Carbonyl nitrogen spiro compound, organic electroluminescent device, display, display screen and electronic equipment

Abstract

The invention discloses a carbonyl nitrogen spiro compound, an organic electroluminescent device, a display, a display screen and electronic equipment, and relates to the technical field of organic electroluminescent materials. The carbonyl nitrogen spiro compound has a structure as shown in a formula (1) or a formula (2). On the basis of a nitrogen / carbonyl multiple resonance skeleton, a three-dimensional indane spiro skeleton is introduced, so that molecular skeleton vibration can be inhibited, aggregation is avoided, and high fluorescence quantum yield and narrow-band emission are realized.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent materials technology, specifically to carbonyl nitrogen spirocyclic compounds and organic electroluminescent devices, displays, screens and electronic devices. Background Technology

[0002] Organic light-emitting diode (OLED) technology has always been at the forefront of optoelectronic materials research. First-generation fluorescent materials laid the foundation for OLED technology, but were limited by theoretical bottlenecks in quantum efficiency. This technological predicament was overcome by the subsequent emergence of second-generation phosphorescent materials: phosphorescent systems based on noble metal complexes effectively improved device efficiency through full exciton utilization, thus spurring the commercialization of modern OLED displays. However, the scarcity and cost constraints of noble metals have prompted the academic community to seek new solutions.

[0003] In recent years, multiple resonance thermally induced delayed fluorescence (MR-TADF) materials have not only broken through the efficiency limitations of traditional fluorescent materials and shown stable performance potential due to their unique exciton regulation mechanism and all-organic material properties, but also have the characteristics of high luminous efficiency and narrow half-width, thus achieving high color purity and high efficiency OLED performance. This has attracted widespread attention from the scientific research and industry communities and has continued to drive the development of organic electronics.

[0004] In existing technologies, combining planar spirocyclic frameworks with multiple resonant frameworks in organic electroluminescent devices can achieve high device efficiency and narrow half-width electroluminescence spectra to a certain extent. However, planar spirocyclic structures are prone to intermolecular π-π stacking, which easily induces molecular aggregation, leading to aggregation-induced spectral broadening at high doping concentrations. In other words, it is difficult to achieve both luminous efficiency and color purity in traditional multiple resonant materials. Summary of the Invention

[0005] One objective of the first aspect of this invention is to provide a carbonyl nitrogen spirocyclic compound that solves the technical problem that the planar spirocyclic framework in the prior art is prone to vibration and easily induces aggregation when doped at high concentrations.

[0006] Another object of the first aspect of the present invention is to further improve the optical properties of carbonyl nitrogen spirocyclic compounds.

[0007] A second aspect of the present invention aims to provide an organic electroluminescent device comprising the carbonyl nitrogen spirocyclic compound described in any of the preceding claims.

[0008] A third aspect of the present invention is to provide a display comprising the organic electroluminescent device described in any of the preceding claims.

[0009] A fourth aspect of the present invention is to provide a display screen comprising the organic electroluminescent device described in any of the preceding claims.

[0010] A fifth aspect of the present invention is to provide an electronic device including the aforementioned display screen.

[0011] According to a first aspect of the present invention, the present invention provides a carbonyl nitrogen spirocyclic compound having a structure as shown in formula (1) or formula (2):

[0012]

[0013] Ar1-Ar2 may be the same or different, Ar1 is a benzene ring or a pyridine ring each time it appears; Ar2 is a benzene ring each time it appears; the rings of Ar1-Ar2 have groups R1, R2, R3 and R4, and R1, R2, R3 and R4 may be the same or different each time they appear;

[0014] R1, each time it appears, is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, cyano, NO2, N(M)2, OM, SM, C(=O)M, P(=O)M, Si(M)3, C1-C20 alkyl substituted with at least one M, C1-C20 alkoxy, C1-C20 alkoxy substituted with at least one M, C3-C10 cycloalkyl, C3-C10 cycloalkyl substituted with at least one M, C2-C20 alkenyl, C2-C20 alkenyl substituted with at least one M, C2-C20 alkynyl, C2-C20 alkynyl substituted with at least one M, C6-C24 aryl, C6-C24 aryl substituted with at least one M, C5-C30 heteroaryl, C5-C30 heteroaryl substituted with at least one M; wherein M is alkyl, alkoxy, cycloalkyl, alkenyl, alkynyl, heteroaryl, or aryl;

[0015] Each time R2 appears, it is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, cyano, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C24 aryl, or C5-C30 heteroaryl.

[0016] R3 is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, cyano, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C24 aryl, and C5-C30 heteroaryl each time it appears.

[0017] R4 is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, cyano, thiobenzene, selenene, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C24 aryl, and C5-C30 heteroaryl each time it appears.

[0018] Optionally, the carbonyl nitrogen spirocyclic compound comprises any of the following structures:

[0019]

[0020]

[0021]

[0022]

[0023] According to a second aspect of the present invention, the present invention also provides an organic electroluminescent device, the organic electroluminescent device comprising an anode, a cathode and at least one organic thin film located between the anode and the cathode, the organic thin film being a carbonyl nitrogen spirocyclic compound as described in any of the preceding claims.

[0024] Optionally, the organic electroluminescent device includes an anode layer, a hole injection layer, a hole transport layer, an electron blocking layer, an organic light-emitting layer, an electron transport layer, and a cathode layer arranged sequentially from bottom to top, wherein at least one of the hole injection layer, the hole transport layer, the electron blocking layer, the organic light-emitting layer, and the electron transport layer is made of an organic thin film.

[0025] Optionally, when the organic light-emitting layer is an organic thin film, the mass concentration of the carbonyl nitrogen spirocyclic compound in the organic light-emitting layer is any value between 1 wt% and 30 wt%.

[0026] According to a third aspect of the present invention, the present invention also provides a display comprising the organic electroluminescent device described in any of the preceding claims.

[0027] According to a fourth aspect of the present invention, the present invention also provides a display screen, including a cover plate, a back plate, and the organic electroluminescent device described in any of the preceding claims.

[0028] According to a fifth aspect of the present invention, the present invention also provides an electronic device, including a housing assembly and the aforementioned display screen, the display screen being located inside the housing assembly.

[0029] This invention obtains carbonyl nitrogen spirocyclic compounds by introducing a stereoscopic indanespirocyclic structure into the carbonyl nitrogen multiple resonance framework. The carbonyl nitrogen spirocyclic compound has a stereoscopic structure, that is, it includes two phenyl groups connected to a five-membered ring and a benzene ring Ar3 connected by π conjugation below the carbonyl nitrogen spirocyclic compound. The introduction of the spirocyclic structure can suppress molecular framework vibrations, and due to its non-planar stereostructure, it can avoid aggregation, thereby achieving high fluorescence quantum yield and narrow band emission.

[0030] Furthermore, by setting multiple substituents R1-R3 (donor substituents and acceptor substituents) of the same or different types around the carbonyl nitrogen spirocyclic compound, the present invention can adjust the emission wavelength and HOMO-LUMO energy level of the luminescent molecule.

[0031] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0032] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0033] Figure 1 The present invention relates to a room temperature fluorescence spectrum, a low temperature fluorescence spectrometer, and a low temperature phosphorescence spectrum of Formula 8 according to an embodiment of the present invention.

[0034] Figure 2 This is an organic electroluminescence spectrum of an organic electroluminescent device of Formula 8 according to an embodiment of the present invention;

[0035] Figure 3 This is a graph showing the external quantum efficiency of an organic electroluminescent device of Formula 8 according to an embodiment of the present invention. Detailed Implementation

[0036] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0037] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0038] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0039] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] Figure 1 The room temperature fluorescence spectrum, low temperature fluorescence spectrometer, and low temperature phosphorescence spectrum of Formula 8 according to an embodiment of the present invention are described. Figure 2 This is an organic electroluminescence spectrum of an organic electroluminescent device of Formula 8 according to an embodiment of the present invention. Figure 3 This is a graph showing the external quantum efficiency of an organic electroluminescent device of Formula 8 according to an embodiment of the present invention.

[0041] This invention provides a carbonyl nitrogen spirocyclic compound having a structure as shown in formula (1) or formula (2):

[0042]

[0043] Among them, Ar1-Ar2 may be the same or different, Ar1 is independently a benzene ring or a pyridine ring each time it appears; Ar2 is independently a benzene ring each time it appears; the rings of Ar1-Ar2 have groups R1, R2, R3 and R4, and R1, R2, R3 and R4 may be the same or different each time they appear;

[0044] R1 is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, cyano, NO2, N(M)2, OM, SM, C(=O)M, P(=O)M, Si(M)3, C1-C20 alkyl substituted with at least one M, C1-C20 alkoxy, C1-C20 alkoxy substituted with at least one M, C3-C10 cycloalkyl, C3-C10 cycloalkyl substituted with at least one M, C2-C20 alkenyl, C2-C20 alkenyl substituted with at least one M, C2-C20 alkynyl, C2-C20 alkynyl substituted with at least one M, C6-C24 aryl, C6-C24 aryl substituted with at least one M, C5-C30 heteroaryl, C5-C30 heteroaryl substituted with at least one M, wherein M is alkyl, alkoxy, cycloalkyl, alkenyl, alkynyl, heteroaryl or aryl;

[0045] Each time R2 appears, it is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, cyano, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C24 aryl, or C5-C30 heteroaryl.

[0046] R3 is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, cyano, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C24 aryl, and C5-C30 heteroaryl each time it appears.

[0047] R4 is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, cyano, thiobenzene, selenene, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C24 aryl, and C5-C30 heteroaryl each time it appears.

[0048] In this embodiment, a carbonyl nitrogen spirocyclic compound is obtained by introducing a stereoscopic indane spirocyclic structure into the carbonyl nitrogen multiple resonance framework. The carbonyl nitrogen spirocyclic compound has a stereoscopic structure, specifically including two phenyl groups connected to a five-membered ring and a benzene ring Ar3 connected via π-conjugation below the carbonyl nitrogen spirocyclic compound. The introduction of the spirocyclic structure can suppress molecular framework vibrations, and due to its non-planar stereoconfiguration, aggregation can be avoided, thereby achieving high fluorescence quantum yield and narrow-band emission. Simultaneously, by placing multiple substituents R1-R3 (donor substituents and acceptor substituents) of the same or different types around the carbonyl nitrogen spirocyclic compound, the emission wavelength and HOMO-LUMO energy levels of the luminescent molecule can be tuned.

[0049] In this embodiment, the molecular rigidity and symmetry of the spirocyclic structure help suppress nonradiative transitions caused by intramolecular vibrations and rotations, thereby reducing the emission bandwidth and improving color purity. The conjugation effect between the carbonyl group (C=O) and nitrogen heterocycles (such as carbazole) in carbonyl nitrogen compounds helps to directionally distribute electron density, further improving the concentration of the emission peak, thus achieving narrow-spectrum luminescence.

[0050] In a further embodiment, the carbonyl nitrogen spirocyclic compound comprises any of the following structures:

[0051]

[0052]

[0053]

[0054]

[0055] Here, carbonyl nitrogen spirocyclic compounds include, but are not limited to, the structures described above.

[0056] The present invention also provides an organic electroluminescent device, comprising an anode, a cathode, and at least one organic thin film located between the anode and the cathode, wherein the organic thin film is a carbonyl nitrogen spirocyclic compound as described above. In this embodiment, by applying a carbonyl nitrogen spirocyclic compound to the organic thin film of the organic electroluminescent device, the luminous efficiency and luminous quality of the organic electroluminescent device are improved.

[0057] Depend on Figures 1 to 3 It is evident that when the compounds of this invention are used as guest materials for the luminescent layer, they exhibit high efficiency and narrow spectral performance. Furthermore, the large steric hindrance of the compounds of this invention avoids spectral broadening and aggregation quenching under high voltage.

[0058] In a further embodiment, the organic electroluminescent device includes an anode layer, a hole injection layer, a hole transport layer, an electron blocking layer, an organic light-emitting layer, an electron transport layer, and a cathode layer stacked sequentially from bottom to top. At least one of the hole injection layer, hole transport layer, electron blocking layer, organic light-emitting layer, and electron transport layer is made of an organic thin film. In this embodiment, at least one of the hole injection layer, hole transport layer, electron blocking layer, organic light-emitting layer, and electron transport layer in the organic electroluminescent device is made of an organic thin film, specifically a carbonyl nitrogen spirocyclic compound. Applying the carbonyl nitrogen spirocyclic compound to at least one of the hole injection layer, hole transport layer, electron blocking layer, organic light-emitting layer, and electron transport layer achieves a narrow operating spectrum and high luminous efficiency in the organic electroluminescent device. Simultaneously, the placement of peripheral substituents in the carbonyl nitrogen spirocyclic compound can adjust the emission wavelength of the luminescent molecules and the HOMO-LUMO energy level, thereby adjusting the color, full width at half maximum (FWHM), and external quantum efficiency of the electroluminescent spectrum of the organic electroluminescent device.

[0059] In a further embodiment, when the organic light-emitting layer is an organic thin film, the mass concentration of the carbonyl nitrogen spirocyclic compound in the organic light-emitting layer is any value between 1 wt% and 10 wt%. That is, the mass concentration of the carbonyl nitrogen spirocyclic compound in the organic light-emitting layer can be 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%, or any other value between 1 wt% and 10 wt%. In this embodiment, by setting the mass concentration of the carbonyl nitrogen spirocyclic compound in the organic light-emitting layer within the above range, the emission color purity of the organic electroluminescent device can be effectively improved, a narrow emission spectrum can be achieved, and the exciton recombination efficiency can be optimized, thereby improving the luminous efficiency of the organic electroluminescent device. In addition, the excellent thermal stability and charge transport capability of this type of compound help to enhance the working stability and lifespan of the organic electroluminescent device.

[0060] The present invention also provides a display comprising any of the above-described organic electroluminescent devices.

[0061] The present invention also provides a display screen, including a cover plate, a back plate, and any of the above-mentioned organic electroluminescent devices.

[0062] The present invention also provides an electronic device, including a housing assembly and the aforementioned display screen, wherein the display screen is located inside the housing assembly.

[0063] The following are examples of synthesis (unless otherwise specified, all raw materials used were commercially available):

[0064] Synthesis Example 1: Synthesis of Formula 3

[0065]

[0066] Synthesis of intermediate 1c: Under nitrogen protection, compound 1a (3.76 g, 1 equivalent), compound 1b (2.81 g, 1 equivalent), copper powder (0.04 g, 0.07 equivalent), cuprous iodide (0.19 g, 0.1 equivalent), heptanedione (0.18 g, 0.1 equivalent), potassium carbonate (2.1 g, 1.5 equivalent), and 50 mL of n-butyl ether were added to a 100 mL double-necked flask containing a stir bar. The reaction system was stirred and heated to 160 °C for 3 days. After cooling to room temperature, the filtrate was obtained by suction filtration, and the filter cake was washed with dichloromethane. The organic phases were combined. The organic phase was subjected to vacuum distillation to remove the solvent, yielding a crude product. The crude product was purified by silica gel column chromatography using dichloromethane and petroleum ether in a volume ratio of 2:3. 3.3 g of compound 1c was finally obtained. Yield: 63%. Mass-to-charge ratio: 529.6 [M] + ].

[0067] Synthesis of intermediate 1d: Compound 1c (529 mg, 1 equivalent) was added to a 100 mL round-bottom flask, followed by the addition of DMF (20 mL) to dissolve it completely. Then, N-bromosuccinimide (178 mg, 1 equivalent) was added, and the mixture was reacted at room temperature for 3 h. The solution was diluted with dichloromethane (200 mL), washed with water (200 mL), and dried over Na₂SO₄ to obtain a yellow solid. The solvent was removed by rotary evaporation, and the crude product was purified by silica gel column chromatography (dichloromethane / petroleum ether 1:3) to give a yellow solid product (434 mg, 73%). Mass-to-charge ratio: 594.6 [M] + ].

[0068] Synthesis of intermediate 1f: Compound 1d (5.9 g, 1 equivalent), sodium hydroxide (4 g, 10 equivalent), 100 mL of water, and 100 mL of ethanol were added to a 500 mL two-necked flask containing a stir bar. The reaction system was stirred and heated under reflux for 2 days. After cooling to room temperature, the reaction solution was concentrated by vacuum distillation to remove most of the ethanol. The pH of the concentrated reaction solution was adjusted to strongly acidic with concentrated hydrochloric acid, at which point a product precipitated. The filtrate was then removed by vacuum filtration to obtain the crude product. The crude product was dried in an oven to finally obtain 4.7 g of compound 1f, with a yield of 82%. Compound 1f could be directly used for the next reaction without purification and identification.

[0069] Synthesis of 1 g of intermediate: Compound 1f (5.8 g, 1 equivalent) and 60 mL of dichloromethane were added to a 250 mL double-necked flask containing a stir bar. The reaction system was stirred and heated to 50 °C, then DMF (two drops, catalytic amount) and oxaloyl chloride (20.0 mL, 2.4 equivalent) were added dropwise, and the reaction was allowed to proceed for 1 h. After the reaction solution became clear, anhydrous tin tetrachloride (28.0 mL, 2.4 equivalent) was added dropwise, and the reaction was allowed to proceed for 5 h. After the reaction was complete, the reaction solution was poured into an aqueous sodium hydroxide solution, and the organic phases were extracted multiple times with dichloromethane and combined. The organic phase was subjected to vacuum distillation to remove the solvent, yielding a crude product. The crude product was purified by silica gel column chromatography using dichloromethane and petroleum ether in a 4:1 volume ratio as the eluent. The final yield was 4.1 g of compound 1 g, yield 75%, mass-to-charge ratio: 544.5 [M]. + ].

[0070] Synthesis of intermediate 1h: Under nitrogen protection, 1g (5.4g, 1 equivalent) of the compound was added to a 250mL double-necked flask containing a stir bar. 200mL of anhydrous and oxygen-free tetrahydrofuran and 80mL of a 1M tetrahydrofuran·borane complex were added sequentially. The reaction system was stirred and heated to 70℃ for 4h. After cooling to room temperature, a small amount of saturated saline solution was slowly added dropwise to carefully quench the reaction. Then, 50mL of sodium hydroxide aqueous solution was added. The organic phase was then separated using a separatory funnel. The aqueous phase was extracted with anhydrous diethyl ether, and the organic phases were combined. The organic phase was subjected to vacuum distillation to remove the solvent, yielding the crude product. The crude product was purified by silica gel column chromatography using a 1:1 volume ratio of dichloromethane and petroleum ether as eluent, ultimately yielding 3.5g of compound 1h, yielding a 68% yield and a mass-to-charge ratio of 516.6 [M]. + ].

[0071] Synthesis of Compound 3: Under nitrogen protection, 5.2 g (1 equivalent) of Compound 1h was added to a 100 mL Shrek reaction tube containing a stir bar. 30 mL of anhydrous and oxygen-free tetrahydrofuran was added. The reaction apparatus was placed in a -78 °C cryogenic reactor. 48 mL of a 2.5 M (1.2 equivalent) n-butyllithium solution was added dropwise. The reaction was maintained at -78 °C for 1 h. After adding 2.8 g (1 equivalent) of Compound 1i, the temperature was slowly raised to room temperature, and the reaction continued overnight. A small amount of methanol was then added to quench the reaction. The solvent was removed from the reaction solution by vacuum distillation to obtain an intermediate product. This intermediate product was then added to a 250 mL two-necked flask containing a stir bar. 100 mL of glacial acetic acid and 5 mL of concentrated hydrochloric acid were added sequentially. The reaction system was stirred and heated to 110 °C overnight. After cooling to room temperature, the reaction solution was poured into an appropriate amount of ice water. Another intermediate product was then obtained by vacuum filtration. The intermediate product was then added to a 250 mL two-necked flask containing a stir bar. 80 mL of dioxane, 40 mL of dichloromethane, 10 mL of water, and DDQ (3.91 g, 6 equivalents) were added sequentially. The reaction system was then gradually heated to room temperature and reacted for 2 days. The reaction mixture was separated into an organic phase using a separatory funnel. The aqueous phase was extracted with dichloromethane, and the organic phases were combined. The organic phase was subjected to vacuum distillation to remove the solvent, yielding a crude product. The crude product was purified by silica gel column chromatography using dichloromethane and petroleum ether in a 4:1 volume ratio as eluent. Finally, 3 g of compound 3 was obtained, with a yield of 38% and a mass-to-charge ratio of 729.9 [M]. + ].

[0072] Synthesis Example 2: Synthesis of Formula 10

[0073]

[0074] Synthesis of intermediate 2c: Under nitrogen protection, compound 2a (2.6 g, 1 equivalent), compound 2b (1.7 g, 1 equivalent), copper powder (0.06 g, 0.1 equivalent), cuprous iodide (0.19 g, 0.1 equivalent), heptanedione (0.18 g, 0.1 equivalent), potassium carbonate (2.1 g, 1.5 equivalent), and 50 mL of n-butyl ether were added to a 100 mL double-necked flask containing a stir bar. The reaction system was stirred and heated to 160 °C for 3 days. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with dichloromethane. The organic phases were combined. The organic phase was purified by vacuum distillation to remove the solvent, yielding a crude product. The crude product was purified by silica gel column chromatography using dichloromethane and petroleum ether in a volume ratio of 2:3. Finally, 2.2 g of compound 2c was obtained, with a yield of 72% and a mass-to-charge ratio of 303.4 [M]. + ].

[0075] Synthesis of intermediate 2d: Compound 2c (303 mg, 1 equivalent) was added to a 100 mL round-bottom flask, followed by the addition of DMF (20 mL) to dissolve it completely. Then, N-bromosuccinimide (178 mg, 1 equivalent) was added, and the mixture was reacted at room temperature for 3 h. The solution was diluted with dichloromethane (200 mL), washed with water (200 mL), and dried over Na₂SO₄ to obtain a yellow solid. The solvent was removed by rotary evaporation, and the crude product was purified by silica gel column chromatography (dichloromethane / petroleum ether 1:3) to give a yellow solid product (279 mg, 73%), mass-to-charge ratio: 382.3 [M]. + ].

[0076] Synthesis of intermediate 2e: Compound 2d (3.8 g, 1 equivalent), sodium hydroxide (4 g, 10 equivalent), 100 mL of water, and 100 mL of ethanol were added to a 500 mL two-necked flask containing a stir bar. The reaction system was stirred and heated under reflux for 2 days. After cooling to room temperature, the reaction solution was concentrated by vacuum distillation to remove most of the ethanol. The pH of the concentrated reaction solution was adjusted to strongly acidic with concentrated hydrochloric acid, at which point a product precipitated. The filtrate was then removed by vacuum filtration to obtain the crude product. The crude product was dried in an oven to finally obtain 2.6 g of compound 2e, with a yield of 70%. Compound 1f could be directly used in the next reaction without purification and identification.

[0077] Synthesis of intermediate 2f: Compound 2e (3.7 g, 1 equivalent) and 60 mL of dichloromethane were added to a 250 mL double-necked flask containing a stir bar. The reaction system was stirred and heated to 50 °C, then DMF (two drops, catalytic amount) and oxaloyl chloride (10.0 mL, 1.2 equivalent) were added dropwise, and the reaction was allowed to proceed for 1 h. After the reaction solution became clear, anhydrous tin tetrachloride (14.0 mL, 1.2 equivalent) was added dropwise, and the reaction was allowed to proceed for another 5 h. After the reaction was complete, the reaction solution was poured into an aqueous sodium hydroxide solution, and the organic phases were extracted multiple times with dichloromethane and combined. The organic phase was subjected to vacuum distillation to remove the solvent, yielding a crude product. The crude product was purified by silica gel column chromatography using dichloromethane and petroleum ether in a 4:1 volume ratio as the eluent. Finally, 2.2 g of compound 2f was obtained, with a yield of 62% and a mass-to-charge ratio of 350.2 [M]. + ].

[0078] Synthesis of intermediate 2g: Under nitrogen protection, compound 2f (3.5g, 1 equivalent) was added to a 250mL two-necked flask containing a stir bar. 200mL of anhydrous and oxygen-free tetrahydrofuran and 40mL of a 1M tetrahydrofuran·borane complex were added sequentially. The reaction system was stirred and heated to 70℃ for 4h. After cooling to room temperature, a small amount of saturated saline solution was slowly added dropwise to carefully quench the reaction. Then, 50mL of sodium hydroxide aqueous solution was added. The organic phase was then separated using a separatory funnel. The aqueous phase was extracted with anhydrous diethyl ether, and the organic phases were combined. The organic phase was subjected to vacuum distillation to remove the solvent, yielding the crude product. The crude product was purified by silica gel column chromatography using dichloromethane and petroleum ether in a 1:1 volume ratio as eluent. Finally, 2.6g of compound 2g was obtained, with a yield of 79% and a mass-to-charge ratio of 336.2 [M]. + ].

[0079] Synthesis of Compound 10: Under nitrogen protection, 2 g (3.4 g, 1 equivalent) of compound 10 was added to a 100 mL Shrek reaction tube containing a stir bar. 30 mL of anhydrous and oxygen-free tetrahydrofuran was added. The reaction apparatus was placed in a -78 °C cryogenic reactor. 48 mL of a 2.5 M (1.2 equivalent) n-butyllithium solution was added dropwise. The reaction was maintained at -78 °C for 1 h. After adding 2.8 g (1 equivalent) of compound 1i, the temperature was slowly raised to room temperature, and the reaction continued overnight. A small amount of methanol was then added to quench the reaction. The solvent was removed from the reaction solution by vacuum distillation to obtain an intermediate product. This intermediate product was then added to a 250 mL two-necked flask containing a stir bar. 100 mL of glacial acetic acid and 5 mL of concentrated hydrochloric acid were added sequentially. The reaction system was stirred and heated to 110 °C overnight. After cooling to room temperature, the reaction solution was poured into an appropriate amount of ice water. Another intermediate product was then obtained by filtration. The intermediate product was then added to a 250 mL two-necked flask containing a stir bar. 80 mL of dioxane, 40 mL of dichloromethane, 10 mL of water, and DDQ (2.4 g, 3 equivalents) were added sequentially. The reaction system was then gradually heated to room temperature and reacted for 2 days. The reaction mixture was separated into organic and aqueous phases using a separatory funnel. The aqueous phase was extracted with dichloromethane, and the organic phases were combined. The organic phase was subjected to vacuum distillation to remove the solvent, yielding the crude product. The crude product was purified by silica gel column chromatography using dichloromethane and petroleum ether in a 4:1 volume ratio as eluent. Finally, 2.2 g of compound 10 was obtained, with a yield of 42% and a mass-to-charge ratio of 535.7 [M]. + ].

[0080] Synthesis Example 3: Synthesis of Formula 47

[0081]

[0082] Synthesis of intermediate 3c: Under nitrogen protection, compound 3a (2.8 g, 1 equivalent), compound 3b (3.0 g, 1 equivalent), copper powder (0.64 g, 0.1 equivalent), cuprous iodide (0.19 g, 0.1 equivalent), heptanedione (0.18 g, 0.1 equivalent), potassium carbonate (2.1 g, 1.5 equiv), and 50 mL of n-butyl ether were added to a 100 mL double-necked flask containing a stir bar. The reaction system was stirred and heated to 160 °C for 3 days. After cooling to room temperature, the filtrate was obtained by suction filtration, and the filter cake was washed with dichloromethane. The organic phases were combined. The organic phase was subjected to vacuum distillation to remove the solvent, yielding a crude product. The crude product was purified by silica gel column chromatography using dichloromethane and petroleum ether in a volume ratio of 2:3. Finally, 1.9 g of compound 3c was obtained, with a yield of 56% and a mass-to-charge ratio of 346.4 [M]. + ].

[0083] Synthesis of intermediate 3d: Compound 3c (346 mg, 1 equivalent) was added to a 100 mL round-bottom flask, followed by the addition of DMF (20 mL) to dissolve it completely. Then, N-bromosuccinimide (178 mg, 1 equivalent) was added, and the mixture was reacted at room temperature for 3 h. The solution was diluted with dichloromethane (200 mL), washed with water (200 mL), and dried over Na₂SO₄ to obtain a yellow solid. The solvent was removed by rotary evaporation, and the crude product was purified by silica gel column chromatography (dichloromethane / petroleum ether 1:3) to obtain a yellow solid product (259 mg, 61%) with a mass-to-charge ratio of 425.3 [M]. + ].

[0084] Synthesis of intermediate 3e: Compound 3d (4.1 g, 1 equivalent), sodium hydroxide (4 g, 10 equivalent), 100 mL of water, and 100 mL of ethanol were added to a 500 mL two-necked flask containing a stir bar. The reaction system was stirred and heated under reflux for 2 days. After cooling to room temperature, the reaction solution was concentrated by vacuum distillation to remove most of the ethanol. The pH of the concentrated reaction solution was adjusted to strongly acidic with concentrated hydrochloric acid, at which point a product precipitated. The filtrate was then removed by vacuum filtration to obtain the crude product. The crude product was dried in an oven to finally obtain 3.4 g of compound 3e, with a yield of 83%. Compound 1f could be directly used in the next reaction without purification and identification.

[0085] Synthesis of intermediate 3f: Compound 3e (3.4 g, 1 equivalent) and 60 mL of dichloromethane were added to a 250 mL double-necked flask containing a stir bar. The reaction system was stirred and heated to 50 °C, then DMF (two drops, catalytic amount) and oxaloyl chloride (10.0 mL, 1.2 equivalent) were added dropwise, and the reaction was allowed to proceed for 1 h. After the reaction solution became clear, anhydrous tin tetrachloride (14.0 mL, 1.2 equivalent) was added dropwise, and the reaction was allowed to proceed for 5 h. After the reaction was complete, the reaction solution was poured into an aqueous sodium hydroxide solution, and the organic phases were extracted multiple times with dichloromethane and combined. The organic phase was subjected to vacuum distillation to remove the solvent, yielding a crude product. The crude product was purified by silica gel column chromatography using dichloromethane and petroleum ether in a 4:1 volume ratio as the eluent. Finally, 2.2 g of compound 3f was obtained, with a yield of 55% and a mass-to-charge ratio of 393.3 [M]. + ].

[0086] Synthesis of intermediate 3g: Under nitrogen protection, compound 3f (3.9g, 1 equivalent) was added to a 250mL double-necked flask containing a stir bar. 200mL of anhydrous and oxygen-free tetrahydrofuran and 40mL of a 1M tetrahydrofuran·borane complex were added sequentially. The reaction system was stirred and heated to 70℃ for 4h. After cooling to room temperature, a small amount of saturated saline solution was slowly added dropwise to carefully quench the reaction. Then, 50mL of sodium hydroxide aqueous solution was added. The organic phase was then separated using a separatory funnel. The aqueous phase was extracted with anhydrous diethyl ether, and the organic phases were combined. The organic phase was subjected to vacuum distillation to remove the solvent, yielding the crude product. The crude product was purified by silica gel column chromatography using dichloromethane and petroleum ether in a 1:1 volume ratio as eluent. Finally, 3.8g of compound 3g was obtained, with a yield of 87% and a mass-to-charge ratio of 379.3 [M]. + ].

[0087] Synthesis of Compound 47: Under nitrogen protection, 3 g (3.8 g, 1 equivalent) of compound 47 was added to a 100 mL Shrek reaction tube containing a stir bar. 30 mL of anhydrous and oxygen-free tetrahydrofuran was added. The reaction apparatus was placed in a -78 °C cryogenic reactor. 48 mL of a 2.5 M (1.2 equivalent) n-butyllithium solution was added dropwise. The reaction was maintained at -78 °C for 1 h. After adding compound 3i (4.4 g, 1 equivalent), the temperature was slowly raised to room temperature, and the reaction continued overnight. A small amount of methanol was then added to quench the reaction. The solvent was removed from the reaction solution by vacuum distillation to obtain an intermediate product. This intermediate product was then added to a 250 mL two-necked flask containing a stir bar. 100 mL of glacial acetic acid and 5 mL of concentrated hydrochloric acid were added sequentially. The reaction system was stirred and heated to 110 °C overnight. After cooling to room temperature, the reaction solution was poured into an appropriate amount of ice water. Another intermediate product was then obtained by vacuum filtration. The intermediate product was then added to a 250 mL double-necked flask containing a stir bar. 80 mL of dioxane, 40 mL of dichloromethane, 10 mL of water, and DDQ (2.4 g, 3 equivalents) were added sequentially. The reaction system was then gradually heated to room temperature and reacted for 2 days. The reaction mixture was separated into an organic phase using a separatory funnel. The aqueous phase was extracted with dichloromethane, and the organic phases were combined. The organic phase was subjected to vacuum distillation to remove the solvent, yielding a crude product. The crude product was purified by silica gel column chromatography using dichloromethane and petroleum ether in a 4:1 volume ratio as eluent. Finally, 2.3 g of compound 47 was obtained, with a yield of 32% and a mass-to-charge ratio of 733.8 [M]. + ].

[0088] The organic electronic device of this invention can be either a bottom-emitting electroluminescent device or a top-emitting electroluminescent device. A bottom-emitting electroluminescent device refers to a device structure that emits light through the anode, while a top-emitting electroluminescent device refers to a device structure that emits light through the cathode. The light-emitting layer can comprise multiple guest materials and multiple host materials. The guest material can be a fluorescent material, a phosphorescent material, and / or a thermally activated delayed fluorescence material. The host material refers to the matrix material that constitutes the majority of the components in the light-emitting layer. A host material doped with a fluorescent material is called a fluorescent host, and a host material doped with a phosphorescent material is called a phosphorescent host. It should be noted that the selection of the host material does not depend on its molecular structure, but is distinguished based on the matrix material that serves as the guest material.

[0089] In a preferred embodiment of the present invention, the compound of the present invention is used as a light-emitting guest material in the light-emitting layer of an organic electroluminescent device.

[0090] The following examples 1-3 and comparative examples 1-2 illustrate in detail the application effects of the compounds of the present invention in organic electroluminescent devices, in order to verify the technical progress and beneficial effects of the compounds of the present invention in this field.

[0091] Device Examples:

[0092] Example 1

[0093] Coated with a thickness of The ITO glass substrate was immersed in distilled water containing detergent and ultrasonically washed. After washing the ITO for 30 min, ultrasonic washing was repeated twice for 15 min each time with distilled water, followed by ultrasonic washing with isopropanol, acetone, and methanol solvents, and then drying. The substrate was then transferred to a plasma cleaner. Additionally, the substrate was cleaned with oxygen plasma for 10 min, and then transferred to a vacuum evaporator.

[0094] Next, HAT-CN with the chemical formula 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene was deposited on a transparent ITO glass substrate under thermal vacuum conditions to a thickness of [missing information]. As a hole injection layer, the compound TAPC (4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline]) was vacuum-deposited onto the hole injection layer, thereby forming a layer with a thickness of [missing information]. The hole transport layer; then, the following compound, 4,4',4”-tris(carbazole-9-yl)triphenylamine (TCTA), is used as an electron blocking material. Vacuum deposition is performed on the hole transport layer to form an electron blocking layer; subsequently, formula 1 and 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) are vacuum deposited on the electron blocking layer at a weight ratio of 1:99, with a thickness of [missing information]. This forms an organic light-emitting layer; subsequently, 1,3,5-tris[(3-pyridyl)-3-phenyl]benzene (TmPyPB) is vacuum-deposited onto the organic light-emitting layer to a thickness of [missing information]. This forms an electron transport layer; finally, the compound lithium 8-hydroxyquinoline (Liq) is formed. and aluminum They are sequentially deposited on the electron transport layer as the electron injection layer and the negative electrode.

[0095] Example 2

[0096] The only difference between Example 2 and Example 1 is that the weight ratio of Formula 1 and 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) in the organic light-emitting layer is 3:97.

[0097] Example 3

[0098] The only difference between Example 3 and Example 1 is that the weight ratio of Formula 1 and 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) in the organic light-emitting layer is 5:95.

[0099] Example 4

[0100] The only difference between Example 4 and Example 1 is that the weight ratio of Formula 1 and 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) in the organic light-emitting layer is 10:90.

[0101] Example 5

[0102] The only difference between Example 5 and Example 1 is that the weight ratio of Formula 3 and 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) in the organic light-emitting layer is 1:99.

[0103] Example 6

[0104] The only difference between Example 6 and Example 1 is that the weight ratio of Formula 3 and 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) in the organic light-emitting layer is 3:97.

[0105] Example 7

[0106] The only difference between Example 7 and Example 1 is that the weight ratio of Formula 3 and 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) in the organic light-emitting layer is 5:95.

[0107] Example 8

[0108] The only difference between Example 8 and Example 1 is that the weight ratio of Formula 3 and 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) in the organic light-emitting layer is 10:90.

[0109] Example 9

[0110] The only difference between Example 9 and Example 1 is that the weight ratio of Formula 10 and 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) in the organic light-emitting layer is 1:99.

[0111] Example 10

[0112] The only difference between Example 10 and Example 1 is that the weight ratio of Formula 10 and 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) in the organic light-emitting layer is 3:97.

[0113] Example 11

[0114] The only difference between Example 11 and Example 1 is that the weight ratio of Formula 10 and 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) in the organic light-emitting layer is 5:95.

[0115] Example 12

[0116] The only difference between Example 12 and Example 1 is that the weight ratio of Formula 10 and 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) in the organic light-emitting layer is 10:90.

[0117] Comparative Example 1

[0118] The only difference between Comparative Example 1 and Example 1 is that Formula 1 in the organic light-emitting layer is replaced with R1.

[0119] Comparative Example 2

[0120] The only difference between Comparative Example 2 and Example 1 is that Formula 1 is replaced with R1 in the organic light-emitting layer, and the weight ratio of Formula 1 to 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) is 3:97.

[0121] Comparative Example 3

[0122] The only difference between Comparative Example 3 and Example 1 is that Formula 1 is replaced with R1 in the organic light-emitting layer, and the weight ratio of Formula 1 to 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) is 5:95.

[0123] Comparative Example 4

[0124] The only difference between Comparative Example 4 and Example 1 is that Formula 1 is replaced with R1 in the organic light-emitting layer, and the weight ratio of Formula 1 to 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) is 10:90.

[0125] Comparative Example 5

[0126] The only difference between Comparative Example 5 and Example 1 is that Formula 1 is replaced with R2 in the organic light-emitting layer, and the weight ratio of Formula 1 to 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) is 1:99.

[0127] Comparative Example 6

[0128] The only difference between Comparative Example 6 and Example 1 is that Formula 1 is replaced with R2 in the organic light-emitting layer, and the weight ratio of Formula 1 to 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) is 3:97.

[0129] Comparative Example 7

[0130] The only difference between Comparative Example 7 and Example 1 is that Formula 1 is replaced with R2 in the organic light-emitting layer, and the weight ratio of Formula 1 to 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) is 5:95.

[0131] Comparative Example 8

[0132] The only difference between Comparative Example 8 and Example 1 is that Formula 1 is replaced with R2 in the organic light-emitting layer, and the weight ratio of Formula 1 to 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP) is 10:90.

[0133] The functional layer compound structures and names involved in the device embodiments are as follows:

[0134]

[0135] The structures and numbering of the carbonyl nitrogen spirocyclic compounds involved in the device embodiments are as follows:

[0136]

[0137] The photoelectric properties of the organic electroluminescent devices prepared in Examples 1-12 and Comparative Examples 1-8 were tested, and the performance data are shown in Table 1.

[0138] Table 1. Device Performance Data

[0139]

[0140]

[0141] The comparative analysis of the data in the table above shows that the organic electroluminescent devices prepared using the compounds of this invention (Formulas 1, 3, and 10) in Examples 1-12 exhibit a narrower full width at half maximum (FWHM) and a significantly improved external quantum efficiency compared to the organic electroluminescent devices prepared using the conventional planar spiro-ring structures (R1-R2) of spirofluorene. Furthermore, under high doping concentration conditions, the spectral broadening phenomenon of the organic electroluminescent devices in Examples 1-12 is effectively suppressed, with the FWHM increasing by only about 5 nm, while the organic electroluminescent devices prepared in Comparative Examples 1-8 show a significant spectral broadening (about 15 nm). These results indicate that the compounds of this invention can effectively suppress the molecular aggregation effect under high doping concentrations, thereby significantly improving the color purity of the luminescent material and enhancing the photoelectric conversion efficiency of the device. This provides an innovative solution to the common efficiency-color purity trade-off problem in organic electroluminescent devices.

[0142] In summary, the spirocyclic narrow-band compounds of this invention, by introducing a non-planar indene-filled spirocyclic structure, possess excellent photoelectric properties and exhibit characteristics of multiple resonance-thermally activated delayed fluorescence materials. The organic electroluminescent devices prepared from these compounds maintain a narrow full width at half maximum (FWHM), resulting in superior performance. Furthermore, the preparation method of the spirocyclic narrow-band nitrogen carbonyl compounds of this invention is simple, and the raw materials are readily available, meeting the needs of industrial development.

[0143] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0144] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A carbonyl nitrogen spirocycle compound, characterized by, The carbonyl nitrogen spiro compound has a structure as shown in formula (1) or formula (2): wherein, Ar1-Ar2 are the same or different, Ar1 is independently a benzene ring or a pyridine ring at each occurrence; Ar2 is independently a benzene ring at each occurrence; Ar1-Ar2 has groups R1, R2, R3 and R4 on the ring; R1, R2, R3 and R4 are the same or different at each occurrence; R1 is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, cyano, NO2, N(M)2, OM, SM, C(=O)M, P(=O)M, Si(M)3, C1-C20 alkyl, C1-C20 alkyl substituted by at least one M, C1-C20 alkoxy, C1-C20 alkoxy substituted by at least one M, C3-C10 cycloalkyl, C3-C10 cycloalkyl substituted by at least one M, C2-C20 alkenyl, C2-C20 alkenyl substituted by at least one M, C2-C20 alkynyl, C2-C20 alkynyl substituted by at least one M, C6-C24 aryl, C6-C24 aryl substituted by at least one M, C5-C30 heteroaryl, C5-C30 heteroaryl substituted by at least one M, at each occurrence of M; R2 is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, cyano, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C24 aryl, C5-C30 heteroaryl, at each occurrence; R3 is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, cyano, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C24 aryl, C5-C30 heteroaryl, at each occurrence. R4 is independently hydrogen, deuterium, fluorine, chlorine, bromine, iodine, cyano, thiophene, selenophene, C1-C20 alkyl, C1-C20 alkoxy, C3-C10 cycloalkyl, C2-C20 alkenyl, C2-C20 alkynyl, C6-C24 aryl, C5-C30 heteroaryl, at each occurrence.

2. The carbonyl nitrogen spirocycle of claim 1, wherein, The carbonyl nitrogen spiro compound includes any one of the following structures:

3. An organic electroluminescent device comprising an anode, a cathode and at least one organic thin film between the anode and the cathode, characterized in that The organic thin film is the carbonyl nitrogen spiro compound according to any one of claims 1-2.

4. The organic electroluminescent device according to claim 3, characterized in that The organic electroluminescent device includes, from bottom to top, an anode layer, a hole injection layer, a hole transport layer, an electron blocking layer, an organic light-emitting layer, an electron transport layer and a cathode layer, and the material of at least one of the hole injection layer, the hole transport layer, the electron blocking layer, the organic light-emitting layer and the electron transport layer is the organic thin film.

5. The organic electroluminescent device according to claim 4, characterized in that When the organic light-emitting layer is the organic thin film, the mass concentration of the carbonyl nitrogen spiro compound in the organic light-emitting layer is any value in the range of 1wt%-30wt%.

6. A display, characterized by The organic electroluminescent device according to any one of claims 3-5.

7. A display screen, characterized by The organic electroluminescent device according to any one of claims 3-5.

8. An electronic device, comprising: including a housing assembly and a display screen as claimed in claim 7, said display screen being located inside said housing assembly.

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