Carbazole-containing compound and organic electroluminescent device thereof

Abstract

The invention belongs to the technical field of organic electroluminescent materials, and particularly relates to a carbazole-containing compound and an organic electroluminescent device.The carbazole-containing compound is applied as a light extraction layer in the organic electroluminescent device, and due to the fact that the carbazole-containing compound has the high refractive index characteristic, the light extraction efficiency of the organic electroluminescent device can be improved; the series of compounds have wide application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescent materials, and in particular relates to a compound containing carbazole and an organic electroluminescent device thereof. Background Art

[0002] In recent years, the application of organic electroluminescent devices (OLED) has been extended from mobile phones to other high-quality information display devices due to its self-luminescence, wide color gamut and viewing angle, fast response, and flexibility. With the development of product types and the requirements of various display devices, the demand for organic electroluminescent devices is increasing, and it is necessary to develop devices with higher resolution, higher efficiency, lower voltage, and longer life.

[0003] In order to improve the performance of the product, a simple and effective method is to form a light extraction layer (CPL) as a functional layer on a transparent metal cathode. By adding a high refractive index light extraction layer to the device, the external quantum efficiency of the device can be significantly improved, the loss of light inside the device can be reduced, and the light extraction efficiency of the device can be improved. Therefore, providing a high refractive index light extraction material to improve the light extraction efficiency of electroluminescent devices has become an urgent problem to be solved in the field. Summary of the invention

[0004] In order to solve the problems existing in the background technology, the first object of the present invention is to provide a compound containing carbazole, and the technical scheme is as follows:

[0005] A carbazole-containing compound, the structure of which is shown in the following general formula I:

[0006]

[0007] In the general formula I, ring A and ring D are aromatic rings; Indicates the presence or absence of R 1 and / or R 2 The bonding relationship of X is selected from C, O, S, and N. When X is selected from O and S, there is no R 1 and R 2 The bonding relationship of R 1 and / or R 2 Y are the same or different and are selected from O or S; Z are the same or different and are selected from C or N;

[0008] R 1 ~R 2 Same or different, selected from C 1 ~C 18 Alkyl, substituted or unsubstituted C 6 ~C 30 Aryl;

[0009] Any two adjacent R 3 Connected into a ring or not, R 3 Each is the same or different and is selected from halogen, C 1 ~C 12 Alkyl, C 2 ~C 10 Alkenyl, C 1 ~C 10 Alkynyl, C 1 ~C 10 Alkoxy or alkylthio, substituted or unsubstituted C 6 ~C 30 Aryloxy or arylthio or arylamine, C 6 ~C 30 Aryl, C 3 ~C 30 heteroaryl;

[0010] R 4 the same or different, each independently selected from hydrogen, deuterium, nitro, cyano, halogen, substituted or unsubstituted C 1 ~C 12 Alkyl, C 6 ~C 30 Aryl, C 3 ~C 30 Cycloalkyl, C 3 ~C 30 Heteroaryl, C 1 ~C 12 Alkoxy, C 6 ~C 30 Aryloxy, C 1 ~C 12 Alkylthio, C 5 ~C 30 Arylthio, C 1 ~C 30 Alkylamine, C 5 ~C 30 Arylamine, C 1 ~C 12 Alkylsilyl, C 5 ~C 30 Arylsilyl;

[0011] When there is a substituent, the substituent is selected from deuterium, cyano, halogen, C 1 ~C 12 Alkyl, C 6 ~C 30 Aryl;

[0012] m and n are each independently selected from 0 to the maximum number of substituents in the ring.

[0013] As a preferred embodiment of the present invention, the ring A and the ring D are benzene rings or pyridine rings, and the R 1 and R 2 Selected from C 1 ~C 12 Alkyl, substituted or unsubstituted C 6 ~C 15 Aryl.

[0014] As a preferred embodiment of the present invention, when X is C, R 1 and R 2 Selected from C 1 ~C 12 Alkyl; when X is N, R 1 or R 2 is phenyl or pentafluorophenyl.

[0015] As a preferred embodiment of the present invention, when m is 1, R 3 Selected from phenyl, biphenyl, naphthyl, anthracenyl, phenanthryl, dimethylfluorenyl, indenyl, benzofuranyl, benzothiophenyl, benzoxazolyl, benzothiazolyl.

[0016] As a preferred embodiment of the present invention, when n is 1, R 4 Selected from methyl, isopropyl, tert-butyl, trifluoromethyl, phenyl and pentafluorophenyl.

[0017] As a preference of the present invention, the Y's and Z's are the same.

[0018] As a preferred embodiment of the present invention, the structure of general formula I is any of the following structures:

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032] Another object of the present invention is to provide an organic electroluminescent device, comprising a substrate layer, a first electrode located on the substrate layer, an organic light-emitting functional layer located on the first electrode, a second electrode located on the organic light-emitting functional layer, and also comprising a covering layer located on the second electrode, wherein the covering layer comprises the above-mentioned carbazole-containing compound, and the refractive index of the covering layer material at a wavelength of 460nm is greater than 1.90.

[0033] As a preferred embodiment of the present invention, the organic electroluminescent device is used to manufacture display devices, lighting sources, signal lights, and signboards. The display devices include mobile phone displays, computer displays, television displays, smart watch displays, smart car display panels, VR or AR helmet displays.

[0034] The beneficial effects of the present invention are as follows:

[0035] The present invention provides a carbazole-containing compound and an organic electroluminescent device thereof, wherein the carbazole-containing compound is used as a light extraction layer in the organic electroluminescent device. Due to its high refractive index characteristics, it can improve the light extraction efficiency of the organic electroluminescent device and has broad application prospects. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The reagents or instruments used in the examples without indicating the manufacturer are all conventional products that can be purchased commercially. Some reaction compounds are purchased from a commodity supplier (Zhengzhou Alpha Chemical Co., Ltd.), and some compounds that cannot be purchased directly are prepared by simple reactions of commercially available raw materials. The percentages all refer to mass percentages, and the temperature is degrees Celsius (°C). Such method principles, operating procedures, conventional post-treatments, silica gel columns, recrystallization purification and other means are well known to synthesizers in the art, and the synthesis process can be fully realized to obtain the target product.

[0038] Preparation Example

[0039] Example 1: Preparation of Compound 1

[0040]

[0041] Synthesis of compound 1-3: Compound 1-1 (9.7 g, 30 mmol), compound 1-2 (10.7 g, 60 mmol), tetrakis(triphenylphosphine)palladium (Pd(PPh 3 ) 4 ) (3.6 g, 3.1 mmol), sodium carbonate (Na 2 CO 3 ) (19.6 g, 184.6 mmol), added to 90 mL of dioxane and 30 mL of distilled water, refluxed and stirred for 12 hours. After the reaction, the solid was filtered, washed with distilled water and methanol, dried, and washed with a mixed solvent (CHCl 3 / MeOH) to solidify to obtain compound 1-3 (5.8 g, 45%);

[0042] Synthesis of compound 1: Under nitrogen protection, compound 1-3 (21.6 g, 50 mmol), compound 1-4 (15.6 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO 4 ) The organic phase was dried and spin-dried, and the compound 1 (28.5 g, 86%) was separated by column chromatography, MS: 663.23.

[0043] Example 2: Preparation of Compound 16

[0044]

[0045] Synthesis of compound 16-2: Compound 1-1 (9.7 g, 30 mmol), compound 16-1 (9.8 g, 60 mmol), Pd(PPh 3 ) 4 (3.6 g, 3.1 mmol), Na 2 CO 3 (19.6 g, 184.6 mmol), added to 90 mL of dioxane and 30 mL of distilled water, refluxed and stirred for 12 hours. After the reaction, the solid was filtered, washed with distilled water and methanol, dried, and washed with a mixed solvent (CHCl 3 / MeOH) to solidify to obtain compound 16-2 (5.9 g, 49%);

[0046] Synthesis of compound 16: Under nitrogen protection, compound 16-2 (20.1 g, 50 mmol), compound 16-3 (14.8 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO 4 ) The organic phase was dried and spin-dried, and the compound 16 (25.9 g, 84%) was separated by column chromatography, MS: 617.32.

[0047] Example 3: Preparation of Compound 30

[0048]

[0049] Synthesis of compound 30-2: Compound 1-1 (9.7 g, 30 mmol), compound 30-1 (10.7 g, 60 mmol), Pd(PPh 3 ) 4 (3.6 g, 3.1 mmol), Na 2 CO 3 (19.6 g, 184.6 mmol), added to 90 mL of dioxane and 30 mL of distilled water, refluxed and stirred for 12 hours. After the reaction, the solid was filtered, washed with distilled water and methanol, dried, and washed with a mixed solvent (CHCl 3 / MeOH) to solidify to obtain compound 30-2 (6.6 g, 51%);

[0050] Synthesis of compound 30-5: Under nitrogen protection, compound 30-3 (12.2 g, 50 mmol), compound 30-4 (7.8 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO4 ) The organic phase was dried, and the organic phase was spin-dried and separated by column chromatography to obtain compound 30-5 (13.0 g, 81%).

[0051] Synthesis of compound 30: Under nitrogen protection, compound 30-5 (16.0 g, 50 mmol), compound 30-2 (21.7 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO 4 ) The organic phase was dried and spin-dried, and the compound 30 (28.0 g, 83%) was separated by column chromatography, MS: 674.32.

[0052] Example 4: Preparation of Compound 56

[0053]

[0054] Synthesis of compound 56: Under nitrogen protection, compound 16-2 (20.1 g, 50 mmol), compound 56-1 (16.1 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO 4 ) The organic phase was dried and spin-dried, and the compound 56 (28.3 g, 88%) was separated by column chromatography, MS: 643.38.

[0055] Example 5: Preparation of Compound 83

[0056]

[0057]

[0058] Synthesis of compound 83-2: Compound 1-1 (9.7 g, 30 mmol), compound 83-1 (9.7 g, 60 mmol), Pd(PPh 3 ) 4 (3.6 g, 3.1 mmol), Na 2 CO 3 (19.6 g, 184.6 mmol), added to 90 mL of dioxane and 30 mL of distilled water, refluxed and stirred for 12 hours. After the reaction, the solid was filtered, washed with distilled water and methanol, dried, and washed with a mixed solvent (CHCl 3 / MeOH) to solidify to obtain compound 83-2 (5.9 g, 49%);

[0059] Synthesis of compound 83-5: Compound 83-3 (6.7 g, 18 mmol) and compound 83-4 (2.8 g, 18 mmol) were completely dissolved in tetrahydrofuran (THF) (50 ml), and 2M potassium carbonate aqueous solution (30 ml) and tetrakis-(triphenylphosphine)palladium (Pd(PPh 3 ) 4 ) (400 mg, 0.34 mmol), and the mixture was heated and stirred for 2 h. Then, the mixture was cooled to room temperature to complete the reaction. After removing the potassium carbonate solution, the solid was filtered out and washed once with tetrahydrofuran and ethanol to obtain compound 83-5 (6.0 g, 92%);

[0060] Synthesis of compound 83: Under nitrogen protection, compound 83-5 (18.1 g, 50 mmol), compound 83-2 (20.0 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO 4 ) The organic phase was dried and spin-dried, and the compound 83 (29.0 g, 85%) was separated by column chromatography, MS: 682.30.

[0061] Example 6: Preparation of Compound 110

[0062]

[0063] Synthesis of compound 110-3: Compound 110-1 (6.7 g, 18 mmol) and compound 110-2 (2.0 g, 18 mmol) were completely dissolved in THF (50 ml), and 2M potassium carbonate aqueous solution (30 ml) and Pd(PPh 3 ) 4 (400 mg, 0.34 mmol), the mixture was heated and stirred for 2 h. Then, the mixture was cooled to room temperature to complete the reaction, and after removing the potassium carbonate solution, the solid was filtered out, and the solid was washed once with tetrahydrofuran and ethanol to obtain compound 110-3 (5.5 g, 95%);

[0064] Synthesis of compound 110: Under nitrogen protection, compound 110-3 (16.1 g, 50 mmol), compound 1-3 (21.6 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO 4 ) The organic phase was dried and spin-dried, and the compound 110 (27.3 g, 81%) was separated by column chromatography, MS: 673.29.

[0065] Example 7: Preparation of Compound 141

[0066]

[0067] Synthesis of compound 141: Under nitrogen protection, compound 30-5 (21.7 g, 50 mmol), compound 141-1 (28.7 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO 4) The organic phase was dried and spin-dried, and the compound 141 (39.9 g, 86%) was separated by column chromatography, MS: 927.27.

[0068] Example 8: Preparation of Compound 168

[0069]

[0070]

[0071] Synthesis of compound 168-3: Compound 83-3 (6.7 g, 18 mmol) and compound 110-2 (2.0 g, 18 mmol) were completely dissolved in THF (50 ml), and 2M potassium carbonate aqueous solution (30 ml) and Pd(PPh 3 ) 4 (400 mg, 0.34 mmol), the mixture was heated and stirred for 2 h. Then, the mixture was cooled to room temperature to complete the reaction, and after removing the potassium carbonate solution, the solid was filtered out, and the solid was washed once with tetrahydrofuran and ethanol to obtain compound 168-3 (5.3 g, 92%);

[0072] Synthesis of compound 168-2: Compound 1-1 (9.7 g, 30 mmol), compound 168-1 (14.3 g, 60 mmol), Pd(PPh 3 ) 4 (3.6 g, 3.1 mmol), Na 2 CO 3 (19.6 g, 184.6 mmol), added to 90 mL of dioxane and 30 mL of distilled water, refluxed and stirred for 12 hours. After the reaction, the solid was filtered, washed with distilled water and methanol, dried, and washed with a mixed solvent (CHCl 3 / MeOH) to solidify to obtain compound 168-2 (8.0 g, 48%);

[0073] Synthesis of compound 168: Under nitrogen protection, compound 168-2 (27.7 g, 50 mmol), compound 168-3 (16.1 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO4 ) The organic phase was dried and spin-dried, and the compound 168 (33.4 g, 84%) was separated by column chromatography, MS: 795.12.

[0074] Example 9: Preparation of Compound 188

[0075]

[0076] Synthesis of compound 188-3: Compound 188-1 (7.0 g, 18 mmol) and compound 188-2 (2.7 g, 18 mmol) were completely dissolved in THF (50 ml), and 2M potassium carbonate aqueous solution (30 ml) and Pd(PPh 3 ) 4 (400 mg, 0.34 mmol), the mixture was heated and stirred for 2 h. Then, the mixture was cooled to room temperature to complete the reaction, and after removing the potassium carbonate solution, the solid was filtered out, and the solid was washed once with tetrahydrofuran and ethanol to obtain compound 188-3 (6.3 g, 93%);

[0077] Synthesis of compound 188: Under nitrogen protection, compound 83-2 (20.0 g, 50 mmol), compound 188-3 (18.9 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO 4 ) The organic phase was dried and spin-dried, and the compound 188 (29.6 g, 85%) was separated by column chromatography, MS: 697.31.

[0078] Example 10: Preparation of Compound 206

[0079]

[0080] Synthesis of compound 206-2: Compound 188-1 (6.7 g, 18 mmol) and compound 206-1 (3.0 g, 18 mmol) were completely dissolved in THF (50 ml), and 2M potassium carbonate aqueous solution (30 ml) and Pd(PPh 3 ) 4(400 mg, 0.34 mmol), the mixture was heated and stirred for 2 h. Then, the mixture was cooled to room temperature to complete the reaction, and after removing the potassium carbonate solution, the solid was filtered out, and the solid was washed once with tetrahydrofuran and ethanol to obtain compound 206-2 (7.2 g, 91%);

[0081] Synthesis of compound 206: Under nitrogen protection, compound 30-5 (21.7 g, 50 mmol), compound 206-2 (21.9 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO 4 ) The organic phase was dried and spin-dried, and the compound 206 (34.0 g, 86%) was separated by column chromatography, MS: 791.05.

[0082] Example 11: Preparation of Compound 216

[0083]

[0084] Synthesis of compound 216-3: Under nitrogen protection, compound 216-1 (12.2 g, 50 mmol), compound 216-2 (12.3 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO 4 ) The organic phase was dried, and the organic phase was spin-dried and separated by column chromatography to obtain compound 216-3 (17.5 g, 85%);

[0085] Synthesis of compound 216: Under nitrogen protection, compound 216-3 (20.5 g, 50 mmol), compound 16-2 (20.1 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd2 (dba) 3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO 4 ) The organic phase was dried and spin-dried, and the compound 216 (30.4 g, 83%) was separated by column chromatography, MS: 732.34.

[0086] Example 12: Preparation of Compound 223

[0087]

[0088] Synthesis of compound 223-3: Compound 188-1 (7.0 g, 18 mmol) and compound 83-4 (2.8 g, 18 mmol) were completely dissolved in THF (50 ml), and 2M potassium carbonate aqueous solution (30 ml) and Pd(PPh 3 ) 4 (400 mg, 0.34 mmol), the mixture was heated and stirred for 2 h. Then, the mixture was cooled to room temperature to complete the reaction, and after removing the potassium carbonate solution, the solid was filtered out, and the solid was washed once with tetrahydrofuran and ethanol to obtain compound 223-3 (6.2 g, 91%);

[0089] Synthesis of compound 223-2: Compound 1-1 (9.7 g, 30 mmol), compound 223-1 (10.6 g, 60 mmol), Pd(PPh 3 ) 4 (3.6 g, 3.1 mmol), Na 2 CO 3 (19.6 g, 184.6 mmol), added to 90 mL of dioxane and 30 mL of distilled water, refluxed and stirred for 12 hours. After the reaction, the solid was filtered, washed with distilled water and methanol, dried, and washed with a mixed solvent (CHCl 3 / MeOH) to solidify to obtain compound 223-2 (6.7 g, 52%);

[0090] Synthesis of compound 223: Under nitrogen protection, compound 223-2 (21.5 g, 50 mmol), compound 223-3 (18.9 g, 50 mmol), tris(dibenzylideneacetone)dipalladium (Pd 2 (dba)3 ) (0.9 g, 1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl (SPhos) (0.8 g, 2 mmol), sodium tert-butoxide (14.4 g, 150 mmol), and 300 mL of toluene were added to a 500 mL three-necked flask, heated under reflux to react overnight, and after the reaction was completed, cooled to room temperature, and then the reaction solution was extracted with dichloromethane and washed with anhydrous sodium sulfate (Na 2 SO 4 ) The organic phase was dried, and then spin-dried to obtain compound 223 (31.3 g, 86%) using column chromatography, MS: 728.36.

[0091] In addition, it should be noted that other compounds of the present application can be obtained by referring to the preparation methods of the above-mentioned embodiments, so they will not be listed one by one here.

[0092] Evaluation of optical properties of compounds:

[0093] Compound 1, Compound 16, Compound 30, Compound 56, Compound 83, Compound 110, Compound 141, Compound 168, Compound 188, Compound 206, Compound 216, Compound 223 and Comparative Compounds ref-1 and ref-2 prepared in the Preparation Example were respectively prepared as single-layer evaporated films with a film thickness of 50 nm on silicon substrates, and the refractive index N value of each single-layer film at different wavelengths and the extinction coefficient K value at 460 nm were measured by ellipsometer. The measured data are shown in Table 1 below:

[0094] Table 1

[0095]

[0096] As can be seen from Table 1 above, the refractive index of the compounds provided by the present invention in each color domain is higher than that of the comparative compound ref-1 and the comparative compound ref-2. Compared with the comparative compound ref-1, the compounds provided by the present invention use a benzo five-membered heterocyclic structure as a stretching group connected to the benzene rings on both sides of the carbazole, and use a dibenzo five-membered ring structure as a stretching group connected to the nitrogen on the carbazole, while the comparative compound ref-1 is all benzene rings. First, the interaction between the heteroatoms in the benzo five-membered heterocyclic structure and the hydrogen on the adjacent benzene ring can make the molecular structure more planar, which is conducive to the improvement of the refractive index. Secondly, the dibenzo five-membered ring structure is a large rigid planar group, which can further improve the refractive index of the series of compound molecules while improving the molecular thermal stability. Compared with the comparative compound ref-2, the core structure is different. The comparative compound ref-2 is based on a triarylamine structure. Compared with the carbazole structure, the triarylamine structure is not as planar as carbazole, so the series of compounds provided by the present invention have a higher refractive index in comparison, and the higher refractive index can improve the effect of emitting light from the inside of the electrode to the outside, thereby improving the efficiency of the device.

[0097] Device Embodiment

[0098] The device structure is: ITO:Ag:ITO / HT:PD(2%,10nm) / HT(100nm) / BP(5nm) / BH:BD(97:3,30nm) / ET:Liq(50:50) / LiF(0.5nm) / Mg:Ag(1:9,10nm) / CPL(65nm).

[0099] Device preparation process: Use an ultrasonic cleaner to wash the alkali-free glass substrate with isopropyl alcohol for 15 minutes, and then perform UV ozone cleaning in air for 30 minutes. The treated substrate is firstly evaporated with ITO / Ag / ITO (100nm) as the anode by vacuum evaporation, and then the hole injection layer (HT:PD, 10nm, 2%), hole transport layer (HT, 100nm), luminescent auxiliary layer (BP, 5nm), blue luminescent layer (main material: doping material = BH:BD (weight ratio 97:3, 30nm)), electron transport layer (ET:Liq = 1:1, 30nm), electron injection layer (LiF, 0.5nm) are sequentially stacked and evaporated, and Mg and Ag (weight ratio 1:9, 10nm) are co-evaporated to make a semi-transparent cathode, and then CPL (65nm) is evaporated as a cover layer (light extraction layer). The vacuum degree during deposition is maintained at 1×10 -7 Up to 5×10 -8 Entrust.

[0100] The structure of the compound used in the above preparation process is as follows:

[0101]

[0102] Among them, compound ref-1 and compound ref-2 as well as compound 1, compound 16, compound 30, compound 56, compound 83, compound 110, compound 141, compound 168, compound 188, compound 206, compound 216, and compound 223 exist as CPLs in the above-mentioned prepared devices.

[0103] Device performance evaluation:

[0104] The IVL (current-voltage-luminance) test system (Suzhou Fushida Scientific Instrument Co., Ltd.) was used, and the current density during the test was 10mA / cm 2 , CE and CIEy were measured for each device in Table 2 below, and the BI value of each device was listed. BI = CE / CIEy, which refers to the Blue Index in blue light and is also a parameter for measuring the luminous efficiency of blue light. CE refers to current efficiency, and CIEy refers to the ordinate color point obtained by bringing the wavelength of the device's luminous half-peak width into the CIE1930 software, as well as the ordinate color point of each device at 50 mA / cm 2 The time required for the brightness to decrease to 97% of the initial brightness (LT97) at a current density of , the test data is shown in Table 2 below:

[0105] Table 2

[0106]

[0107] As can be seen from Table 2 above, the devices of Examples 1-12 use the carbazole-containing compounds of the present invention as the covering layer (CPL) material. Compared with Comparative Example 3, the luminous efficiency is greatly improved, indicating that adding a light extraction layer (covering layer) to the device structure can improve the luminous efficiency of the device; compared with Comparative Examples 1 and 2, it is shown that as the refractive index of the CPL layer material increases, the high efficiency characteristics of the device are better utilized.

Claims

1. A carbazole-containing compound, characterized in that The structure is shown in the following general formula I: In the general formula I, ring A and ring D are aromatic rings; Indicates that there is or is not a bonding relationship between R1 and / or R2; X is selected from C, O, S, and N. When X is selected from O and S, there is no bonding relationship between R1 and R2; when X is C and N, there is a bonding relationship between R1 and / or R2; Y is the same or different and is selected from O or S; Z is the same or different and is selected from C or N; R1~R2 are the same or different and are selected from C1~C 18 Alkyl, substituted or unsubstituted C6~C 30 Aryl; Any two adjacent R3 are connected to form a ring or not, and R3 are the same or different and are selected from halogen, C1~C 12 Alkyl, C2~C 10 Alkenyl, C1~C 10 Alkynyl, C1~C 10 Alkoxy or alkylthio, substituted or unsubstituted C6~C 30 Aryloxy or arylthio or arylamine, C6~C 30 Aryl, C3~C 30 heteroaryl; R4 are the same or different and are independently selected from hydrogen, deuterium, nitro, cyano, halogen, substituted or unsubstituted C1-C 12 Alkyl, C6~C 30 Aryl, C3~C 30 Cycloalkyl, C3~C 30 Heteroaryl, C1~C 12 Alkoxy, C6~C 30 Aryloxy, C1~C 12 Alkylthio, C5~C 30 Arylthio, C1~C 30 Alkylamine, C5~C 30 Arylamine, C1~C 12 Alkylsilyl, C5~C 30 Arylsilyl; When there is a substituent, the substituent is selected from deuterium, cyano, halogen, C1-C 12 Alkyl, C6~C 30 Aryl; m and n are each independently selected from 0 to the maximum number of substituents in the ring.

2. The carbazole-containing compound according to claim 1, characterized in that The ring A and the ring D are benzene rings or pyridine rings, and the R1 and R2 are selected from C1 to C 12 Alkyl, substituted or unsubstituted C6~C 15 Aryl.

3. The carbazole-containing compound according to claim 2, characterized in that When X is C, R1 and R2 are selected from C1 to C 12 Alkyl; when X is N, R1 or R2 is phenyl or pentafluorophenyl.

4. The carbazole-containing compound according to claim 1, characterized in that When m is 1, R3 is selected from phenyl, biphenyl, naphthyl, anthracenyl, phenanthryl, dimethylfluorenyl, indenyl, benzofuranyl, benzothiophenyl, benzoxazolyl, benzothiazolyl.

5. The carbazole-containing compound according to claim 1, characterized in that When n is 1, R4 is selected from methyl, isopropyl, tert-butyl, trifluoromethyl, phenyl, pentafluorophenyl.

6. The carbazole-containing compound according to claim 1, characterized in that The Y and Z are the same.

7. The carbazole-containing compound according to claim 1, characterized in that Its structure is any of the following:

8. An organic electroluminescent device, comprising a substrate layer, a first electrode located on the substrate layer, an organic light-emitting functional layer located on the first electrode, and a second electrode located on the organic light-emitting functional layer, characterized in that: The invention also comprises a covering layer located on the second electrode, wherein the covering layer comprises the carbazole-containing compound according to any one of claims 1 to 7, and the refractive index of the covering layer material at a wavelength of 460 nm is greater than 1.

90.

9. The organic electroluminescent device according to claim 8, characterized in that: The organic electroluminescent device is used to manufacture display devices, lighting sources, signal lights, and signboards. The display devices include mobile phone display screens, computer display screens, television display screens, smart watch display screens, smart car display panels, and VR or AR helmet display screens.

Images