Narrow emission compound of tetraboron rigid heterocyclic ring as well as preparation method and application of narrow emission compound

Abstract

The invention belongs to the field of organic electroluminescent materials, and particularly relates to a tetraboron rigid heterocyclic narrow emission compound as well as a preparation method and application thereof. According to the invention, a plurality of boron atoms are introduced and embedded into a molecular skeleton in a W-shaped arrangement, and intermolecular aggregation is inhibited by utilizing a steric hindrance effect. The electron delocalization characteristic is enhanced by expanding a conjugated system, the carrier mobility is improved, and the host-guest energy transmission efficiency is optimized. On the basis, intramolecular closed loop occurs in a molecular skeleton, and the conjugate length is further increased, so that the molecule has higher color purity and excellent luminescence property while emitting light at long wavelength. The novel organic light-emitting material provided by the invention can be applied to the organic light-emitting device as a guest doping material, and the device has the characteristics of high external quantum efficiency, high brightness, good stability and the like.

Description

Technical Field

[0001] The invention belongs to the field of organic electroluminescent materials, and particularly relates to a tetraboron rigid heterocyclic narrow emission compound and a preparation method and application thereof. Background Art

[0002] Organic electroluminescent materials have shown great application potential in the fields of display and lighting. For example, organic light-emitting diode (OLED) technology is widely used in high-end display devices such as smartphones and televisions. It has advantages such as self-luminescence, wide viewing angle, and fast response speed. MR-TADF (multiple resonance thermally activated delayed fluorescence) materials are a type of organic light-emitting materials that achieve narrow spectrum emission, high color purity, and efficient exciton utilization through intramolecular multiple resonance effects. Its core mechanism is based on the cooperative resonance effect of electron donors (such as boron, nitrogen, oxygen, etc.) in the molecular skeleton. By regulating the distribution of frontier molecular orbitals (HOMO / LUMO), the excited state structural relaxation is reduced, thereby narrowing the emission spectrum half-maximum (FWHM) and improving the luminous efficiency. In recent years, MR-TADF materials have received widespread attention due to their narrow spectrum, high efficiency, and tunable emission wavelength.

[0003] At present, the exciton lifetime of most MR-TADF molecules is still relatively long (>10μs), which often causes a significant efficiency roll-off in the device at high brightness and also affects the stability of the device. When pursuing long-wavelength emission (such as red and near-infrared emission), it is often difficult to achieve narrow-band emission at the same time. Long-wavelength emission usually requires a larger conjugated system, but this will increase intermolecular interactions, resulting in a broadening of the emission spectrum, making it difficult to meet some applications with special requirements for long-wavelength narrow-band emission, such as bioimaging and optical communications. In this context, the design of efficient MR-TADF material molecular structures remains an urgent need. Summary of the Invention

[0004] To address the shortcomings of the existing technology, the present invention proposes a tetraboron rigid heterocyclic narrow-emission compound, its preparation method, and its application. By introducing multiple boron atoms and embedding them into the molecular backbone in a "W"-shaped arrangement, the present invention utilizes steric hindrance to inhibit intermolecular aggregation. By extending the conjugated system, electron delocalization is enhanced, carrier mobility is improved, and host-guest energy transfer efficiency is optimized, thereby achieving a highly efficient, long-lifetime, narrow-emission luminescent material.

[0005] The first object of the present invention is achieved through the following technical solutions:

[0006] A tetraboron rigid heterocyclic narrow emission compound having the general structural formula shown in the following chemical formula I or chemical formula II;

[0007]

[0008] In Chemical Formula I and Chemical Formula II, R and R' can be independently selected from one or more of a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, an alkyl group, an aromatic ring composed of carbon and hydrogen atoms, an aromatic heterocycle composed of carbon, nitrogen and hydrogen atoms, an aromatic heterocycle composed of carbon, nitrogen, oxygen and hydrogen atoms, an aromatic heterocycle composed of carbon, sulfur and hydrogen atoms, and an aromatic heterocycle composed of carbon, nitrogen, sulfur and hydrogen atoms.

[0009] The present invention introduces multiple boron atoms and embeds them into the molecular backbone in a "W"-shaped arrangement, thereby enhancing molecular planarity and influencing their solid-state stacking, thereby effectively regulating luminescence properties. This also results in intramolecular ring closure within the molecular backbone, further increasing the conjugation length. This results in long-wavelength emission with higher color purity and excellent luminescence properties.

[0010] Preferably, R or R' is one or more of the following structures:

[0011]

[0012] In some preferred embodiments, the specific structure of the tetraboron rigid heterocyclic narrow emission compound is any one of the following structures:

[0013]

[0014]

[0015]

[0016]

[0017]

[0018] By introducing different units at different sites on the tetraboron rigid heterocyclic core, the present invention further improves the material's electron transport properties while maintaining its narrow-band luminescence, significantly enhancing the fabrication of efficient narrow-band blue OLED devices. By simultaneously introducing symmetrical moieties on both sides of the tetraboron rigid heterocyclic core, the conjugated structure is hindered, resulting in deep-blue emission wavelengths. This significantly improves the material's efficiency through a multi-channel radiative attenuation process and energy transfer mechanism.

[0019] The second object of the present invention is achieved through the following technical solutions:

[0020] When the structural formula of the tetraboron rigid heterocyclic narrow emission compound is as shown in Chemical Formula I, the preparation method thereof comprises the following steps:

[0021] a) using an aniline derivative and a halogenated benzene as raw materials, a series of CN coupling reactions were performed to synthesize an intermediate 3 having a structure of chemical formula III;

[0022] b) intermediate 3 is dissolved in a solvent and reacted with a boron halide to produce the final luminescent material;

[0023] When the general structural formula of the tetraboron rigid heterocyclic narrow emission compound is as shown in Chemical Formula II, the preparation method thereof comprises the following steps:

[0024] a) using an aniline derivative and a halogenated benzene as raw materials, a series of CN coupling reactions were performed to synthesize an intermediate 3 having a structure of chemical formula III;

[0025] b) intermediate 3 is dissolved in a solvent and reacted under the action of a boron halide to obtain intermediate 4 having a structure of chemical formula I;

[0026] c) dissolving the intermediate 4 in a solvent and heating the mixture to react to obtain the final luminescent material;

[0027]

[0028] Preferably, when the general structural formula of the tetraboron rigid heterocyclic narrow emission compound is as shown in Chemical Formula I or Chemical Formula II, step a) comprises the following steps:

[0029] a)-1. An aniline derivative is reacted with a halogenated benzene under conditions including a solvent, a catalyst, a catalyst ligand and a base to obtain an intermediate 1 having a structure of chemical formula IV;

[0030]

[0031] In a)-1, the molar ratio of the aniline derivative to the halogenated benzene is preferably 1:1-2. Preferably, the reaction temperature is 90-150°C, and the reaction time is 5-40 hours. After the reaction, the reaction solution is filtered and washed, and the concentrated solid is further separated and purified using a chromatographic column.

[0032] a)-2. Intermediate 1 is reacted with 1,3-dibromo-5-chlorobenzene under conditions including a solvent, a catalyst, a catalyst ligand and a base to obtain an intermediate 2 having a structure of chemical formula V;

[0033]

[0034] In a)-2, preferably, the molar ratio of intermediate 1 to 1,3-dibromo-5-chlorobenzene is 1:0.3-1. Preferably, the reaction temperature is 90-150°C, and the reaction time is 5-40 hours. After the reaction is completed, the reaction solution is filtered and washed, and the concentrated solid is further separated and purified using a chromatographic column.

[0035] a)-3. Intermediate 2 reacts with N1,N3-di-p-toluene-1,3-diamine under conditions including a solvent, a catalyst, a catalyst ligand and a base to obtain intermediate 3.

[0036] In a)-3, preferably, the molar ratio of intermediate 2 to N1,N3-di-p-toluene-1,3-diamine is 1:0.2-1. Preferably, the reaction temperature is 90-150°C, and the reaction time is 5-40 hours. After the reaction is completed, the reaction solution is filtered and washed, and the concentrated solid is further separated and purified using a chromatographic column.

[0037] The CN coupling reaction in step a) is carried out under the conditions comprising solvent, catalyst, catalyst ligand and alkali.Solvent, catalyst, catalyst ligand and alkali are solvents, catalyst, catalyst ligand and alkali available in any CN coupling reaction.Preferably, the solvent is one or more of o-Xylol, p-Xylol, m-Xylol, o-dichlorobenzene, 1,3,5-mesitylene, toluene etc.The catalyst is a palladium catalyst, and the palladium catalyst comprises one or more of tris (dibenzylideneacetone) dipalladium [Pd2(dba)3], tetrakis (triphenylphosphine) palladium [Pd(PPh3)4], bis(triphenylphosphine palladium dichloride) (Pd(PPh3)2Cl2), bis(acetic acid palladium) [Pd(OAc)2] etc. Catalyst ligands include phosphorus ligands, nitrogen ligands, carbon ligands, oxygen ligands, and heteroatom ligands, and examples thereof include tri-tert-butylphosphine tetrafluoroborate (t-Bu3PHBF4), triphenylphosphine (PPh3), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos), 2-dicyclohexylphosphino-2',6'-dimethoxy-1,1'-biphenyl (SPhos), and 2-dicyclohexylphosphino-2',6'-diisopropoxy-1,1'-biphenyl (Ru-Phos). The base is one or more of potassium carbonate, cesium carbonate, sodium sec-butoxide (s-BuONa), and sodium tert-butoxide (t-BuONa).

[0038] Preferably, when the general structural formula of the narrow-emitting compound of the tetraboron rigid heterocyclic ring is as shown in Chemical Formula I, step b) comprises the following steps: Preferably, the boron halide is one or more of BBr3, BI3 or BCl3. Preferably, the molar ratio of intermediate 3 to boron halide is 1:50-80. Preferably, the solvent is one or more of dichlorobenzene, isotrichlorobenzene, n-butyl ether, phenyl ether, etc. Preferably, the reaction temperature is 180-250°C, and the reaction time is 10-50h. Preferably, after the reaction in step b) is completed, an alcohol reagent is added for quenching, and the alcohol reagent can be listed as one or more of methanol, ethanol, isopropanol, n-butanol, etc. After the reaction in step b) is completed, optionally, post-treatment is carried out, and the post-treatment includes: concentrating the reaction solution, and further purifying the residual solid by a chromatographic column.

[0039] Preferably, when the general structural formula of the tetraboron rigid heterocyclic narrow-emission compound is as shown in Chemical Formula II, step b) comprises the following steps: Preferably, the boron halide is one or more of BBr3, BI3, or BCl3. Preferably, the molar ratio of intermediate 3 to the boron halide is 1:50-80. Preferably, the solvent is one or more of dichlorobenzene, m-trichlorobenzene, n-butyl ether, phenyl ether, etc. Preferably, the reaction temperature is 180-250°C, and the reaction time is 10-50 hours.

[0040] Preferably, when the general structural formula of the tetraboron rigid heterocyclic narrow-emission compound is as shown in Chemical Formula II, in step c), the reaction temperature is 255-350°C and the reaction time is 10-50 hours. Preferably, after the reaction in step c), an alcohol reagent is added for quenching. The alcohol reagent can be one or more of methanol, ethanol, isopropanol, n-butanol, etc. After the reaction in step c), post-treatment is optionally performed. The post-treatment includes: concentrating the reaction solution and further purifying the residual solid by chromatographic column.

[0041] Preferably, the aniline derivative has the structure shown in the following chemical formula VI:

[0042]

[0043] R1, R2, R3, R4, and R5 are independently selected from one or more of H, F, Br, Cl, CN, a straight-chain alkyl group having 1 to 30 carbon atoms, a branched-chain alkyl group having 3 to 30 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, an aromatic ring consisting of carbon and hydrogen, an aromatic heterocycle consisting of carbon, nitrogen and hydrogen, an aromatic heterocycle consisting of carbon, oxygen and hydrogen, an aromatic heterocycle consisting of carbon, sulfur and hydrogen, and an aromatic heterocycle consisting of carbon, nitrogen, sulfur and hydrogen.

[0044] Preferably, the entire reaction process is carried out under an inert atmosphere, which includes nitrogen, argon, etc.

[0045] The third object of the present invention is achieved through the following technical solutions:

[0046] A light-emitting layer comprises one or more of the above-mentioned tetraboron rigid heterocyclic narrow emission compounds.

[0047] More preferably, the compound further comprises one or more of the group consisting of triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, azadibenzothiophene, azadibenzofuran, azadibenzoselenophene and triazine.

[0048] Preferably, in the light-emitting layer, the mass percentage of the tetraboron rigid heterocyclic narrow emission compound is 0.1%-20%.

[0049] The fourth object of the present invention is achieved through the following technical solutions:

[0050] An organic electroluminescent device, comprising the above-mentioned light-emitting layer. Specifically, the organic electroluminescent device comprises: a glass substrate, an anode, a hole injection layer, a hole transport layer, an exciton blocking layer, the above-mentioned light-emitting layer, an electron transport layer, an electron injection layer, and a cathode.

[0051] Preferably, the anode is indium tin oxide; preferably, the hole injection layer is one or more of HAT-CN, F4TCNQ, and NDP-9; preferably, the hole transport layer is one or more of TAPC, TCTA, and NPB; preferably, the exciton blocking layer is one or more of mCP, PPF, and DPEPO; preferably, the electron transport layer is one or more of TmPyPB; preferably, the electron injection layer is one or more of LiQ, LiF, and Yb; preferably, the cathode is Al and / or Ag; wherein the structural formulas of HAT-CN, F4TCNQ, NDP-9, TAPC, TCTA, NPB, mCP, PPF, DPEPO, and TmPyPB are as follows:

[0052]

[0053] Preferably, the hole injection layer has a thickness of 2-8 nm; preferably, the hole transport layer has a thickness of 30-50 nm; preferably, the exciton blocking layer has a thickness of 15-25 nm; preferably, the light-emitting layer has a thickness of 20-40 nm; preferably, the electron transport layer has a thickness of 30-50 nm; preferably, the electron injection layer has a thickness of 0.5-2 nm; preferably, the cathode has a thickness of 100-200 nm.

[0054] The fifth object of the present invention is achieved through the following technical solutions:

[0055] A method for preparing the organic electroluminescent device as described above comprises the following steps:

[0056] a) cleaning, drying, and oxygen-plasma treating an indium tin oxide glass substrate;

[0057] b) depositing a hole injection layer, a hole transport layer, an exciton blocking layer, a light-emitting layer, an electron transport layer, and a cathode on the indium tin oxide glass substrate treated in step a) to obtain an organic electroluminescent device.

[0058] Preferably, in step a), the transparent conductive indium tin oxide glass substrate is cleaned by ultrasonic cleaning with a micron-grade semiconductor-specific detergent, deionized water, acetone, and isopropyl alcohol in sequence for 5-25 minutes, more preferably 15 minutes; preferably, the drying temperature is 60-100° C., more preferably 80° C.; preferably, the oxygen-plasma treatment time is 3-10 minutes, more preferably 5 minutes.

[0059] Preferably, the deposition method in step b) is thermal evaporation or spin coating.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] 1. This system, based on MR-TADF heterocyclic compounds, further enhances the electron transport properties of the molecule, resulting in excellent thermodynamic stability, rapid radiative decay, low non-radiative decay, and a high photoluminescence quantum yield (PLQY). The introduction of multiple boron atoms and their "W"-shaped arrangement within the molecular backbone further enhances molecular planarity, influences solid-state stacking, and effectively modulates luminescence properties. Furthermore, a series of molecules, based on this structure, exhibit intramolecular ring closure within the molecular backbone, further increasing the conjugation length. This results in higher color purity and excellent luminescence properties while emitting at long wavelengths.

[0062] 2. The preparation method of the compound disclosed in the present invention has the outstanding advantages of being simple to operate, repeatable, capable of large-scale production and having strong adaptability to substrates.

[0063] 3. The narrow emission multiple resonance luminescent material provided by the present invention is insensitive to water and oxygen, has good solubility in common organic solvents, and has good thermal stability. In particular, the prepared electroluminescent device has a significantly improved external quantum efficiency under the premise that the FWHM value is effectively controlled.

[0064] 4. After the luminescent material of the present invention is prepared into an organic light-emitting diode, the material exhibits high-efficiency luminescence performance, significantly improved quantum efficiency, a narrow-bandwidth emission spectrum, and excellent characteristics of low sensitivity to doping concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 is the single crystal structure of compound 1;

[0066] Figure 2 is the H NMR spectrum of compound 1 in deuterated dichloromethane;

[0067] Figure 3 is the high-resolution mass spectrum of compound 1;

[0068] Figure 4 is the single crystal structure of compound 26;

[0069] Figure 5 is the H NMR spectrum of compound 26 in deuterated dichloromethane;

[0070] Figure 6 is the high-resolution mass spectrum of compound 26;

[0071] Figure 7 Thermogravimetric analysis and differential scanning calorimetry curves of compounds 1 and 26;

[0072] Figure 8 The absorption and emission spectra of compounds 1 and 26 in toluene solution. DETAILED DESCRIPTION

[0073] The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present invention so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other unless there is a conflict.

[0074] The present invention provides a tetraboron rigid heterocyclic narrow emission compound having a general structural formula of chemical formula I or chemical formula II.

[0075] The compounds prepared in Examples 1-25 have the general structural formula of Chemical Formula I, and the compounds prepared in Examples 26-50 have the general structural formula of Chemical Formula II.

[0076] Example 1

[0077] The tetraboron rigid heterocyclic narrow emission compound of Example 1 was prepared by the following method:

[0078] a) In a 100 mL, three-necked, round-bottomed reaction flask filled with argon, a mixture of bromobenzene (3.14 g, 20.0 mmol), 2,6-dimethylaniline (2.90 g, 24.0 mmol), Pd2(dba)3 (0.92 g, 1 mmol), tBu3PHBF4 (0.88 g, 3 mmol), tBuONa (5.76 g, 60.0 mmol), and 50 mL of toluene was stirred at 110°C overnight. The cooled mixture was filtered through celite and washed with dichloromethane. After removal of the organic solvent, the remaining solid was further isolated and purified by silica gel column chromatography (eluted with petroleum ether / dichloromethane) to provide pure intermediate 1 as a white solid (5.21 g, 90% yield).

[0079] b) In a 100 mL, three-necked, round-bottomed reaction flask filled with argon, Intermediate 1 (7.8 g, 40.0 mmol), 1,3-dibromo-5-chlorobenzene (5.40 g, 20.0 mmol), Pd(dba) (0.92 g, 1 mmol), tBuPHBF (0.88 g, 3 mmol), tBuONa (5.76 g, 60.0 mmol), and 50 mL of toluene were stirred at 100°C overnight. The cooled mixture was filtered through celite and washed with dichloromethane. After removal of the organic solvent, the remaining solid was further isolated and purified by silica gel column chromatography (eluted with petroleum ether / dichloromethane) to provide pure Intermediate 2 as a white solid (6.63 g, 80% yield).

[0080] c) In a 100 mL three-necked round-bottom reaction flask filled with argon, N1,N1'-(1,3-phenyl)bis(3,5-diphenyl-2,6-dimethylphenyl-1-(p-tolyl)benzene-triamine) (1.44 g, 5.0 mmol), Intermediate 2 (6.28 g, 12.5 mmol), Pd2(dba)3 (0.14 g, 0.15 mol), tBu3PHBF4 (0.88 g, 3 mmol), tBuONa (1.44 g, 15.0 mmol), and 40 mL of toluene were stirred at 120°C overnight. The cooled mixture was filtered through celite and washed with dichloromethane. After removal of the organic solvent, the residual solid was further separated and purified by silica gel column chromatography (eluted with petroleum ether / dichloromethane) to obtain pure Intermediate 3 as a white solid (4.96 g, 75% yield).

[0081] d) In a 120 mL argon-sealed pressure tube, intermediate 3 (0.61 g, 0.5 mmol) and 15 mL of o-dichlorobenzene were added. Boron tribromide (2.69 mL, 28.0 mmol) was added, and the reaction was stirred at 220° C. for 48 h. After cooling to room temperature, an alcohol reagent (100 mL) was slowly added in an ice bath to quench the reaction. The organic solvent was concentrated under vacuum, and the residual solid was further separated and purified by silica gel chromatography (eluted with petroleum ether / dichloromethane) to obtain pure bright yellow solid compound 1 in a 25% yield.

[0082] The molecule was grown into a single crystal and tested by X-ray diffraction, and the Figure 1 , showing the single crystal structure of compound 1 of the present invention.

[0083] Figure 2 This is the H NMR spectrum of compound 1 in deuterated dichloromethane. 1 The HNMR data are as follows: 1HNMR(600MHz,CD2Cl2)δ[ppm]: δ10.20(s,1H),9.38(d,J=7.3Hz,2H),8.88(d,J=7.6Hz,2H),8.62(s,2H),8.56(s,1H ),8.50(d,J=8.7Hz,2H),7.76(d,J=8.5Hz,2H),7.55(dt,J=21.4,7.1Hz,4H),7.45(t,J=7.8Hz,2H),7.33(t,J=7.4Hz ,2H),7.19(t,J=7.8Hz,4H),7.11(d,J=8.0Hz,2H),7.07(d,J=7.8Hz,4H),7.01(d,J=7.7Hz,2H),6.79(d,J=8.4Hz,2H ), 6.73(d,J=8.4Hz,2H),5.33(s,1H),5.13(s,1H),2.69(s,6H),1.74(s,6H),1.73(s,6H),1.59(s,6H),1.57(s,6H).

[0084] Figure 3 This is the high-resolution mass spectrum of compound 1. The theoretical molecular weight of compound 1 [M+H]+ peak is 1253.5951, and the measured accurate molecular weight is 1253.6034. The molecular weights are basically consistent, verifying the accuracy of compound 1.

[0085] The reaction flow diagram of steps a)-d) of Example 1 is as follows:

[0086]

[0087] Example 2

[0088] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 2, steps b) to d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of p-cyanoaniline, and the other raw materials and steps are the same as in Example 1, and compound 2 is finally obtained with a yield of 75%.

[0089] Example 3

[0090] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 3, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 4-methylaniline, and the other raw materials and steps are the same as in Example 1, and compound 3 is finally obtained with a yield of 70%.

[0091] Example 4

[0092] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 4, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,6-diisopropylaniline, and the other raw materials and steps are the same as in Example 1, and compound 4 is finally obtained with a yield of 76%.

[0093] Example 5

[0094] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 5, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 3,5-dimethylaniline, and the other raw materials and steps are the same as in Example 1, and compound 5 is finally obtained with a yield of 74%.

[0095] Example 6

[0096] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 6, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,4,6-trimethylaniline, and the other raw materials and steps are the same as in Example 1, and compound 6 is finally obtained with a yield of 71%.

[0097] Example 7

[0098] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 7, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2-fluoroaniline, and the other raw materials and steps are the same as in Example 1, and compound 7 is finally obtained with a yield of 72%.

[0099] Example 8

[0100] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 8, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 4-fluoroaniline, and the other raw materials and steps are the same as in Example 1, and compound 8 is finally obtained with a yield of 70%.

[0101] Example 9

[0102] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 9, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,6-difluoroaniline, and the other raw materials and steps are the same as in Example 1, and compound 9 is finally obtained with a yield of 72%.

[0103] Example 10

[0104] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 10, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,3,4,5,6-pentafluoroaniline, and the other raw materials and steps are the same as in Example 1, and compound 10 is finally obtained with a yield of 78%.

[0105] Example 11

[0106] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 11, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of p-cyanoaniline, and the other raw materials and steps are the same as in Example 1, and finally compound 11 is obtained with a yield of 76%.

[0107] Example 12

[0108] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 12, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2-aminoisophthalonitrile, and the other raw materials and steps are the same as in Example 1, and finally compound 12 is obtained with a yield of 71%.

[0109] Example 13

[0110] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 13, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 3-aminophthalonitrile, and the other raw materials and steps are the same as in Example 1, and finally compound 13 is obtained with a yield of 78%.

[0111] Example 14

[0112] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 14, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 4-aminoisophthalonitrile, and the other raw materials and steps are the same as in Example 1, and finally compound 14 is obtained with a yield of 72%.

[0113] Example 15

[0114] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 15, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 5-aminoisophthalonitrile, and the other raw materials and steps are the same as in Example 1, and compound 15 is finally obtained with a yield of 77%.

[0115] Example 16

[0116] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 16, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of o-chloroaniline, and the other raw materials and steps are the same as in Example 1, and compound 16 is finally obtained with a yield of 70%.

[0117] Example 17

[0118] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 17, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 4-chloroaniline, and the other raw materials and steps are the same as in Example 1, and finally compound 17 is obtained with a yield of 77%.

[0119] Example 18

[0120] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 18, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,6-dichloroaniline, and the other raw materials and steps are the same as in Example 1, and compound 18 is finally obtained with a yield of 71%.

[0121] Example 19

[0122] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 19, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,3-dichloroaniline, and the other raw materials and steps are the same as in Example 1, and finally compound 19 is obtained with a yield of 74%.

[0123] Example 20

[0124] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 20, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,4-dichloroaniline, and the other raw materials and steps are the same as in Example 1, and finally compound 20 is obtained with a yield of 72%.

[0125] Example 21

[0126] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 21, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 3,5-dichloroaniline, and the other raw materials and steps are the same as in Example 1, and finally compound 21 is obtained with a yield of 76%.

[0127] Example 22

[0128] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 22, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2-aminonaphthalene, and the other raw materials and steps are the same as in Example 1, and finally compound 22 is obtained with a yield of 73%.

[0129] Example 23

[0130] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 23, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 3-aminobiphenyl, and the other raw materials and steps are the same as in Example 1, and finally compound 23 is obtained with a yield of 69%.

[0131] Example 24

[0132] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 24, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of [1,1':3',1"-terphenyl]-5'-amine, and the other raw materials and steps are the same as in Example 1, and finally compound 24 is obtained with a yield of 78%.

[0133] Example 25

[0134] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 25, steps b)-d) are the same as in Example 1, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 4-dibenzhydrylaniline, and the other raw materials and steps are the same as in Example 1, and finally compound 25 is obtained with a yield of 71%.

[0135] Example 26

[0136] The tetraboron rigid heterocyclic narrow emission compound of Example 26 was prepared by the following method:

[0137] a) In a 100 mL, three-necked, round-bottomed reaction flask filled with argon, a mixture of bromobenzene (3.14 g, 20.0 mmol), 2,6-dimethylaniline (2.90 g, 24.0 mmol), Pd2(dba)3 (0.92 g, 1 mmol), tBu3PHBF4 (0.88 g, 3 mmol), tBuONa (5.76 g, 60.0 mmol), and 50 mL of toluene was stirred at 110°C overnight. The cooled mixture was filtered through celite and washed with dichloromethane. After removal of the organic solvent, the remaining solid was further isolated and purified by silica gel column chromatography (eluted with petroleum ether / dichloromethane) to obtain pure solid intermediate 1.

[0138] b) In a 100 mL three-necked round-bottom reaction flask filled with argon, Intermediate 1 (7.8 g, 40.0 mmol), 1,3-dibromo-5-chlorobenzene (5.40 g, 20.0 mmol), Pd2(dba)3 (0.92 g, 1 mmol), tBu3PHBF4 (0.88 g, 3 mmol), tBuONa (5.76 g, 60.0 mmol), and 50 mL of toluene were stirred at 100°C overnight. The cooled mixture was filtered through celite and washed with dichloromethane. After removal of the organic solvent, the remaining solid was further isolated and purified by silica gel column chromatography (eluted with petroleum ether / dichloromethane) to obtain pure solid Intermediate 2.

[0139] c) In a 100 mL three-necked round-bottom reaction flask filled with argon, N1,N1'-(1,3-phenyl)bis(3,5-diphenyl-2,6-dimethylphenyl-1-(p-tolyl)benzene-triamine) (1.44 g, 5.0 mmol), Intermediate 2 (6.28 g, 12.5 mmol), Pd2(dba)3 (0.92 g, 1 mmol), tBu3PHBF4 (0.88 g, 3 mmol), tBuONa (1.44 g, 15.0 mmol), and 40 mL of toluene were stirred at 120°C overnight. The cooled mixture was filtered through celite and washed with dichloromethane. After removal of the organic solvent, the residual solid was further separated and purified by silica gel column chromatography (eluted with petroleum ether / dichloromethane) to obtain pure solid Intermediate 3.

[0140] d) In a 120 mL argon-sealed pressure-resistant tube, intermediate 3 (1.1 g, 0.9 mmol) and 15 mL of o-dichlorobenzene were added. Boron tribromide (4.84 mL, 50.4 mmol) was added, and the reaction was stirred at 220° C. for 48 h, then the temperature was gradually increased to 280° C. and the reaction was continued for 48 h. After cooling to room temperature, an alcohol reagent (100 mL) was slowly added in an ice bath to quench the reaction. The organic solvent was concentrated under vacuum, and the residual solid was further separated and purified by silica gel chromatography (eluted with petroleum ether / dichloromethane) to obtain pure compound 26 as a bright yellow solid (0.24 g, 22% yield).

[0141] The molecule was grown into a single crystal and tested by X-ray diffraction, and the Figure 4 , showing that compound 26 of the present invention has a single crystal structure.

[0142] Figure 5 The H NMR spectrum of compound 26 in deuterated dichloromethane is shown. 1 The HNMR data are as follows: 1HNMR (600MHz, CD2Cl2) δ[ppm]: δ10.78(s,1H),9.62(d,J=7.1Hz,1H),9.52(d,J=7.4Hz,1H),9.22(t,J=8.2Hz,2H),8.90(s,1H),8.84(s,1H),7. 87(d,J=8.6Hz,1H),7.65(t,J=7.2Hz,1H),7.59(dt,J=18.9,7.0Hz,4H) ,7.50(s,2H),7.38(t,J=7.3Hz,1H),7.26(td,J=8.0,4.7Hz,4H),7.18(d ,J=8.6Hz,3H),7.16(s,1H),7.14-7.11(m,4H),7.10(s,1H),6.97(s,1H ),6.90(s,1H),6.88(d,J=5.4Hz,1H),6.86(s,1H),6.82(d,J=8.6Hz,1H ),5.33(s,1H),5.27(s,1H),2.59(d,J=22.0Hz,6H),1.87(s,3H),1.84( s,3H),1.80(s,3H),1.79(s,3H),1.75(s,6H),1.73(s,3H),1.71(s,3H). and Figure 3 By comparison, the chemical shift ranges are similar, the low-field peak intensity is enhanced, and the high-field peak intensity is weakened, which shows that the molecular structure has changed and the chemical formula 26 has formed an inner ring.

[0143] Figure 6 This is the high-resolution mass spectrum of compound 26. The theoretical molecular weight of compound 26 [M+H] + peak is 1251.5794, and the measured accurate molecular weight is 1251.5652. The molecular weights are basically consistent, which verifies the accuracy of compound 26. Figure 3 (Compound 1) and Figure 6 Comparative analysis of (Compound 26) showed that the molecular weight of Compound 26 was reduced by 2 Da compared with Compound 1 (measured value: ΔM = -2.0003), which was highly consistent with the theoretical prediction of the removal of two hydrogen atoms during the endocyclization reaction (ΔM theoretical value = -2.0156 Da).

[0144] Figure 7 Thermogravimetric analysis and differential scanning calorimetry curves of compounds 1 and 26 are shown. Based on the coordinated characterization of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), compound 1 exhibits excellent thermal stability below 576°C (Δm <5%, no glass transition); the thermal degradation onset temperature of compound 26 is 567°C (Δm = 5% corresponding to the Td value), indicating that the narrow emission multiple resonance luminescent material provided by the present invention has good thermal stability.

[0145] Figure 8 The following are the UV-visible absorption and fluorescence spectra of Compound 1 and Compound 26 in toluene solution (0.01 mM). The emission peaks of Compound 1 and Compound 26 are located in the blue light range. Compound 1 has a maximum emission wavelength of 451 nm and a full width at half maximum (FWHM) of 19 nm, which is relatively narrow. Compound 26 has a maximum emission wavelength of 477 nm and a full width at half maximum (FWHM) of 15 nm, which is relatively narrow.

[0146] The reaction flow diagram of steps a)-d) of Example 26 is as follows:

[0147]

[0148] Example 27

[0149] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 27, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 4-tert-butylaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 27 is obtained with a yield of 75%.

[0150] Example 28

[0151] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 28, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 4-methylaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 28 is obtained with a yield of 70%.

[0152] Example 29

[0153] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 29, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,6-diisopropylaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 29 is obtained with a yield of 76%.

[0154] Example 30

[0155] In the preparation method of the tetraboron rigid heterocyclic narrow emission compound of Example 30, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 3,5-dimethylaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 30 is obtained with a yield of 74%.

[0156] Example 31

[0157] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 31, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,4,6-trimethylaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 31 is obtained with a yield of 71%.

[0158] Example 32

[0159] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 32, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2-fluoroaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 32 is obtained with a yield of 72%.

[0160] Example 33

[0161] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 33, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 4-fluoroaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 33 is obtained with a yield of 70%.

[0162] Example 34

[0163] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 34, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,6-difluoroaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 34 is obtained with a yield of 72%.

[0164] Example 35

[0165] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 35, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,3,4,5,6-pentafluoroaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 35 is obtained with a yield of 78%.

[0166] Example 36

[0167] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 36, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of p-cyanoaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 36 is obtained with a yield of 76%.

[0168] Example 37

[0169] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 37, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2-aminoisophthalonitrile, and the other raw materials and steps are the same as in Example 26, and finally compound 37 is obtained with a yield of 71%.

[0170] Example 38

[0171] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 38, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 3-aminophthalonitrile, and the other raw materials and steps are the same as in Example 26, and finally compound 38 is obtained with a yield of 78%.

[0172] Example 39

[0173] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 39, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 4-aminoisophthalonitrile, and the other raw materials and steps are the same as in Example 26, and compound 39 is finally obtained with a yield of 72%.

[0174] Example 40

[0175] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 40, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 5-aminoisophthalonitrile, and the other raw materials and steps are the same as in Example 26, and finally compound 40 is obtained with a yield of 77%.

[0176] Example 41

[0177] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 41, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of o-chloroaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 41 is obtained with a yield of 70%.

[0178] Example 42

[0179] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 42, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 4-chloroaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 42 is obtained with a yield of 77%.

[0180] Example 43

[0181] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 43, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,6-dichloroaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 43 is obtained with a yield of 71%.

[0182] Example 44

[0183] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 44, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,3-dichloroaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 44 is obtained with a yield of 74%.

[0184] Example 45

[0185] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 45, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2,4-dichloroaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 45 is obtained with a yield of 72%.

[0186] Example 46

[0187] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 46, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 3,5-dichloroaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 46 is obtained with a yield of 76%.

[0188] Example 47

[0189] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 47, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 2-aminonaphthalene, and the other raw materials and steps are the same as in Example 26, and finally compound 47 is obtained with a yield of 73%.

[0190] Example 48

[0191] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 48, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 3-aminobiphenyl, and the other raw materials and steps are the same as in Example 26, and finally compound 48 is obtained with a yield of 69%.

[0192] Example 49

[0193] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 49, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of [1,1':3',1"-terphenyl]-5'-amine, and the other raw materials and steps are the same as in Example 26, and finally compound 49 is obtained with a yield of 78%.

[0194] Example 50

[0195] In the preparation method of the tetraboron rigid heterocyclic narrow-emission compound of Example 50, steps b)-d) are the same as in Example 26, 2,6-dimethylaniline in step a) is replaced with an equivalent amount of 4-dibenzhydrylaniline, and the other raw materials and steps are the same as in Example 26, and finally compound 50 is obtained with a yield of 71%.

[0196] Example 51

[0197] The structure of the organic optoelectronic device based on the tetraboron rigid heterocyclic narrow-emission, high-efficiency, multi-resonance luminescent material of Example 51 is: glass substrate / indium tin oxide / HATCN (5 nm) / TAPC (30 nm) / TCTA (10 nm) / mCP (10 nm) / luminescent layer (30 nm) / PPF (10 nm) / TmPyPB (40 nm) / lithium fluoride (1 nm) / aluminum (150 nm). Indium tin oxide is the anode, HATCN is the hole injection layer, TAPC and TCTA are the hole transport layers, mCP and PPF are the exciton blocking layers, the luminescent layer is a mixture of Compound 1 and DOBNA-oAr in a ratio of 1:99 by weight, TmPyPB is the electron transport layer, lithium fluoride is the electron injection layer, and aluminum is the cathode.

[0198] The organic photoelectric device is prepared by the following method:

[0199] a) Ultrasonic cleaning of a transparent conductive indium tin oxide glass substrate was performed using a micron-grade semiconductor detergent, deionized water, acetone, and isopropyl alcohol for 15 minutes.

[0200] b) placing the indium tin oxide glass substrate treated in step a) in a constant temperature oven at 80° C. for drying.

[0201] c) treating the indium tin oxide glass substrate treated in step b) with oxygen-plasma for 5 minutes.

[0202] d) HATCN, TAPC, TCTA, mCP, compound 1 / DOBNA-oAr (mass percentage 1:99), PPF, TmPyPB, lithium fluoride, and aluminum were thermally deposited on the indium tin oxide glass substrate treated in step c) by vacuum thermal evaporation to obtain an organic electroluminescent device 1.

[0203] Example 52

[0204] In the preparation method of an organic optoelectronic device based on a tetraboron rigid heterocycle narrow emission high-efficiency multi-resonance luminescent material in Example 52, steps a)-c) are the same as in Example 51, compound 1 / DOBNA-oAr (mass percentage 1:99) in step d) is replaced with compound 1 / DOBNA-oAr (mass percentage 2:98), and the other raw materials and steps are the same as in Example 51 to obtain an organic electroluminescent device 2.

[0205] Example 53

[0206] In the preparation method of an organic optoelectronic device based on a tetraboron rigid heterocycle narrow emission high-efficiency multi-resonance luminescent material in Example 53, steps a)-c) are the same as in Example 51, compound 1 / DOBNA-oAr (mass percentage 1:99) in step d) is replaced with compound 1 / DOBNA-oAr (mass percentage 3:97), and the other raw materials and steps are the same as in Example 51 to obtain an organic electroluminescent device 3.

[0207] Example 54

[0208] In the preparation method of an organic optoelectronic device based on a tetraboron rigid heterocycle narrow emission high-efficiency multi-resonance luminescent material in Example 54, steps a)-c) are the same as in Example 51, compound 1 / DOBNA-oAr (mass percentage 1:99) in step d) is replaced with compound 1 / DOBNA-oAr (mass percentage 5:95), and the other raw materials and steps are the same as in Example 51 to obtain an organic electroluminescent device 4.

[0209] Example 55

[0210] In the preparation method of an organic optoelectronic device based on a tetraboron rigid heterocycle narrow emission high-efficiency multi-resonance luminescent material in Example 55, steps a)-c) are the same as in Example 51, compound 1 / DOBNA-oAr (mass percentage 1:99) in step d) is replaced with compound 26 / DOBNA-oAr (mass percentage 1:99), and the other raw materials and steps are the same as in Example 51 to obtain an organic electroluminescent device 5.

[0211] Example 56

[0212] In the preparation method of an organic optoelectronic device based on a tetraboron rigid heterocycle narrow emission high-efficiency multi-resonance luminescent material in Example 56, steps a)-c) are the same as in Example 51, compound 1 / DOBNA-oAr (mass percentage 1:99) in step d) is replaced with compound 26 / DOBNA-oAr (mass percentage 2:98), and the other raw materials and steps are the same as in Example 51 to obtain an organic electroluminescent device 6.

[0213] Example 57

[0214] In the preparation method of an organic optoelectronic device based on a tetraboron rigid heterocycle narrow emission high-efficiency multi-resonance luminescent material in Example 57, steps a)-c) are the same as in Example 51, compound 1 / DOBNA-oAr (mass percentage 1:99) in step d) is replaced with compound 26 / DOBNA-oAr (mass percentage 3:97), and the other raw materials and steps are the same as in Example 51 to obtain an organic electroluminescent device 7.

[0215] Example 58

[0216] In the preparation method of an organic optoelectronic device based on a tetraboron rigid heterocycle narrow emission high-efficiency multi-resonance luminescent material in Example 57, steps a)-c) are the same as in Example 51, compound 1 / DOBNA-oAr (mass percentage 1:99) in step d) is replaced with compound 26 / DOBNA-oAr (mass percentage 5:95), and the other raw materials and steps are the same as in Example 51 to obtain an organic electroluminescent device 8.

[0217] The aforementioned organic electroluminescent devices were tested. Device characteristics, including current, voltage, brightness, and luminescence spectrum, were measured simultaneously using a PhotoResearch PR655 spectral scanning luminance meter and a Keithley K2400 digital source meter system. Device performance was tested at room temperature and in ambient atmosphere. The device's external quantum efficiency (EQE) was calculated from the current density, brightness, and electroluminescence spectrum, combined with a view function, assuming a Lambertian luminescence distribution. The test results for the vapor-deposited devices are denoted as Dn (n = 1-20). Table 1 shows the test results.

[0218] Table 1 Device performance parameters of Examples 51-58

[0219]

[0220] As shown in the table, binary devices prepared with compounds 1 and 26 doped at 1, 2, 3, and 5%, respectively, exhibit a slight red shift and a broadening of the half-maximum width (WFWHM) emission with increasing doping ratio. Compound 26 exhibits a red shift of approximately 25 nm compared to compound 1, but this does not compromise color purity. Instead, it achieves a narrower WFWHM and superior electroluminescent performance.

[0221] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitute similar methods for the specific embodiments described without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

Claims

1. A tetraboron rigid heterocyclic narrow emission compound, characterized in that: The tetraboron rigid heterocyclic narrow emission compound has the general structural formula of Chemical Formula I or Chemical Formula II: Among them, R and R' can be independently selected from one or more of hydrogen atoms, fluorine atoms, chlorine atoms, cyano groups, alkyl groups, aromatic rings composed of carbon and hydrogen atoms, aromatic heterocycles composed of carbon, nitrogen and hydrogen atoms, aromatic heterocycles composed of carbon, nitrogen, oxygen and hydrogen atoms, aromatic heterocycles composed of carbon, sulfur and hydrogen atoms, and aromatic heterocycles composed of carbon, nitrogen, sulfur and hydrogen atoms.

2. The tetraboron rigid heterocyclic narrow emission compound according to claim 1, characterized in that: The R or R' is one or more of the following structures:

3. The tetraboron rigid heterocyclic narrow emission compound according to claim 1 or 2, characterized in that: The specific structure of the tetraboron rigid heterocyclic narrow emission compound is any one of the following structures:

4. A method for preparing a tetraboron rigid heterocyclic narrow emission compound as claimed in claim 1, characterized in that: When the structural formula of the tetraboron rigid heterocyclic narrow emission compound is as shown in Chemical Formula I, the preparation method thereof comprises the following steps: a) using an aniline derivative and a halogenated benzene as raw materials, a series of CN coupling reactions were performed to synthesize an intermediate 3 having a structure of chemical formula III; b) intermediate 3 is dissolved in a solvent and reacted with a boron halide to produce the final luminescent material; When the general structural formula of the tetraboron rigid heterocyclic narrow emission compound is as shown in Chemical Formula II, the preparation method thereof comprises the following steps: a) using an aniline derivative and a halogenated benzene as raw materials, a series of CN coupling reactions were performed to synthesize an intermediate 3 having a structure of chemical formula III; b) intermediate 3 is dissolved in a solvent and reacted under the action of a boron halide to obtain intermediate 4 having a structure of chemical formula I; c) dissolving the intermediate 4 in a solvent and heating the mixture to react to obtain the final luminescent material; 5. The preparation method according to claim 4, characterized in that Step a) comprises the following steps: a)-1. An aniline derivative reacts with a halogenated benzene under conditions including a solvent, a catalyst, a catalyst ligand and a base to obtain an intermediate 1 having a structure of chemical formula IV; a)-2. Intermediate 1 reacts with 1,3-dibromo-5-chlorobenzene in the presence of a solvent, a catalyst, a catalyst ligand, and a base to obtain intermediate 2 having a structure of formula V; a)-3. Intermediate 2 reacts with N1,N3-di-p-toluene-1,3-diamine in the presence of a solvent, a catalyst, a catalyst ligand, and a base to obtain intermediate 3; 6. The preparation method according to claim 4, characterized in that In step b), the boron halide is one or more of BBr3, BI3 or BCl3; The reaction temperature in step b) is 180-250° C. and the reaction time is 10-60 h; When the general structural formula of the tetraboron rigid heterocyclic narrow-emission compound is as shown in Chemical Formula II, the reaction temperature in step c) is 255-350° C., and the reaction time is 10-50 h.

7. A light-emitting layer, characterized in that: A narrow emission compound comprising one or more tetraboron rigid heterocycles as claimed in any one of claims 1 to 3.

8. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the light-emitting layer according to claim 7.

9. A method for preparing an organic electroluminescent device according to claim 8, characterized in that: Including steps: a) cleaning, drying, and oxygen-plasma treating an indium tin oxide glass substrate; b) depositing a hole injection layer, a hole transport layer, an exciton blocking layer, a light-emitting layer, an electron transport layer, and a cathode on the indium tin oxide glass substrate treated in step a) to obtain an organic electroluminescent device.

10. The preparation method according to claim 9, characterized in that: The drying temperature in step a) is 60-100° C.; The oxygen-Plasma treatment time in step a) is 3-10 min; The deposition method in step b) is thermal evaporation or spin coating.

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