Boron-nitrogen heterocyclic compound with seven-membered ring and organic electroluminescent device

Abstract

The application provides a boron-nitrogen heterocyclic compound with a seven-membered ring, as shown in formula 1. A seven-membered ring-fused spiro type multi-resonance thermal activation delayed fluorescence (MR-TADF) green light emitting material is disclosed, a boron-nitrogen multi-resonance skeleton is used as a light emitting core, and a seven-membered ring-fused carbazole and a spiro ring lock structure are introduced to be modified in cooperation. The two structures are used for synergistically controlling the electronic configuration of the molecule and the rigidity of the skeleton, and the obtained material has high color purity, high light efficiency and long service life, and can be widely applied to super-high-definition wide-gamut OLED display devices, and has excellent industrial application prospects.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescence technology, and more particularly to a boron-nitrogen heterocyclic compound with a seven-membered ring and an organic electroluminescent device. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are a core technology for next-generation flexible and ultra-high-definition displays, and the industrialization of full-color displays relies on high-performance red, green, and blue luminescent materials. Since luminescent materials directly determine the color purity, luminous efficiency, and stability of devices, they have become a key research focus for both academia and industry. Existing green luminescent materials generally suffer from poor color purity, low exciton utilization, difficulty in balancing efficiency and lifetime, poor energy level compatibility of device functional layers, and significant efficiency roll-off at high brightness, failing to meet the commercial demands of BT.2020 ultra-high-definition and large-size flexible panels. Therefore, the commercial demand for developing new high-performance green luminescent materials is increasing daily. Summary of the Invention

[0003] To develop organic electroluminescent materials with better device performance, this invention provides a boron-nitrogen heterocyclic compound with a seven-membered ring, characterized as shown in Formula 1: Among them, R4-R 18 Each is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl, substituted or unsubstituted C6~C30 aryl, substituted or unsubstituted C5~C30 heteroaryl; Z7 is selected from O, S, N-Ar1, where Ar1 is selected from substituted or unsubstituted C6~C20 aryl groups; Z2-Z5 are CR, where R is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl groups, substituted or unsubstituted C6~C30 aryl groups, and substituted or unsubstituted C5~C30 heteroaryl groups. When Z7 is N-Ar1, Ar1 and Z2 are connected by CR. 1 CR 2 Bridged, and / or connected between Z3 and Z4 via CR 3 R 4 Bridge; where R 1 R 2 The elements are either not connected or connected in a loop, R 3 R 4 They are either not connected or connected in a loop; Ar1 ​​and Z5 are not connected or connected via a single key or CR. 5 R 6 NR 7 O, S, Se, Te bridging; R 1 R 2 R 3 R 4R 5 R 6 R 7 Each is independently selected from substituted or unsubstituted C1~C10 straight-chain or branched alkyl groups, substituted or unsubstituted C6~C30 aryl groups, and substituted or unsubstituted C5~C30 heteroaryl groups; The substituents are selected from hydrogen, deuterium, fluorine, deuterated or undeuterated C1-C20 alkyl, deuterated or undeuterated C6-C20 aryl, and deuterated or undeuterated C5-C20 heteroaryl.

[0004] As an alternative embodiment of the present invention, boron-nitrogen heterocyclic compounds are shown in Formulas 2-3: Among them, R4-R 18 Each is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl, substituted or unsubstituted C6~C30 aryl, substituted or unsubstituted C5~C30 heteroaryl; Z2-Z5 are CR, where R is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl, substituted or unsubstituted C6~C30 aryl, or substituted or unsubstituted C5~C30 heteroaryl; Z3 and Z4 can be connected by CR. 3 R 4 Bridging; R 3 R 4 They are either not connected or connected in a loop; The substituents are selected from hydrogen, deuterium, fluorine, deuterated or undeuterated C1-C20 alkyl, deuterated or undeuterated C6-C20 aryl, and deuterated or undeuterated C5-C20 heteroaryl.

[0005] As an alternative embodiment of the present invention, the boron-nitrogen heterocyclic compound is shown in Formula 4: Among them, R1-R 18 Each is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl, substituted or unsubstituted C6~C30 aryl, substituted or unsubstituted C5~C30 heteroaryl; Z1-Z6 are CR, where R is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl, substituted or unsubstituted C6~C30 aryl, and substituted or unsubstituted C5~C30 heteroaryl; Z1 and Z2 are connected by CR. 1 CR 2 Bridged, and / or connected between Z3 and Z4 via CR 3 R 4 Bridging; R 1 R 2 The elements are either not connected or connected in a loop, R3 R 4 Z5 and Z6 are either not connected or connected in a loop; Z5 and Z6 are not connected or connected via a single key or CR. 5 R 6 NR 7 O, S, Se, Te bridging; R 1 R 2 R 3 R 4 R 5 R 6 R 7 Each is independently selected from substituted or unsubstituted C1~C10 straight-chain or branched alkyl groups, substituted or unsubstituted C6~C30 aryl groups, and substituted or unsubstituted C5~C30 heteroaryl groups; The substituents are selected from hydrogen, deuterium, fluorine, deuterated or undeuterated C1-C20 alkyl, deuterated or undeuterated C6-C20 aryl, and deuterated or undeuterated C5-C20 heteroaryl.

[0006] As an alternative embodiment of the present invention, boron-nitrogen heterocyclic compounds are shown in Formulas 5-9: Z5 and Z6 are CR, and R is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl, substituted or unsubstituted C6~C30 aryl, substituted or unsubstituted C5~C30 heteroaryl. In formulas 5-7, Z5 and Z6 are not connected or are bridged by single bonds, O, S, Se, or Te. In formulas 5-9, R1-R 28 Each of the following is independently selected from H, D, F, cyano, substituted or unsubstituted C1-C10 straight-chain or branched alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C5-C30 heteroaryl; the substituent is selected from hydrogen, deuterium, fluorine, deuterated or undeuterated C1-C20 alkyl, deuterated or undeuterated C6-C20 aryl, deuterated or undeuterated C5-C20 heteroaryl, and a, b, c, d, e, f are each independently selected from integers from 0 to 8.

[0007] As an optional embodiment of the present invention, R1-R in equations 5-9 28 Each is independently selected from H, D, F, cyano, deuterated or undeuterated methyl, deuterated or undeuterated ethyl, deuterated or undeuterated tert-butyl, deuterated or undeuterated phenyl, alkyl-substituted phenyl, deuterated or undeuterated biphenyl, deuterated or undeuterated carbazolyl, deuterated or undeuterated dibenzothiophene, and deuterated or undeuterated dibenzofuran.

[0008] As a preferred embodiment of the present invention, R1-R in equations 5-9 28Each is independently selected from H, D, deuterated or undeuterated methyl, deuterated or undeuterated tert-butyl, deuterated or undeuterated phenyl, and alkyl-substituted phenyl.

[0009] As an alternative embodiment of the present invention, the boron-nitrogen heterocyclic compound is one of the following structural formulas: .

[0010] The present invention provides an organic electroluminescent device, comprising a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode, wherein the organic layer contains any of the aforementioned boron-nitrogen heterocyclic compounds with a seven-membered ring.

[0011] Furthermore, the organic layer comprises a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, wherein at least one of the hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, and electron injection layer contains any one of the aforementioned boron-nitrogen heterocyclic compounds with a seven-membered ring.

[0012] Furthermore, the light-emitting layer contains any of the aforementioned boron-nitrogen heterocyclic compounds with a seven-membered ring.

[0013] Compared with the prior art, the present invention provides a boron-nitrogen heterocyclic compound with a seven-membered ring, which has the following beneficial effects: By replacing the traditional six-membered ring structure with a seven-membered ring fused carbazole, molecular aggregation quenching is suppressed, frontier orbital distribution is optimized, and a narrow green emission spectrum is obtained, significantly improving the color purity of the device. The introduction of a spiro-ring locking rigid structure fixes the molecular spatial configuration, greatly reducing molecular vibrational torsional losses, minimizing excited-state structural relaxation, and improving radiative transition efficiency. The steric hindrance effect of the spiro-ring structure effectively enhances the molecular's thermal stability, chemical stability, and electro-degradation resistance, extending the device's lifespan. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the organic electroluminescent device of the present invention.

[0015] The labels in the diagram represent: 1-anode, 2-hole injection layer, 3-first hole transport layer, 4-second hole transport layer, 5-light-emitting layer, 6-hole blocking layer, 7-electron transport layer, 8-electron injection layer, and 9-cathode.

[0016] Figure 2 This is an HPLC chromatogram of compound 1 prepared by synthesis example 1 of the present invention.

[0017] Figure 3 The TGA spectrum of compound 1 prepared in Synthesis Example 1 of this invention is shown below. Figure 3 It can be seen that the Td value of compound 1 is 436.32℃.

[0018] Figure 4 The DSC spectrum of compound 1 prepared in Synthesis Example 1 of this invention is shown below. Figure 4 It can be seen that the Tg value of compound 1 is 109.02℃. Detailed Implementation

[0019] Embodiments of various aspects are further illustrated and described below. It should be understood that the description herein is not intended to limit the claims to the specific aspects described. Rather, it is intended to cover substitutions, modifications, and equivalents that may be included within the spirit and scope of this disclosure as defined by the appended claims.

[0020] As used herein, in the terms “deuterated” and “undeuterated,” the term “deuterated” means that at least one hydrogen atom in the group is substituted with deuterium. The term “undeuterated” means that none of the hydrogen atoms in the group are substituted with deuterium.

[0021] In this document, "aromatic group," "aryl," or "aromatic group" refers to a group containing one or more aromatic rings, including but not limited to benzene, naphthalene, phenanthrene, fluorene, acenaphthene, pyridine, pyrrole, furan, and thiophene. In C6-C30 aryl groups, C6-C30 means the group contains 6-30 carbon atoms; in C1-C10 straight-chain or branched alkyl groups, C1-C10 means the group contains 1-10 carbon atoms; and in C5-C30 heteroaryl groups, C5-C30 means the group contains 5-30 carbon atoms. Aryl groups can be classified as monocyclic aryl and polycyclic aryl. Specific aromatic groups in this invention include, but are not limited to, phenyl, biphenyl, terphenyl, anthracene, naphthyl, phenanthrene, fluorene, dibenzofuranyl, dibenzothiophene, 9,9-spirodifluorenyl, 9,9-dimethylfluorenyl, or 9,9-diphenylfluorenyl. Aromatic groups can be substituted or unsubstituted.

[0022] In this article, "deuterated methyl" refers to any one of monodeuterated methyl, dideuterated methyl, or trideuterated methyl.

[0023] In this article, "heteroaryl" refers to a heteroaryl group obtained by replacing one or more C atoms in the structure of "aryl" with one or more heteroatoms (such as N, O or S).

[0024] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0025] Synthesis example 1: .

[0026] .

[0027] S1: Under nitrogen protection, compound a (1 eq, 4.73 g, 236.45 g / mol, 20.00 mmol), compound b (1 eq, 4.38 g, 219.09 g / mol, 20.00 mmol), potassium carbonate (2 eq, 5.53 g, 138.21 g / mol, 40.00 mmol), tetraphenylphosphine palladium (0.05 eq, 1.15 g, 1155.56 g / mol, 1.00 mmol), and 200 mL of a toluene:water mixture (1:1) were added to a reaction flask. After the addition was complete, the reaction was carried out at 110 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature and extracted three times with dichloromethane. The organic phase was dried over anhydrous magnesium sulfate and then evaporated to dryness. After purification by column chromatography, compound c (4.52 g, yield 91.2%) was obtained. MS (EI): 248.04 (M+).

[0028] S2: Under nitrogen protection, sodium nitrite (1.1 eq, 1.38 g, 68.99 g / mol, 18.00 mmol), sulfuric acid (5 ml), and acetic acid (50 ml) were slowly added to a mixed solution and stirred at room temperature for 1 h. Potassium iodide (1.1 eq, 3.32 g, 166.00 g / mol, 20 mmol) was dissolved in 20 ml of water and added dropwise to the above reaction solution. The mixture was stirred at 70 °C for 1 h. After the reaction was completed, the mixture was cooled to room temperature and extracted three times with dichloromethane. The organic phase was dried over anhydrous magnesium sulfate and then evaporated to dryness. After purification by column chromatography, compound d (6.15 g, yield 95.0%) was obtained, MS (EI): 358.92 (M+).

[0029] S3: Under nitrogen protection, compound d (1 eq, 7.19 g, 358.92 g / mol, 20.00 mmol), compound e (1 eq, 3.32 g, 166.20 g / mol, 20.00 mmol), potassium carbonate (2 eq, 5.53 g, 138.21 g / mol, 40.00 mmol), tetraphenylphosphine palladium (0.05 eq, 1.15 g, 1155.56 g / mol, 1.00 mmol), and 200 mL of a toluene:water mixture (volume ratio) of 1:1 were added to a reaction flask. After the addition was complete, the reaction was carried out at 110 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature and extracted three times with dichloromethane. The organic phase was dried over anhydrous magnesium sulfate and then evaporated to dryness. After purification by column chromatography, compound f (7.10 g, yield 89.4%) was obtained, MS (EI): 398.08 (M+).

[0030] S4: Under nitrogen protection, compound f (1 eq, 8.00 g, 398.08 g / mol, 20.00 mmol), palladium acetate (0.05 eq, 0.22 g, 224.51 g / mol, 1.00 mmol), tri-tert-butylphosphine (0.05 eq, 0.20 g, 202.32 g / mol, 1.00 mmol), cesium carbonate (2 eq, 13.03 g, 325.82 g / mol, 40.00 mmol), and 150 mL of xylene were added to a reaction flask. After the addition was complete, the reaction was carried out at 140 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature and extracted with ethyl acetate and water. The organic phase was washed with water and extracted three times. The organic phase was dried with anhydrous magnesium sulfate and then evaporated to dryness. After purification by column chromatography, compound g (6.16 g, yield 85.3%) was obtained. MS (EI): 362.11 (M+).

[0031] S5: Under nitrogen protection, compound g (1 eq, 6.00 g, 362.11 g / mol, 16.55 mmol), triphenylphosphine (4.00 eq, 17.36 g, 262.29 g / mol, 66.20 mmol), and 100 mL of o-dichlorobenzene were added to a reaction flask. After the addition was complete, the reaction was carried out at 180 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature, stirred, and then a large amount of anhydrous zinc chloride was added. The mixture was stirred for 0.5 h, filtered, and the filtrate was dried over anhydrous magnesium sulfate and then evaporated to dryness. After purification by column chromatography, precursor 1 (4.37 g, yield 80.5%) was obtained, MS (EI): 330.12 (M+).

[0032] S6: Under nitrogen protection, compound 1-a (1 eq, 20.00 g, 227.43 g / mol, 87.94 mmol), compound 1-b (1 eq, 14.87 g, 169.09 g / mol, 87.94 mmol), cesium carbonate (1 eq, 28.65 g, 325.82 g / mol, 87.94 mmol), and N,N-dimethylformamide (200 mL) were added to a reaction flask. After the addition was complete, the reaction was carried out at room temperature for 12 h. After the reaction was complete, 500 mL of water was added and stirred for 15 min. After all the solids precipitated, the solid was filtered to obtain a white solid. After purification by column chromatography, compound 1-c (28.23 g, yield 85.6%) was obtained. MS (EI): 374.98 (M+).

[0033] S7: Under nitrogen protection, compound 1-c (1 eq, 31.79 g, 374.98 g / mol, 84.77 mmol) and tetrahydrofuran (2 L) were added to the reaction flask. The mixture was then cooled to -78°C, and a solution of n-butyllithium hexane (1.1 eq, 2.5 M, 37.30 mL, 93.25 mmol) was slowly added dropwise. After the addition was complete, the mixture was stirred at -78°C for 2 h. After stirring, a tetrahydrofuran solution (200 mL) of compound 9-fluorenone (1.3 eq, 19.75 g, 180.21 g / mol, 109.62 mmol) was slowly added dropwise. The mixture was then slowly restored to room temperature and stirred for 12 h. After the reaction was complete, the mixture was cooled to 0°C, and a 1 M hydrochloric acid aqueous solution (100 mL) was slowly added to quench the reaction. 400 mL of the solution was then added. The crude product was extracted three times with 1L × 3 mL of dichloromethane, and the combined organic phases were dried over anhydrous sodium sulfate. After filtration, the mixture was distilled under reduced pressure. The crude product was dissolved in 5L of dichloromethane, and 20 mL of 47% boron trifluoride diethyl ether solution was slowly added at room temperature. The reaction was carried out at room temperature for 12 h. After the reaction was completed, 500 mL of saturated sodium bicarbonate aqueous solution was slowly added, and the mixture was extracted three times with 1L × 3 mL of dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, and after filtration, the mixture was distilled under reduced pressure. The product was purified by column chromatography to give compound 1-d (18.41 g, yield 47.3%), MS (EI): 459.12 (M+).

[0034] S8: Under nitrogen protection, compound 1-d (1 eq, 10.26 g, 459.12 g / mol, 18.00 mmol), precursor 1 (1 eq, 5.94 g, 330.12 g / mol, 18.00 mmol), cesium carbonate (1 eq, 5.86 g, 325.82 g / mol, 18.00 mmol), and N,N-dimethylformamide (50 mL) were added to a reaction flask. After the addition was complete, the temperature was raised to 120 °C and the reaction was carried out for 12 h. After the reaction was completed, 500 mL of water was added and stirred for 15 min. After all the solid precipitated, the mixture was filtered to obtain a white solid. After purification by column chromatography, compound 1-e (11.24 g, yield 81.2%) was obtained. MS (EI): 769.23 (M+).

[0035] S9: Under nitrogen protection, compound 1-e (1 eq, 13.08 g, 769.23 g / mol, 17.00 mmol) was added to tert-butylbenzene (250 mL), and the mixture was cooled to -78 °C. A hexane solution of tert-butyllithium (2.2 eq, 1.3 M, 29 mL, 37.4 mmol) was slowly added dropwise. After the addition was complete, the mixture was brought back to room temperature and stirred for 2 h. Then, the mixture was cooled to -78 °C again, and boron tribromide (2 eq, 8.51 g, 250.52 g / mol, 34.00 mmol) was slowly added. After stirring for 50 min, N,N-diisopropylamine (2 eq, 3.44 g, 101.19 g / mol, 34.00 mmol) was slowly added, and the mixture was heated to 140 °C and reacted for 12 minutes. After h, the mixture was cooled to room temperature, and the reaction solution was slowly poured into an ice-water mixture to quench it. The organic phase was separated, dried over anhydrous magnesium sulfate, and then evaporated to dryness. After purification by column chromatography, compound 1 (6.45 g, yield 44.5%) was obtained. ESI-MS (m / z) (M+): theoretical value 743.25, measured value 743.31. Elemental analysis results (molecular formula C) 55 H 30 BN3): Theoretical values: C, 88.83 H, 4.07 B, 1.45 N, 5.65; Measured values: C, 88.88 H, 4.09 B, 1.42 N, 5.61.

[0036] Synthesis example 2 .

[0037] The preparation method was basically the same as that of Synthesis Example 1, and the reaction yielded compound 7 (yield 8.1%). ESI-MS (m / z) (M+): theoretical value 769.27, measured value 769.24. Elemental analysis results (molecular formula C...) 57 H 32 BN3): Theoretical values: C, 88.95 H, 4.19 B, 1.40 N, 5.46; Measured values: C, 88.90 H, 4.17 B, 1.45 N, 5.48.

[0038] Synthesis example 3 .

[0039] The preparation method was basically the same as that in Synthesis Example 1, yielding compound 11 (yield 9.3%). ESI-MS (m / z) (M+): theoretical value 757.23, measured value 757.29. Elemental analysis results (molecular formula C...) 55 H 28OBN3): Theoretical values: C, 87.19 H, 3.73 O, 2.11 B, 1.43 N, 5.55; Measured values: C, 87.10 H, 3.76 O, 2.12 B, 1.46 N, 5.57.

[0040] Synthesis example 4 .

[0041] The preparation method was basically the same as that of Synthesis Example 1, and the reaction yielded compound 17 (yield 6.8%). ESI-MS (m / z) (M+): theoretical value 933.33, measured value 933.29. Elemental analysis results (molecular formula C...) 70 H 40 BN3): Theoretical values: C, 90.03 H, 4.32 B, 1.16 N, 4.50; Measured values: C, 90.08 H, 4.35 B, 1.12 N, 4.46.

[0042] Synthesis example 5 .

[0043] The preparation method was basically the same as that of Synthesis Example 1, and the reaction yielded compound 22 (yield 7.5%). ESI-MS (m / z) (M+): theoretical value 931.32, measured value 931.39. Elemental analysis results (molecular formula C...) 70 H 38 BN3): Theoretical values: C, 90.22 H, 4.11 B, 1.16 N, 4.51; Measured values: C, 90.20 H, 4.10 B, 1.15 N, 4.55.

[0044] Synthesis example 6 .

[0045] The preparation method was basically the same as in Synthesis Example 1, yielding compound 31 (yield 10.1%). ESI-MS (m / z) (M+): theoretical value 743.25, measured value 743.31. Elemental analysis results (molecular formula C...) 55 H 30 BN3): Theoretical values: C, 88.83 H, 4.07 B, 1.45 N, 5.65; Measured values: C, 88.73 H, 4.09 B, 1.49 N, 5.69.

[0046] Synthesis Example 7 .

[0047] The preparation method was basically the same as that in Synthesis Example 1, yielding compound 37 (yield 8.7%). ESI-MS (m / z) (M+): theoretical value 769.27, measured value 769.21. Elemental analysis results (molecular formula C...) 57 H 32 BN3): Theoretical value C, 88.95 H, 4.19 B, 1.40 N, 5.46; Measured value C, 88.90 H, 4.17 B, 1.45 N, 5.48.

[0048] Synthesis example 8 .

[0049] The preparation method was basically the same as that of Synthesis Example 1, and the reaction yielded compound 47 (yield 6.1%). ESI-MS (m / z) (M+): theoretical value 799.32, measured value 799.38. Elemental analysis results (molecular formula C...) 59 H 38 BN3): Theoretical values: C, 88.61 H, 4.79 B, 1.35 N, 5.25; Measured values: C, 88.51 H, 4.82 B, 1.38 N, 5.29.

[0050] Synthesis example 9 .

[0051] The preparation method was basically the same as that of Synthesis Example 1, and the reaction yielded compound 53 (yield 7.7%). ESI-MS (m / z) (M+): theoretical value 881.39, measured value 881.32. Elemental analysis results (molecular formula C...) 65 H 48 BN3): Theoretical value C, 88.52 H, 5.49 B, 1.23 N, 4.76; Measured value C, 88.50 H, 5.44 B, 1.27 N, 4.79.

[0052] Synthesis example 10 .

[0053] The preparation method was basically the same as that of Synthesis Example 1, and the reaction yielded compound 62 (yield 4.9%). ESI-MS (m / z) (M+): theoretical value 883.41, measured value 883.39. Elemental analysis results (molecular formula C) 65 H 50 BN3): Theoretical value C, 88.32 H, 5.70 B, 1.22 N, 4.75; Measured value C, 88.38 H, 5.72 B, 1.18 N, 4.71.

[0054] Synthesis example 11 .

[0055] The preparation method was basically the same as that of Synthesis Example 1, and the reaction yielded compound 68 (yield 8.2%). ESI-MS (m / z) (M+): theoretical value 965.49, measured value 965.42. Elemental analysis results (molecular formula C) 71 H 60 BN3): Theoretical value C, 88.27 H, 6.26 B, 1.12 N, 4.35; Measured value C, 88.20 H, 6.24 B, 1.19 N, 4.37.

[0056] Synthesis example 12 .

[0057] The preparation method was basically the same as that of Synthesis Example 1, yielding compound 76 (yield 9.1%). ESI-MS (m / z) (M+): theoretical value 855.38, measured value 855.32. Elemental analysis results (molecular formula C...) 63 H 46 BN3): Theoretical values: C, 88.41 H, 5.42 B, 1.26 N, 4.91; Measured values: C, 88.31 H, 5.45 B, 1.28 N, 4.95.

[0058] Synthesis example 13 .

[0059] The preparation method was basically the same as that of Synthesis Example 1, and the reaction yielded compound 82 (yield 6.6%). ESI-MS (m / z) (M+): theoretical value 881.39, measured value 881.41. Elemental analysis results (molecular formula C...) 65 H 48 BN3): Theoretical values: C, 88.52 H, 5.49 B, 1.23 N, 4.76; Measured values: C, 88.42 H, 5.54 B, 1.25 N, 4.79.

[0060] Synthesis example 14 .

[0061] The preparation method was basically the same as that of Synthesis Example 1, and the reaction yielded compound 92 (yield 10.7%). ESI-MS (m / z) (M+): theoretical value 799.32, measured value 799.38. Elemental analysis results (molecular formula C...) 59 H 38 BN3): Theoretical values: C, 88.61 H, 4.79 B, 1.35 N, 5.25; Measured values: C, 88.68 H, 4.75 B, 1.34 N, 5.22.

[0062] Synthesis Example 15 .

[0063] The preparation method was basically the same as that of Synthesis Example 1, and the reaction yielded compound 98 (yield 7.2%). ESI-MS (m / z) (M+): theoretical value 897.43, measured value 897.49. Elemental analysis results (molecular formula C...) 66 H 52 BN3): Theoretical values: C, 88.28 H, 5.84 B, 1.20 N, 4.68; Measured values: C, 88.20 H, 5.82 B, 1.25 N, 4.73.

[0064] Synthesis example 16 .

[0065] The preparation method was basically the same as in Synthesis Example 1, yielding compound 108 (yield 6.9%). ESI-MS (m / z) (M+): theoretical value 1073.49, measured value 1073.52. Elemental analysis results (molecular formula C...) 80 H 60 BN3): Theoretical values: C, 89.45 H, 5.63 B, 1.01 N, 3.91; Measured values: C, 89.41 H, 5.61 B, 1.04 N, 3.94.

[0066] Synthesis Example 17 .

[0067] The preparation method was basically the same as that in Synthesis Example 1, yielding compound 112 (yield 8.3%). ESI-MS (m / z) (M+): theoretical value 987.38, measured value 987.32. Elemental analysis results (molecular formula C...) 74 H 46 BN3): Theoretical values: C, 89.96 H, 4.69 B, 1.09 N, 4.25; Measured values: C, 89.90 H, 4.71 B, 1.11 N, 4.27.

[0068] Material performance testing.

[0069] The thermogravimetric temperature (Td) and glass transition temperature (Tg) of compound 1 prepared by synthesis example 1 of this invention were tested. The Td was measured at a mass loss of 5% in a nitrogen atmosphere using a TGAN-1000 thermogravimetric analyzer at a nitrogen flow rate of 10 mL / min. The Tg (glass transition temperature) was measured by differential scanning calorimetry (DSC, Shinco DSC N-650) at a heating rate of 10 °C / min. The test results are as follows: Figure 3 , Figure 4 As shown, the thermogravimetric temperature (Td) of compound 1 is 436.32℃, and the glass transition temperature (Tg) of compound 1 is 109.02℃. The test results indicate that the compounds prepared in the synthesis examples of this invention have high thermogravimetric temperatures and suitable glass transition temperatures. Therefore, the compounds of this invention possess excellent thermal stability, meeting the requirements for vapor deposition and use as organic electroluminescent compounds.

[0070] The synthesis yields, measured mass-to-nucleus ratios, and Td values ​​for Synthetic Examples 1-17 are shown in Table 1 below:

[0071] Table 1 Device performance testing.

[0072] Application Example 1 ITO / Ag / ITO was used as the anode substrate material, and its surface was treated sequentially with water, acetone, and N2 ions. A hole injection layer (HIL) is formed by depositing 10 nm of HT1 doped with 3% NDP-9 on top of the ITO / Ag / ITO anode substrate. A first hole transport layer (HTL) is formed by vacuum evaporating 100 nm of HT1 above the hole injection layer (HIL); A second hole transport layer (GPL) is formed by vacuum evaporating 40 nm of GP-1 above the first hole transport layer (HTL); GH-1 and GH-2 are used as the light-emitting host material in a 5:5 ratio, GD-1 is used as the first light-emitting dopant material (GD-1 doping ratio 2%), and compound 1 of the present invention is used as the second light-emitting dopant material (compound 1 doping ratio 0.5%). They are co-deposited on the second hole transport layer (GPL) to form a light-emitting layer (EML) with a thickness of 40 nm. HB-1 was deposited onto the light-emitting layer (EML) to obtain a hole blocking layer (HBL) with a thickness of 5 nm. ET-1 and LiQ were co-deposited onto the hole blocking layer (HBL) in a 5:5 ratio to obtain an electron transport layer (ETL) with a thickness of 30 nm. Ytterbium (Yb) is vapor-deposited onto the electron transport layer (ETL) to form an electron injection layer (EIL) with a thickness of 1 nm; Magnesium (Mg) and silver (Ag) are mixed in a 1:9 ratio and vapor-deposited onto the electron injection layer (EIL) to form a cathode with a thickness of 12 nm. A CP-1 layer with a thickness of 60 nm is then deposited on the cathode to form a light extraction layer (CPL). Finally, the device surface is sealed with a UV-curable adhesive and a sealing cap containing a desiccant to protect the organic electroluminescent device from the influence of oxygen or moisture in the atmosphere. This completes the fabrication of the organic electroluminescent device.

[0073] .

[0074] Application Examples 2-17 Compounds 7, 11, 17, 22, 31, 37, 47, 53, 62, 68, 76, 82, 92, 98, 108, and 112, prepared in Synthesis Examples 2 to 16 of the present invention, were used as the second doping material for the light-emitting layer. The remaining parts were the same as in Application Example 1, thereby preparing the organic electroluminescent devices of Application Examples 2 to 17.

[0075] Compare with Examples 1-4 Using BD1-3, BD1-4, BD1-5, and BD1-13 from patent CN115073501A as the second doping material of the light-emitting layer, and the rest being the same as in application example 1, comparative examples 1 to 4 were prepared.

[0076] .

[0077] The organic electroluminescent devices prepared in Application Examples 1-17 and Comparative Examples 1-4 were subjected to device performance tests at a current density of 10 mA / cm². 2 The measurements were performed under the specified conditions, and the test results are shown in Table 2 below.

[0078]

[0079] Table 2 As shown in Table 2 above, when the compounds of the present invention are applied to organic electroluminescent devices, the luminous efficiency is significantly improved at the same current density, the device start-up voltage is reduced, and the device performance is effectively improved.

[0080] The organic electroluminescent devices prepared in Comparative Examples 1-4 and Application Examples 1-17 of this invention were subjected to lifetime tests to obtain the luminescence lifetime T97% data (the time for the luminescence brightness to drop to 97%). Comparative Example 1 was used as the 100% baseline, and the testing equipment was a TEO light-emitting device lifetime testing system. The test results are shown in Table 3 below:

[0081] Table 3 As shown in Table 3 above, when the compounds of this invention are applied to organic electroluminescent devices, the device lifetime of the organic electroluminescent devices prepared with the compounds of this invention is improved at the same current density. The organic electroluminescent devices prepared with the compounds of this invention show improvements in start-up voltage, luminous efficiency, and lifetime, and have broad application prospects.

[0082] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention. Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This descriptive method is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A boron-nitrogen heterocyclic compound with a seven-membered ring, characterized in that, As shown in Equation 1: Among them, R4-R 18 Each is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl, substituted or unsubstituted C6~C30 aryl, substituted or unsubstituted C5~C30 heteroaryl; Z7 is selected from O, S, N-Ar1, where Ar1 is selected from substituted or unsubstituted C6~C20 aryl groups; Z2-Z5 are CR, where R is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl groups, substituted or unsubstituted C6~C30 aryl groups, and substituted or unsubstituted C5~C30 heteroaryl groups. When Z7 is N-Ar1, Ar1 and Z2 are connected by CR. 1 CR 2 Bridged, and / or connected between Z3 and Z4 via CR 3 R 4 Bridge; where R 1 R 2 The elements are either not connected or connected in a loop, R 3 R 4 Ar1 and Z5 are either not connected or connected in a loop; Ar1 ​​and Z5 are not connected or connected via a single key or CR. 5 R 6 NR 7 O, S, Se, Te bridging; R 1 R 2 R 3 R 4 R 5 R 6 R 7 Each is independently selected from substituted or unsubstituted C1~C10 straight-chain or branched alkyl groups, substituted or unsubstituted C6~C30 aryl groups, and substituted or unsubstituted C5~C30 heteroaryl groups; The substituents are selected from hydrogen, deuterium, fluorine, deuterated or undeuterated C1-C20 alkyl, deuterated or undeuterated C6-C20 aryl, and deuterated or undeuterated C5-C20 heteroaryl.

2. A boron-nitrogen heterocyclic compound with a seven-membered ring as described in claim 1, characterized in that, As shown in Equations 2 and 3: Among them, R4-R 18 Each is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl, substituted or unsubstituted C6~C30 aryl, substituted or unsubstituted C5~C30 heteroaryl; Z2-Z5 are CR, where R is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl, substituted or unsubstituted C6~C30 aryl, or substituted or unsubstituted C5~C30 heteroaryl; Z3 and Z4 are connected by CR. 3 R 4 Bridged or not connected; R 3 R 4 They are either not connected or connected in a loop; The substituents are selected from hydrogen, deuterium, fluorine, deuterated or undeuterated C1-C20 alkyl, deuterated or undeuterated C6-C20 aryl, and deuterated or undeuterated C5-C20 heteroaryl.

3. A boron-nitrogen heterocyclic compound with a seven-membered ring as described in claim 1, characterized in that, As shown in Equation 4: Among them, R1-R 18 Each is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl, substituted or unsubstituted C6~C30 aryl, substituted or unsubstituted C5~C30 heteroaryl; Z1-Z6 are CR, where R is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl, substituted or unsubstituted C6~C30 aryl, and substituted or unsubstituted C5~C30 heteroaryl; Z1 and Z2 are connected by CR. 1 CR 2 Bridged, and / or connected between Z3 and Z4 via CR 3 R 4 Bridge; R 1 R 2 The elements are either not connected or connected in a loop, R 3 R 4 Z5 and Z6 are either not connected or connected in a loop; Z5 and Z6 are not connected or connected via a single key or CR. 5 R 6 NR 7 O, S, Se, Te bridging; R 1 R 2 R 3 R 4 R 5 R 6 R 7 Each is independently selected from substituted or unsubstituted C1~C10 straight-chain or branched alkyl groups, substituted or unsubstituted C6~C30 aryl groups, and substituted or unsubstituted C5~C30 heteroaryl groups; The substituents are selected from hydrogen, deuterium, fluorine, deuterated or undeuterated C1-C20 alkyl, deuterated or undeuterated C6-C20 aryl, and deuterated or undeuterated C5-C20 heteroaryl.

4. A boron-nitrogen heterocyclic compound with a seven-membered ring as described in claim 1, characterized in that, As shown in equations 5-9: Z5 and Z6 are CR, and R is independently selected from H, D, F, cyano, substituted or unsubstituted C1~C10 straight-chain or branched alkyl, substituted or unsubstituted C6~C30 aryl, substituted or unsubstituted C5~C30 heteroaryl. In formulas 5-7, Z5 and Z6 are not connected or are bridged by single bonds, O, S, Se, or Te. In formulas 5-9, R1-R 28 Each of the following is independently selected from H, D, F, cyano, substituted or unsubstituted C1-C10 straight-chain or branched alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C5-C30 heteroaryl; the substituent is selected from hydrogen, deuterium, fluorine, deuterated or undeuterated C1-C20 alkyl, deuterated or undeuterated C6-C20 aryl, deuterated or undeuterated C5-C20 heteroaryl, and a, b, c, d, e, f are each independently selected from integers from 0 to 8.

5. A boron-nitrogen heterocyclic compound with a seven-membered ring as described in claim 4, characterized in that, In equations 5-9, R1-R 28 Each is independently selected from H, D, F, cyano, deuterated or undeuterated methyl, deuterated or undeuterated ethyl, deuterated or undeuterated tert-butyl, deuterated or undeuterated phenyl, alkyl-substituted phenyl, deuterated or undeuterated biphenyl, deuterated or undeuterated carbazolyl, deuterated or undeuterated dibenzothiophene, and deuterated or undeuterated dibenzofuran.

6. A boron-nitrogen heterocyclic compound with a seven-membered ring as described in claim 4, characterized in that, In equations 5-9, R1-R 28 Each is independently selected from H, D, deuterated or undeuterated methyl, deuterated or undeuterated tert-butyl, deuterated or undeuterated phenyl, and alkyl-substituted phenyl.

7. A boron-nitrogen heterocyclic compound with a seven-membered ring as described in claim 1, characterized in that, The boron-nitrogen heterocyclic compound is one of the following structural formulas: 。 8. An organic electroluminescent device, characterized in that, It includes a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode, wherein the organic layer contains a boron-nitrogen heterocyclic compound with a seven-membered ring as described in any one of claims 1 to 7.

9. An organic electroluminescent device according to claim 8, characterized in that, The organic layer comprises a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, wherein at least one of the hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, and electron injection layer contains a boron-nitrogen heterocyclic compound with a seven-membered ring as described in any of claims 1 to 7.

10. An organic electroluminescent device according to claim 9, characterized in that, The luminescent layer contains any one of the boron-nitrogen heterocyclic compounds with a seven-membered ring as described in claims 1 to 7.

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