Heterospirocyclic compound, mixture, and electroluminescent device

Abstract

Disclosed are a heterospirocyclic compound, a mixture, and an electroluminescent device. The structural general formula of the heterospirocyclic compound is as shown in the following formula (I), wherein X is selected from a single bond, Se or Te; Y is not bonded or is bonded to A4; A1 to A5 are selected from substituted or unsubstituted aryl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted heteroaryl; G is selected from an aromatic group or a heteroaromatic group; G and A1 form a ring or do not form a ring; G and A2 form a ring or do not form a ring.

Description

Heterospirocyclic compound, mixture and electroluminescent device

[0001] This application claims priority to Chinese patent application No. 202410370150.5 filed on March 28, 2024, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of organic optoelectronic materials, and in particular to a heterospiro compound, a mixture and an electroluminescent device. Background Art

[0003] Organic light-emitting diodes (OLEDs) have become a key development direction in the commercial display and lighting sectors due to their advantages of active emission, wide viewing angle, low driving voltage, low energy consumption, thinness, and suitability for flexible displays. Based on their different emission mechanisms, the organic luminescent materials used in OLEDs can be broadly categorized as fluorescent, phosphorescent, and thermally activated fluorescent. Early OLEDs used fluorescent materials as the luminescent guest materials. Under electric field excitation, the ratio of singlet to triplet excitons was 1:3. The theoretical internal quantum efficiency of fluorescent OLEDs was only 25%, significantly limiting the application of fluorescent electroluminescent devices. While phosphorescent materials can achieve 100% internal quantum efficiency (IQE) due to the spin-orbit coupling of heavy atoms, they are mostly based on precious metals such as iridium (Ir) and platinum (Pt), making them less environmentally friendly. Organic thermally activated delayed fluorescence (TADF) materials, through molecular design to achieve donor-acceptor orbital separation or atomic-level orbital distribution, can promote reverse intersystem crossing and similarly achieve 100% exciton utilization.

[0004] However, under electric field conditions, the singlet-triplet states of TADF materials are subject to exciton-exciton quenching and dipole-exciton quenching mechanisms, which significantly affect the device lifespan and are not conducive to improving luminous efficiency. Therefore, the lifespan and luminous efficiency of existing TADF-OLED devices need to be improved.

[0005] Summary of the Invention

[0006] Existing TADF-OLED devices have technical problems such as lifespan and luminous efficiency that need to be improved.

[0007] In a first aspect, embodiments of the present application provide a heterospiro compound, the general structural formula of the heterospiro compound being as shown in formula (I):

[0008] wherein X is selected from a single bond, Se or Te;

[0009] When X is selected from a single bond, Y is bonded to A4 and is selected from O, S, Se or Te;

[0010] When X is selected from Se or Te, Y is not bonded or is bonded to A4; when Y is bonded to A4, it is selected from O, S, Se or Te;

[0011] A1 to A5 are each independently selected from a substituted or unsubstituted aryl group having 5 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 50 carbon atoms;

[0012] G is selected from an aromatic group having 6 to 50 carbon atoms and containing an electron-withdrawing atom and / or an electron-withdrawing group, or a heteroaromatic group having 6 to 50 carbon atoms and containing an electron-withdrawing atom and / or an electron-withdrawing group;

[0013] G and A1 may form a ring or not; G and A2 may form a ring or not.

[0014] In a second aspect, an embodiment of the present application further provides a mixture comprising at least one functional material and the above-mentioned heterospirocyclic compound.

[0015] In a third aspect, an embodiment of the present application further provides an electroluminescent device comprising an anode and a cathode, and a light-emitting layer located between the anode and the cathode, wherein the light-emitting layer comprises the above-mentioned heterospirocyclic compound or the above-mentioned mixture. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0017] FIG1 is a schematic diagram of a film stack structure of an electroluminescent device provided in an embodiment of the present application. Modes for Carrying Out the Invention

[0018] This application provides a heterospirocyclic compound, a mixture, and an electroluminescent device. To clarify and clarify the objectives, technical solutions, and effects of this application, the application is described in further detail below. It should be understood that the specific embodiments described herein are intended only to illustrate this application and are not intended to limit this application.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. In this application, "substituted" means that a hydrogen atom in a substituted group is replaced by a substituent; "non-bonding" means that the structural unit does not exist.

[0020] In this application, "substituted or unsubstituted" means that the hydrogen atoms on the defined group may be substituted or unsubstituted. When the defined group is substituted, it should be understood that it is substituted by heavy hydrogen (deuterium, tritium) or halogen atoms.

[0021] Aryl refers to a hydrocarbon group containing at least one aromatic ring. Heteroaryl refers to an aromatic hydrocarbon group containing at least one heteroatom. The heteroatom is preferably selected from Si, N, P, O, S and / or Ge, and particularly preferably selected from Si, N, P, O and / or S.

[0022] The general structural formula of the heterospirocyclic compound provided in the examples of the present application is shown in formula (I):

[0023] In some embodiments of the present application, X is selected from a single bond, Se or Te.

[0024] In some embodiments of the present application, when X is selected from a single bond, Y is bonded to A4 and is selected from O, S, Se or Te.

[0025] In some embodiments of the present application, when X is selected from Se or Te, Y is not bonded or is bonded to A4, and when Y is bonded to A4, it is selected from O, S, Se or Te.

[0026] In some embodiments of the present application, A1 to A5 are each independently selected from a substituted or unsubstituted aryl group having 5 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 50 carbon atoms.

[0027] In some embodiments of the present application, G is selected from an aromatic group having 6-50 carbon atoms and containing an electron-withdrawing atom and / or an electron-withdrawing group, or a heteroaromatic group having 6-50 carbon atoms and containing an electron-withdrawing atom and / or an electron-withdrawing group;

[0028] In some embodiments of the present application, G may or may not form a ring with A1.

[0029] In some embodiments of the present application, G may or may not form a ring with A2.

[0030] The main reason why existing TADF materials cause the degradation of electroluminescent devices is the dissipation process of triplet and singlet excitons through different mechanisms under high brightness. The heterospirocyclic compounds provided in the embodiments of the present application reduce the exciton dissipation caused by the aggregation of luminescent materials by utilizing the steric hindrance of the spirocyclic structure, reduce the non-radiative transitions of the material due to vibration rotation and molecular stacking, and enhance the electron transport ability of the material by introducing electron-donating atoms or groups. At the same time, heteroatoms are introduced to increase the reverse intersystem crossing rate, thereby improving the performance of TADF materials when applied to the light-emitting layer of electroluminescent devices, and ultimately improving the luminous efficiency and life of the electroluminescent devices.

[0031] In some embodiments of the application, the electron-withdrawing atom is B, and the electron-withdrawing group is one of a carbonyl group, a phosphino group, and a sulfone group. By introducing an electron-withdrawing atom or group such as B, a carbonyl group, a phosphino group, or a sulfone group into the group G, the group becomes an electron acceptor, thereby enhancing the electron transport ability of the heterospirocyclic compound.

[0032] In some embodiments of the application, when G forms a ring with A1 or A2, it can be achieved by bonding O, S or B in G to A1 or A2.

[0033] In some embodiments of the present application, A1 to A5 may be independently selected from a benzene ring, naphthalene, and tert-butylbenzene.

[0034] In some embodiments of the present application, the heterospirocyclic compound is selected from one of the compounds shown in Formulas I-1 to I-3:

[0035] wherein X1 is selected from Se or Te, and X2 is selected from O, S, Se or Te.

[0036] Furthermore, in some embodiments, the heterospirocyclic compound is selected from one of the compounds shown in the following formulae 1-1-1 to 1-7-13:

[0037] Optionally, X1 is selected from Se or Te, and X2 is selected from O.

[0038] Furthermore, in some embodiments, the heterospirocyclic compound is selected from one of the compounds shown in the following formulas 2-1-1 to 2-8-6:

[0039] Optionally, X1 is selected from Se, and X2 is selected from O or S.

[0040] The present application also provides a mixture comprising the heterospiro compound of the above embodiments and a functional material. The mixture can be used in the light-emitting layer of an electroluminescent device, wherein the heterospiro compound can be used as a host material, a guest material, or a sensitizer in the light-emitting layer. The functional material can be another of the host material, the guest material, or the sensitizer.

[0041] An embodiment of the present application further provides an electroluminescent device, comprising an anode, a cathode, and a light-emitting layer 6 located between the anode and the cathode.

[0042] The material of the light-emitting layer may include the mixture in the above embodiment or the heterospiro compound in the above embodiment.

[0043] In some embodiments, the electroluminescent device further comprises a hole injection layer, a hole transport layer, and an electron blocking layer located between the anode and the light-emitting layer and sequentially stacked on the anode. The hole transport layer may be a multilayer composite film layer including a first hole transport layer and a second hole transport layer stacked together.

[0044] In some embodiments, the electroluminescent device further comprises an electron transport layer and an electron injection layer located between the light-emitting layer and the cathode and sequentially stacked on the light-emitting layer. The electron transport layer may be a multi-layer composite film layer including a stacked first electron transport layer and a second electron transport layer.

[0045] The electroluminescent device described in the present application can be selected from, but not limited to, organic light emitting diodes (OLEDs), organic photovoltaic cells, organic light emitting cells, organic field effect transistors, organic light emitting field effect transistors, organic lasers, organic spintronic devices, organic sensors and organic plasmon emission diodes, etc., with OLED being particularly preferred.

[0046] In an embodiment of the present application, the anode may include a conductive metal, a metal oxide, or a conductive polymer. The anode can easily inject holes into the hole injection layer, the hole transport layer, or the light emitting layer.

[0047] In some embodiments, examples of anode materials include, but are not limited to, Al, Cu, Au, Ag, Mg, Fe, Co, Ni, Mn, Pd, Pt, ITO, aluminum-doped zinc oxide (AZO), and the like. Other anode materials are known and can be readily selected and used by one of ordinary skill in the art. The anode material can be deposited using any suitable technique, such as a suitable physical vapor deposition method, including radio frequency magnetron sputtering, vacuum thermal evaporation, electron beam (e-beam), and the like.

[0048] In some embodiments, the anode is patterned. Patterned ITO conductive substrates are commercially available and can be used to prepare electroluminescent devices according to the present application.

[0049] In the present invention, the cathode may comprise a conductive metal or metal oxide, and may easily inject electrons into the electron injection layer or the electron transport layer or directly into the light emitting layer.

[0050] In principle, any material that can be used as a cathode in an OLED is suitable for use as the cathode material in the device of this application. Examples of cathode materials include, but are not limited to, Al, Au, Ag, Ca, Ba, Mg, LiF / Al, MgAg alloys, BaF2 / Al, Cu, Fe, Co, Ni, Mn, Pd, Pt, and ITO. The cathode material can be deposited using any suitable technique, such as physical vapor deposition (PVD), including radio frequency magnetron sputtering, vacuum thermal evaporation, and electron beam (e-beam).

[0051] The hole injection material, hole transport material, electron blocking material, electron transport material and electron injection material used in the electroluminescent device of the present application are not particularly limited, and any compound can be used as long as the compound is commonly used as a hole injection material, hole transport material, electron blocking material, electron transport material and electron injection material.

[0052] The present application also relates to applications of the electroluminescent device according to the present application in various electronic devices, including, but not limited to, display devices, lighting devices, light sources, sensors, and the like.

[0053] Specific embodiments

[0054] The present invention is described in detail below through specific examples. The following examples are only partial embodiments of the present invention and are not intended to limit the present invention. The raw materials used in the following examples, unless otherwise specified, are all commercially available products. Among them, CuI: cuprous iodide; DCB: o-dichlorobenzene; PPA: polyphosphoric acid; n-BuLi: n-butyllithium; THF: tetrahydrofuran; HCL: hydrochloric acid; Pd(OAc)2: palladium acetate; t-BuONa: sodium tert-butoxide; (t-Bu)3PHBF4: tri-tert-butylphosphine tetrafluoroborate; tol.: toluene; reflux: reflux; Ar: argon; PA: pivalic acid; AgO: silver oxide; DMF: N,N-dimethylformamide; DIPEA: N,N-diisopropylethylamine; BBr3: boron tribromide; o-xylene: o-xylene.

[0055] Example 1

[0056] The synthetic route of compound 1 in this example is as follows:

[0057] Synthesis steps:

[0058] 1.1 Synthesis of intermediate 1-a: Methyl o-iodobenzoate (13.1 g, 50 mmol), phenoselenazine (12.3 g, 50 mmol), copper powder (0.32 g, 5 mmol), cuprous iodide (0.019 g, 1 mmol), potassium carbonate (8.3 g, 60 mmol) and o-dichlorobenzene (150 mL) were added to a 500 mL round-bottom flask, followed by three cycles of vacuum evacuation and argon gas flow. The mixture was stirred at 180 ° C for 18 hours under an argon atmosphere. After the resulting reaction solution was cooled to room temperature, the mixture was poured into 150 mL of water and then extracted with dichloromethane (150 mL × 3). The combined organic phase was washed twice with saturated brine (100 mL × 2). After removing the organic solvent by rotary evaporation, the crude product was purified by silica gel column chromatography using petroleum ether / dichloromethane (V / V = 3 / 2) as eluent. The crude product was added to polyphosphoric acid (150 mL) and heated to 130°C with stirring for 5 hours. After cooling to room temperature, the mixture was poured into 150 mL of water and then extracted with dichloromethane (150 mL × 3). The combined organic phase was washed twice with saturated brine (100 mL × 2). After removing the organic solvent by rotary evaporation, the product was purified by silica gel column chromatography using petroleum ether / dichloromethane (V / V = 1 / 1) as eluent. A total of 11.3 g of intermediate 1-a was obtained with a yield of 65%.

[0059] 1.2 Synthesis of intermediate 1-b: In a dry Schlenk tube (reaction tube), under an inert argon atmosphere, the compound tert-butyl 2-bromophenylphenylcarbamate (11.3 g, 32.5 mmol) was dissolved in anhydrous tetrahydrofuran (250 mL) and cooled to -78 ° C. Then, n-butyl lithium (2.5 mol / L hexane solution, 14.25 mL) was slowly added dropwise to the solution and stirred at -78 ° C for 2 hours. Then, intermediate 1-a (8.95 g, 33 mmol) dissolved in anhydrous tetrahydrofuran (250 mL) was slowly added dropwise to the above mixture and stirred at -78 ° C for 2 hours, and then stirred at 35 ° C for another 2 hours. After adding dilute hydrochloric acid solution (3 mol / L, 40 mL×3), the mixture was stirred at 35 ° C for 12 hours. After removing tetrahydrofuran by rotary evaporation, extracting with dichloromethane (50 mL×3) and water, and removing dichloromethane by rotary evaporation, the collected mixture was further purified by column chromatography using petroleum ether / dichloromethane (V / V=1 / 1) as eluent to obtain 4.95 g of intermediate 1-b with a yield of 30%.

[0060] 1.3 Synthesis of Target Compound 1: Under an inert argon atmosphere, 1-b (4.95 g, 9.9 mmol) was mixed with 2-(4-bromophenyl)-4,6-diphenyl-1,3,5-triazine (3.9 g, 10 mmol), palladium acetate (46 mg, 0.2 mmol), sodium tert-butoxide (1.44 g, 15 mmol), and tri-tert-butylphosphine tetrafluoroborate (174 mg, 0.6 mmol) in dry toluene (50 mL) and stirred at reflux for 24 hours. The mixture was extracted with water and dichloromethane (100 mL x 3). The concentrated organic phase was purified by column chromatography on petroleum ether / dichloromethane (V / V = 1 / 1) and further purified by vacuum sublimation to obtain 5.0 g of target compound 1 with a yield of 62%.

[0061] Example 2

[0062] The synthetic route of compound 2 in this embodiment is as follows:

[0063] Synthesis steps:

[0064] 2.1 Synthesis of intermediate 2-a: The raw material phenoselenazine (12.3 g, 50 mmol) in the synthesis process of intermediate 1-a in Example 1 was replaced with phentellurizine (14.7 g, 50 mmol). The other synthesis process was the same as the synthesis process of intermediate 1-a to obtain intermediate 2-a (12.1 g, 30.5 mmol) with a yield of 61%.

[0065] 2.2 Synthesis of intermediate 2-b: Intermediate 1-a in the synthesis process of intermediate 1-b in Example 1 was replaced by intermediate 2-a, and the other synthesis process was the same as the synthesis process of intermediate 1-b to obtain intermediate 2-b (3.85 g, 7.0 mmol) with a yield of 23%.

[0066] 2.3 Synthesis of target compound 2: The intermediate 1-b in the synthesis process of target compound 1 in Example 1 was replaced by 2-b. The other synthesis process was the same as the synthesis process of target compound 1 to obtain target compound 2 (3.2 g, 3.8 mmol) with a yield of 54%.

[0067] Example 3:

[0068] The synthetic route of target compound 3 is as follows:

[0069] Synthesis steps:

[0070] 3.1 Synthesis of intermediate 3-a: Methyl o-iodobenzoate (13.1 g, 50 mmol), phenoxazine (9.15 g, 50 mmol), copper powder (0.32 g, 5 mmol), cuprous iodide (0.019 g, 1 mmol), potassium carbonate (8.3 g, 60 mmol) and o-dichlorobenzene (150 mL) were added to a 500 mL round-bottom flask, and the vacuum argon gas step was cycled three times. The mixture was stirred at 180 ° C for 18 hours under an argon atmosphere. After cooling to room temperature, the mixture was poured into 150 mL of water and then extracted with dichloromethane (150 mL × 3). The combined organic phase was washed twice with saturated brine (100 mL × 2). After removing the organic solvent by rotary evaporation, petroleum ether / dichloromethane (V / V=3 / 2) was used as eluent and purified by silica gel column chromatography to obtain a crude product. The crude product was added to polyphosphoric acid (150 mL) and heated to 130° C. with stirring for 5 hours. After cooling to room temperature, the mixture was poured into 150 mL of water and then extracted with dichloromethane (150 mL×3). The combined organic phase was washed twice with saturated brine (100 mL×2). After removing the organic solvent by rotary evaporation, the product was purified by silica gel column chromatography using petroleum ether / dichloromethane (V / V=1 / 1) as eluent. A total of 8.9 g of intermediate 3-a was obtained with a yield of 63%.

[0071] 3.2 Synthesis of Intermediate 3-b: Intermediate 3-a (8.9 g, 31.5 mmol), palladium acetate (142 mg, 0.63 mmol), silver oxide (729 mg, 3.1 mmol), potassium carbonate (5.53 g, 40 mmol), and pivalic acid (150 mL) were added to a 500 mL round-bottom flask. The mixture was evacuated and purged with argon three times, and stirred at 160°C under an argon atmosphere for 24 hours. After cooling to room temperature, the mixture was poured into 150 mL of water and extracted with dichloromethane (150 mL x 3). The combined organic phases were washed twice with saturated brine (100 mL x 2). The organic solvent was removed by rotary evaporation, and the product was purified by silica gel column chromatography using petroleum ether / dichloromethane (v / v = 2 / 1) as the eluent. A total of 3.7 g of intermediate 3-b was obtained with a yield of 41%.

[0072] 3.3 Synthesis of intermediate 3-c: In a dry Schlenk tube, under an inert argon atmosphere, the compound tert-butyl 2-bromophenylphenylcarbamate (4.5 g, 13 mmol) was dissolved in anhydrous tetrahydrofuran (140 mL) and cooled to -78 ° C. Then, n-butyl lithium (2.5 mol / L hexane solution, 5.3 mL) was slowly added dropwise to the solution and stirred at -78 ° C for 2 hours. Then, intermediate 3-b (3.7 g, 12.9 mmol) dissolved in anhydrous tetrahydrofuran (140 mL) was slowly added dropwise to the above mixture and stirred at -78 ° C for 2 hours, and then stirred at 35 ° C for another 2 hours. After adding dilute hydrochloric acid solution (3 mol / L, 30 mL×3), the mixture was stirred at 35 ° C for 12 hours. After removing tetrahydrofuran by rotary evaporation, extracting with dichloromethane (50 mL×3) and water, and removing dichloromethane by rotary evaporation, the collected mixture was further purified by column chromatography using petroleum ether / dichloromethane (V / V=2 / 1) as eluent to obtain 1.68 g of intermediate 3-c with a yield of 30%.

[0073] 3.4. Synthesis of Compound 3: Under an inert argon atmosphere, intermediate 3-c (1.68 g, 3.9 mmol) was mixed with 2-(4-bromophenyl)-4,6-diphenyl-1,3,5-triazine (1.56 g, 4 mmol), palladium acetate (18 mg, 0.08 mmol), sodium tert-butoxide (0.48 g, 5 mmol), and tri-tert-butylphosphine tetrafluoroborate (70 mg, 0.24 mmol) in dry toluene (20 mL) and stirred at reflux for 24 hours. The mixture was extracted with water and dichloromethane (100 mL x 3). The concentrated organic phase was purified by column chromatography on petroleum ether / dichloromethane (V / V = 5 / 2) and further purified by vacuum sublimation. 1.3 g of the target compound 3 was obtained with a yield of 45%.

[0074] Example 4:

[0075] The synthetic route of target compound 4 is as follows:

[0076] Synthesis steps:

[0077] 4.1 Synthesis of Intermediate 4-a: 2-Fluoro-6-methylformate-iodobenzene (14.0 g, 50 mmol), o-hydroxy-Boc-phenoselenazine (31.12 g, 50 mmol), potassium carbonate (6.9 g, 60 mmol), and N,N-dimethylformamide (150 mL) were added to a 500 mL round-bottom flask. The mixture was evacuated and purged with argon three times. Stirred at 90°C under an argon atmosphere for 12 hours. After cooling to room temperature, the mixture was poured into 150 mL of water and extracted with dichloromethane (150 mL x 3). The combined organic phases were washed twice with saturated brine (100 mL x 2). The organic solvent was removed by rotary evaporation, and the crude product was purified by silica gel column chromatography using petroleum ether / dichloromethane (v / v = 3 / 1) as the eluent. A total of 22.1 g of Intermediate 4-a was obtained with a yield of 71%.

[0078] 4.2 Synthesis of Intermediate 4-b: Intermediate 4-a (22.1 g, 35.5 mmol) was stirred in tetrafluoroacetic acid in THF at room temperature for 2 h, acidified, and then washed with water. The product after rapid column chromatography was dried and added to a 500 mL round-bottom flask along with copper powder (0.32 g, 5 mmol), cuprous iodide (0.019 g, 1 mmol), potassium carbonate (8.3 g, 60 mmol), and o-dichlorobenzene (150 mL). The mixture was evacuated and purged with argon three times, and stirred at 180°C under an argon atmosphere for 12 h. After cooling to room temperature, the mixture was poured into 150 mL of water and extracted with dichloromethane (150 mL x 3). The combined organic phases were washed twice with saturated brine (100 mL x 2). The organic solvent was removed by rotary evaporation, and the crude product was purified by silica gel column chromatography using petroleum ether / dichloromethane (v / v = 3 / 1) as eluent. The crude product was added to polyphosphoric acid (150 mL) and heated to 130°C with stirring for 5 hours. After cooling to room temperature, the mixture was poured into 150 mL of water and extracted with dichloromethane (150 mL x 3). The combined organic phases were washed twice with saturated brine (100 mL x 2). After removing the organic solvent by rotary evaporation, the product was purified by silica gel column chromatography using petroleum ether / dichloromethane (v / v = 3 / 1) as the eluent. A total of 6.05 g of intermediate 4-b was obtained with a yield of 47%.

[0079] 4.3 Synthesis of intermediate 4-c: In a dry Schlenk tube, the compound tert-butyl 2-bromophenylphenylcarbamate (4.5 g, 17 mmol) was dissolved in anhydrous tetrahydrofuran (170 mL) under an inert argon atmosphere and cooled to -78 ° C. Then, n-butyl lithium (2.5 mol / L hexane solution, 7 mL) was slowly added dropwise to the solution and stirred at -78 ° C for 2 hours. Then, intermediate 4-b (6.05 g, 16.7 mmol) dissolved in anhydrous tetrahydrofuran (160 mL) was slowly added dropwise to the above mixture and stirred at -78 ° C for 2 hours, and then stirred at 35 ° C for another 2 hours. After adding dilute hydrochloric acid solution (3 mol / L, 30 mL×3), the mixture was stirred at 35 ° C for 12 hours. After removing tetrahydrofuran by rotary evaporation, extracting with dichloromethane (50 mL×3) and water, and removing dichloromethane by rotary evaporation, the collected mixture was further purified by column chromatography using petroleum ether / dichloromethane (V / V=3 / 1) as eluent to obtain 2.46 g of intermediate 4-c with a yield of 29%.

[0080] 4.4 Synthesis of target compound 4: Under an inert argon atmosphere, intermediate 4-c (2.46 g, 4.8 mmol) was mixed with 2-(4-bromophenyl)-4,6-diphenyl-1,3,5-triazine (1.94 g, 5 mmol), palladium acetate (23 mg, 0.1 mmol), sodium tert-butoxide (0.58 g, 6 mmol) and tri-tert-butylphosphine tetrafluoroborate (87 mg, 0.3 mmol) in dry toluene (25 mL) and stirred at reflux temperature for 24 hours. The mixture was extracted with water and dichloromethane (100 mL × 3). The concentrated organic phase was purified by petroleum ether / dichloromethane (V / V = 4 / 1) column chromatography and further purified by vacuum sublimation. A total of 2.17 g of target compound 4 was obtained with a yield of 55%.

[0081] Example 5:

[0082] The synthetic route of target compound 5 is as follows:

[0083] The synthesis steps of target compound 5 were similar to those of Example 4, except that o-hydroxy-Boc phenaselenazine in the synthesis of intermediate 4-a was replaced with o-mercapto-Boc phentetrazine. Target compound 5 was obtained with a yield of 5.4%.

[0084] Example 6:

[0085] The synthetic route of target compound 6 is as follows:

[0086] Synthesis steps:

[0087] 6.1 Synthesis of Intermediate 6-a: Under an inert argon atmosphere, Intermediate 1-b (2.50 g, 5 mmol) was mixed with 5-bromo-1,3-diphenylaminobenzene (2.45 g, 5 mmol), palladium acetate (23 mg, 0.1 mmol), sodium tert-butoxide (0.58 g, 6 mmol), and tri-tert-butylphosphine tetrafluoroborate (87 mg, 0.3 mmol) in dry o-xylene (25 mL) and stirred at reflux for 24 hours. The mixture was extracted with water and dichloromethane (100 mL x 3). The concentrated organic phase was purified by column chromatography on petroleum ether / dichloromethane (v / v = 4 / 1) and further purified by vacuum sublimation. A total of 3.41 g of Intermediate 6-a was obtained with a yield of 75%.

[0088] 6.2 Synthesis of Target Compound 6: Intermediate 6-a (18.20 g, 20 mmol) was added to a 500 mL Schlenk flask and the evacuation and argon purging steps were repeated three times. Ultra-dry mesitylene (180 mL) was then added. After cooling in an ice bath for 10 minutes, boron tribromide (3.9 mL, 40 mmol) was quickly added and the reaction was stirred at 40°C for 2 hours. After cooling to room temperature, N,N-diisopropylethylamine (7 mL, 40 mmol) was slowly added in an ice bath. After stirring at room temperature for 30 minutes, the temperature was raised to 160°C in the dark and stirred at this temperature for 48 hours. After the reaction was complete, the mixture was cooled to room temperature and poured into 150 mL of water, followed by extraction with dichloromethane (150 mL x 3). The combined organic phases were washed twice with saturated brine (100 mL x 2). After removing the organic solvent by rotary evaporation, the product was slowly purified by chromatography on a silica gel column using petroleum ether / dichloromethane (V / V=10 / 1) as eluent to obtain 4.5 g of the target compound 6 with a reaction yield of 25%.

[0089] Example 7:

[0090] The synthetic route of target compound 7 is as follows:

[0091] Synthesis steps:

[0092] 7.1 Synthesis of Intermediate 7-a: Under an inert argon atmosphere, 1-b (2.50 g, 5 mmol) was mixed with 1-diphenylamino-5-bromobenzene (1.620 g, 5 mmol), palladium acetate (23 mg, 0.1 mmol), sodium tert-butoxide (0.58 g, 6 mmol), and tri-tert-butylphosphine tetrafluoroborate (87 mg, 0.3 mmol) in dry o-xylene (25 mL) and stirred at reflux for 24 hours. The mixture was extracted with water and dichloromethane (100 mL x 3). The concentrated organic phase was purified by column chromatography on petroleum ether / dichloromethane (v / v = 4 / 1) and further purified by vacuum sublimation. A total of 2.67 g of Intermediate 7-a was obtained with a yield of 72%.

[0093] 7.2 Synthesis of Target Compound 7: Intermediate 7-a (14.85 g, 20 mmol) was added to a 500 mL Schlenk flask and the evacuation and argon purging steps were repeated three times. Ultra-dry mesitylene (180 mL) was then added. After cooling in an ice bath for 10 minutes, boron tribromide (3.9 mL, 40 mmol) was quickly added and the reaction was stirred at 40°C for 2 hours. After cooling to room temperature, N,N-diisopropylethylamine (7 mL, 40 mmol) was slowly added in an ice bath. After stirring at room temperature for 30 minutes, the temperature was raised to 160°C in the dark and stirred at this temperature for 48 hours. After the reaction was complete, the mixture was cooled to room temperature and poured into 150 mL of water, followed by extraction with dichloromethane (150 mL x 3). The combined organic phases were washed twice with saturated brine (100 mL x 2). After removing the organic solvent by rotary evaporation, the product was slowly purified by silica gel column chromatography using petroleum ether / dichloromethane (V / V=10 / 1) as eluent to obtain 3.75 g of the target compound 7 with a yield of 25%.

[0094] The mass spectrometry (MS) and elemental analysis (EA) results of target compounds 1-7 are shown in Table 1 below.

[0095] Table 1

[0096] The performance of the electroluminescent device including the above-mentioned compounds is tested through a specific device embodiment. Among them, the schematic diagram of the film stack structure of the electroluminescent device is shown in Figure 1, wherein: 1 - glass and conductive glass (ITO anode) substrate layer; 2 - hole injection layer (HAT-CN, 5nm); 3 - first hole transport layer (TAPC, 30nm); 4 - second hole transport layer (TCTA, 15nm); 5 - electron blocking layer (mCBP, 10nm); 6 - light-emitting layer (the above-mentioned compounds 1-7 of the present application or the compound A shown in the following structure and the PPF host are evaporated in a ratio of 9:91, 20nm); 7 - first electron transport layer (POT2T, 10nm); 8 - second electron transport layer (ANT-BIZ, 30nm); 9 - electron injection layer (Liq, 2nm); 10 - cathode (Al, 100nm).

[0097] The above-mentioned electroluminescent device can be made according to known methods in the art, for example, it can be made according to the method disclosed in the reference (Nature Photon. 2022, 16, 803–810). The specific method is: under high vacuum conditions, the hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer and cathode are sequentially deposited on a cleaned conductive glass (ITO) substrate. The device shown in Figure 1 is prepared by this method. At a current density of 10 mA / cm 2 The luminescence characteristics of the prepared devices were recorded under the following conditions, as shown in Table 2. The preparation processes and structures of Comparative Example 1 and Examples 1-7 were the same, except that the materials of the luminescent layers were different. The luminescent layer material of OLED-Ref was compound A and PPF host in a ratio of 9:91; the luminescent layer material of OLED-1 was compound 1; the luminescent layer material of OLED-2 was compound 2; the luminescent layer material of OLED-3 was compound 3; the luminescent layer material of OLED-4 was compound 4; the luminescent layer material of OLED-5 was compound 5; the luminescent layer material of OLED-6 was compound 6; and the luminescent layer material of OLED-7 was compound 7.

[0098] Table 2

[0099] As can be seen from Table 2, compared with the electroluminescent device prepared in device comparative example 1, the external quantum efficiency (EQE) and lifespan of the electroluminescent devices prepared in device examples 1-7 provided in the embodiments of the present application are improved. The possible reason is that when the heterospirocyclic compound provided in the embodiments of the present application is applied to the electroluminescent device, the steric hindrance of the spirocyclic structure can reduce the exciton dissipation caused by the aggregation of the luminescent material, reduce the non-radiative transition caused by the vibration rotation and molecular stacking of the material, and enhance the electron transport ability of the material by introducing electron-donating atoms or groups, while introducing heteroatoms to enhance the reverse intersystem crossing rate, thereby ultimately improving the efficiency and lifespan of the device.

[0100] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0101] The above is a detailed description of a heterospirocyclic compound, mixture and electroluminescent device provided in the embodiments of the present application. The above description is only used to help understand the technical solution and its core idea of ​​the present application; ordinary technicians in this field can modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents, without causing the essence of the corresponding technical solution to deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A heterospirocyclic compound, wherein The general structural formula of the heterospirocyclic compound is shown in formula (I): wherein X is selected from a single bond, Se or Te; When X is selected from a single bond, Y is bonded to A4 and is selected from O, S, Se or Te; When X is selected from Se or Te, Y is not bonded or is bonded to A4; when Y is bonded to A4, it is selected from O, S, Se or Te; A1 to A5 are each independently selected from a substituted or unsubstituted aryl group having 5 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 50 carbon atoms; G is selected from an aromatic group having 6 to 50 carbon atoms and containing an electron-withdrawing atom and / or an electron-withdrawing group, or a heteroaromatic group having 6 to 50 carbon atoms and containing an electron-withdrawing atom and / or an electron-withdrawing group; G and A1 may form a ring or not; G and A2 may form a ring or not.

2. The heterospiro compound according to claim 1, wherein The electron-withdrawing atom is B, and the electron-withdrawing group is one of a carbonyl group, a phosphorus oxide group, and a sulfone group.

3. The heterospiro compound according to claim 1, wherein O, S or B in G is bonded to A1 or A2.

4. The heterospiro compound according to claim 1, wherein The heterospirocyclic compound is selected from one of the compounds shown in Formulas I-1 to I-3: Wherein, X1 is selected from Se or Te, and X2 is selected from O, S, Se or Te.

5. The heterospiro compound according to claim 4, wherein The heterospirocyclic compound is selected from one of the compounds shown in the following formulas 1-1-1 to 1-7-13:

6. The heterospiro compound according to claim 5, wherein X1 is selected from Se or Te, and X2 is selected from O.

7. The heterospiro compound according to claim 4, wherein The heterospirocyclic compound is selected from one of the compounds shown in the following formulas 2-1-1 to 2-8-6:

8. The heterospiro compound according to claim 7, wherein X1 is selected from Se, and X2 is selected from O or S.

9. A mixture comprising at least one functional material and a heterospirocyclic compound, wherein: The general structural formula of the heterospirocyclic compound is shown in formula (I): wherein X is selected from a single bond, Se or Te; When X is selected from a single bond, Y is bonded to A4 and is selected from O, S, Se or Te; When X is selected from Se or Te, Y is not bonded or is bonded to A4; when Y is bonded to A4, it is selected from O, S, Se or Te; A1 to A5 are each independently selected from a substituted or unsubstituted aryl group having 5 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 50 carbon atoms; G is selected from an aromatic group having 6 to 50 carbon atoms and containing an electron-withdrawing atom and / or an electron-withdrawing group, or a heteroaromatic group having 6 to 50 carbon atoms and containing an electron-withdrawing atom and / or an electron-withdrawing group; G and A1 may form a ring or not; G and A2 may form a ring or not.

10. An electroluminescent device comprising an anode and a cathode, and a light-emitting layer located between the anode and the cathode, wherein the light-emitting layer comprises a heterospiro compound, wherein: The general structural formula of the heterospirocyclic compound is shown in formula (I): wherein X is selected from a single bond, Se or Te; When X is selected from a single bond, Y is bonded to A4 and is selected from O, S, Se or Te; When X is selected from Se or Te, Y is not bonded or is bonded to A4; when Y is bonded to A4, it is selected from O, S, Se or Te; A1 to A5 are each independently selected from a substituted or unsubstituted aryl group having 5 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 50 carbon atoms; G is selected from an aromatic group having 6 to 50 carbon atoms and containing an electron-withdrawing atom and / or an electron-withdrawing group, or a heteroaromatic group having 6 to 50 carbon atoms and containing an electron-withdrawing atom and / or an electron-withdrawing group; G and A1 may form a ring or not; G and A2 may form a ring or not.

11. The electroluminescent device according to claim 10, wherein The electron-withdrawing atom is B, and the electron-withdrawing group is one of a carbonyl group, a phosphorus oxide group, and a sulfone group.

12. The electroluminescent device according to claim 10, wherein O, S or B in G is bonded to A1 or A2.

13. The electroluminescent device according to claim 10, wherein The heterospirocyclic compound is selected from one of the compounds shown in Formulas I-1 to I-3: Wherein, X1 is selected from Se or Te, and X2 is selected from O, S, Se or Te.

14. The electroluminescent device according to claim 13, wherein The heterospirocyclic compound is selected from one of the compounds shown in the following formulas 1-1-1 to 1-7-13:

15. The electroluminescent device according to claim 14, wherein X1 is selected from Se or Te, and X2 is selected from O.

16. The electroluminescent device according to claim 13, wherein The heterospirocyclic compound is selected from one of the compounds shown in the following formulas 2-1-1 to 2-8-6:

17. The electroluminescent device according to claim 16, wherein X1 is selected from Se, and X2 is selected from O or S.

18. The electroluminescent device according to claim 10, wherein The heterospirocyclic compound is one of the luminescent host material, luminescent guest material, or sensitizer of the luminescent layer.

19. The electroluminescent device according to claim 10, wherein The electroluminescent device includes a hole injection layer, a hole transport layer and an electron blocking layer located between the anode and the light-emitting layer and sequentially stacked on the anode, and an electron transport layer and an electron injection layer located between the light-emitting layer and the cathode and sequentially stacked on the light-emitting layer.

20. The electroluminescent device according to claim 10, wherein The electroluminescent device is one of the organic light emitting diode, organic photovoltaic cell, organic light emitting cell, organic field effect transistor, organic laser, and organic spintronic device.

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