-emitting layer and the electron transport layer.

[0030] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages:

[0031] (1) The boron-nitrogen heterocyclic derivatives based on fusion donors provided by this invention not only have the characteristics of high efficiency of delayed fluorescence materials, but also increase the overall steric hindrance effect of the molecule due to the introduction of fusion donors, reduce the energy difference between the lowest singlet and triplet states of the molecule, and improve the photoluminescence quantum yield, which is conducive to achieving higher device efficiency. Compared with the MR-TADF molecules of general simple groups, it has greater application potential.

[0032] (2) The boron-nitrogen heterocyclic derivatives based on fusion donors described in this invention have strong molecular rigidity, which is beneficial for improving the oscillator strength of the molecule, reducing the excited-state structural relaxation of the molecule, suppressing vibrational coupling, and obtaining a smaller spectral half-width. In addition, these new compounds have large steric hindrance, which can effectively suppress intermolecular interactions and avoid broadening of the emission spectrum when the film is prepared by high-vacuum thermal evaporation.

[0033] (3) The boron-nitrogen heterocyclic derivative preparation process based on fusion donor described in this invention is highly operable, simple and easy to implement, and uses inexpensive and readily available raw materials, which is conducive to large-scale, low-cost preparation. Moreover, using the same intermediate, luminescent molecules containing single boron atoms, double boron atoms, and triple boron atoms can be obtained according to the reaction conditions, which greatly expands the narrow-band material system and meets the current demand of the panel manufacturing industry for wide color gamut materials. Attached Figure Description

[0034] Figure 1 This is a structural diagram of a light-emitting device using the boron-nitrogen heterocyclic derivative described in this invention.

[0035] Figure 2 Normalized electroluminescence spectra of novel boron-nitrogen heterocyclic derivatives a-1, b-20, c-39, a-76, and b-93.

[0036] Figure 3 The diagram shows the specific device structure, device efficiency-brightness, and spectral characteristic curves for Device Example 1. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0038] In summary, the boron-nitrogen heterocyclic derivatives based on fusion donors in this invention are organic materials with boron-nitrogen heterocycles containing different numbers of cyclic boron atoms as the core, which are conjugated and cyclically fused through fusion donors of peripheral chemical groups R1 and R2 to extend the molecular skeleton.

[0039] The boron-nitrogen heterocyclic derivative based on the fusion donor in this invention has a structure as shown in any one of formulas a to c, and the intermediate of the boron-nitrogen heterocyclic derivative based on the fusion donor is shown in the formula intermediate:

[0040]

[0041] Wherein, R1 is independently selected from: aromatic amine groups with 12-31 carbon atoms, and aromatic amine heterocyclic groups with 12-31 carbon atoms; and R2 is independently selected from: aromatic amine groups with 12-31 carbon atoms, aromatic amine heterocyclic groups with 12-31 carbon atoms, and aromatic fluorene groups with 13-38 carbon atoms; and R1 and R2 form a novel fusion donor group and the fusion site of R1 and R2 is a benzene ring group; the carbon atom bonded to the boron atom is the carbon atom at position 1 of the benzene ring at the fusion site of R1 and R2, or the carbon atom at position 1 of the unfused benzene ring on the R1 group.

[0042] In this case, either R1 or R2 has a carbon atom bonded to the boron atom in the general formula, and this carbon atom is located adjacent to the nitrogen atom. It is preferably a carbon atom on the benzene ring at the fusion of R1 and R2, and secondarily a carbon atom adjacent to the nitrogen atom of the R1 group.

[0043] In some embodiments, the group of the fusion donor may be selected from: the aromatic amine group being diphenylamine, carbazole, 9,10-dihydroacridyl, 9,10-dihydrophenazinyl, 9,9-diphenylacridyl, 9,9-dimethylacridyl, diphenylamine derivative, carbazole derivative, 9,10-dihydroacridyl derivative, 9,10-dihydrophenazinyl derivative, 9,9-diphenylacridyl derivative, or 9,9-dimethylacridyl derivative. In particular, this invention can yield 119 different fusion donor boron-nitrogen heterocyclic derivatives in three categories based on different numbers of boron atoms.

[0044] As a further preferred embodiment of the present invention, the structural formula of the boron-nitrogen heterocyclic derivative based on the fusion donor is shown in any one of formulas a-1 to a-119, b-1 to b-119, and c-1 to c-119, wherein:

[0045] Equations a-1 to a-119 satisfy general equation a, b-1 to b-119 satisfy general equation b, and c-1 to c-119 satisfy general equation c; and:

[0046] In formulas a-1 to a-17, b-1 to b-17 and c-1 to c-17, R1 is a diphenylamino group;

[0047] In formulas a-1, b-1 and c-1, R2 is a diphenylamine group;

[0048] In formulas a-2, b-2 and c-2, R2 is a nitrogen-phenylcarbazolium group, and the boron ring-closure position is at position 2 of the carbazolium group;

[0049] In formulas a-3, b-3 and c-3, R2 is a nitrogen-phenylcarbazolium group, and the boron ring-closure position is at position 3 of the carbazolium group;

[0050] In formulas a-4, b-4 and c-4, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl, and the boron ring closure position is at position 3 of 9,10-dihydroacrylyl.

[0051] In formulas a-5, b-5 and c-5, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacridinyl, and the boron ring closure position is at position 2 of 9,10-dihydroacridinyl.

[0052] In formulas a-6, b-6 and c-6, R2 is 10-phenyl-10H-phenoxazine, and the boron ring closure position is at the 3rd position of the phenoxazine.

[0053] In formulas a-7, b-7 and c-7, R2 is a 10-phenyl-10H-phenoxazine group, and the boron ring closure position is at position 2 of the phenoxazine group;

[0054] In formulas a-8, b-8 and c-8, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring-closure position is at position 3 of the phenoxazine.

[0055] In formulas a-9, b-9 and c-9, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring-closure position is at position 2 of the phenoxazine.

[0056] In formulas a-10, b-10 and c-10, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-dimethyl-9H-fluorenyl;

[0057] In formulas a-11, b-11 and c-11, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-dimethyl-9H-fluorenyl;

[0058] In formulas a-12, b-12 and c-12, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-diphenyl-9H-fluorenyl;

[0059] In formulas a-13, b-13 and c-13, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-diphenyl-9H-fluorenyl;

[0060] In formulas a-14, b-14 and c-14, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 2 of 9,9'-spirobisfluorene;

[0061] In formulas a-15, b-15 and c-15, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 3 of 9,9'-spirobisfluorene;

[0062] In formulas a-16, b-16 and c-16, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 2 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0063] In formulas a-17, b-17 and c-17, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 3 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0064] In formulas a-18 to a-34, b-18 to b-34 and c-18 to c-34, R1 is a carbazoyl group;

[0065] In formulas a-18, b-18 and c-18, R2 is a diphenylamine group;

[0066] In formulas a-19, b-19 and c-19, R2 is a nitrogen-phenylcarbazole group, and the boron ring-closure position is at position 2 of the nitrogen-phenylcarbazole group;

[0067] In formulas a-20, b-20 and c-20, R2 is a nitrogen-phenylcarbazole group, and the boron ring-closure position is at position 3 of the nitrogen-phenylcarbazole group;

[0068] In formulas a-21, b-21 and c-21, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacridinyl, and the boron ring closure position is at position 3 of 9,10-dihydroacridinyl.

[0069] In formulas a-22, b-22 and c-22, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacridinyl, and the boron ring closure position is at position 2 of 9,10-dihydroacridinyl;

[0070] In formulas a-23, b-23 and c-23, R2 is 10-phenyl-10H-phenoxazine, and the boron ring-closure position is at the 3rd site of the phenoxazine.

[0071] In formulas a-24, b-24 and c-24, R2 is 10-phenyl-10H-phenoxazine, and the boron ring-closure position is at position 2 of the phenoxazine.

[0072] In formulas a-25, b-25 and c-25, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring-closure position is at position 3 of the phenoxazine.

[0073] In formulas a-26, b-26 and c-26, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring-closure position is at position 2 of the phenoxazine.

[0074] In formulas a-27, b-27 and c-27, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-dimethyl-9H-fluorenyl;

[0075] In formulas a-28, b-28 and c-28, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-dimethyl-9H-fluorenyl;

[0076] In formulas a-29, b-29 and c-29, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-diphenyl-9H-fluorenyl;

[0077] In formulas a-30, b-30 and c-30, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-diphenyl-9H-fluorenyl;

[0078] In formulas a-31, b-31 and c-31, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 2 of 9,9'-spirobisfluorene;

[0079] In formulas a-32, b-32 and c-32, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 3 of 9,9'-spirobisfluorene;

[0080] In formulas a-33, b-33 and c-33, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 2 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0081] In formulas a-34, b-34 and c-34, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 3 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0082] In formulas a-35 to a-51, b-35 to b-51 and c-35 to c-51, R1 is 9,10-dihydroacridinyl;

[0083] In formulas a-35, b-35 and c-35, R2 is a diphenylamine group;

[0084] In formulas a-36, b-36 and c-36, R2 is a nitrogen-phenylcarbazole group, and the boron ring-closure position is at position 2 of the nitrogen-phenylcarbazole group;

[0085] In formulas a-37, b-37 and c-37, R2 is a nitrogen-phenylcarbazole group, and the boron ring-closure position is at position 3 of the nitrogen-phenylcarbazole group;

[0086] In formulas a-38, b-38 and c-38, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 3 of 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl.

[0087] In formulas a-39, b-39 and c-39, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 2 of 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl.

[0088] In formulas a-40, b-40 and c-40, R2 is 10-phenyl-10H-phenoxazine, and the boron ring closure position is at the 3rd position of the phenoxazine.

[0089] In formulas a-41, b-41 and c-41, R2 is 10-phenyl-10H-phenoxazine, and the boron ring closure position is at position 2 of the phenoxazine.

[0090] In formulas a-42, b-42 and c-42, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring-closure position is at position 3 of the phenoxazine.

[0091] In formulas a-43, b-43 and c-43, R2 is 10-phenyl-10H-phenthiazine R2, and the boron ring-closure position is at position 2 of the phenoxazine.

[0092] In formulas a-44, b-44 and c-44, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-dimethyl-9H-fluorenyl;

[0093] In formulas a-45, b-45 and c-45, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-dimethyl-9H-fluorenyl;

[0094] In formulas a-46, b-46 and c-46, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-diphenyl-9H-fluorenyl;

[0095] In formulas a-47, b-47 and c-47, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-diphenyl-9H-fluorenyl;

[0096] In formulas a-48, b-48 and c-48, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 2 of 9,9'-spirobisfluorene;

[0097] In formulas a-49, b-49 and c-49, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 3 of 9,9'-spirobisfluorene;

[0098] In formulas a-50, b-50 and c-50, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 2 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0099] In formulas a-51, b-51 and c-51, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 3 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0100] In formulas a-52 to a-68, b-52 to b-68 and c-52 to c-68, R1 is a phenoxazine group;

[0101] In formulas a-52, b-52 and c-52, R2 is a diphenylamine group;

[0102] In formulas a-53, b-53 and c-53, R2 is a nitrogen-phenylcarbazole group, and the boron ring-closure position is at position 2 of the nitrogen-phenylcarbazole group;

[0103] In formulas a-54, b-54 and c-54, R2 is a nitrogen-phenylcarbazole group, and the boron ring-closure position is at position 3 of nitrogen-phenylcarbazole.

[0104] In formulas a-55, b-55 and c-55, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 3 of 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl.

[0105] In formulas a-56, b-56 and c-56, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 2 of 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl.

[0106] In formulas a-57, b-57 and c-57, R2 is 10-phenyl-10H-phenoxazine, and the boron ring closure position is at position 3 of 10-phenyl-10H-phenoxazine.

[0107] In formulas a-58, b-58 and c-58, R2 is 10-phenyl-10H-phenoxazine, and the boron ring-closure position is at position 2 of 10-phenyl-10H-phenoxazine.

[0108] In formulas a-59, b-59 and c-59, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring-closure position is at the 3rd position of the phenoxazine.

[0109] In formulas a-60, b-60 and c-60, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring-closure position is at position 2 of the phenoxazine.

[0110] In formulas a-61, b-61 and c-61, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-dimethyl-9H-fluorenyl;

[0111] In formulas a-62, b-62 and c-62, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-dimethyl-9H-fluorenyl;

[0112] In formulas a-63, b-63 and c-63, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-diphenyl-9H-fluorenyl;

[0113] In formulas a-64, b-64 and c-64, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-diphenyl-9H-fluorenyl;

[0114] In formulas a-65, b-65 and c-65, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 2 of 9,9'-spirobisfluorene;

[0115] In formulas a-66, b-66 and c-66, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 3 of 9,9'-spirobisfluorene;

[0116] In formulas a-67, b-67 and c-67, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 2 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0117] In formulas a-68, b-68 and c-68, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 3 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0118] In formulas a-69 to a-85, b-69 to b-85 and c-69 to c-85, R1 is phenthiazinyl;

[0119] In formulas a-69, b-69 and c-69, R2 is a diphenylamine group;

[0120] In formulas a-70, b-70 and c-70, R2 is a nitrogen-phenylcarbazole group, and the boron ring-closure position is at position 2 of the nitrogen-phenylcarbazole group;

[0121] In formulas a-71, b-71 and c-71, R2 is a nitrogen-phenylcarbazole group, and the boron ring-closure position is at position 3 of nitrogen-phenylcarbazole.

[0122] In formulas a-72, b-72 and c-72, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 3 of 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl.

[0123] In formulas a-73, b-73 and c-73, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacridinyl, and the boron ring-closure position is at position 2 of 9,9-dimethyl-10-phenyl-9,10-dihydroacridinyl.

[0124] In formulas a-74, b-74 and c-74, R2 is 10-phenyl-10H-phenoxazine, and the boron ring closure position is at position 3 of 10-phenyl-10H-phenoxazine.

[0125] In formulas a-75, b-75 and c-75, R2 is 10-phenyl-10H-phenoxazine, and the boron ring closure position is at position 2 of 10-phenyl-10H-phenoxazine.

[0126] In formulas a-76, b-76 and c-76, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring-closure position is at position 3 of 10-phenyl-10H-phenthiazine.

[0127] In formulas a-77, b-77 and c-77, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring closure position is at position 2 of 10-phenyl-10H-phenthiazine.

[0128] In formulas a-78, b-78 and c-78, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-dimethyl-9H-fluorenyl;

[0129] In formulas a-79, b-79 and c-79, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-dimethyl-9H-fluorenyl;

[0130] In formulas a-80, b-80 and c-80, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-diphenyl-9H-fluorenyl;

[0131] In formulas a-81, b-81 and c-81, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-diphenyl-9H-fluorenyl;

[0132] In formulas a-82, b-82 and c-82, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 2 of 9,9'-spirobisfluorene;

[0133] In formulas a-83, b-83 and c-83, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 3 of 9,9'-spirobisfluorene;

[0134] In formulas a-84, b-84 and c-84, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 2 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0135] In formulas a-85, b-85 and c-85, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 3 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0136] In formulas a-86 to a-102, b-86 to b-102 and c-86 to c-102, R1 is 5-phenyl-5,10-dihydrophenazinyl;

[0137] In formulas a-86, b-86, and c-86, R2 is a diphenylamine group;

[0138] In formulas a-87, b-87 and c-87, R2 is a nitrogen-phenylcarbazole group, and the boron ring-closure position is at position 2 of the nitrogen-phenylcarbazole group;

[0139] In formulas a-88, b-88, and c-88, R2 is a nitrogen-phenylcarbazole group, and the boron ring-closure position is at position 3 of the nitrogen-phenylcarbazole group;

[0140] In formulas a-89, b-89 and c-89, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 3 of 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl.

[0141] In formulas a-90, b-90 and c-90, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 2 of 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl.

[0142] In formulas a-91, b-91 and c-91, R2 is 10-phenyl-10H-phenoxazine, and the boron ring-closure position is at position 3 of 10-phenyl-10H-phenoxazine.

[0143] In formulas a-92, b-92 and c-92, R2 is 10-phenyl-10H-phenoxazine, and the boron ring-closure position is at position 2 of 10-phenyl-10H-phenoxazine.

[0144] In formulas a-93, b-93 and c-93, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring-closure position is at position 3 of 10-phenyl-10H-phenthiazinyl.

[0145] In formulas a-94, b-94 and c-94, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring-closure position is at position 2 of 10-phenyl-10H-phenthiazinyl.

[0146] In formulas a-95, b-95 ​​and c-95, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-dimethyl-9H-fluorenyl;

[0147] In formulas a-96, b-96 and c-96, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-dimethyl-9H-fluorenyl;

[0148] In formulas a-97, b-97 and c-97, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-diphenyl-9H-fluorenyl;

[0149] In formulas a-98, b-98 and c-98, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-diphenyl-9H-fluorenyl;

[0150] In formulas a-99, b-99 and c-99, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 2 of 9,9'-spirobisfluorene;

[0151] In formulas a-100, b-100, and c-100, R2 is a 9,9'-spirobisfluorene group, and the boron ring closure position is at position 3 of 9,9'-spirobisfluorene;

[0152] In formulas a-101, b-101 and c-101, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 2 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0153] In formulas a-102, b-102 and c-102, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 3 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0154] In formulas a-103 to a-119, b-103 to b-119 and c-103 to c-119, R1 is 9,9-diphenyl-9,10-dihydroacridinyl;

[0155] In formulas a-103, b-103, and c-103, R2 is diphenylamine;

[0156] In formulas a-104, b-104 and c-104, R2 is a nitrogen-phenylcarbazole group, and the boron ring-closure position is at position 2 of the nitrogen-phenylcarbazole group.

[0157] In formulas a-105, b-105, and c-105, R2 is a nitrogen-phenylcarbazole group, and the boron ring-closure position is at position 3 of the nitrogen-phenylcarbazole group.

[0158] In formulas a-106, b-106, and c-106, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 3 of 9,9-dimethyl-10-phenyl-9,10-dihydroacrylyl.

[0159] In formulas a-107, b-107 and c-107, R2 is 9,9-dimethyl-10-phenyl-9,10-dihydroacridinyl, and the boron ring-closure position is at position 2 of 9,9-dimethyl-10-phenyl-9,10-dihydroacridinyl.

[0160] In formulas a-108, b-108, and c-108, R2 is 10-phenyl-10H-phenoxazine, and the boron ring-closure position is at position 3 of 10-phenyl-10H-phenoxazine.

[0161] In formulas a-109, b-109, and c-109, R2 is 10-phenyl-10H-phenoxazine, and the boron ring-closure position is at position 2 of 10-phenyl-10H-phenoxazine.

[0162] In formulas a-110, b-110 and c-110, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring closure position is at position 3 of 10-phenyl-10H-phenthiazine.

[0163] In formulas a-111, b-111, and c-111, R2 is 10-phenyl-10H-phenthiazinyl, and the boron ring closure position is at position 2 of 10-phenyl-10H-phenthiazine.

[0164] In formulas a-112, b-112 and c-112, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-dimethyl-9H-fluorenyl;

[0165] In formulas a-113, b-113 and c-113, R2 is 9,9-dimethyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-dimethyl-9H-fluorenyl;

[0166] In formulas a-114, b-114 and c-114, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 2 of 9,9-diphenyl-9H-fluorenyl;

[0167] In formulas a-115, b-115 and c-115, R2 is 9,9-diphenyl-9H-fluorenyl, and the boron ring closure position is at position 3 of 9,9-diphenyl-9H-fluorenyl.

[0168] In formulas a-116, b-116 and c-116, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 2 of 9,9'-spirobisfluorene;

[0169] In formulas a-117, b-117 and c-117, R2 is 9,9'-spirobisfluorene, and the boron ring closure position is at position 3 of 9,9'-spirobisfluorene;

[0170] In formulas a-118, b-118, and c-118, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 2 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0171] In formulas a-119, b-119 and c-119, R2 is 9,9,10-triphenyl-9,10-dihydroacrylyl, and the boron ring-closure position is at position 3 of 9,9,10-triphenyl-9,10-dihydroacrylyl.

[0172] According to another aspect of the present invention, the present invention provides a method for preparing the above-mentioned boron-nitrogen heterocyclic derivative based on a fusion donor, characterized in that it includes the following steps:

[0173] (1) Using fusion donors and meta-trihalobenzene (fluorine, chlorine, bromine, iodine) compounds as raw materials, intermediates based on boron-nitrogen resonance derivatives of fusion donors are obtained through CN coupling reaction;

[0174] (2) The intermediate was subjected to a tandem Bora-Friedel-Crafts reaction using boron trihalide via a “high-temperature one-pot boronization method” to obtain a boron-nitrogen resonance derivative based on a fusion donor.

[0175] As a further preferred embodiment of the present invention, the preparation step (1) is as follows: the specific process is as follows: the bromine- or iodinated meta-trihalobenzene and fusion donor raw material, palladium catalyst, ligand selected as phosphorus-containing ligand such as tri-tert-butylphosphine tetrafluoroborate (t-Bu3PHBF4), base selected as organic base such as sodium tert-butoxide (t-BuONa), solvent selected as dry toluene, the bromine- or iodinated meta-trihalobenzene and fusion donor raw material, tridibenzylacetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide and toluene are added to the reaction apparatus in a molar or volume ratio (toluene) of 1 mmol: 3.1-4 mmol: 0.03-0.15 mmol: 0.09-0.15 mmol: 3-5 mmol: 5-10 ml, the air is purged with nitrogen for 15 minutes, and then heated to reflux under nitrogen protection for 8-48 hours. After the reaction is complete as detected by thin-layer chromatography, it is cooled to room temperature for post-processing purification to obtain the compound in step (1).

[0176] Alternatively: a chloro-m-trihalobenzene and a fusion donor, a palladium catalyst such as palladium acetate (Pd(OAc)2), a phosphine-containing ligand such as 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (SPhos), a base such as an organic base such as sodium tert-butoxide (t-BuONa), and a solvent such as dry toluene are prepared by mixing the chloro-m-trihalobenzene, the fusion donor, palladium acetate, 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl, sodium tert-butoxide, and toluene in a molar or volume ratio (toluene) of 1 mmol: 3.1-5. mmol:0.03-0.16mmol:0.09-0.20mmol:3-6mmol:6-15ml was added to the reaction apparatus, and the air was purged with nitrogen for 15 minutes. Then, the mixture was heated to reflux under nitrogen protection for 12-60 hours. After the reaction was confirmed to be complete by thin-layer chromatography, it was cooled to room temperature for post-processing and purification to obtain the compound in step (1).

[0177] Alternatively: fluorinated meta-trihalobenzene and fused donor raw materials, palladium catalyst such as palladium acetate (Pd(OAc)2), phosphine-containing ligand such as tri-tert-butylphosphine, base such as sodium tert-butoxide (t-BuONa), and solvent such as dried toluene are added to the reaction apparatus in a molar or volume ratio of 1 mmol:3.1-5 mmol:0.03-0.16 mmol:0.09-0.20 mmol:3-6 mmol:6-16 ml. The air is purged with nitrogen for 15 minutes, and then heated to reflux under nitrogen protection for 16-60 hours. After the reaction is complete as detected by thin-layer chromatography, it is cooled to room temperature for post-processing purification to obtain the compound in step (1).

[0178] Alternatively: Fluorinated meta-trihalobenzene and fused donor raw materials, cesium carbonate catalysis, N,N-dimethylformamide as solvent, the fluorinated meta-trihalobenzene and fused donor, cesium carbonate, N,N-dimethylformamide (DMF) are added to the reaction apparatus in a molar or volume ratio (DMF) of 1 mmol: 3-5 mmol: 3-4 mmol: 5-10 ml, sonicated to fully dissolve and remove air, and then heated to reflux under nitrogen protection for 15-60 hours. After the reaction is complete as detected by thin-layer chromatography, it is cooled to room temperature for post-processing purification to obtain the compound in step (1).

[0179] As a further preferred embodiment of the present invention, the specific process of preparation step (2) is as follows: the intermediate of the boron-nitrogen heterocyclic derivative of the fusion donor is vacuum dried at 80-120°C for 8-24 hours before the reaction, then the intermediate is dissolved in o-dichlorobenzene (o-DCB) solvent, sonicated to completely dissolve, purged with nitrogen, and then stirred at room temperature under nitrogen protection. Boron tribromide (or a mixture of boron tribromide and triphenylboron, for compounds of general formulas 1-4) is slowly added dropwise at below room temperature. After the addition is complete, the system is heated to 150°C-250°C and stirred for 20-48 hours. After cooling to room temperature, the system is placed in an ice bath and kept below 0°C. NN-diisopropylethylamine (DIPEA) is added, and the reaction is carried out for 1-5 hours. After several hours, the solvent was removed by vacuum distillation, followed by column chromatography to purify the product and obtain a boron-nitrogen heterocyclic derivative based on the fusion donor. The feed ratio of the intermediate of the boron-nitrogen heterocyclic derivative of the fusion donor, the volume of the o-dichlorobenzene, the amount of boron tribromide, and the amount of N-diisopropylethylamine (DIPEA) was as follows: Compound of general formula a: 1 mmol: 10-30 ml: 1.5-8 mmol: 12-18 mmol, corresponding to reaction condition (a); Compound of general formula b: 1 mmol: 10-30 ml: 12-28 mmol: 12-18 mmol, corresponding to reaction condition (b); Compound of general formula c: 1 mmol: 10-30 ml: 2-10 mmol (BBr3) + 1-5 mmol (BPh3): 12-18 mmol, corresponding to reaction condition (c).

[0180] According to another aspect of the invention, the invention provides the application of the boron-nitrogen heterocyclic compounds based on fusion donors in organic electroluminescent devices.

[0181] As a further preferred embodiment of the present invention, the boron-nitrogen heterocyclic derivative based on the fusion donor is mainly used as the host material, sensitizer material or luminescent material in organic electroluminescent devices.

[0182] As a further preferred embodiment of the present invention, the organic electroluminescent device comprises, from top to bottom, an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode.

[0183] Preferably, an exciton blocking and electron blocking layer is further provided between the hole transport layer and the light-emitting layer, and an exciton blocking and hole blocking layer is further provided between the electron transport layer and the light-emitting layer.

[0184] When the compound contains only one cyclic boron atom, i.e., the compound represented by general formula a, the following 119 boron-nitrogen heterocyclic derivatives based on fusion donors are preferred:

[0185]

[0186]

[0187]

[0188] When the compound contains only two cyclic boron atoms, i.e., the compound represented by general formula b, the following 119 boron-nitrogen heterocyclic derivatives based on fusion donors are preferred:

[0189]

[0190]

[0191]

[0192] When a compound contains three cyclic boron atoms, corresponding to the compound represented by general formula c, the following 119 boron-nitrogen heterocyclic derivatives based on fusion donors are preferred:

[0193]

[0194]

[0195]

[0196] The aforementioned boron-nitrogen heterocyclic derivative based on the fusion donor can be applied in organic electroluminescent devices, that is, the boron-nitrogen heterocyclic derivative of the fusion donor can be used as the host material, sensitizer material, or luminescent material of the light-emitting layer in the organic electroluminescent device. The resulting organic electroluminescent device includes a counter electrode and a transport layer, a light-emitting layer, and an injection layer between the counter electrodes, wherein the light-emitting layer contains the boron-nitrogen heterocyclic derivative of the fusion donor in this invention.

[0197] The preparation methods of the fusion donor boron-nitrogen heterocyclic derivative compounds in this invention are briefly described below, depending on the number of boron atoms:

[0198] When a compound contains only one cyclic boron atom, its general reaction formula can be represented as follows. First, an equivalent of the intermediate is dissolved in o-dichlorobenzene. Under nitrogen atmosphere, four equivalents of BBr3 are added, and the reaction is carried out at 180°C under N2 for 20 h, allowing the BBr3 to undergo an electrophilic substitution reaction with the intermediate. Subsequently, the reaction temperature is slowly lowered to room temperature, and at 0°C, 15 equivalents of N,N-diisopropylethylamine are added to initiate a tandem Bora-Friedel-Crafts reaction to obtain the target product a.

[0199]

[0200] More specifically, the following are the synthetic methods of the corresponding representative compounds, wherein synthetic examples 1-14 are boron-nitrogen heterocyclic derivatives containing a single boron atom, synthetic examples 15-28 are boron-nitrogen heterocyclic derivatives containing a single boron atom, and synthetic examples 29-42 are boron-nitrogen heterocyclic derivatives containing three boron atoms.

[0201] Synthesis Example 1: Compound a-1 of the present invention was synthesized via the following route:

[0202]

[0203] Reaction a: 4-Bromo-N,N-diphenylaniline (5 g, 15.40 mmol), aniline (1.60 g, 16.95 mmol), tris(dibenzylacetone)palladium (Pd2(dba)3) (0.14 g, 0.154 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (SPhos) (0.125 g, 0.308 mmol), and sodium tert-butoxide (0.89 g, 9.24 mmol) were added to a 100 mL three-necked flask. 40 mL of dry toluene was added, and the mixture was heated to 100 °C under nitrogen atmosphere and stirred under reflux for 12 hours. The mixture was then cooled to room temperature. The toluene solvent was removed by vacuum distillation, followed by extraction three times with dichloromethane and water to obtain an organic liquid. This liquid was dried, filtered, and concentrated under vacuum. The crude product was purified by column chromatography (eluent: petroleum ether) to give 5.00 g of white solid product a-1-1, with a yield of 96.68%.

[0204] Reaction b process: N 1 N 1 N 4 Triphenylbenzene-1,4-diamine, i.e., a-1-1 (3.31 g, 9.85 mmol), m-tribromobenzene (1 g, 3.18 mmol), Pd2(dba)3 (0.029 g, 0.0318 mmol), SPhos (0.026 g, 0.0636 mmol), and sodium tert-butoxide (0.916 g, 9.54 mmol) were added to a 250 mL three-necked flask, followed by 60 mL of dry toluene. The mixture was then heated to 120 °C under nitrogen and refluxed with stirring for 12 hours, followed by cooling to room temperature. The toluene solvent was removed by vacuum distillation, followed by extraction three times with dichloromethane and water to obtain an organic liquid, which was dried, filtered, and concentrated under vacuum. The crude product was purified by column chromatography (eluent volume ratio: petroleum ether: dichloromethane = 10:1) to give a white solid a-1-2, 2.96 g, in 86.2% yield.

[0205] Reaction c: Under nitrogen atmosphere at room temperature, 0.36 mL of boron tribromide (density 2.6 g / mL) was added to a solution of o-dichlorobenzene (100 mL) containing 1 g a-1-2 (0.92 mmol). After stirring at 180 °C for 20 h, the reaction mixture was cooled to room temperature. 2.30 mL of N,N-diisopropylethylamine (density 0.782 g / mL) was added to an ice bath at 0 °C, and the mixture was stirred at low temperature for half an hour. The pH was adjusted to neutral by adding sodium acetate aqueous solution (pH 8). The mixture was washed with water, extracted with toluene to obtain the organic layer, dried over anhydrous magnesium sulfate, and filtered. The solvent was removed by vacuum distillation. The yellow solid powder, initially recrystallized from toluene and acetonitrile, was further purified by column chromatography (eluent: cyclohexane) to obtain the target product a-1, 0.621 g of yellow solid, yield 62.01%. High-resolution mass spectrometry (MS-APCI) (m / z): 1089.4653, theoretical molecular weight: 1088.4738. Elemental analysis: Theoretical values: C: 86.02%; H: 5.28%; B: 0.99%; N: 7.72%. Measured values: C: 86.16%; H: 5.13%; B: 1.10%; N: 7.57%. Based on the combined results of mass spectrometry and elemental analysis, the product is identified as the target compound a-1. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 400℃.

[0206] Synthesis Example 2: Compound a-3 of the present invention was synthesized via the following route:

[0207]

[0208] Reaction a: 2-Bromo-9-phenyl-9H-carbazole (10 g, 31.15 mmol), aniline (3.19 g, 34.27 mmol), Pd2(dba)3 (0.29 g, 0.313 mmol), SPhos (0.52 g, 1.25 mmol), and sodium tert-butoxide (8.98 g, 93.45 mmol) were added to a 500 mL three-necked flask. 160 mL of dry toluene was added, and the mixture was heated to 80 °C under nitrogen atmosphere and stirred under reflux for 16 hours. The mixture was then cooled to room temperature. The toluene solvent was removed by vacuum distillation, followed by extraction three times with dichloromethane and water to obtain an organic liquid. The liquid was dried, filtered, and concentrated under vacuum. The crude product was purified by column chromatography (eluent: petroleum ether) to give 10.25 g of a white solid product a-3-1, yielding 98.44%.

[0209] Reaction b: Intermediate a-3-1 (10 g, 29.93 mmol), m-tribromobenzene (3.08 g, 9.81 mmol), Pd2(dba)3 (0.09 g, 0.098 mmol), SPhos (0.121 g, 0.294 mmol), and sodium tert-butoxide (2.83 g, 29.43 mmol) were added to a 500 mL three-necked flask. 150 mL of dry toluene was added, and the mixture was heated to 120 °C under nitrogen atmosphere and stirred under reflux for 15 hours. The mixture was then cooled to room temperature. The toluene solvent was removed by vacuum distillation, followed by extraction three times with dichloromethane and water to obtain an organic liquid. The liquid was dried, filtered, and concentrated under vacuum. The crude product was purified by column chromatography (eluent volume ratio: petroleum ether: ethyl acetate = 50:1) to give 8.46 g of white solid a-3-2, with a yield of 80.20%.

[0210] Reaction procedure c: Before the reaction, intermediate a-3-2 was dried in a vacuum drying oven for 8 hours to ensure complete removal of solvent. Then, under nitrogen atmosphere at room temperature, 1.79 mL of boron tribromide (density 2.6 g / mL) was added to a solution of o-dichlorobenzene (100 mL) containing 5 g of a-3-2 (4.66 mmol). The reaction was stirred at 180 °C for 24 hours. The reaction mixture was cooled to room temperature and then cooled to 0 °C in an ice bath. 11.54 mL of N,N-diisopropylethylamine (density 0.782 g / mL) was added, and the mixture was stirred at low temperature for 0.5 hours. The pH was adjusted to neutral by adding sodium acetate aqueous solution (pH 8). The mixture was washed with water, extracted with petroleum ether to obtain the organic layer, dried over anhydrous magnesium sulfate, and filtered. The solvent was removed by vacuum distillation. The yellow solid powder obtained by preliminary recrystallization from toluene and acetonitrile was further purified by column chromatography (eluent: cyclohexane) to obtain the target product a-3, 2.90 g of yellow solid, yield 49.88%. High-resolution mass spectrometry (MS-APCI) (m / z): 1083.5343, theoretical molecular weight: 1082.4268. Elemental analysis: Theoretical values: C: 86.50%; H: 4.75%; B: 1.00%; N: 7.76%. Measured values: C: 86.42%; H: 4.81%; B: 1.02%; N: 7.75%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound a-3. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 450℃.

[0211] Synthesis Example 3: Compound a-4 of the present invention was synthesized via the following route:

[0212]

[0213] Reaction a: 3-Bromo-9,9-dimethyl-10-phenyl-9,10-dihydroacridine (10 g, 27.54 mmol), aniline (2.82 g, 30.30 mmol), Pd₂(dba)₃ (0.251 g, 0.275 mmol), SPhos (0.338 g, 0.825 mmol), and sodium tert-butoxide (7.93 g, 82.5 mmol) were added to a 500 mL three-necked flask. 120 mL of dry toluene was added, and the mixture was heated to 100 °C under nitrogen atmosphere and stirred under reflux for 10 hours. The mixture was then cooled to room temperature. The toluene solvent was removed by vacuum distillation, followed by extraction three times with dichloromethane and water to obtain an organic liquid. The liquid was dried, filtered, and concentrated under vacuum. The crude product was purified by column chromatography (eluent: petroleum ether) to give 9.99 g of a white solid a-4-1, yield 96.43%.

[0214] Reaction b: Intermediate a-4-1 (9.99 g, 26.56 mmol), m-tribromobenzene (2.73 g, 8.71 mmol), Pd2(dba)3 (0.080 g, 0.087 mmol), SPhos (0.107 g, 0.261 mmol), and sodium tert-butoxide (2.51 g, 26.1 mmol) were added to a 250 mL three-necked flask. 60 mL of dry toluene was added, and the mixture was heated to 120 °C under nitrogen atmosphere and stirred under reflux for 16 hours. The mixture was then cooled to room temperature. The toluene solvent was removed by vacuum distillation, followed by extraction three times with dichloromethane and water to obtain an organic liquid. The liquid was dried, filtered, and concentrated under vacuum. The crude product was purified by column chromatography (eluent ratio: petroleum ether: dichloromethane = 25:1) to give a white solid a-4-2, 9.27 g, yield 88.62%.

[0215] Reaction c: Under nitrogen atmosphere at room temperature, 0.36 mL of boron tribromide (density 2.6 g / mL) was added to a solution of o-dichlorobenzene (100 mL) containing 1 g a-1-2 (0.92 mmol). After stirring at 180 °C for 20 h, the reaction mixture was cooled to room temperature. 2.30 mL of N,N-diisopropylethylamine (density 0.782 g / mL) was added at 0 °C, and the mixture was stirred at low temperature for half an hour. The pH was adjusted to neutral by adding sodium acetate aqueous solution (pH 8). The mixture was washed with water, extracted with toluene to obtain the organic layer, dried over anhydrous magnesium sulfate, and filtered. The solvent was removed by vacuum distillation. The yellow solid powder obtained by preliminary recrystallization from toluene and acetonitrile was further purified by column chromatography to obtain the yellow solid product (yield 62%). High-resolution mass spectrometry (MS-APCI) (m / z): 1083.5343, theoretical molecular weight: 1082.4268. Elemental analysis: Theoretical values: C: 86.50%; H: 4.75%; B: 1.00%; N: 7.76%. Measured values: C: 86.42%; H: 4.81%; B: 1.02%; N: 7.75%. Based on the combined results of mass spectrometry and elemental analysis, the product is identified as the target compound a-3. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 450℃.

[0216] Synthesis Example 4: Compound a-8 of the present invention was synthesized via the following route:

[0217]

[0218] The specific process of this embodiment can be referred to the conditions of Example 3, except that the acridine series intermediate is replaced with an equimolar amount of phenothiazine. Because the phenothiazine series has a strong electron-donating ability, the ratio of boron tribromide in process c is reduced to 2 equivalents, while other conditions remain unchanged. After post-processing purification, 7.92 g of the pale green target compound was obtained, with a yield of 66.21%. High-resolution mass spectrometry (MS-APCI) (m / z): 1179.3464, theoretical molecular weight: 1178.3430. Elemental analysis: Theoretical values: C: 79.44%; H: 4.36%; B: 0.92%; N: 7.13%; S: 8.16%. Measured values: C: 79.42%; H: 4.33%; B: 0.95%; N: 7.09%; S: 8.22%. Based on the combined results of mass spectrometry and elemental analysis, the product can be identified as the target compound a-8. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 420℃.

[0219] Synthesis Example 5: Compound a-11 of the present invention was synthesized via the following route:

[0220]

[0221] The specific process of this embodiment can be referred to the conditions of Example 3, except that the acridine series intermediates are replaced with an equimolar amount of 9,9-dimethylfluorene series intermediates. Since the electron-donating ability of the 9,9-dimethylfluorene series is weaker than that of acridine, the ratio of boron tribromide in process c is increased to 4 equivalents, while the other conditions remain unchanged. After post-treatment purification, 4.89 g of the pale yellow target compound was obtained, with a yield of 52.32%. High-resolution mass spectrometry (MS-APCI) (m / z): 936.4444, theoretical molecular weight: 935.4411. Elemental analysis: Theoretical values: C: 88.54%; H: 5.82%; B: 1.15%; N: 4.49%. Measured values: C: 88.48%; H: 5.83%; B: 1.08%; N: 4.61%. Based on the combined results of mass spectrometry and elemental analysis, the product can be identified as the target compound a-11. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 440℃.

[0222] Synthesis Example 6: Compound a-15 of the present invention was synthesized via the following route:

[0223]

[0224] The specific process of this embodiment can be referred to the conditions of Example 3, except that the acridine series intermediate is replaced with an equimolar amount of 9-spirofluorene series intermediate. Because the spirofluorene series molecules are relatively rigid, they are more difficult to handle during the dehydrogenation process and ring-closing reaction. Therefore, the ratio of boron tribromide to 5 equivalents in process c is increased, the reaction temperature is adjusted to 200℃, and the reaction time is adjusted to 24 h, while other conditions remain unchanged. After post-processing purification, 2.68 g of the pale yellow target compound is obtained, with a yield of 28.42%. High-resolution mass spectrometry (MS-APCI) (m / z): 1302.4914, theoretical molecular weight: 1301.4880. Elemental analysis: Theoretical values: C: 91.30%; H: 4.64%; B: 0.83%; N: 3.23%. Measured values: C: 91.14%; H: 4.66%; B: 0.98%; N: 3.35%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound a-15. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 500℃.

[0225] Synthesis Example 7: Compound a-18 of the present invention was synthesized via the following route:

[0226]

[0227] Reaction a: In a 500 mL three-necked flask, 3-bromo-9-hydro-carbazole (5 g, 20.41 mmol), m-trifluorobenzene (0.90 g, 6.80 mmol), cesium carbonate (33.23 g, 102 mmol), and anhydrous N,N-dimethylformamide (180 mL) were added sequentially. Air was repeatedly evacuated, and the mixture was heated to 160 °C under nitrogen protection and refluxed for 20 h. After the reaction, the solvent was removed by vacuum distillation, and then the cesium carbonate was removed by repeated extraction with a dichloromethane and water system. The organic phase was collected, concentrated, and purified by column chromatography (eluent: petroleum ether) to obtain 5.32 g of intermediate a-18-1, a white solid powder, with a yield of 96.65%.

[0228] Reaction b: Intermediate a-18-1 (5.00 g, 6.18 mmol), diphenylamine (3.24 g, 19.16 mmol), Pd2(dba)3 (0.057 g, 0.0618 mmol), SPhos (0.076 g, 0.0185 mmol), and sodium tert-butoxide (1.78 g, 18.54 mmol) were added to a 250 mL three-necked flask. 80 mL of dry toluene was added, and the mixture was heated to 120 °C under nitrogen atmosphere and stirred under reflux for 15 hours. The mixture was then cooled to room temperature. The toluene solvent was removed by vacuum distillation, followed by extraction three times with dichloromethane and water to obtain an organic liquid. The liquid was dried, filtered, and concentrated under vacuum. The crude product was purified by column chromatography (eluent volume ratio: petroleum ether: dichloromethane = 1:1) to give a white solid a-18-2, 5.60 g, with a yield of 84.36%.

[0229] Reaction c: Under nitrogen atmosphere at room temperature, 1.12 mL of boron tribromide (density 2.6 g / mL) was added to a solution of o-dichlorobenzene (120 mL) containing 5 g a-18-2 (4.65 mmol). After stirring at 180 °C for 20 h, the reaction mixture was cooled to room temperature. 11.53 mL of N,N-diisopropylethylamine (density 0.782 g / mL) was added in an ice bath at 0 °C, and the reaction was stirred at low temperature for half an hour. The pH was adjusted to neutral by adding sodium acetate aqueous solution (pH 8). The mixture was washed with water, extracted with toluene to obtain the organic layer, dried over anhydrous magnesium sulfate, and filtered. The solvent was removed by vacuum distillation. The yellow solid powder obtained by preliminary recrystallization from toluene and acetonitrile was further purified by column chromatography (eluent ratio: cyclohexane:dichloromethane = 4:1) to obtain the target product a-18, a yellow solid of 3.36 g, with a yield of 66.82%. High-resolution mass spectrometry (MS-APCI) (m / z): 1083.4302, theoretical molecular weight: 1082.4268. Elemental analysis: Theoretical values: C: 86.50%; H: 4.75%; B: 1.00%; N: 7.76%. Measured values: C: 86.46%; H: 4.79%; B: 1.03%; N: 7.72%. Based on the combined results of mass spectrometry and elemental analysis, the product is identified as the target compound a-1. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 300℃.

[0230] Synthesis Example 8: Compound a-20 of the present invention was synthesized via the following route:

[0231]

[0232] Reaction a: In a 500 mL three-necked flask, (9-phenyl-9H-carbazole-1-yl)boric acid (10 g, 34.83 mmol), 1-bromo-2-nitrobenzene (7.38 g, 36.57 mmol), 60 mL of potassium carbonate aqueous solution (2 mol / L), toluene (120 mL), and ethanol (60 mL) were added sequentially. Air was evacuated several times, and the mixture was stirred under nitrogen protection for 0.5 h. Then, the catalyst tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) (0.39 g, 0.35 mmol) was added. The mixture was heated to 110 °C and refluxed for 14 h. After the reaction was complete, the mixture was allowed to cool naturally to room temperature. The mixture was then extracted multiple times with a dichloromethane and water system. The organic phase was collected, dried over anhydrous magnesium sulfate for 2 h, and purified by column chromatography (eluent: petroleum ether) to obtain 11.0 g of intermediate a-20-1, a white solid powder, with a yield of 87.02%.

[0233] Reaction b: Intermediate a-20-1 (10.0 g, 29.50 mmol), triphenylphosphine (19.34 g, 73.74 mmol), and 150 mL of dry 1,2-dichlorobenzene solvent were added to a 500 mL three-necked flask. The mixture was heated to 180 °C under nitrogen atmosphere and stirred under reflux for 24 h. The reaction was detected by thin-layer chromatography, and the solvent was removed by vacuum distillation after the reaction was completed. Column chromatography was used to separate and purify intermediate a-20-2 into a white solid, yielding 7.70 g (78.62%).

[0234] Reaction procedure c: Intermediate a-20-2 (7.0 g, 21.08 mmol), m-trifluorobenzene (1.0 g, 7.03 mmol), cesium carbonate (20.60 g, 63.23 mmol), and 150 mL of dry DMF solvent were added to a 500 mL three-necked flask. The mixture was heated to 150 °C under nitrogen atmosphere and stirred under reflux for 24 h. The reaction was detected by thin-layer chromatography, and the solvent was removed by distillation under reduced pressure after the reaction was completed. Column chromatography was used to separate and purify intermediate a-20-3 into 7.21 g of a white solid, with a yield of 96.13%.

[0235] Reaction procedure d: Under nitrogen atmosphere at room temperature, 1.12 mL of boron tribromide (density 2.6 g / mL) was added to a solution of o-dichlorobenzene (120 mL) containing a-20-3 (5 g, 4.65 mmol). After stirring at 180 °C for 20 h, the reaction mixture was cooled to room temperature. 11.53 mL of N,N-diisopropylethylamine (density 0.782 g / mL) was added in an ice bath at 0 °C, and the reaction was stirred at low temperature for half an hour. The pH was adjusted to neutral by adding sodium acetate aqueous solution (pH 8). The mixture was washed with water, extracted with toluene to obtain the organic layer, dried over anhydrous magnesium sulfate, and filtered. The solvent was removed by vacuum distillation. The yellow solid powder obtained by preliminary recrystallization from toluene and acetonitrile was further purified by column chromatography (eluent ratio: cyclohexane:dichloromethane = 4:1) to obtain the target product a-18, a bright yellow solid, 2.94 g, yield 58.66%. High-resolution mass spectrometry (MS-APCI) (m / z): 1077.3832, theoretical molecular weight: 1076.3799. Elemental analysis: Theoretical values: C: 86.98%; H: 4.21%; B: 1.00%; N: 7.80%. Measured values: C: 86.86%; H: 4.39%; B: 1.01%; N: 7.79%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound a-20. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 480℃.

[0236] Synthesis Example 9: Compound a-23 of the present invention was synthesized via the following route:

[0237]

[0238] The specific process of this embodiment can be referred to the conditions of Example 8, except that the carbazole series intermediates are replaced with an equimolar amount of N-phenyl-phenoxazine series intermediates, while the other conditions remain unchanged. After post-processing purification, 3.82 g of the pale green target compound was obtained, with a yield of 24.28%. High-resolution mass spectrometry (MS-APCI) (m / z): 1125.3680, theoretical molecular weight: 1124.3646. Elemental analysis: Theoretical values: C: 83.27%; H: 4.03%; B: 0.96%; N: 7.47%, O: 4.27%. Measured values: C: 83.19%; H: 4.11%; B: 0.95%; N: 7.46%, O: 4.30%. Based on the combined results of mass spectrometry and elemental analysis, the product can be identified as the target compound a-23. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 450℃.

[0239] Synthesis Example 10: Compound a-28 of the present invention was synthesized via the following route:

[0240]

[0241] The specific process of this embodiment can be referred to the conditions of Example 8, except that the carbazole series intermediates are replaced with an equimolar amount of 9,9-dimethylfluorene series intermediates, while the other conditions remain unchanged. After post-processing purification, 6.79 g of the pale green target compound was obtained, with a yield of 65.84%. High-resolution mass spectrometry (MS-APCI) (m / z): 930.3975, theoretical molecular weight: 929.3941. Elemental analysis: Theoretical values: C: 89.12%; H: 5.20%; B: 1.16%; N: 4.52%. Measured values: C: 88.99.19%; H: 5.28%; B: 1.18%; N: 4.55%. Based on the combined results of mass spectrometry and elemental analysis, the product can be identified as the target compound a-28. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 440℃.

[0242] Synthetic Example 11: Compound a-35 of the present invention was synthesized via the following route:

[0243]

[0244] The specific process of this embodiment can be referred to the conditions of Example 7, except that the carbazole series intermediates are replaced with an equimolar amount of 9,9-dimethylacridine series intermediates, while the other conditions remain unchanged. After post-processing purification, 5.43 g of the pale green target compound was obtained, with a yield of 38.66%. High-resolution mass spectrometry (MS-APCI) (m / z): 1209.5970, theoretical molecular weight: 1208.5677. Elemental analysis: Theoretical values: C: 86.41%; H: 5.75%; B: 0.89%; N: 6.95%. Measured values: C: 86.66%; H: 5.69%; B: 0.85%; N: 6.80%. Based on the combined results of mass spectrometry and elemental analysis, the product can be identified as the target compound a-35. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 520℃.

[0245] Synthetic Example 12: Compound a-39 of the present invention was synthesized via the following route:

[0246]

[0247] Reaction a: Methyl anthranilate (3.02 g, 20 mmol), m-diiodobenzene (3.30 g, 10 mmol), copper powder (0.128 g, 2 mmol), and potassium carbonate (2.76 g, 20 mmol) were dissolved in 100 mL of o-dichlorobenzene. The system was subjected to multiple nitrogen purgings. The mixture was heated to 180 °C under nitrogen atmosphere and stirred for 8 h. After the reaction was completed, the mixture was cooled to room temperature, and the solvent was removed by vacuum distillation. The mixture was then extracted multiple times with a dichloromethane and water system. The organic phase was collected, dried with anhydrous magnesium sulfate, filtered, and concentrated for column chromatography. The eluent was petroleum ether:dichloromethane = 10:1. The crude product was recrystallized and purified to obtain a bright green intermediate a-39-1 (3.50 g, yield 93.58%).

[0248] Reaction b: Under nitrogen atmosphere, methyl magnesium chloride (15.60 ml, 3 M) was slowly added dropwise to intermediate a-39-1 (3.50 g, 9.35 mmol), stirred overnight at room temperature, and then water was slowly added dropwise to quench the reaction. Tetrahydrofuran was removed by vacuum distillation, and then recrystallized with dichloromethane and methanol to obtain a green solid.

[0249] Reaction process c: The solid was directly dissolved in a mixed solvent of glacial acetic acid and concentrated hydrochloric acid (volume ratio 60 ml: 6 ml) and heated under reflux for 10 h. After the reaction was completed, the mixture was extracted with dichloromethane and water, the organic phase was collected, dried and concentrated, and then purified by column chromatography. The eluent was petroleum ether: ethyl acetate = 20:1, to obtain a bright green intermediate a-39-3 (3.08 g, yield 96.86%).

[0250] Reaction procedure d: Intermediate a-39-3 (3.08 g, 9.06 mmol), 1-bromobenzene (1.42 g, 9.05 mmol), Pd2(dba)3 (0.008 g, 0.009 mmol), SPhos (0.012 g, 0.027 mmol), and sodium tert-butoxide (2.61 g, 27.18 mmol) were added to a 250 mL three-necked flask. 80 mL of dry toluene was added, and the mixture was heated to 120 °C under nitrogen atmosphere and stirred under reflux for 15 hours. The mixture was then cooled to room temperature. The toluene solvent was removed by vacuum distillation, followed by extraction three times with dichloromethane and water to obtain an organic liquid. The liquid was dried, filtered, and concentrated under vacuum. The crude product was purified by column chromatography (eluent: petroleum ether) to give a white solid a-39-4 (2.98 g, yield 79.00%).

[0251] The reaction conditions for processes e and f were similar to the final step of the boron addition reaction in Example 1, except that the intermediate was replaced with an equal amount, while the other conditions remained unchanged. Finally, 1.28 g of the bright green target compound was obtained, with a yield of 42.67%. High-resolution mass spectrometry (MS-APCI) (m / z): 1329.5560, theoretical molecular weight: 1328.6616. Elemental analysis: Theoretical values: C: 86.72%; H: 6.14%; B: 0.81%; N: 6.32%. Measured values: C: 86.68%; H: 6.19%; B: 0.84%; N: 6.29%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound a-39. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 510℃.

[0252] Synthetic Example 13: Compound a-76 of the present invention was synthesized via the following route:

[0253]

[0254] Reaction a: 1-fluoro-10-phenyl-10H-phenthiazine (10.0 g, 34.12 mmol), o-nitrobenzenethiophenol (5.55 g, 35.83 mmol), tris(dibenzylideneacetone)dipalladium (0.3 g, 3.4 mmol), sodium tert-butoxide (9.8 g, 102.36 mmol), and 120 mL of dry toluene were sequentially added to a 500 mL flask. Nitrogen gas was evacuated, and the mixture was heated to 110 °C for 12 hours. After the reaction, column chromatography purified the intermediate a-76-1, yielding 12.99 g (88.9%).

[0255] Reaction b: Intermediate a-76-1 (10.0 g, 23.36 mmol), triphenylphosphine (18.38 g, 70.08 mmol), and 150 mL of dry 1,2-dichlorobenzene solvent were added to a 500 mL three-necked flask. The mixture was heated to 180 °C under nitrogen atmosphere and stirred under reflux for 24 h. The reaction was detected by thin-layer chromatography, and the solvent was removed by distillation under reduced pressure after the reaction was completed. Column chromatography purification yielded 7.52 g of intermediate a-76-2 as a white solid, with a yield of 81.23%.

[0256] Reaction procedure c: Intermediate a-76-2 (7.52 g, 18.98 mmol), m-tribromobenzene (2.43 g, 6.33 mmol), Pd2(dba)3 (0.080 g, 0.087 mmol), SPhos (0.107 g, 0.261 mmol), and sodium tert-butoxide (5.47 g, 56.94 mmol) were added to a 250 mL three-necked flask. 160 mL of dry toluene was added, and the mixture was heated to 120 °C under nitrogen atmosphere and stirred under reflux for 16 hours. The mixture was then cooled to room temperature. The toluene solvent was removed by vacuum distillation, followed by extraction three times with dichloromethane and water to obtain an organic liquid. The liquid was dried, filtered, and concentrated under vacuum. The crude product was purified by column chromatography (eluent ratio: petroleum ether: dichloromethane = 25:1) to give a white solid a-76-3, 7.07 g, yield 88.62%.

[0257] Reaction procedure d: Under nitrogen atmosphere at room temperature, 1.36 mL of boron tribromide (density 2.6 g / mL) was added to a solution of o-dichlorobenzene (100 mL) containing α-76-3 (7.0 g, 5.55 mmol). After stirring at 180 °C for 20 hours, the reaction mixture was cooled to room temperature. 2.30 mL of N,N-diisopropylethylamine (density 0.782 g / mL) was added at 0 °C, and the mixture was stirred at low temperature for half an hour. The pH was adjusted to neutral by adding sodium acetate aqueous solution (pH 8). The mixture was washed with water, extracted with toluene to obtain the organic layer, dried over anhydrous magnesium sulfate, and filtered. The solvent was removed by vacuum distillation. The yellow solid powder obtained by preliminary recrystallization from toluene and acetonitrile was further purified by column chromatography to obtain the yellow solid product (yield 58%). High-resolution mass spectrometry (MS-APCI) (m / z): 1269.6157, theoretical molecular weight: 1268.2123. Elemental analysis: Theoretical values: C: 73.80%; H: 3.57%; B: 0.85%; N: 6.62%; S: 15.15%. Measured values: C: 73.82%; H: 3.54%; B: 0.86%; N: 6.64%; S: 15.13%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound a-76. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 490℃.

[0258] Synthetic Example 14: Compound a-93 of the present invention was synthesized via the following route:

[0259]

[0260] The specific process of this embodiment can be referred to the conditions of Example 13, except that the carbazole series intermediates are replaced with an equimolar amount of 9,9-diphenylphenazine series intermediates, while the other conditions remain unchanged. After post-processing purification, 5.43 g of the pale green target compound was obtained, with a yield of 31.62%. High-resolution mass spectrometry (MS-APCI) (m / z): 1446.4260, theoretical molecular weight: 1445.4227. Elemental analysis: Theoretical values: C: 79.71%; H: 4.18%; B: 0.75%; N: 8.71%; S: 6.65%. Measured values: C: 79.74%; H: 4.16%; B: 0.76%; N: 8.70%; S: 6.66%. Based on the combined results of mass spectrometry and elemental analysis, the product can be identified as the target compound a-93. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 530℃.

[0261] When only two cyclic boron atoms are present in the compound, its general reaction formula can be represented as follows. First, an equivalent of the intermediate is dissolved in o-dichlorobenzene, and 24 equivalents of BBr3 are added under nitrogen atmosphere. The reaction is then carried out at 180°C under N2 atmosphere for 20 h, allowing the BBr3 to undergo an electrophilic substitution reaction with the intermediate. Subsequently, the reaction temperature is slowly lowered to room temperature, and 80 equivalents of N,N-diisopropylethylamine are added at 0°C to carry out a tandem Bora-Friedel-Crafts reaction to obtain the target product b.

[0262]

[0263] More specifically, the synthetic methods of the corresponding representative compounds are given below.

[0264] Synthetic Example 15: Compound b-1 of the present invention was synthesized via the following route:

[0265]

[0266] The specific process of this embodiment can be referred to the conditions of Example 1, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 7.88 g of the pale green target compound was obtained, with a yield of 65.96%. High-resolution mass spectrometry (MS-APCI) (m / z): 1097.4630, theoretical molecular weight: 1096.4596. Elemental analysis: Theoretical values: C: 85.41%; H: 4.96%; B: 1.97%; N: 7.66%. Measured values: C: 85.42%; H: 4.89%; B: 1.88%; N: 7.81%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-1. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 420℃.

[0267] Synthesis Example 16: Compound b-3 of the present invention was synthesized via the following route:

[0268]

[0269] The specific process of this embodiment can be referred to the conditions of Example 2, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 1.24 g of the yellow target compound was obtained, with a yield of 18.94%. High-resolution mass spectrometry (MS-APCI) (m / z): 1091.4160, theoretical molecular weight: 1090.4127. Elemental analysis: Theoretical values: C: 85.88%; H: 4.44%; B: 1.98%; N: 7.70%. Measured values: C: 85.78%; H: 4.48%; B: 1.99%; N: 7.75%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-3. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 460℃.

[0270] Synthesis Example 17: Compound b-4 of the present invention was synthesized via the following route:

[0271]

[0272] The specific process of this embodiment can be referred to the conditions of Example 3, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 2.13 g of the yellow target compound was obtained, with a yield of 17.65%. High-resolution mass spectrometry (MS-APCI) (m / z): 1217.1470, theoretical molecular weight: 1216.5535. Elemental analysis: Theoretical values: C: 85.85%; H: 5.47%; B: 1.78%; N: 6.90%. Measured values: C: 85.88%; H: 5.44%; B: 1.89%; N: 6.78%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-4. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 470℃.

[0273] Synthetic Example 18: Compound b-8 of the present invention was synthesized via the following route:

[0274]

[0275] The specific process of this embodiment can be referred to the conditions of Example 4, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 1.09 g of the yellow target compound was obtained, with a yield of 14.46%. High-resolution mass spectrometry (MS-APCI) (m / z): 1187.0840, theoretical molecular weight: 1186.3289. Elemental analysis: Theoretical values: C: 78.92%; H: 4.08%; B: 1.82%; N: 7.08%; S: 8.10%. Measured values: C: 79.02%; H: 4.03%; B: 1.79%; N: 7.11%; S: 8.05%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-8. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 440℃.

[0276] Synthetic Example 19: Compound b-11 of the present invention was synthesized via the following route:

[0277]

[0278] The specific process of this embodiment can be referred to the conditions of Example 5, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 2.79 g of the yellow target compound was obtained, with a yield of 28.53%. High-resolution mass spectrometry (MS-APCI) (m / z): 944.4303, theoretical molecular weight: 943.4269. Elemental analysis: Theoretical values: C: 87.81%; H: 5.45%; B: 2.29%; N: 4.45%. Measured values: C: 87.88%; H: 5.43%; B: 2.26%; N: 4.53%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-11. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 480℃.

[0279] Synthesis Example 20: Compound b-15 of the present invention was synthesized via the following route:

[0280]

[0281] The specific process of this embodiment can be referred to the conditions of Example 6, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 2.88 g of the yellow target compound was obtained, with a yield of 26.98%. High-resolution mass spectrometry (MS-APCI) (m / z): 1311.1896, theoretical molecular weight: 1310.4772. Elemental analysis: Theoretical values: C: 90.76%; H: 4.39%; B: 1.65%; N: 3.21%. Measured values: C: 91.00%; H: 4.25%; B: 1.69%; N: 3.46%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-15. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 540℃.

[0282] Synthetic Example 21: Compound b-18 of the present invention was synthesized via the following route:

[0283]

[0284] The specific process of this embodiment can be referred to the conditions of Example 7, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 2.88 g of the yellow target compound was obtained, with a yield of 26.98%. High-resolution mass spectrometry (MS-APCI) (m / z): 1091.4160, theoretical molecular weight: 1090.4127. Elemental analysis: Theoretical values: C: 85.88%; H: 4.44%; B: 1.98%; N: 7.70%. Measured values: C: 85.69%; H: 4.48%; B: 2.04%; N: 7.79%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-18. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 380℃.

[0285] Synthesis Example 22: Compound b-20 of the present invention was synthesized via the following route:

[0286]

[0287] The specific process of this embodiment can be referred to the conditions of Example 8, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 2.31 g of the yellow target compound was obtained, with a yield of 22.99%. High-resolution mass spectrometry (MS-APCI) (m / z): 1085.3691, theoretical molecular weight: 1084.3657. Elemental analysis: Theoretical values: C: 86.36%; H: 3.90%; B: 1.99%; N: 7.75%. Measured values: C: 86.44%; H: 3.92%; B: 1.94%; N: 7.70%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-20. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 540℃.

[0288] Synthesis Example 23: Compound b-23 of the present invention was synthesized via the following route:

[0289]

[0290] The specific process of this embodiment can be referred to the conditions of Example 9, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 2.46 g of the yellow target compound was obtained, with a yield of 23.87%. High-resolution mass spectrometry (MS-APCI) (m / z): 1133.3538, theoretical molecular weight: 1132.3505. Elemental analysis: Theoretical values: C: 82.70%; H: 3.74%; B: 1.91%; N: 7.42%; O: 4.24%. Measured values: C: 82.73%; H: 3.76%; B: 1.94%; N: 7.40%; O: 4.30%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-23. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 490℃.

[0291] Synthesis Example 24: Compound b-28 of the present invention was synthesized via the following route:

[0292]

[0293] The specific process of this embodiment can be referred to the conditions of Example 10, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 3.08 g of the yellow target compound was obtained, with a yield of 32.16%. High-resolution mass spectrometry (MS-APCI) (m / z): 938.7633, theoretical molecular weight: 937.3800. Elemental analysis: Theoretical values: C: 88.38%; H: 4.84%; B: 2.31%; N: 4.48%. Measured values: C: 88.41%; H: 4.85%; B: 2.33%; N: 4.42%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-28. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 540℃.

[0294] Synthetic Example 25: Compound b-35 of the present invention was synthesized via the following route:

[0295]

[0296] The specific process of this embodiment can be referred to the conditions of Example 11, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 1.97 g of the bright green target compound was obtained, with a yield of 18.75%. High-resolution mass spectrometry (MS-APCI) (m / z): 1217.1470, theoretical molecular weight: 1216.5535. Elemental analysis: Theoretical values: C: 85.85%; H: 5.47%; B: 1.78%; N: 6.90%. Measured values: C: 85.92%; H: 5.50%; B: 1.74%; N: 6.84%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-35. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 550℃.

[0297] Synthesis Example 26: Compound b-39 of the present invention was synthesized via the following route:

[0298]

[0299] The specific process of this embodiment can be referred to the conditions of Example 12, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 1.66 g of the bright green target compound was obtained, with a yield of 15.74%. High-resolution mass spectrometry (MS-APCI) (m / z): 1338.6474, theoretical molecular weight: 1337.6508. Elemental analysis: Theoretical values: C: 86.22%; H: 5.88%; B: 1.62%; N: 6.28%. Measured values: C: 86.19%; H: 5.86%; B: 1.64%; N: 6.30%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-39. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 560℃.

[0300] Synthesis Example 27: Compound b-76 of the present invention was synthesized via the following route:

[0301]

[0302] The specific process of this embodiment can be referred to the conditions of Example 13, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 1.69 g of the bright green target compound was obtained, with a yield of 15.54%. High-resolution mass spectrometry (MS-APCI) (m / z): 1277.2019, theoretical molecular weight: 1276.1981. Elemental analysis: Theoretical values: C: 73.35%; H: 3.31%; B: 1.69%; N: 6.58%; S: 15.06%. Measured values: C: 73.30%; H: 3.33%; B: 1.68%; N: 6.59%; S: 15.08%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-76. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 510℃.

[0303] Synthesis Example 28: Compound b-93 of the present invention was synthesized via the following route:

[0304]

[0305] The specific process of this embodiment can be referred to the conditions of Example 14, except that in the tandem Bora-Friedel-Crafts reaction, the proportion of BBr3 was adjusted to 24 equivalents and the proportion of N,N-diisopropylethylamine was adjusted to 80 equivalents, while the other conditions remained unchanged. After post-processing purification, 1.23 g of the bright green target compound was obtained, with a yield of 12.14%. High-resolution mass spectrometry (MS-APCI) (m / z): 1456.4089, theoretical molecular weight: 1454.4159. Elemental analysis: Theoretical values: C: 79.28%; H: 3.95%; B: 1.49%; N: 8.67%; S: 6.61%. Measured values: C: 79.31%; H: 3.92%; B: 1.47%; N: 8.68%; S: 6.62%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound b-93. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 540℃.

[0306] When only three cyclic boron atoms are present in the compound, its general reaction formula can be represented as follows. First, one equivalent of the intermediate is dissolved in o-dichlorobenzene. Under nitrogen atmosphere, five equivalents of BBr3 and two equivalents of triphenylboron (BPh3) are added, and the reaction is carried out at 180 °C under N2 for 20 h, allowing BBr3 to undergo an electrophilic substitution reaction with the intermediate. Subsequently, the reaction temperature is slowly lowered to room temperature, and at 0 °C, 20 equivalents of N,N-diisopropylethylamine are added to carry out a tandem borazeid-Friedel-Crafts reaction to obtain the target product c.

[0307]

[0308] More specifically, the synthetic methods of the corresponding representative compounds are given below.

[0309] Synthesis Example 29: Compound c-1 of the present invention was synthesized via the following route:

[0310]

[0311] The specific process of this embodiment can be referred to the conditions of Example 1, except that 5 equivalents of BBr3 and 2 equivalents of BPh3 were added to the tandem Bora-Friedel-Crafts reaction, and the proportion of N,N-diisopropylethylamine was adjusted to 20 equivalents, while other conditions remained unchanged. After post-processing purification, 1.08 g of the pale green target compound was obtained, with a yield of 15.96%. High-resolution mass spectrometry (MS-APCI) (m / z): 1105.7380, theoretical molecular weight: 1104.4454. Elemental analysis: theoretical values: C: 84.80%; H: 4.65%; B: 2.94%; N: 7.61%. Measured values: C: 84.83%; H: 4.64%; B: 2.95%; N: 7.62%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as target compound c-1. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 450℃.

[0312] Synthesis Example 30: Compound c-3 of the present invention was synthesized via the following route:

[0313]

[0314] The specific process of this embodiment can be referred to the conditions of Example 2, except that 5 equivalents of BBr3 and 2 equivalents of BPh3 were added to the tandem Bora-Friedel-Crafts reaction, and the proportion of N,N-diisopropylethylamine was adjusted to 20 equivalents, while other conditions remained unchanged. After post-processing purification, 0.97 g of the yellow target compound was obtained, with a yield of 9.64%. High-resolution mass spectrometry (MS-APCI) (m / z): 1099.4918, theoretical molecular weight: 1098.3985. Elemental analysis: Theoretical values: C: 85.27%; H: 4.13%; B: 2.95%; N: 7.65%. Measured values: C: 85.32%; H: 4.12%; B: 2.90%; N: 7.66%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-3. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 480℃.

[0315] Synthesis Example 31: Compound c-4 of the present invention was synthesized via the following route:

[0316]

[0317] The specific process of this embodiment can be referred to the conditions of Example 3, except that 5 equivalents of BBr3 and 2 equivalents of BPh3 were added to the tandem Bora-Friedel-Crafts reaction, and the proportion of N,N-diisopropylethylamine was adjusted to 20 equivalents, while other conditions remained unchanged. After post-processing purification, 1.13 g of the yellow target compound was obtained, with a yield of 10.05%. High-resolution mass spectrometry (MS-APCI) (m / z): 1225.5330, theoretical molecular weight: 1224.5393. Elemental analysis: theoretical values: C: 85.31%; H: 5.18%; B: 2.65%; N: 6.86%. Measured values: C: 85.33%; H: 5.20%; B: 2.66%; N: 6.85%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-4. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 500℃.

[0318] Synthesis Example 32: Compound c-8 of the present invention was synthesized via the following route:

[0319]

[0320] The specific process of this embodiment can be referred to the conditions of Example 4, except that in the tandem Bora-Friedel-Crafts reaction, the ratio of 5 equivalents of BBr3 and 2 equivalents of BPh3, and N,N-diisopropylethylamine was adjusted to 20 equivalents, while the other conditions remained unchanged. After post-processing purification, 0.82 g of the yellow target compound was obtained, with a yield of 8.16%. High-resolution mass spectrometry (MS-APCI) (m / z): 1195.3181, theoretical molecular weight: 1194.3147. Elemental analysis: Theoretical values: C: 78.41%; H: 3.80%; B: 2.71%; N: 7.03%; S: 8.05%. Measured values: C: 78.40%; H: 3.84%; B: 2.73%; N: 7.01%; S: 8.09%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-8. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 470℃.

[0321] Synthetic Example 33: Compound c-11 of the present invention was synthesized via the following route:

[0322]

[0323] The specific process of this embodiment can be referred to the conditions of Example 5, except that in the tandem Bora-Friedel-Crafts reaction, the ratio of 5 equivalents of BBr3 and 2 equivalents of BPh3, and N,N-diisopropylethylamine was adjusted to 20 equivalents, while the other conditions remained unchanged. After post-processing purification, 1.79 g of the bright green target compound was obtained, with a yield of 18.65%. High-resolution mass spectrometry (MS-APCI) (m / z): 952.3562, theoretical molecular weight: 951.4127. Elemental analysis: Theoretical values: C: 87.09%; H: 5.08%; B: 3.41%; N: 4.42%. Measured values: C: 87.08%; H: 5.03%; B: 3.46%; N: 4.43%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-11. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 490℃.

[0324] Synthesis Example 34: Compound c-15 of the present invention was synthesized via the following route:

[0325]

[0326] The specific process of this embodiment can be referred to the conditions of Example 6, except that in the tandem Bora-Friedel-Crafts reaction, the ratio of 5 equivalents of BBr3 and 2 equivalents of BPh3, and N,N-diisopropylethylamine was adjusted to 20 equivalents, while the other conditions remained unchanged. After post-processing purification, 0.88 g of the yellow target compound was obtained, with a yield of 7.58%. High-resolution mass spectrometry (MS-APCI) (m / z): 1317.9787, theoretical molecular weight: 1317.4597. Elemental analysis: Theoretical values: C: 90.22%; H: 4.13%; B: 2.46%; N: 3.19%. Measured values: C: 90.30%; H: 4.14%; B: 2.41%; N: 3.15%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-15. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 550℃.

[0327] Synthesis Example 35: Compound c-18 of the present invention was synthesized via the following route:

[0328]

[0329] The specific process of this embodiment can be referred to the conditions of Example 7, except that in the tandem Bora-Friedel-Crafts reaction, the ratio of 5 equivalents of BBr3 and 2 equivalents of BPh3, and N,N-diisopropylethylamine was adjusted to 20 equivalents, while the other conditions remained unchanged. After post-processing purification, 0.88 g of the yellow target compound was obtained, with a yield of 7.98%. High-resolution mass spectrometry (MS-APCI) (m / z): 1099.4018, theoretical molecular weight: 1098.3985. Elemental analysis: Theoretical values: C: 85.27%; H: 4.13%; B: 2.95%; N: 7.65%. Measured values: C: 85.33%; H: 4.18%; B: 2.89%; N: 7.59%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-18. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 450℃.

[0330] Synthesis Example 36: Compound c-20 of the present invention was synthesized via the following route:

[0331]

[0332] The specific process of this embodiment can be referred to the conditions of Example 8, except that in the tandem Bora-Friedel-Crafts reaction, the ratio of 5 equivalents of BBr3 and 2 equivalents of BPh3, and N,N-diisopropylethylamine was adjusted to 20 equivalents, while the other conditions remained unchanged. After post-processing purification, 1.11 g of the yellow target compound was obtained, with a yield of 10.59%. High-resolution mass spectrometry (MS-APCI) (m / z): 1093.2461, theoretical molecular weight: 1092.3515. Elemental analysis: theoretical values: C: 85.74%; H: 3.60%; B: 2.97%; N: 7.69%. Measured values: C: 85.77%; H: 3.62%; B: 2.98%; N: 7.63%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-20. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 550℃.

[0333] Synthesis Example 37: Compound c-23 of the present invention was synthesized via the following route:

[0334]

[0335] The specific process of this embodiment can be referred to the conditions of Example 9, except that in the tandem Bora-Friedel-Crafts reaction, the ratio of 5 equivalents of BBr3 and 2 equivalents of BPh3, and N,N-diisopropylethylamine was adjusted to 20 equivalents, while the other conditions remained unchanged. After post-processing purification, 1.24 g of the yellow target compound was obtained, with a yield of 11.32%. High-resolution mass spectrometry (MS-APCI) (m / z): 1141.6390, theoretical molecular weight: 1140.3363. Elemental analysis: Theoretical values: C: 82.13%; H: 3.45%; B: 2.84%; N: 7.37%; O: 4.21%. Measured values: C: 82.15%; H: 3.44%; B: 2.85%; N: 7.38%; O: 4.18%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-23. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 500℃.

[0336] Synthesis Example 38: Compound c-28 of the present invention was synthesized via the following route:

[0337]

[0338] The specific process of this embodiment can be referred to the conditions of Example 10, except that in the tandem Bora-Friedel-Crafts reaction, the ratio of 5 equivalents of BBr3 and 2 equivalents of BPh3, and N,N-diisopropylethylamine was adjusted to 20 equivalents, while the other conditions remained unchanged. After post-processing purification, 1.08 g of the yellow target compound was obtained, with a yield of 12.06%. High-resolution mass spectrometry (MS-APCI) (m / z): 946.3694, theoretical molecular weight: 945.3658. Elemental analysis: Theoretical values: C: 87.65%; H: 4.48%; B: 3.43%; N: 4.44%. Measured values: C: 87.66%; H: 4.45%; B: 3.44%; N: 4.45%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-28. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 550℃.

[0339] Synthesis Example 39: Compound c-35 of the present invention was synthesized via the following route:

[0340]

[0341] The specific process of this embodiment can be referred to the conditions of Example 11, except that in the tandem Bora-Friedel-Crafts reaction, the ratio of 5 equivalents of BBr3 and 2 equivalents of BPh3, and N,N-diisopropylethylamine was adjusted to 20 equivalents, while the other conditions remained unchanged. After post-processing purification, 0.92 g of the bright green target compound was obtained, with a yield of 8.75%. High-resolution mass spectrometry (MS-APCI) (m / z): 1225.5430, theoretical molecular weight: 1224.5393. Elemental analysis: theoretical values: C: 85.31%; H: 5.18%; B: 2.65%; N: 6.86%. Measured values: C: 85.32%; H: 5.16%; B: 2.63%; N: 6.88%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-35. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 560℃.

[0342] Synthetic Example 40: Compound c-39 of the present invention was synthesized via the following route:

[0343]

[0344] The specific process of this embodiment can be referred to the conditions of Example 12, except that in the tandem Bora-Friedel-Crafts reaction, the ratio of 5 equivalents of BBr3 and 2 equivalents of BPh3, and N,N-diisopropylethylamine was adjusted to 20 equivalents, while the other conditions remained unchanged. After post-processing purification, 0.87 g of the bright green target compound was obtained, with a yield of 7.64%. High-resolution mass spectrometry (MS-APCI) (m / z): 1345.1280, theoretical molecular weight: 1344.6332. Elemental analysis: Theoretical values: C: 85.72%; H: 5.62%; B: 2.41%; N: 6.25%. Measured values: C: 85.79%; H: 5.66%; B: 2.34%; N: 6.21%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-39. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 570℃.

[0345] Synthetic Example 41: Compound c-76 of the present invention was synthesized via the following route:

[0346]

[0347] The specific process of this embodiment can be referred to the conditions of Example 13, except that in the tandem Bora-Friedel-Crafts reaction, the ratio of 5 equivalents of BBr3 and 2 equivalents of BPh3, and N,N-diisopropylethylamine was adjusted to 20 equivalents, while the other conditions remained unchanged. After post-processing purification, 1.24 g of the bright green target compound was obtained, with a yield of 11.56%. High-resolution mass spectrometry (MS-APCI) (m / z): 1285.1873, theoretical molecular weight: 1284.1840. Elemental analysis: Theoretical values: C: 72.91%; H: 3.06%; B: 2.52%; N: 6.54%; S: 14.97%. Measured values: C: 72.94%; H: 3.04%; B: 2.50%; N: 6.56%; S: 14.98%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-76. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 520℃.

[0348] Synthesis Example 42: Compound c-93 of the present invention was synthesized via the following route:

[0349]

[0350] The specific process of this embodiment can be referred to the conditions of Example 14, except that in the tandem Bora-Friedel-Crafts reaction, the ratio of 5 equivalents of BBr3 and 2 equivalents of BPh3, and N,N-diisopropylethylamine was adjusted to 20 equivalents, while the other conditions remained unchanged. After post-processing purification, 1.09 g of the bright green target compound was obtained, with a yield of 10.18%. High-resolution mass spectrometry (MS-APCI) (m / z): 1462.4013, theoretical molecular weight: 1461.3943. Elemental analysis: Theoretical values: C: 78.86%; H: 3.72%; B: 2.22%; N: 8.62%; S: 6.58%. Measured values: C: 78.84%; H: 3.73%; B: 2.23%; N: 8.64%; S: 6.56%. Based on the combined results of mass spectrometry and elemental analysis, the product was identified as the target compound c-93. This material exhibits excellent thermal stability, with a thermal decomposition temperature above 540℃.

[0351] The method described in the above-described examples of the synthesis process of the target compounds can be used to synthesize monoboron compound a1-119, diboron compound b1-119, and triboron compound c1-119.

[0352] The aforementioned fused donor-type boron-nitrogen heterocyclic derivatives can be applied in organic electroluminescent devices, particularly as host materials, sensitizer materials, or guest luminescent materials in the luminescent layer of electroluminescent devices. Figure 1 A schematic diagram of an electroluminescent device is attached. Figure 2 Electroluminescence spectra of devices prepared by using partially fused donor boron-nitrogen heterocyclic derivatives from this invention as luminescent materials.

[0353] The fusion donor type boron-nitrogen heterocyclic derivative described in this invention is preferably used as a guest luminescent material in electroluminescent devices. The specific device fabrication process includes: (1) substrate pretreatment, in which the ITO (indium tin oxide) glass substrate is ultrasonically cleaned for 30 minutes in ITO cleaning agent, isopropanol, acetone, ethanol, and deionized water, dried with nitrogen, and then dried in an oven at 120°C for 2 hours. Before fabricating the device, the ITO glass substrate is surface treated with oxygen plasma for 5 minutes, and then transferred to an organic vacuum chamber to evaporate organic functional layer materials. After completion, the vacuum is transferred to a metal vacuum chamber to evaporate metal electrodes. In the specific fabrication process, the optimal host material, exciton blocking layer material, carrier injection layer material, and carrier transport layer material can be selected according to the properties of the fusion donor type boron-nitrogen heterocyclic derivative. In addition, the film thickness of each functional layer and the concentration of host and guest doping have also been systematically studied and optimized.

[0354] Device Example 1:

[0355] ITO / MoO3(10nm) / TAPC(30nm) / TCTA(20nm) / mCP(5nm) / mCP: Dopant(30nm,1wt%) / DPEPO(15nm) / TmPyPB(30nm) / LiF(1nm) / Al(100 nm).

[0356] The dopant light-emitting layer is a-1, a single boron molecule based on a diphenylamine fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits deep blue light, such as... Figure 2 The image shows the electroluminescence spectrum of compound a-1, with a peak at 450 nm, a full width at half maximum (FWHM) of only 18 nm, and a maximum external quantum efficiency (EQE). max The percentage was 16.6%, and the device lifetime was LT. 95 For 118 hours @ initial brightness 2000 cd / m² 2 .like Figure 3 The diagram shows the specific device structure, device efficiency-brightness, and spectral characteristic curves.

[0357] Device Example 2:

[0358] ITO / NPB:MoOx(5:1,50nm) / TAPC(25nm) / CBP(5nm) / mCBP:Dopant (30nm,3wt%) / DPEPO(5nm) / TmPyPB(10nm) / TmPyPB:LiQ(9:1,30nm) / Al (110nm).

[0359] The emitting layer, Dopant, is a single boron molecule a-20 based on a carbazole-based fusion donor in the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits sky blue light, and the peak value of its electroluminescence spectrum is located at 492 nm, with a full width at half maximum (FWHM) of only 27 nm. EQE max The device lifetime is 28.3%, LT. 95 For 216 hours @ initial brightness 2000 cd / m² 2 .

[0360] Device Example 3:

[0361] ITO / TAPC:HATCN(9:1,60nm) / TAPC(25nm) / CBP(5nm) / mCBP: Dopant(30nm,3wt%) / DPEPO(15nm) / TPBi(45nm) / LiF(1nm) / Al(130nm).

[0362] The dopant light-emitting layer is a-39, a single boron molecule based on a 9,9-dihydroacridine fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits green light, with an electroluminescence spectrum peak at 520 nm and a full width at half maximum (FWHM) of only 28 nm. EQE max The device lifetime was 27.9%, and the LT (Long-Term) device lifetime was 100%. 95 213 hours @ initial brightness 2000 cd / m² 2 .

[0363] Device Example 4:

[0364] ITO / MoO3(10nm) / TAPC(50nm) / mCP(5nm) / 2,6-DCZPPY:Dopant(15 nm,5wt%) / DPEPO(15nm) / TmPyPB(30nm) / LiF(1nm) / Al(100nm).

[0365] The dopant light-emitting layer is a-76, a single boron molecule based on a phenothiazine fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits yellow light, with an electroluminescence peak wavelength of 548 nm, an FWHM of 32 nm, and an EQE of... max The device lifetime was 27.8%, and the LT (Long-Term) device lifespan was 100%. 95 189 hours @ initial brightness 2000 cd / m² 2 .

[0366] Device Example 5:

[0367] ITO / m-MTADTA:MoO3(4:1,60nm) / TCTA(25nm) / mCP(5nm) / mCBP: Dopant(20nm,1wt%) / DPEPO(15nm) / TmPyPB(40nm) / TmPyPB:LiQ(15nm) / LiQ(1nm) / Al(100nm).

[0368] The dopant light-emitting layer is a-93, a single boron molecule based on a phenazine fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits red light, with an electroluminescence spectrum peak at 618 nm and a full width at half maximum (FWHM) of only 30 nm. EQE max The device lifetime is 21.2%, and the LT (Long-Term Lifetime) is 100%. 95 For 208 hours @ initial brightness 2000 cd / m² 2 .

[0369] Device Example 6:

[0370] ITO / PEDOT: PSS(30nm) / TAPC(30nm) / mCP(5nm) / mCP:Dopant(30 nm, 3wt%) / DPEPO(5nm) / TmPyPB(30nm) / LiF(1nm) / Al(100nm).

[0371] The dopant light-emitting layer is b-1, a diphenylamine-based fusion donor from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits deep blue light, with a peak electroluminescence spectrum at 452 nm, a full width at half maximum (FWHM) of only 21 nm, and a maximum external quantum efficiency (EQE). max The percentage was 17.0%, and the device lifetime was LT. 95 121 hours @ initial brightness 2000 cd / m² 2 .

[0372] Device Example 7:

[0373] ITO / NPB:HATCN(9:1,50nm) / TAPC(30nm) / CBP(5nm) / mCBP:Dopant(30nm,8wt%) / DPEPO(15nm) / TmPyPB(40nm) / LiF(1nm) / Al(110nm).

[0374] The dopant light-emitting layer is b-20, a carbazole-based fusion donor in the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits sky blue light, with an electroluminescence spectrum peak at 488 nm and a full width at half maximum (FWHM) of only 25 nm. EQE max The device lifetime is 18.3% (LT). 95 For 206 hours @ initial brightness 2000 cd / m² 2 .

[0375] Device Example 8:

[0376] ITO / NPD (60nm) / TAPC (25nm) / CBP (5nm) / DPEPO: Dopant (30nm, 5 wt%) / DPEPO (15nm) / TmPyPB (45nm) / LiF (1nm) / Al (130nm).

[0377] The dopant light-emitting layer is b-39, a diboron molecule based on a 9,9-dihydroacridine fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits green light, with an electroluminescence spectrum peak at 518 nm and a full width at half maximum (FWHM) of only 29 nm. EQE max The device lifetime was 28.1%, and the LT (Long-Term) device lifespan was 28.1%. 95115 hours @ initial brightness 2000 cd / m² 2 .

[0378] Device Example 9:

[0379] ITO / MoO3(10nm) / TAPC(30nm) / mCBP(5nm) / 2,6-DCzppy:Dopant(15 nm, 3wt%) / DPEPO(15nm) / TmPyPB(30nm) / LiF(1nm) / Al(100nm).

[0380] The dopant light-emitting layer is b-76, a phenothiazine-based fusion donor from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits yellow light, with an electroluminescence peak wavelength of 551 nm, a full width at half maximum (FWHM) of 29 nm, and an EQE of [missing information]. max The device lifetime is 24.9%, and the LT (Long-Term) device lifetime is 24.9%. 95 For 89 hours @ initial brightness 2000 cd / m² 2 .

[0381] Device Example 10:

[0382] ITO / NPD (60nm) / TCTA (25nm) / mCBP (5nm) / mCBP: Dopant (20nm, 3 wt%) / DPEPO (15nm) / TPBi (40nm) / LiF (1nm) / Al (100nm).

[0383] The dopant light-emitting layer is b-93, a phenazine-based fusion donor of a fused donor boron-nitrogen heterocyclic derivative in this invention. The device emits orange-red light, with an electroluminescence spectrum peak at 598 nm and a full width at half maximum (FWHM) of only 33 nm. EQE max The device lifetime is 27.2%, and the LT (Long-Term) device lifetime is 100%. 95 For 94 hours @ initial brightness 2000 cd / m² 2 .

[0384] Device Example 11:

[0385] ITO / MoO3(10nm) / TAPC(30nm) / mCBP(5nm) / mCBP:Dopant(30nm, 1 wt%) / DPEPO(15nm) / TmPyPB(30nm) / LiF(1nm) / Al(100nm).

[0386] The dopant light-emitting layer is c-1 of a triboron molecule based on a diphenylamine fusion donor in the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits deep blue light, with a peak electroluminescence spectrum at 459 nm and a full width at half maximum (FWHM) of only 27 nm. (EQE) max The device lifetime is 19.8% (LT). 95 For 108 hours @ initial brightness 2000 cd / m² 2 .

[0387] Device Example 12:

[0388] ITO / NPB: TAPC: HATCN (5:4:1, 50nm) / TAPC (30nm) / CBP (5 nm) / mCBP: Dopant (30nm, 8wt%) / B3MPYMPM: LiQ (6:4, 35nm) / TPBi (40nm) / LiF (1nm) / Al (110nm).

[0389] The dopant emitting layer is c-20, a triboron molecule based on a carbazole-based fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits sky blue light, with an electroluminescence spectrum peak at 484 nm and a full width at half maximum (FWHM) of only 29 nm. EQE max The device lifetime is 19.6%, LT. 95 For 203 hours @ initial brightness 2000 cd / m² 2 .

[0390] Device Example 13:

[0391] ITO / NPD (60nm) / TAPC (25nm) / CBP (5nm) / DPEPO: Dopant (30nm, 5 wt%) / DPEPO (15nm) / TmPyPB (45nm) / LiF (1nm) / Al (130nm).

[0392] The dopant light-emitting layer is c-39, a triboron molecule based on a 9,9-dihydroacridine fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits green light, with an electroluminescence spectrum peak at 512 nm and a full width at half maximum (FWHM) of only 27 nm. EQE max It is 26.7%, and the device lifetime LT 95 106 hours @ initial brightness 2000 cd / m² 2 .

[0393] Device Example 14:

[0394] ITO / MoO3(10nm) / TAPC(30nm) / mCBP(5nm) / 2,6-DCZPPY:Dopant (15nm, 3wt%) / DPEPO(15nm) / TSPO1(5nm) / TmPyPB(30nm) / LiF(1 nm) / Al(100nm).

[0395] The dopant light-emitting layer is c-76, a triboron molecule based on a phenothiazine fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits yellow light, with an electroluminescence peak wavelength of 549 nm, an FWHM of 33 nm, and an EQE of... max The device lifetime is 25.9%, and the LT (Long-Term) device lifetime is 100%. 95 For 126 hours @ initial brightness 2000 cd / m² 2 .

[0396] Device Example 15:

[0397] ITO / NPD (60nm) / TCTA (25nm) / mCBP (5nm) / mCBP: Dopant (20nm, 3 wt%) / TPBi (40nm) / LiF (1nm) / Al (100nm).

[0398] The dopant light-emitting layer is c-93, a triboron molecule based on a phenazine-based fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits red light, with an electroluminescence spectrum peak at 611 nm and a full width at half maximum (FWHM) of only 34 nm. EQE max The device lifetime is 19.9% ​​(LT). 95 107 hours @ initial brightness 2000 cd / m² 2 .

[0399] Device Example 16:

[0400] ITO / NPD(50nm) / TCTA(20nm) / mCBP(5nm) / Host:Dopant(20nm, 3 wt%) / TPBi(40nm) / LiF(1nm) / Al(100nm).

[0401] In the luminescent layer, the Host is a single boron molecule a-1 based on a diphenylamine-based fusion donor, a boron-nitrogen heterocyclic derivative of the present invention, and the Dopant is a triboron molecule c-39 based on a 9,9-dihydroacridine-based fusion donor, a boron-nitrogen heterocyclic derivative of the present invention. The device emits green light, with a peak electroluminescence spectrum at 510 nm and a full width at half maximum (FWHM) of only 26 nm. EQE max The device lifetime is 28.2%, and the LT (Long-Term) device lifetime is 100%. 95112 hours @ initial brightness 2000 cd / m² 2 .

[0402] Device Example 17:

[0403] ITO / NPB:MoO3(4:1,40nm) / TCTA(25nm) / Host:Dopant(30nm,1 wt%) / DPEPO(10nm) / TSPO1(5nm) / TmPyPB:LiQ(3:2,30nm) / LiQ(2 nm) / Al(100nm).

[0404] In the luminescent layer, the Host is a diboron molecule b-1 based on a diphenylamine-based fusion donor, a boron-nitrogen heterocyclic derivative of the present invention, and the Dopant is a diboron molecule b-76 based on a phenothiazine-based fusion donor, a diboron derivative of the fusion donor type in the present invention. The device emits yellow light, and the peak value of the electroluminescence spectrum is located at 552 nm, with a full width at half maximum (FWHM) of only 27 nm. EQE max The device lifetime is 27.2%, and the LT (Long-Term) device lifetime is 100%. 95 229 hours @ initial brightness 2000 cd / m² 2 .

[0405] Device Example 18:

[0406] ITO / m-MTDATA:MoO3(9:1,40nm) / TAPC(20nm) / TCTA(15nm) / mCP (5nm) / Host:Dopant(20nm,5wt%) / DPEPO(10nm) / TPBi:LiQ(3:2,40 nm) / Al(100nm).

[0407] In the luminescent layer, the Host is a carbazole-based triboron molecule (c-20) of the boron-nitrogen heterocyclic derivative based on a fusion donor, and the Dopant is a phenazine-based triboron molecule (c-93) of the fusion donor-type boron-nitrogen heterocyclic derivative. The device emits red light, with a peak electroluminescence spectrum at 602 nm and a full width at half maximum (FWHM) of only 30 nm. (EQE) max The device lifetime is 20.4%, and the LT (Long-Term) device lifetime is 10.4%. 95 182 hours @ initial brightness 2000 cd / m² 2 .

[0408] Device Example 19:

[0409] ITO / NPB:MoO3(5:1,20nm) / TCTA(10nm) / TAPC(30nm) / mCP(5 nm) / DPEPO:Sensitizer:Dopant(15nm,25wt%:1wt%) / DPEPO(15nm) / TSPO1(5nm) / TPBi:LiQ(3:2,30nm) / LiQ(2nm) / Al(100nm).

[0410] The sensitizer in the luminescent layer is a-1, a single boron molecule based on a diphenylamine fusion donor in the fusion donor-type boron-nitrogen heterocyclic derivative of this invention, and a-20, a single boron molecule based on a carbazole fusion donor in the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits sky blue light, with an electroluminescence peak wavelength of 494 nm, an FWHM of 28 nm, and an EQE... max The device lifetime is 30.2% (LT). 95 113 hours @ initial brightness 2000 cd / m² 2 .

[0411] Device Example 20:

[0412] ITO / HATCN(5nm) / TAPC(30nm) / mCP(5nm) / mCP:DPEPO:Sensitizer: Dopant(25nm,30wt%:1wt%) / DPEPO(15nm) / TSPO1(5nm) / TmPyPB(45nm) / LiF(1nm) / Al(100nm).

[0413] The main mCP:DPEPO ratio in the luminescent layer is 1:1. The sensitizer is b-20, a carbazole-based fusion donor in the fusion donor type boron-nitrogen heterocyclic derivative of this invention, and the dopant is b-39, a 9,9-dihydroacridine-based fusion donor in the fusion donor type boron-nitrogen heterocyclic derivative of this invention. The device emits green light, with an electroluminescence peak wavelength of 524 nm, an FWHM of 29 nm, and an EQE... max The device lifetime is 30.6%, and the LT (Long-Term) device lifetime is 10.6%. 95 205 hours @ initial brightness 2000 cd / m² 2 .

[0414] Device Example 21:

[0415] ITO / HATCN(5nm) / TAPC(35nm) / mCP(5nm) / DPEPO:Sensitizer: Dopant(15nm,20wt%:1wt%) / DPEPO(15nm) / PPF(5nm) / TPBi(35nm) / LiF(1nm) / Al(100nm).

[0416] The sensitizer in the light-emitting layer is triboron molecule c-39, based on a 9,9-dihydroacridine fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The dopant is triboron molecule c-76, based on a phenothiazine fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits yellow light, with an electroluminescence peak wavelength of 555 nm, an FWHM of 34 nm, and an EQE... max The device lifetime is 28.5%, LT. 95 For 95 hours @ initial brightness 2000 cd / m² 2 .

[0417] Device Example 22:

[0418] ITO / HATCN(5nm) / TAPC(35nm) / mCP(5nm) / mCBP:TPBi:Sensitizer: Dopant(15nm,20wt%:1wt%) / DPEPO(5nm) / DPPyA(5nm) / TPBi:LiQ(3:2,35nm) / Al(100nm).

[0419] The main material mCBP:TPBi in the luminescent layer is in a 1:1 ratio. The sensitizer is triboron molecule c-39, based on a 9,9-dihydroacridine fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The dopant is triboron molecule c-93, based on a phenazine fusion donor, from the fusion donor-type boron-nitrogen heterocyclic derivative of this invention. The device emits red light, with an electroluminescence peak wavelength of 615 nm, an FWHM of 36 nm, and an EQE... max The device lifetime is 24.2%, LT. 95 147 hours @ initial brightness 2000 cd / m² 2 .

[0420] The above embodiments have verified that the compounds of the present invention achieve spectral modulation over a wide wavelength range from deep blue to red light while maintaining an extremely narrow emission half-width. Applying the compounds of the present invention to OLED devices yielded excellent device performance. Table 1 below lists the device performance of devices in Examples 1-22, from which it can be clearly determined that the compounds of the present invention possess excellent electroluminescence properties and have great potential for industrial applications.

[0421] Table 1 Device Performance List

[0422]

[0423]

[0424] a Start-up voltage; b Maximum brightness; c Maximum current efficiency; d Maximum power efficiency; e Maximum external quantum efficiency; f Electroluminescence peak and full width at half maximum (FWHM); g Color coordinates

[0425] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A boron-nitrogen heterocycle derivative based on a fusion donor, characterized in that, The structure of the boron-nitrogen heterocyclic derivative based on the fusion donor is: , , , , , , , , , , , , , or .

2. Use of the fused donor-based boronazacycle derivative according to claim 1 in an organic electroluminescent device.

3. Use according to claim 2, wherein the compound is ###0002### The fused donor-based boronazacycle derivative is used as a light-emitting layer material in an organic electroluminescent device.

4. An organic electroluminescent device, characterized by comprising From bottom to top, it comprises an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer and a cathode; the material of the light-emitting layer is the fused donor-based boronazacycle derivative according to claim 1.

5. The organic electroluminescent device according to claim 4, wherein It further comprises an electron blocking layer between the hole transport layer and the light-emitting layer, and a hole blocking layer between the light-emitting layer and the electron transport layer.

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