Spiroimidazole compound for organic electroluminescent device

Abstract

The invention discloses a spiroimidazole compound for an organic electroluminescent device, and belongs to the technical field of organic electroluminescent materials. According to the compound, a spiro derivative is used as a parent nucleus, and the spiro imidazole compound obtained by introducing a group for modification has relatively excellent front line orbital energy level and triplet state energy. The red light host material is applied to an organic electroluminescent device, can significantly improve the performance of the luminescent device, improves the luminous efficiency of the device, and prolongs the service life of the device. Compared with an existing OLED device, the luminous efficiency of the OLED device of which the luminous layer takes the spiroimidazole compound as a red light host material is improved by 15.2-41.6%, and the service life of the device is prolonged by 15.3-56.2%.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescent materials and relates to a spiroimidazole compound used for an organic electroluminescent device. Background Art

[0002] Organic electroluminescent device (OLED) is a current-type organic light-emitting device with the advantages of high efficiency, low power consumption, high contrast, thinness, and flexibility. It is widely used in the fields of display and lighting. Under the action of an external electric field, the physical process inside the device is as follows: holes are injected from the anode into the organic layer, and electrons are injected from the cathode into the organic layer. When these injected holes and electrons meet in the light-emitting layer, they combine to form excitons. When the excitons re-transition to the ground state, energy is released, and this energy is emitted in the form of light, thereby achieving a luminous effect.

[0003] Exciton quenching refers to the phenomenon that excitons lose energy prematurely during the luminescence process due to various reasons (such as interaction with impurities, defects or other excitons), resulting in reduced luminescence efficiency. In order to further improve the photoelectric properties of OLED devices such as efficiency, brightness and service life, the existing technology usually dopes the luminescent material into a specific host material to reduce the exciton quenching effect and optimize the luminescence performance of the device. Since the increase in the concentration of the luminescent material will lead to an increase in the probability of non-radiative transitions, which in turn leads to a decrease in luminescence efficiency, doping the luminescent material into the host material can disperse the excitons, optimize molecular stacking, and enhance reverse intersystem crossing, thereby reducing the exciton quenching effect and improving the photoelectric performance of the device.

[0004] For phosphorescent devices, the host material not only needs to have good carrier transport properties to ensure that holes and electrons can be efficiently injected into the light-emitting layer, but also needs to have high triplet energy to avoid exciton energy backtransfer. However, how to develop high-quality host materials that meet the above requirements and have good stability has always been a difficult and hot issue in the field of OLED technology. At present, although some host materials have been developed and applied to OLED devices, they still have certain limitations in performance and cannot meet the growing demand for higher quality OLED devices. Therefore, developing a high-performance host material is crucial to obtaining high-quality OLED devices. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a spiroimidazole compound for an organic electroluminescent device. The compound uses a spiro derivative as a parent core, and the spiroimidazole compound obtained by group modification has a relatively good frontier orbital energy level and triplet energy. It is used as a red light host material in an organic electroluminescent device, and plays a key role in improving the device's luminous efficiency, service life and other performance.

[0006] To achieve the technical purpose of the present invention, on the one hand, the present invention provides a spiroimidazole compound having a structure as shown in formula (I), ; X in the formula (I) is one of CR3R4, NR5, O, S, and Se; R1 and R2 in the formula (I) are independently selected from one of hydrogen, deuterium, cyano, substituted or unsubstituted amino derivatives, C6-C30 aryl, and heteroaryl; L1 and L2 in the formula (I) are independently selected from a single bond, an aryl group, and a heteroaryl group; Ar1 and Ar2 in the formula (I) are independently selected from hydrogen, an amino derivative, a substituted or unsubstituted C6-C30 aryl group, and a heteroaryl group.

[0007] Furthermore, R3 and R4 in the CR3R4 are independently selected from one of a methyl group and a phenyl group; and R5 in the NR5 is one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted heteroaryl group.

[0008] Furthermore, the heteroaryl group contains at least one heteroatom, and the heteroatom in the heteroaryl group is selected from N, O, and S atoms; the heteroaryl group includes carbazolyl, furyl, acridinyl, fluorenyl, thienyl, triazine, pyrimidine, pyrazinyl, phenazine, pyridyl, benzimidazolyl, and phenanthroline.

[0009] Further, when R1 and R2 are C6-C30 aryl groups, they are selected from any one of phenyl, biphenyl and naphthyl. When Ar1 and Ar2 are substituted or unsubstituted C6-C30 aryl groups, they are selected from any one of phenyl, biphenyl, naphthyl, phenanthrenyl and triphenylenyl.

[0010] Preferably, any of the above substituted or unsubstituted groups is as follows:

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[0021] Furthermore, the spiroimidazole compounds provided by the present invention have structures as shown in A1 to A5, .

[0022] Specifically, A1 to A5 have the following structures:

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[0067] .

[0068] On the other hand, the present invention claims protection for the use of the above-mentioned spiroimidazole compounds in organic electroluminescent devices, wherein the compounds are used as red light host materials in the light-emitting layer of the organic electroluminescent device.

[0069] Furthermore, the spiroimidazole compounds of the present invention have better frontier orbital energy levels and triplet energy, and are used as the main material of the light-emitting layer in red organic electroluminescent devices, which have a better effect of improving the efficiency and life of the devices.

[0070] Specifically, the present invention applies the prepared spiroimidazole compounds as red light host materials to OLED devices, which have better performance than existing OLED devices, with luminous efficiency increased by 15.2-41.6%, and device life extended by 15.3-56.2%.

[0071] On the other hand, the present invention claims protection for an organic electroluminescent device comprising a light-emitting layer, wherein the main material of the light-emitting layer comprises the above-mentioned spiroimidazole compound.

[0072] Furthermore, the present invention seeks to protect a display component comprising the above-mentioned organic electroluminescent device.

[0073] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages: (1) The compound prepared by the present invention is based on spiroimidazole as the core, and after introducing specific groups for modification, a compound with high mobility and high thermal stability is obtained. The present invention makes full use of the polarity of heteroatoms in spiroimidazole and the molecular distortion of the compound to improve the carrier mobility of the compound and the triplet energy of the material and the glass transition temperature. On this basis, it is further modified with typical electron-donating groups such as amino, carbazole, acridinium or typical electron-withdrawing groups such as triazine and pyrimidine to optimize the frontier orbital energy level and triplet energy of the compound, thereby meeting the application of red light main material and achieving high efficiency and long life of the device. The present invention simulates and calculates the physicochemical properties of spiroimidazole compounds and finds that the compound has relatively suitable HOMO, LUMO, and T1 values, and is suitable for use as a red light main material. When applied to OLED devices, it can effectively improve the luminous efficiency and service life of the device.

[0074] (2) The spiroimidazole compounds prepared by the present invention can be applied to organic electroluminescent devices as the main material of the light-emitting layer, which significantly improves the efficiency, life and other properties of the organic electroluminescent devices. The present invention applies the prepared spiroimidazole compounds as the main material of red light to OLED devices, which has better performance than the existing OLED devices, with the luminous efficiency increased by 15.2~41.6%, and the device life extended by 15.3~56.2%. Compared with the comparative example, the luminous efficiency and service life of the device are significantly improved by using the partially deuterated compound 171 as the first main material of red light, the luminous efficiency is increased by 41.6%, and the device life is increased by 53.8%; compared with the comparative example, the luminous efficiency of the device is increased by 28.9% and the device life is increased by 55.3% by using the compound 79 as the second main material of red light; using the partially deuterated compound 179 and the partially deuterated compound 164 as the first main material of red light and the second main material of red light, respectively, compared with the comparative example, the luminous efficiency of the device is increased by 39.3%, and the device life is increased by 56.2%. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention.

[0076] Figure 1 Schematic diagram of the structure of an organic electroluminescent device, wherein 1 is a substrate, 2 is an anode layer, 3 is a hole injection layer, 4 is a first hole transport layer, 5 is a second hole transport layer, 6 is a light-emitting layer, 7 is a hole blocking layer, 8 is an electron transport layer, 9 is an electron injection layer, and 10 is a cathode layer. DETAILED DESCRIPTION

[0077] The technical scheme of the present invention is described below in conjunction with the embodiments, but the present invention is not limited to the following embodiments. The experimental methods and detection methods described in each embodiment are conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.

[0078] Example 1 This example provides the synthesis of compound 6 (X is O, R1 and R2 are both H, L1 and L2 are both phenyl, Ar1 and Ar2 are both N-containing heteroaryl (carbazolyl)). The synthesis route is shown below, which specifically includes the following steps: ; S1: Under nitrogen protection, raw material A (50.10 g, 136.9 mmol), raw material 1 (26.89 g, 137.0 mmol), ammonium acetate (26.37 g, 342.5 mmol) and glacial acetic acid (200 mL) were added to the reaction bottle, and the mixture was heated to reflux (110 ° C) for 5 h. After cooling to room temperature, the reaction solution was poured into cold water to produce a yellow precipitate, which was filtered. The filter cake was washed with water until neutral, and then washed with ethanol. After drying, the intermediate 6 (55.65 g, yield 75%) was obtained.

[0079] S2: Under nitrogen protection, add intermediate 6 (30.00 g, 55.4 mmol), raw material 2 (20.32 g, 121.8 mmol), sodium tert-butoxide (13.31 g, 138.5 mmol) and DMF (500 mL) to the reaction bottle, then add Pd2(dba)3 (0.51 g, 0.55 mmol) and X-Phos (0.52 g, 1.11 mmol) and heat to 106 ° C for 4 h. After the reaction is completed, cool to room temperature, pour into water to form a white precipitate, and filter. Wash the precipitate with water and ethanol in turn. Finally, pass through a silica gel column and recrystallize to obtain compound 6 (27.77 g, yield 70%).

[0080] The characterization results of compound 6 are as follows: HRMS: measured value: 717.2636 [M+H] + ; Exact mass: 717.2649. C 51 H 32 ON4 (%) calculated value: C, 85.45%; H, 4.50%; N, 7.82%; measured value: C, 85.38%; H, 4.50%; N, 7.82%.

[0081] Example 2 This example provides the synthesis of compound 10 (X is CR3R4, R3 and R4 are both methyl groups, R1 and R2 are both H, L1 and L2 are both phenyl groups, Ar1 and Ar2 are both N-containing heteroaryl groups (carbazolyl groups)). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 6, except that: in S1, raw material 1 is replaced by raw material 3, and compound 10 (28.36 g, yield 77%) is synthesized.

[0082] ; The characterization results of compound 10 are as follows: HRMS: measured value: 743.3158 [M+H] + ; Exact mass: 743.3169. C 54 H 38 N4 (%) calculated value: C, 87.30%; H, 5.16%; N, 7.54%; measured value: C, 87.21%; H, 5.08%; N, 7.48%.

[0083] Example 3 This example provides the synthesis of compound 24 (X is NR5, R5 is phenyl, R1 and R2 are both H, L1 and L2 are both phenyl, Ar1 and Ar2 are both N-containing heteroaryl (triazine substituted by phenyl at the 3 and 5 positions)). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 6, except that: in S1, raw material 1 is replaced by raw material 4, and intermediate 24 (59.39 g, yield 72%) is synthesized.

[0084] S2: Under nitrogen protection, add intermediate 24 (35.00 g, 56.5 mmol), raw material 5 (60.90 g, 169.5 mmol), potassium carbonate (23.40 g, 170.0 mmol), water (100 mL) and THF (500 mL) to the reaction bottle, then add Pd-132 (0.20 g, 0.55 mmol), heat to 60 ° C and react for 6 h. After the reaction is completed, cool to room temperature, pour into water to form a white precipitate, filter. Wash the precipitate with water and ethanol in turn. Finally, pass through a silica gel column and recrystallize to obtain compound 24 (40.36 g, yield 78%).

[0085] ; The characterization results of compound 24 are as follows: HRMS: measured value: 924.3548 [M+H] + ; Exact mass: 924.3558. C 63 H 41 N9 (%) calculated value: C, 81.89%; H, 4.47%; N, 13.64%; measured value: C, 81.76%; H, 4.38%; N, 13.54%.

[0086] Example 4 This example provides the synthesis of compound 51 (X is S, R1 and R2 are both H, L1 and L2 are both phenyl groups, Ar1 and Ar2 are both N-containing heteroaryl groups (carbazolyl groups substituted by phenyl groups)). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 24, except that raw material 4 is replaced by raw material 6 in S1, and raw material 5 is replaced by raw material 7 in S2, and compound 51 (59.39 g, yield 72%) is obtained by synthesis.

[0087] ; The characterization results of compound 51 are as follows: HRMS: measured value: 885.3034 [M+H] + ; Exact mass: 885.3046. C 63 H 40 N4S (%) calculated value: C, 85.49%; H, 4.56%; N, 6.33%; measured value: C, 85.40%; H, 4.57%; N, 6.25%.

[0088] Example 5 This example provides the synthesis of compound 106 (X is O, R1 and R2 are both deuterated heteroaryl (carbazole-D8 group), L1 and L2 are both phenyl groups, Ar1 and Ar2 are both hydrogen). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 6, except that: in S1, raw material A is replaced by raw material B, and raw material 1 is replaced by raw material 8; in S2, raw material 2 is replaced by raw material 9, and compound 106 (25.36 g, yield is 70%) is synthesized.

[0089] ; The characterization results of compound 106 are as follows: HRMS: measured value: 733.3647 [M+H] + ; Exact mass: 733.3653. C 51 H 16 D 16 N4O (%) calculated value: C, 83.58%; H, 6.60%; N, 7.64%; measured value: C, 83.50%; H, 6.51%; N, 7.55%.

[0090] Example 6 This example provides the synthesis of compound 110 (X is CR3R4, R3 and R4 are both methyl groups, R1 and R2 are both deuterated heteroaryl groups (carbazole-D8 groups), L1 and L2 are both phenyl groups, and Ar1 and Ar2 are both hydrogen). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 106, except that in S1, raw material 8 is replaced by raw material 10, and compound 110 (26.23 g, yield is 74%) is synthesized.

[0091] ; The characterization results of compound 110 are as follows: HRMS: measured value: 759.4162 [M+H] + ; Exact mass: 759.4174. C 54 H 22 D 16 N4 (%) calculated value: C, 85.45%; H, 7.17%; N, 7.38%; measured value: C, 85.38%; H, 7.10%; N, 7.26%.

[0092] Example 7 This example provides the synthesis of compound 144 (X is NR5, R5 is a phenyl group with 6 hydrogen atoms deuterated, R1 and R2 are both heteroaryl groups (triazine groups substituted with phenyl groups at the 3 and 5 positions), L1 and L2 are both phenyl groups, and Ar1 and Ar2 are both hydrogen). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 24, except that in S1, raw material A is replaced by raw material B, and raw material 4 is replaced by raw material 11, to obtain compound 144 (59.39 g, yield is 72%).

[0093] ; The characterization results of compound 144 are as follows: HRMS: measured value: 929.3864 [M+H] + ; Exact mass: 929.3872. C 63 H 36 D5N9 (%) calculated value: C, 81.44%; H, 4.99%; N, 13.57%; measured value: C, 81.38%; H, 4.79%; N, 13.46%.

[0094] Example 8 This example provides the synthesis of compound 171 (X is NR5, R5 is a C18 heteroaryl group, R1 and R2 are both hydrogen, L1 and L2 are both phenyl groups, and Ar1 and Ar2 are both hydrogen). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 110, except that in S1, raw material 10 is replaced by raw material 12 to obtain compound 171 (21.52 g, yield 79%).

[0095] ; The characterization results of compound 171 are as follows: HRMS: measured value: 635.3036 [M+H] + ; Exact mass: 635.3045. C 45 H 22 D8N4 (%) calculated value: C, 85.14%; H, 6.03%; N, 8.83%; measured value: C, 85.05%; H, 5.92%; N, 8.71%.

[0096] Example 9 This example provides the synthesis of compound 186 (X is NR5, R5 is a C18 heteroaryl group, R1 and R2 are both hydrogen, L1 and L2 are both heteroaryl groups (pyridine), and Ar1 and Ar2 are both hydrogen). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 6, except that in S1, raw material A is replaced by raw material C, and raw material 1 is replaced by raw material 12. In S2, raw material 2 is replaced by raw material 9, and compound 186 (25.36 g, yield is 70%) is obtained by synthesis.

[0097] ; The characterization results of compound 186 are as follows: HRMS: measured value: 637.2576 [M+H] + ; Exact mass: 637.2590. C 43 H 20 D8N6 (%) calculated value: C, 81.11%; H, 5.70%; N, 13.20%; measured value: C, 81.02%; H, 5.58%; N, 13.09%.

[0098] Example 10 This example provides the synthesis of compound 191 (X is CR3R4, R3 and R4 are both methyl, R1 and R2 are both deuterated heteroaryl (carbazole-D8 group), L1 and L2 are both heteroaryl (pyridine), Ar1 and Ar2 are both hydrogen). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 186, except that: in S1, raw material 12 is replaced by raw material 10, and compound 191 (29.35 g, yield is 74%) is synthesized.

[0099] ; The characterization results of compound 191 are as follows: HRMS: measured value: 743.3158 [M+H] + ; Exact mass: 743.3169. C 52 H 20 D 16N6 (%) calculated value: C, 82.11%; H, 4.29%; N, 8.42%; measured value: C, 82.02%; H, 4.20%; N, 8.38%.

[0100] Embodiment 11 This example provides the synthesis of compound 194 (X is NR5, R5 is a phenyl group in which 6 hydrogen atoms are deuterated, R1 and R2 are both heteroaryl groups (carbazolyl), L1 and L2 are both heteroaryl groups (pyridine), and Ar1 and Ar2 are both hydrogen). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 186, except that raw material 12 is replaced by raw material 11 in S1, and raw material 9 is replaced by raw material 2 in S2, and compound 194 (27.58 g, yield 70%) is obtained by synthesis.

[0101] ; The characterization results of compound 194 are as follows: HRMS: measured value: 799.3334 [M+H] + ; Exact mass: 799.3341. C 55 H 30 D5N7 (%) calculated value: C, 82.68%; H, 4.95%; N, 12.27%; measured value: C, 82.52%; H, 4.83%; N, 12.05%.

[0102] Example 12 This example provides the synthesis of compound 208 (X is NR5, R5 is a heteroaryl group (triazine group substituted by phenyl at the 3,5 positions), R1 and R2 are both hydrogen, L1 and L2 are both heteroaryl groups (pyridine), and Ar1 and Ar2 are both hydrogen). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 186, except that: in S1, raw material 12 is replaced by raw material 13, and intermediate 208 (56.31 g, yield 72%) is synthesized.

[0103] S2: Under nitrogen protection, intermediate 208 (35.00 g, 90.3 mmol), raw material 14 (31.47 g, 117.6 mmol), potassium carbonate (18.72 g, 135.6 mmol) and DMF (300 mL) were added to the reaction bottle, and then heated to 150 ° C for 8 h. After the reaction, it was cooled to room temperature and poured into water to form a white precipitate, which was filtered. The precipitate was washed with water and ethanol in turn. Finally, it was passed through a silica gel column and recrystallized to obtain compound 208 (39.10 g, yield 70%).

[0104] ; The characterization results of compound 208 are as follows: HRMS: measured value: 618.7158 [M+H] +; Calculated value: 618.8360. C 40 H 26 N8 (%) calculated value: C, 77.65%; H, 4.24%; N, 18.11%; measured value: C, 77.56%; H, 4.16%; N, 18.03%.

[0105] Example 13 This example provides the synthesis of compound 236 (X is O, R1 is carbazole, R2 is phenyl, L1 and L2 are both phenyl, Ar1 and Ar2 are both hydrogen). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 144 and compound 171, except that: in S1, raw material 12 is replaced by raw material 15, and in S2, raw material 9 is replaced by raw material 2, and intermediate 236-2 (50.25 g, yield 70%) is obtained.

[0106] S3: Under nitrogen protection, add intermediate 236-2 (33.05 g, 56.5 mmol), raw material 16 (7.50 g, 62.15 mmol), potassium carbonate (11.69 g, 84.72 mmol), water (10 mL) and THF (30 mL) to the reaction bottle, then add Pd-132 (0.05 g, 0.55 mmol), heat to 60 ° C and react for 6 h. After the reaction is completed, cool to room temperature, pour into water to form a white precipitate, and filter. Wash the precipitate with water and ethanol in turn. Finally, pass through a silica gel column and recrystallize to obtain compound 236 (43.56 g, yield 74%).

[0107] ; The characterization results of compound 236 are as follows: HRMS: measured value: 628.2374 [M+H]+; accurate mass: 628.2383. 45 H 29 ON3(%) calculated value: C, 86.10%; H, 4.66%, N, 6.69%; measured value: C, 86.02%; H, 4.58%, N, 6.60%.

[0108] Embodiment 14 This example provides a synthesis of compound 254 (X is NR5, R5 is phenyl, R1 and R2 are both hydrogen, Ar1 is carbazole, Ar2 is phenyl, L1 and L2 are both phenyl). The synthesis route is shown below. The synthesis method refers to the synthesis of compound 236, except that: in S1, raw material 15 is replaced by raw material 4 to obtain compound 254 (26.53 g, yield 69%).

[0109] ; The characterization results of compound 254 are: HRMS: m / z: 702.8642 [M+H] + ; C 51 H 34 N4 (%) calculated value: C, 87.15%; H, 4.88%; N, 7.97%; measured value: C, 87.21%; H, 4.63%; N, 7.89%.

[0110] Embodiment 15 This example performs simulation calculations on the physicochemical properties of the compound.

[0111] The HOMO, LUMO and triplet energy of compound 4, compound 6, compound 9, compound 10, compound 19, compound 21, compound 24, compound 29, compound 34, compound 39, compound 43, compound 51, compound 54, compound 67, compound 74, compound 75, compound 79, compound 81, compound 101, compound 104, compound 106, compound 110, compound 115, compound 144, compound 154, compound 165, compound 171, compound 179, compound 186, compound 191, compound 194, compound 208, compound 236, compound 254 and the existing red light emitting layer host materials RH1 and RH2 (the structural formula is shown below) were simulated and calculated. HOMO and LUMO are the data obtained by simulation calculation, and the calculation method adopts B3LYP hybrid functional, basis set 6-31g (d, P), and the results are shown in Table 1.

[0112] .

[0113] Table 1 T1 energy level and HOMO, LUMO simulation calculation results of the compounds

[0114] As shown in Table 1, the compound with spiroimidazole as the core prepared in the present invention has relatively suitable HOMO, LUMO and T1 values, and is suitable for use as a red light host material. When applied to OLED devices, it can effectively improve the luminous efficiency and service life of the device.

[0115] Embodiment 14 This embodiment provides an application of the compound as a red light host material in an organic electroluminescent device.

[0116] The structure of organic electroluminescent devices is as follows Figure 1As shown, it includes a substrate 1, an anode layer 2, a hole injection layer 3, a first hole transport layer 4, a second hole transport layer 5, a light emitting layer 6, a hole blocking layer 7, an electron transport layer 8, an electron injection layer 9 and a cathode layer 10 which are stacked in sequence.

[0117] In the comparative example, the material of the anode layer 2 of the organic electroluminescent device is indium tin oxide (ITO) with a high work function; the material of the hole injection layer 3 is HAT-CN with a thickness of 5 nm; the material of the first hole transport layer 4 is HT1 doped with HAT-CN, the mass percentage of HT1 and HAT-CN is 95%:5%, and the thickness is 60 nm; the material of the second hole transport layer 5 is HT2 with a thickness of 15 nm; the light-emitting layer 6 uses the first main material RH1 doped with the second main material RH2 as a mixed main material, the mass percentage of RH1 and RH2 is 47.5%:47.5%, RD01 is used as the light-emitting material, the doping mass percentage is 5%, and the thickness of the light-emitting layer 6 is 30 nm; the material of the hole blocking layer 7 is HB with a thickness of 10 nm; the electron transport layer 8 is composed of ET-1 doped with Liq, the mass percentage of ET-1 and Liq is 50%:50%, and the thickness is 30 nm; the material of the electron injection layer 9 is Liq with a thickness of 2 nm; the material of the cathode layer is Al with a thickness of 100 nm.

[0118] The structural formula of the material used in each functional layer of the organic electroluminescent device of the comparative example is as follows: .

[0119] The preparation of the comparative example organic electroluminescent device comprises the following steps: 1) Clean the ITO anode on the transparent glass or plastic substrate, and ultrasonically clean it with deionized water, acetone, and ethanol for 20 minutes respectively, and then perform plasma treatment in an oxygen atmosphere for 5 minutes; 2) Vacuum evaporation is used to deposit a hole injection layer on the ITO anode layer; 3) Vacuum co-evaporation is used to deposit a first hole transport layer HT1:HAT-CN on the hole injection layer; 4) Vacuum evaporation is used to deposit a second hole transport layer on the first hole transport layer HT1:HAT-CN; 5) Vacuum evaporation is used to co-evaporate a light-emitting layer on the second hole transport layer; 6) Vacuum evaporation is used to deposit a hole blocking layer on the light-emitting layer; 7) Vacuum co-evaporation is used to deposit an electron transport material layer ET-1:Liq on the hole blocking layer; 8) Vacuum evaporation is used to deposit an electron injection layer on the electron transport layer; 9) Vacuum evaporation is used to deposit cathode Al on the electron injection layer.

[0120] The implementation process of device 1 to device 20 is the same as that of the comparative example, except that the first main material of the light-emitting layer is replaced by the compound with spiroimidazole as the core prepared by the present invention instead of RH1. The implementation process of device 21 to device 32 is the same as that of the comparative example, except that the second main material of the light-emitting layer is replaced by the compound with spiroimidazole as the core prepared by the present invention instead of RH2. The implementation process of device 33 to device 36 is the same as that of the comparative example, except that the first main material and the second main material of the light-emitting layer are replaced by the compound with spiroimidazole as the core prepared by the present invention instead of RH1 and RH2 respectively. The light-emitting layer composition of device 1 to device 36 is shown in Table 2.

[0121] Devices 1 to 37 and the comparative organic electroluminescent devices were connected to the cathode and anode using a known driving circuit, and the voltage-efficiency-current density relationship of the OLED devices was tested by a standard method using a Keithley 2400 power supply combined with a PR670 photometer; the life of the red light device was tested by a constant current method under the condition of applying 20 mA / cm 2 Under constant current density, the initial brightness of the device is 100%. The time required for the brightness to decay to 95% of the initial brightness is the LT95 life of the device. The test results are shown in Table 2, and the test data are relative values.

[0122] Table 2 Performance parameters of organic electroluminescent devices

[0123] As shown in Table 2, the compounds prepared by the present invention are applied as red light host materials to OLED devices, which have better performance than existing OLED devices, with luminous efficiency increased by 15.2~41.6%, and device life extended by 15.3~56.2%. For example, in device 16, compared with the comparative example, the luminous efficiency and service life of the partially deuterated compound 171 as the first red light host material are significantly improved, with the luminous efficiency increased by 41.6% and the device life increased by 53.8%; in device 28, compared with the comparative example, the luminous efficiency of the device is increased by 28.9% and the device life is increased by 55.3% using compound 79 as the second red light host material; using partially deuterated compound 179 and partially deuterated compound 164 as the first red light host material and the second red light host material, respectively, compared with the comparative example, the luminous efficiency is increased by 39.3% and the device life is increased by 56.2%. It can be seen that the application of the compound with spiroimidazole as the core of the present invention as the main material of the red light emitting layer in OLED light emitting devices has greatly improved the luminous efficiency and life performance compared with the existing material devices. It has great application value in the application of OLED devices and has good industrialization prospects.

[0124] The embodiments described above are part of the embodiments of the present invention, rather than all of the embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. All other embodiments obtained without creative work and related deductions and substitutions made by ordinary technicians in the field under the conditions of the concept of the present invention belong to the scope of protection of the present invention.

Claims

1. A compound, characterized in that Having a structure as shown in formula (I), ； X in the formula (I) is one of CR3R4, NR5, O, S, and Se; R1 and R2 in the formula (I) are independently selected from one of hydrogen, deuterium, cyano, substituted or unsubstituted amino derivatives, C6-C30 aryl, and heteroaryl; L1 and L2 in the formula (I) are independently selected from a single bond, an aryl group, and a heteroaryl group; Ar1 and Ar2 in the formula (I) are independently selected from hydrogen, an amino derivative, a substituted or unsubstituted C6-C30 aryl group, and a heteroaryl group.

2. The compound according to claim 1, characterized in that R3 and R4 in the CR3R4 are independently selected from methyl and phenyl; R5 in the NR5 is one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted heteroaryl group.

3. The compound according to claim 1, characterized in that The heteroaryl group contains at least one heteroatom, and the heteroatom in the heteroaryl group is selected from N, O, and S atoms; The heteroaryl group includes carbazolyl, furanyl, acridinyl, fluorenyl, thienyl, triazine, pyrimidinyl, pyrazinyl, phenazinyl, pyridinyl, benzimidazolyl, and phenanthroline.

4. The compound according to claim 1, characterized in that When R1 and R2 are C6-C30 aryl groups, the C6-C30 aryl groups include phenyl, biphenyl and naphthyl.

5. The compound according to claim 1, characterized in that When Ar1 and Ar2 are substituted or unsubstituted C6-C30 aryl groups, the C6-C30 aryl groups include phenyl, biphenyl, naphthyl, phenanthrenyl, and triphenylenyl.

6. The compound according to claim 1, characterized in that Having the structures shown in A1 to A5, 。 7. The compound according to claim 6, characterized in that The structures of A1 to A5 are as follows: 。 8. Use of the compound according to any one of claims 1 to 7 in an organic electroluminescent device, characterized in that: The compound is used as a red light host material in a light-emitting layer of an organic electroluminescent device.

9. An organic electroluminescent device comprising a light-emitting layer, characterized in that: The host material of the light-emitting layer includes the compound according to any one of claims 1 to 7.

10. A display component, characterized in that: An organic electroluminescent device comprising the organic electroluminescent device according to claim 9.

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