Compound with benzobisoxazole structure and organic light-emitting device using same

Abstract

The invention belongs to the technical field of organic semiconductors, and discloses a compound with a benzobisoxazole structure and an organic electroluminescent device containing the compound. The compound with the benzobisoxazole structure has the following mechanism: # imgabs0 #, which is used as a charge transport material and a charge injection material in the organic electroluminescent device, especially as a hole injection layer material, and can greatly improve the voltage, service life and other properties of the organic electroluminescent device.

Description

Technical Field

[0001] The invention belongs to the technical field of organic semiconductors, and particularly relates to a compound with a benzobisoxazole structure and an organic electroluminescent device containing the compound. Background Art

[0002] Organic Light-Emitting diodes (OELDs) have the characteristics of self-luminescence, wide viewing angle, low driving voltage, light and thin devices, easy large-area preparation and flexibility, and are widely used in the display and lighting fields.

[0003] The device structure of OLED mainly includes ITO anode, hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, and metal cathode. The preparation methods of these functional layers mainly include vacuum evaporation and solution processing. OLED devices use hole injection layer and electron injection layer to promote charge injection, and use hole transport layer and electron transport layer to promote charge transport. Among them, the hole injection layer is a functional layer formed by one or more materials. The method of one material is to use the material with a deep lowest unoccupied molecular orbital (LUMO) energy level, while the method of multiple materials is formed by doping P-type, deep LUMO materials into hole transport materials. Therefore, the deep LUMO energy level is crucial for the hole injection layer material. However, materials with deep LUMO energy levels usually have one or more strongly electron-withdrawing substituents, which makes their synthesis difficult. And it is difficult to achieve properties such as deep LUMO energy level, high stability and high film forming properties at the same time. Since the hole injection layer has a great influence on the voltage, efficiency and life of OLED devices, it is very important and urgent to develop P-type materials with deep LUMO energy level, high stability and high film-forming properties in the field of organic electroluminescence. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a compound having a benzobisoxazole structure. The compound can be used as a charge transport material and a charge injection material in an organic electroluminescent device, especially a hole injection layer material, which can greatly improve the voltage and life of the organic electroluminescent device.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned compound having a benzobisoxazole structure.

[0006] Another object of the present invention is to provide an electronic device comprising the compound having a benzobisoxazole structure.

[0007] A compound having a benzobisoxazole structure, which is a compound having a structure of formula (I):

[0008]

[0009] Among them, Z 1 and Z 2 are relatively independently selected from CR"R"'; R" and R"' are relatively independently selected from one of hydrogen, halogen, cyano, halogen-substituted alkyl, halogen-substituted aryl, halogen-substituted heteroaryl, sulfonyl-substituted aromatic, sulfonyl-substituted heteroaryl, cyano-substituted alkyl, cyano-substituted aromatic, cyano-substituted heteroaryl, cyano-and halogen-substituted aromatic, and cyano-and halogen-substituted heteroaryl;

[0010] R 1 , R 2 Each occurrence is identical or different and is selected from one of deuterium, substituted or unsubstituted deuterated alkyl having 1 to 30 carbon atoms, substituted or unsubstituted deuterated alkoxy having 1 to 30 carbon atoms, substituted or unsubstituted deuterated aryl having 6 to 30 carbon atoms, and substituted or unsubstituted deuterated heteroaryl having 6 to 30 carbon atoms, and R 1 and R 2 At least one of them is a group containing an electron-withdrawing group; wherein deuterated alkyl, deuterated alkoxy, and deuterated aryl refer to deuterium replacing all hydrogens on the alkyl, alkoxy, aryl, or heteroaryl groups; substitution refers to at least one of the deuterium being replaced by halogen, -CF 3 , -C 3 F 7 , -C 4 F 9 , -C 5 F 11 , -C 6 F 13 、-OCF 3 、-OC 2 F 5 、-OC 3 F 7 、-OC 4 F 9 、-SF 5 、-SCF 3、 -SO 2 CF 3 、-SO 2 CD 3 、-NO 2, an alkyl group having 1 to 20 ring carbon atoms, a cycloalkyl group having 3 to 20 ring carbon atoms, a heteroalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 3 to 12 carbon atoms, an amine group having 0 to 20 ring carbon atoms, an acyl group having 0 to 20 ring carbon atoms, a carbonyl group having 0 to 20 ring carbon atoms, a carboxylic acid group having 0 to 20 ring carbon atoms, an ester group having 0 to 20 ring carbon atoms, a cyano group having 0 to 20 ring carbon atoms, an isocyano group having 0 to 20 ring carbon atoms, a nitro group having 0 to 20 ring carbon atoms, and a sulfonyl group having 0 to 20 ring carbon atoms.

[0011] Preferably, the electron withdrawing group is selected from the group consisting of: halogen, nitro, acyl, carbonyl, carboxylic acid, ester, cyano, SF 5 , sulfonyl, deuterated nitrogen heteroaromatic ring group, alkyl group with 1-20 carbon atoms, cycloalkyl group with 3-20 ring carbon atoms, heteroalkyl group with 1-20 carbon atoms, alkoxy group with 1-20 carbon atoms, alkenyl group with 2-20 carbon atoms, alkynyl group with 2-20 carbon atoms, aryl group with 6-12 carbon atoms, heteroaryl group with 3-12 carbon atoms or a combination thereof. More preferably, the electron withdrawing group is selected from: F, CF 3 ,OCF 3 ,SF 5 ,SO 2 CF 3 , cyano, pyrimidine or a combination thereof.

[0012] Preferably, the Z 1 and Z 2 Each occurrence is identically or differently selected from the group consisting of:

[0013]

[0014]

[0015] wherein Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, the same or different at each occurrence;

[0016] In the present invention, "*" indicates that Z 1 and Z 2 The group is attached to the position of the oxazole in the benzodioxazole of formula I.

[0017] Preferably, the R 1 and R2 Each occurrence is identically or differently selected from the group consisting of:

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] In the invention, "*" indicates that the R 1 and R 2 The position at which the group is attached to the benzene in the middle of the benzodioxazole in formula I.

[0025] A method for preparing the above-mentioned compound having a benzobisoxazole structure comprises the following steps:

[0026] (1) 2,5-Diamino-3,6-dibromobenzene-1,4-diphenol, HC(OEt) 3 、Y(OTf) 3 The reaction was carried out in a solvent to obtain the intermediate product 1;

[0027] (2) Reaction of intermediate 1 with R 1 -B(OH) 2 , R 2 -B(OH) 2 The reaction is carried out in a solvent in the presence of a base and a catalyst to obtain an intermediate product 2;

[0028] (3) reacting the intermediate product 2 with n-butyl lithium and then adding elemental iodine to continue the reaction to obtain the intermediate product 3;

[0029] (4) NaH is added to CR'R" to react, and then the intermediate product 3 is added to continue the reaction to obtain the intermediate product 4;

[0030] (5) PIFA is added to the intermediate product 4 and reacted in a solvent to obtain a compound having a benzobisoxazole structure.

[0031]

[0032] The solvent in step (1) is preferably DMSO; the reaction is preferably carried out by stirring at 55-65° C. overnight.

[0033] The solvent in step (2) is dioxane, and the reaction is preferably carried out by heating under reflux overnight.

[0034] The reaction of the intermediate product 2 with n-butyl lithium in step (3) refers to stirring the reaction at -85--95°C for 1 hour and then heating to -75--85°C for 8 hours; the further addition of elemental iodine for continued reaction refers to reacting at room temperature overnight.

[0035] The step (4) of adding NaH to CR'R" to react means adding NaH at -10-5°C, heating to room temperature and stirring for 15-35 minutes after mixing; the step of adding intermediate product 3 to continue the reaction means adding intermediate product 3 and then heating to 85-95°C and stirring for 24-48 hours.

[0036] The step (5) of adding PIFA to the intermediate product 4 means adding it at -10-5°C, mixing it evenly, and then stirring and reacting it at room temperature for 2-5 days. The solvent is preferably dichloromethane.

[0037] An application of the above-mentioned compound having a benzobisoxazole structure in an organic electroluminescent device, especially as a hole injection material.

[0038] According to one embodiment of the present invention, an electroluminescent device comprises an anode, a cathode, and an organic layer disposed between the anode and the cathode, wherein the organic layer is a hole injection layer, and the hole injection layer is formed solely from the compound of formula (I).

[0039] According to one embodiment of the present invention, an electroluminescent device includes an anode, a cathode, and an organic layer arranged between the anode and the cathode. The organic electroluminescent device, wherein the organic layer is a hole injection layer, and the hole injection layer is formed by the compound containing doping, the doping contains at least one hole transport material; the hole transport material contains at least one of a compound having a triarylamine unit, a spirobifluorene compound, a pentacene compound, an oligothiophene compound, and an oligophenyl compound, wherein the molar doping ratio of the compound to the hole transport material is 10000:1 to 1:10000.

[0040] According to one embodiment of the present invention, in the electroluminescent device, the molar doping ratio of the compound to the hole transport material is 10:1 to 1:100.

[0041] According to another embodiment of the present invention, a compound formulation is also disclosed, which comprises a compound represented by Formula I. The specific structure of the compound is shown in the aforementioned Formula (I).

[0042] The compounds with benzobisoxazole structure disclosed in the present invention can be used as charge transport materials and charge injection materials in organic electroluminescent devices. These compounds can greatly improve the performance of organic electroluminescent devices such as voltage and life span.

[0043] Devices manufactured according to embodiments of the present invention may be used in a variety of consumer products having one or more electronic component modules of the device. Some examples of these consumer products include flat panel displays, monitors, medical monitors, televisions, billboards, lights for indoor or outdoor lighting and / or signaling, flat panel displays, flexible displays, smart phones, wearable devices, smart watches, smart phones, digital cameras, camcorders.

[0044] Compared with the prior art, the present invention has the following beneficial technical effects:

[0045] The compounds can be used as charge transport materials, charge injection materials and charge generation materials in electroluminescent devices. These novel compounds can greatly improve the voltage and life of organic electroluminescent devices. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below in conjunction with the examples, but the embodiments of the present invention are not limited thereto. If the specific conditions are not specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0047] Material synthesis example:

[0048] The preparation method of the compound of the present invention is not limited, and the following compounds are typically but not limitedly exemplified, and their synthetic routes and preparation methods are as follows:

[0049] Synthesis Example 1: Synthesis of Compound 59

[0050] Step 1: Synthesis of intermediate M59a

[0051]

[0052] Under nitrogen protection, add HC(OEt) into a 500mL three-necked flask. 3 (11.1 g, 75 mmol), Y(OTf) 3(1.07g, 4mmol), 2,5-diamino-3,6-dibromobenzene-1,4-diphenol (4.47g, 15mmol), 100mL DMSO solvent. Heat to 60°C, heat and stir to react overnight. Add 500mL DCM / PE (v:v=1:1) to a three-necked flask, filter and collect the solid, and wash with acetone. After filtration and drying, a white solid (3.58g, yield: 75%) was obtained. MALDI-TOF-MS: m / z=317.92 (M + ).Elemental analysis (C 8 H 2 Br 2 N 2 O 2 ):C 29.82,H 0.50,N 8.69.

[0053] Step 2: Synthesis of intermediate M59b

[0054] Under nitrogen protection, add Pd(OAc) into a 500mL three-necked flask. 2 (450mg, 10mol%, 2.0mmol), XPhos (2.0g, 4.2mmol), intermediate M59a (6.36g, 20mmol), deuterated p-propoxyphenylboronic acid (11.28g, 80mmol), potassium carbonate (16.68g, 120mmol), 100mL dioxane solvent. Heat to 110℃ and reflux, heat and stir to react overnight. After the reaction is completed, filter with diatomaceous earth, wash thoroughly with dichloromethane, and separate by silica gel column chromatography to obtain a white solid (6.38g, yield: 91%). MALDI-TOF-MS: m / z=350.36 (M + ).Elemental analysis (C 26 H 2 D 8 F 14 N 2 O 4 ):C 45.13,HD2.50,N3.92.

[0055] Step 3: Synthesis of intermediate M59c

[0056]

[0057] Under nitrogen protection, add intermediate M59b (3.15 g, 9 mmol) and 100 mL of THF solvent after dehydration to a 500 mL three-necked flask. Under stirring, slowly cool to -94 ° C, then slowly add n-butyl lithium (13.8 mL, 20.93 mmol, 1.6 M n-hexane solution). After the addition is complete, keep stirring at -94 ° C for 1 hour, then slowly increase to -78 ° C for 8 hours. Add 15 mL of THF solution of elemental iodine (6.93 g, 27.3 mmol), slowly increase to room temperature after the addition is complete, react overnight, add a small amount of saturated ammonium chloride aqueous solution to quench, then directly add diatomaceous earth to mix the sample, and purify by silica gel column chromatography to obtain a white solid product M59c (3.25 g, yield: 60%). MALDI-TOF-MS: m / z=602.15 (M + ).Elemental analysis (C 26 D 8 F 14 I 2 N 2 O 4 ):C 33.10,D1.57,N2.86.

[0058] Step 4: Synthesis of intermediate M59d

[0059] Under nitrogen protection, malononitrile (2.78 g, 42 mmol) was added to 70 mL of anhydrous DMF, and NaH (1.67 g, 42 mmol, 60% content) was added in several portions at 0°C. The mixture was stirred at 0°C for 10 min, then slowly heated to room temperature, and stirred for 20 min. M59c (4.22 g, 7 mmol) and Pd(PPh 3 ) 4 (1.62 g, 1.4 mmol), gradually heated to 90 ° C, continued to stir and react for 36 hours, then poured into ice water, added dilute hydrochloric acid to adjust the pH <1, after sufficient stirring, a large amount of yellow solid precipitated, filtered, and the precipitated solid was collected. Washed with dichloromethane to obtain a yellow solid, then washed twice with dichloromethane, filtered to obtain a yellow solid M59d (3.28 g, yield: 98%). MALDI-TOF-MS: m / z = 478.45 (M + ).Elemental analysis (C 32 H 2 D 8 F 14 N 6 O 4 ):C 46.95,HD2.09,N 10.14.

[0060] Step 5: Synthesis of compound 59

[0061]

[0062] Under nitrogen protection, intermediate M59d (2.39 g, 5 mmol) and 150 mL of dichloromethane solvent were added to a 1000 mL three-necked flask. Under stirring, the temperature was slowly lowered to 0 ° C, and then PIFA (6.45 g, 15 mmol) was added in batches. After stirring for 1 hour, the temperature was slowly raised to room temperature. The reaction was stirred at room temperature for 3 days, and then 400 mL of n-hexane was added to the reaction solution. After stirring for 10 minutes, it was filtered to obtain a dark green solid. It was washed twice with a DCM / PE mixed solvent (v:v=1:1) to obtain a dark green solid compound 59 (1.98 g, yield: 83%). MALDI-TOF-MS: m / z=476.44 (M + ).Elemental analysis (C 32 D 8 F 14 N 6 O 4 ):C 47.02,D1.83,N 10.18.

[0063] Synthesis Example 2: Synthesis of Compound 92

[0064] Step 1: Synthesis of intermediate M92a

[0065] Under nitrogen protection, add Pd(OAc) into a 500mL three-necked flask. 2 (450mg, 10mol%, 2.0mmol), XPhos (2.0g, 4.2mmol), intermediate M59a (6.36g, 20mmol), deuterated 2-trifluoromethylpyridine-4-boronic acid (15.51g, 80mmol), potassium carbonate (16.68g, 120mmol), 100mL dioxane solvent. Heat to 110℃ and reflux, heat and stir to react overnight. After the reaction is completed, filter with diatomaceous earth, wash thoroughly with dichloromethane, and separate by silica gel column chromatography to obtain a white solid (7.76g, yield: 85%). MALDI-TOF-MS: m / z=456.34 (M + ).Elemental analysis (C 20 H 2 D 6 F 6 N 4 O 2 ):C 52.50,HD2.94,N 12.12.

[0066] Step 2: Synthesis of intermediate M92b

[0067]

[0068] Under nitrogen protection, add intermediate M92a (4.11 g, 9 mmol) and 100 mL of THF solvent after dehydration to a 500 mL three-necked flask. Under stirring, slowly cool to -94 ° C, then slowly add n-butyl lithium (13.8 mL, 20.93 mmol, 1.6 M n-hexane solution). After the addition is complete, keep stirring at -94 ° C for 1 hour, then slowly increase to -78 ° C for 8 hours. Add 15 mL of THF solution of elemental iodine (6.93 g, 27.3 mmol), slowly increase to room temperature after the addition is complete, react overnight, add a small amount of saturated ammonium chloride aqueous solution to quench, then directly add diatomaceous earth to mix the sample, and purify by silica gel column chromatography to obtain a white solid product M92b (3.44 g, yield: 54%). MALDI-TOF-MS: m / z = 708.13 (M + ).Elemental analysis (C 20 D 6 F 6 I 2 N 4 O 2 ):C 33.80,D1.58,N7.75.

[0069] Step 3: Synthesis of intermediate M92c

[0070] Under nitrogen protection, malononitrile (2.78 g, 42 mmol) was added to 70 mL of anhydrous DMF, and NaH (1.67 g, 42 mmol, 60% content) was added at 0°C in several portions. The mixture was stirred at 0°C for 10 min, then slowly heated to room temperature, and stirred for 20 min. M92b (4.96 g, 7 mmol) and Pd(PPh 3 ) 4 (1.62 g, 1.4 mmol), gradually heated to 90 ° C, continued to stir and react for 36 h, then poured into ice water, added dilute hydrochloric acid to adjust the pH <1, after sufficient stirring, a large amount of yellow solid precipitated, filtered, collected the precipitated solid, washed with dichloromethane to obtain a yellow solid, then washed twice with dichloromethane, filtered to obtain a yellow solid M92c (3.68 g, yield: 90%). 1 H NMR (500MHz, CDCl3) δ (ppm): 4.78 (m, 2H). MALDI-TOF-MS: m / z = 584.43 (M + ).Elemental analysis (C 26 H 2 D 6 F 6 N 8 O 2 ):C 53.35,HD2.30,N 19.02.

[0071] Step 4: Synthesis of compound 92

[0072]

[0073] Under nitrogen protection, intermediate M92c (2.92 g, 5 mmol) and 150 mL of dichloromethane solvent were added to a 1000 mL three-necked flask. Under stirring, the temperature was slowly lowered to 0 ° C, and then PIFA (6.45 g, 15 mmol) was added in batches. After stirring for 1 hour, the temperature was slowly raised to room temperature. The reaction was stirred at room temperature for 3 days, and then 400 mL of n-hexane was added to the reaction solution. After stirring for 10 minutes, it was filtered to obtain a dark green solid. It was washed twice with a DCM / PE mixed solvent (v:v=1:1) to obtain a dark green solid compound 92 (2.18 g, yield: 75%). MALDI-TOF-MS: m / z=582.42 (M + ).Elemental analysis (C 26 D 6 F 6 N 8 O 2 ):C 53.49,D 1.95,N 19.11.

[0074] Synthesis Example 3: Synthesis of Compound 175

[0075] Step 1: Synthesis of intermediate M175a

[0076] Under nitrogen protection, add Pd(OAc) into a 500mL three-necked flask. 2 (450mg, 10mol%, 2.0mmol), XPhos (2.0g, 4.2mmol), intermediate M59a (6.36g, 20mmol), (3'-(trifluoromethoxy)-[1,1'-biphenyl]-3-yl-2,2',4,4',5,5',6,6'-d8)boric acid (23.21g, 80mmol), potassium carbonate (16.68g, 120mmol), 100mL dioxane solvent. The temperature was raised to 110°C and refluxed, and the reaction was stirred overnight. After the reaction was completed, it was filtered with diatomaceous earth, washed thoroughly with dichloromethane, and separated by silica gel column chromatography to obtain a white solid (10.38g, yield: 80%). MALDI-TOF-MS: m / z=648.62 (M + ).Elemental analysis (C 34 H 2 D 16 F 6 N 2 O 4 ):C 62.79,HD5.13,N 4.12.

[0077] Step 2: Synthesis of intermediate M175b

[0078]

[0079] Under nitrogen protection, add intermediate M175a (5.84 g, 9 mmol) and 100 mL of THF solvent after dehydration to a 500 mL three-necked flask. Under stirring, slowly cool to -94 ° C, then slowly add n-butyl lithium (13.8 mL, 20.93 mmol, 1.6 M n-hexane solution). After the addition is complete, keep stirring at -94 ° C for 1 hour, then slowly increase to -78 ° C for 8 hours. Add 15 mL of THF solution of elemental iodine (6.93 g, 27.3 mmol), slowly increase to room temperature after the addition is complete, react overnight, add a small amount of saturated ammonium chloride aqueous solution to quench, then directly add diatomaceous earth to mix the sample, and purify by silica gel column chromatography to obtain a white solid product M175b (4.54 g, yield: 56%). MALDI-TOF-MS: m / z = 900.41 (M + ).Elemental analysis (C 34 D 16 F 6 I 2 N 2 O 4 ):C 45.16,D3.32,N2.97.

[0080] Step 3: Synthesis of intermediate M175c

[0081] Under nitrogen protection, malononitrile (2.78 g, 42 mmol) was added to 70 mL of anhydrous DMF, and NaH (1.67 g, 42 mmol, 60% content) was added at 0°C in several portions. The mixture was stirred at 0°C for 10 min, then slowly heated to room temperature, and stirred for 20 min. M175b (6.30 g, 7 mmol) and Pd(PPh 3 ) 4 (1.62 g, 1.4 mmol), gradually heated to 90 ° C, continued to stir and react for 36 hours, then poured into ice water, added dilute hydrochloric acid to adjust the pH <1, after sufficient stirring, a large amount of yellow solid precipitated, filtered, and the precipitated solid was collected. Washed with dichloromethane to obtain a yellow solid, then washed twice with dichloromethane, filtered to obtain a yellow solid M175c (4.62 g, yield: 85%). MALDI-TOF-MS: m / z = 776.71 (M + ).Elemental analysis (C 40 H 2 D 16 F 6 N 6 O 4):C 61.69,HD4.28,N 10.63.

[0082] Step 4: Synthesis of compound 175

[0083]

[0084] Under nitrogen protection, intermediate M175c (3.88 g, 5 mmol) and 150 mL of dichloromethane solvent were added to a 1000 mL three-necked flask. Under stirring, the temperature was slowly lowered to 0 ° C, and then PIFA (6.45 g, 15 mmol) was added in batches. After stirring for 1 hour, the temperature was slowly raised to room temperature. The reaction was stirred at room temperature for 3 days, and then 400 mL of n-hexane was added to the reaction solution. After stirring for 10 minutes, it was filtered to obtain a dark green solid. It was washed twice with a DCM / PE mixed solvent (v:v=1:1) to obtain a dark green solid compound 175 (2.79 g, yield: 72%). MALDI-TOF-MS: m / z=774.69 (M + ).Elemental analysis (C 40 D 16 F 6 N 6 O 4 ):C 61.78,D4.01,N 10.60.

[0085] Synthesis Example 4: Synthesis of Compound 234

[0086] Step 1: Synthesis of intermediate M234a

[0087] Under nitrogen protection, add Pd(OAc) into a 500mL three-necked flask. 2 (450mg, 10mol%, 2.0mmol), XPhos (2.0g, 4.2mmol), intermediate M59a (6.36g, 20mmol), (2',3-bis(trifluoromethyl)-[1,1'-biphenyl]-4-yl-2,3',4',5,5',6,6'-d7)boric acid (27.29g, 80mmol), potassium carbonate (16.68g, 120mmol), 100mL dioxane solvent. The temperature was raised to 110°C and refluxed, and the reaction was stirred overnight. After the reaction was completed, it was filtered with diatomaceous earth, washed thoroughly with dichloromethane, and separated by silica gel column chromatography to obtain a white solid (10.96g, yield: 73%). MALDI-TOF-MS: m / z=750.60 (M + ).

[0088] Step 2: Synthesis of intermediate M234b

[0089]

[0090] Under nitrogen protection, add intermediate M234a (6.76g, 9mmol) and 100mL of THF solvent after dehydration to a 500mL three-necked flask. Under stirring, slowly cool to -94°C, then slowly add n-butyl lithium (13.8mL, 20.93mmol, 1.6M n-hexane solution). After the addition is complete, keep stirring at -94°C for 1h, then slowly increase to -78°C for 8h. Add 15mL of THF solution of elemental iodine (6.93g, 27.3mmol), slowly increase to room temperature after the addition is complete, react overnight, add a small amount of saturated ammonium chloride aqueous solution to quench, then directly add diatomaceous earth to mix the sample, and purify by silica gel column chromatography to obtain a white solid product M234b (4.69g, yield: 52%). MALDI-TOF-MS: m / z=1002.4 (M + ).Elemental analysis (C 36 D 14 F 12 I 2 N 2 O 2 ):C 42.97,D2.63,N 2.62.

[0091] Step 3: Synthesis of intermediate M234c

[0092] Under nitrogen protection, malononitrile (2.78 g, 42 mmol) was added to 70 mL of anhydrous DMF, and NaH (1.67 g, 42 mmol, 60% content) was added at 0°C in several portions. The mixture was stirred at 0°C for 10 min, then slowly heated to room temperature, and stirred for 20 min. M234b (7.01 g, 7 mmol) and Pd(PPh 3 ) 4 (1.62 g, 1.4 mmol), gradually heated to 90 ° C, continued to stir and react for 36 hours, then poured into ice water, added dilute hydrochloric acid to adjust the pH <1, after sufficient stirring, a large amount of yellow solid precipitated, filtered, and the precipitated solid was collected. Washed with dichloromethane to obtain a yellow solid, then washed twice with dichloromethane, filtered to obtain a yellow solid M234c (5.04 g, yield: 82%). MALDI-TOF-MS: m / z = 877.69 (M + ).Elemental analysis (C 42 H 2 D 14 F 12 N 6 O 2 ):C 57.29,HD3.30,N 9.43.

[0093] Step 4: Synthesis of compound 234

[0094]

[0095] Under nitrogen protection, intermediate M234c (4.39 g, 5 mmol) and 150 mL of dichloromethane solvent were added to a 1000 mL three-necked flask. Under stirring, the temperature was slowly lowered to 0 ° C, and then PIFA (6.45 g, 15 mmol) was added in batches. After stirring for 1 hour, the temperature was slowly raised to room temperature. The reaction was stirred at room temperature for 3 days, and then 400 mL of n-hexane was added to the reaction solution. After stirring for 10 minutes, it was filtered to obtain a dark green solid. It was washed twice with a DCM / PE mixed solvent (v:v=1:1) to obtain a dark green solid compound 234 (3.06 g, yield: 70%). MALDI-TOF-MS: m / z=875.67 (M + ).Elemental analysis (C 42 D 14 F 12 N 6 O 2 ):C 57.39,D3.01,N 9.43.

[0096] Synthesis Example 5: Synthesis of Compound 323

[0097] Step 1: Synthesis of intermediate M323a

[0098]

[0099] Under nitrogen protection, add Pd(OAc) into a 500mL three-necked flask. 2 (450mg, 10mol%, 2.0mmol), XPhos (2.0g, 4.2mmol), intermediate M59a (6.36g, 20mmol), (4-((trifluoromethyl)sulfonyl)phenyl-2,3,5,6-d4)boric acid (20.64g, 80mmol), potassium carbonate (16.68g, 120mmol), 100mL dioxane solvent. The temperature was raised to 110°C and refluxed, and the reaction was stirred overnight. After the reaction was completed, it was filtered with diatomaceous earth, washed thoroughly with dichloromethane, and separated by silica gel column chromatography to obtain a white solid M323a-1 (6.32g, yield: 70%). MALDI-TOF-MS: m / z=451.21 (M + According to the same preparation method as M323a-1, the intermediate (4-(4,4,4,4,4,4,4,4,4-perfluoro-4λ 12 -Butane-1,3-diyl)benzene-2,3,5,6-d 4 ) Phenylboronic acid reacts with M323a-1 to obtain M323a (4.83 g, yield: 65%). MALDI-TOF-MS: m / z = 670.45 (M+ ).Elemental analysis (C 25 H 2 D 8 F 12 N 2 O 4 S):C 44.67,HD2.58,N 4.06.

[0100] Step 2: Synthesis of intermediate M323b

[0101]

[0102] Under nitrogen protection, add intermediate M323a (4.06g, 9mmol) and 100mL of THF solvent after dehydration to a 500mL three-necked flask. Under stirring, slowly cool to -94°C, then slowly add n-butyl lithium (13.8mL, 20.93mmol, 1.6M n-hexane solution). After the addition is complete, keep stirring at -94°C for 1h, then slowly increase to -78°C for 8h. Add 15mL of THF solution of elemental iodine (6.93g, 27.3mmol), slowly increase to room temperature after the addition is complete, react overnight, add a small amount of saturated ammonium chloride aqueous solution to quench, then directly add diatomaceous earth to mix the sample, and purify by silica gel column chromatography to obtain a white solid product M323b (2.80g, yield: 50%). MALDI-TOF-MS: m / z=922.25 (M + ).Elemental analysis (C 25 D 8 F 12 I 2 N 2 O 4 S): C 32.42, D, 1.60, N 2.98.

[0103] Step 3: Synthesis of intermediate M323c

[0104]

[0105] Under nitrogen protection, A17 (7.78 g, 42 mmol) was added to 70 mL of anhydrous DMF, and NaH (1.67 g, 42 mmol, 60% content) was added in several portions at 0°C. The mixture was stirred at 0°C for 10 min, then slowly heated to room temperature, and stirred for 20 min. M323b (4.92 g, 7 mmol) and Pd (PPh 3 ) 4(1.62 g, 1.4 mmol), gradually heated to 90 ° C, continued to stir and react for 36 hours, then poured into ice water, added dilute hydrochloric acid to adjust the pH <1, after sufficient stirring, a large amount of yellow solid precipitated, filtered, and the precipitated solid was collected. Washed with dichloromethane to obtain a yellow solid, then washed twice with dichloromethane, filtered to obtain a yellow solid M323c (4.03 g, yield: 78%). MALDI-TOF-MS: m / z = 817.69 (M + ).Elemental analysis (C 43 H 10 D 8 F 18 N 4 O 4 S):C 49.70,HD2.39,N 5.28.

[0106] Step 4: Synthesis of compound 323

[0107]

[0108] Under nitrogen protection, intermediate M323c (4.09 g, 5 mmol) and 150 mL of dichloromethane solvent were added to a 1000 mL three-necked flask. Under stirring, the temperature was slowly lowered to 0 ° C, and then PIFA (6.45 g, 15 mmol) was added in batches. After stirring for 1 hour, the temperature was slowly raised to room temperature. The reaction was stirred at room temperature for 3 days, and then 400 mL of n-hexane was added to the reaction solution. After stirring for 10 minutes, it was filtered to obtain a dark green solid. It was washed twice with a DCM / PE mixed solvent (v:v=1:1) to obtain a dark green solid compound 323 (2.29 g, yield: 62%). MALDI-TOF-MS: m / z=1036.68 (M + ).Elemental analysis (C 41 H 6 D 8 F 18 N 6 O 4 S):C 47.38,HD1.96,N 7.97.

[0109] Synthesis Example 6: Synthesis of Compound 328

[0110] Step 1: Synthesis of intermediate M328a

[0111] Under nitrogen protection, add Pd(OAc) into a 500mL three-necked flask. 2(450mg, 10mol%, 2.0mmol), XPhos (2.0g, 4.2mmol), intermediate M59a (6.36g, 20mmol), (4-(perfluoroethoxy)phenyl-2,3,5,6-d4)boric acid (20.80g, 80mmol), potassium carbonate (16.68g, 120mmol), 100mL dioxane solvent. The temperature was raised to 110°C and refluxed, and the reaction was stirred overnight. After the reaction was completed, it was filtered with diatomaceous earth, washed thoroughly with dichloromethane, and separated by silica gel column chromatography to obtain a white solid (8.83g, yield: 75%). MALDI-TOF-MS: m / z=588.39 (M + ).Elemental analysis (C 24 H 2 D 8 F 10 N 2 O 4 ):C48.82,HD2.97,N 4.63.

[0112] Step 2: Synthesis of intermediate M328b

[0113]

[0114] Under nitrogen protection, add intermediate M328a (5.30 g, 9 mmol) and 100 mL of THF solvent after dehydration to a 500 mL three-necked flask. Under stirring, slowly cool to -94 °C, then slowly add n-butyl lithium (13.8 mL, 20.93 mmol, 1.6 M n-hexane solution). After the addition is complete, keep stirring at -94 °C for 1 h, then slowly increase to -78 °C for 8 h. Add 15 mL of THF solution of elemental iodine (6.93 g, 27.3 mmol), slowly increase to room temperature after the addition is complete, react overnight, add a small amount of saturated ammonium chloride aqueous solution to quench, then directly add diatomaceous earth to mix the sample, and purify by silica gel column chromatography to obtain a white solid product M328b (3.78 g, yield: 50%). MALDI-TOF-MS: m / z = 840.18 (M+). Elemental analysis (C24D8F10I2N2O4): C 34.18, D 1.76, N 3.20.

[0115] Step 3: Synthesis of intermediate M328c

[0116]

[0117] Under nitrogen protection, A18 (10.72 g, 42 mmol) was added to 70 mL of anhydrous DMF, and NaH (1.67 g, 42 mmol, 60% content) was added at 0°C in several portions, and the mixture was stirred and reacted for 10 min at 0°C, and then slowly heated to room temperature, and stirred and reacted for 20 min, and then M328b (5.88 g, 7 mmol) and Pd(PPh3)4 (1.62 g, 1.4 mmol) were added, and the temperature was gradually raised to 90°C, and stirred and reacted for 36 h, and then poured into ice water, and diluted hydrochloric acid was added to adjust the pH to <1. After sufficient stirring, a large amount of yellow solid precipitated, and the precipitated solid was collected by filtration. Wash with dichloromethane to obtain a yellow solid, and then wash with dichloromethane twice continuously, and filter to obtain a yellow solid M328c (6.51 g, yield: 85%). MALDI-TOF-MS: m / z = 868.68 (M+). Elemental analysis (C42H10D8F10N6O4): C 57.94, HD2.90, N 9.53.

[0118] Step 4: Synthesis of compound 328

[0119]

[0120] Under nitrogen protection, add intermediate M328c (5.47 g, 5 mmol) and 150 mL of dichloromethane solvent to a 1000 mL three-necked flask. Under stirring, slowly cool to 0 ° C, then add PIFA (6.45 g, 15 mmol) in batches, stir and react for 1 hour, and then slowly warm to room temperature. Stir and react at room temperature for 3 days, then add 400 mL of n-hexane to the reaction solution, stir and react for 10 minutes, and filter to obtain a dark green solid. Wash twice with DCM / PE mixed solvent (v:v=1:1), and finally obtain dark green solid compound 328 (4.04 g, yield: 74%). MALDI-TOF-MS: m / z=866.66 (M+). Elemental analysis (C42H8D8F10N6O4): C 58.09, HD2.63, N 9.56.

[0121] Synthesis Example 7: Synthesis of Compound 329

[0122] Step 1: Synthesis of intermediate M329a

[0123] Under nitrogen protection, add Pd(OAc) into a 500mL three-necked flask. 2(450mg, 10mol%, 2.0mmol), XPhos (2.0g, 4.2mmol), intermediate M59a (6.36g, 20mmol), (2,3,5,6-tetrafluorobenzene-4-d)boric acid (15.59g, 80mmol), potassium carbonate (16.68g, 120mmol), 100mL dioxane solvent. Heat to 110℃ and reflux, heat and stir to react overnight. After the reaction is completed, filter with diatomaceous earth, wash thoroughly with dichloromethane, and separate by silica gel column chromatography to obtain a white solid (6.60g, yield: 72%). MALDI-TOF-MS: m / z=458.26 (M + ).Elemental analysis (C 20 H 2 D 2 F 8 N 2 O 2 ):C 52.29,HD1.18,N 5.97.

[0124] Step 2: Synthesis of intermediate M329b

[0125]

[0126] Under nitrogen protection, add intermediate M329a (4.12g, 9mmol) and 100mL of THF solvent after dehydration to a 500mL three-necked flask. Under stirring, slowly cool to -94°C, then slowly add n-butyl lithium (13.8mL, 20.93mmol, 1.6M n-hexane solution). After the addition is complete, keep stirring at -94°C for 1h, then slowly increase to -78°C for 8h. Add 15mL of THF solution of elemental iodine (6.93g, 27.3mmol), slowly increase to room temperature after the addition is complete, react overnight, add a small amount of saturated ammonium chloride aqueous solution to quench, then directly add diatomaceous earth to mix the sample, and purify by silica gel column chromatography to obtain a white solid product M329b (3.00g, yield: 47%). MALDI-TOF-MS: m / z=710.06 (M + ).Elemental analysis (C 20 D 2 F 8 I 2 N 2 O 2 ):C 33.69,D0.42,N3.81.

[0127] Step 3: Synthesis of intermediate M329c

[0128]

[0129] Under nitrogen protection, A22 (6.01 g, 42 mmol) was added to 70 mL of anhydrous DMF, and NaH (1.67 g, 42 mmol, 60% content) was added in several portions at 0°C. The mixture was stirred at 0°C for 10 min, then slowly heated to room temperature, and stirred for 20 min. M329b (4.97 g, 7 mmol) and Pd(PPh 3 ) 4 (1.62 g, 1.4 mmol), gradually heated to 90 ° C, continued to stir and react for 36 hours, then poured into ice water, added dilute hydrochloric acid to adjust pH <1, after sufficient stirring, a large amount of yellow solid precipitated, filtered, and the precipitated solid was collected. Washed with dichloromethane to obtain a yellow solid, then washed twice with dichloromethane, filtered to obtain a yellow solid M329c (4.20 g, yield: 81%). MALDI-TOF-MS: m / z = 740.53 (M + ).Elemental analysis (C 36 H 8 D 2 F 8 N 8 O 2 ):C 58.25,HD1.47,N 14.98.

[0130] Step 4: Synthesis of compound 329

[0131]

[0132] Under nitrogen protection, intermediate M329c (3.70 g, 5 mmol) and 150 mL of dichloromethane solvent were added to a 1000 mL three-necked flask. Under stirring, the temperature was slowly lowered to 0 ° C, and then PIFA (6.45 g, 15 mmol) was added in batches. After stirring for 1 hour, the temperature was slowly raised to room temperature. The reaction was stirred at room temperature for 3 days, and then 400 mL of n-hexane was added to the reaction solution. After stirring for 10 minutes, it was filtered to obtain a dark green solid. It was washed twice with a DCM / PE mixed solvent (v:v=1:1) to obtain a dark green solid compound 329 (2.51 g, yield: 68%). MALDI-TOF-MS: m / z=738.51 (M + ).Elemental analysis (C 36 H 6 D 2 F 8 N 8 O 2 ):C 58.41,HD1.22,N 15.03.

[0133] Device Example 1

[0134] A glass substrate with an 80 nm thick indium tin oxide (ITO) transparent anode was treated with oxygen plasma and UV ozone. The cleaned glass substrate was dried on a hot plate in a glove box. The vacuum was about 10 -8 The following materials were sequentially deposited on the surface of the glass substrate at a rate of 0.2-2A / s under the condition of 1000 Å. The compound 59 of the present invention was deposited on the surface of the glass substrate to form a 5nm thick film as a hole injection layer (HIL). Next, the compound NPB was deposited on the above-mentioned HIL film to form a 120nm thick film as a hole transport layer (HTL). Then, the compound EB was deposited on the above-mentioned HTL film to form a 5nm thick film as an electron blocking layer (HBL). Next, the compound BH and the compound BD (mass ratio of 96:4) were co-deposited on the above-mentioned HBL film to form a 25nm thick film as a light-emitting layer (EML). Then LiQ (8-hydroxyquinoline-lithium) and the compound ET (weight ratio of 60:40) were co-deposited on the above-mentioned light-emitting layer film to form a 30nm thick film as an electron transport layer (ETL). Finally, Liq was deposited to form a 1nm thick film as an electron injection layer (EIL) and a 120nm thick metal aluminum was deposited as a cathode. Finally, the device was transferred back to the glove box and encapsulated with a glass cover and a moisture absorbent to complete the device preparation.

[0135] Device Example 2

[0136] Device Example 2 was fabricated in the same manner as Device Example 1, except that Compound 92 was used instead of Compound 59 to form a 5 nm thick film as the HIL.

[0137] Device Example 3

[0138] Device Example 3 was fabricated in the same manner as Device Example 1, except that Compound 175 was used instead of Compound 59 to form a 5 nm thick film as the HIL.

[0139] Device Example 4

[0140] Device Example 4 was fabricated in the same manner as Device Example 1, except that Compound 234 was used instead of Compound 59 to form a 5 nm thick film as the HIL.

[0141] Device Example 5

[0142] Device Example 5 was fabricated in the same manner as Device Example 1, except that Compound 323 was used instead of Compound 59 to form a 5 nm thick film as the HIL.

[0143] Device Example 6

[0144] Device Example 6 was fabricated in the same manner as Device Example 1, except that Compound 328 was used instead of Compound 59 to form a 5 nm thick film as the HIL.

[0145] Device Example 7

[0146] Device Example 7 was fabricated in the same manner as Device Example 1, except that Compound 329 was used instead of Compound 59 to form a 5 nm thick film as the HIL.

[0147] The detailed device layer structure and thickness are shown in Table 1. For layers using more than one material, different compounds are doped in the weight ratios recorded.

[0148] Device Comparison Example 1

[0149] Device Comparative Example 1 was prepared in the same manner as Device Example 1, except that Compound HI-a was used instead of Compound 59 to form a 5 nm thick film as the HIL, wherein the preparation method of Compound HI-a was based on the preparation method of Compound 59, with the only difference being that the deuterated p-propoxyphenylboronic acid was replaced with an equal molar amount of p-propoxyphenylboronic acid.

[0150] Device Comparison Example 2

[0151] Device Comparative Example 1 was prepared in the same manner as Device Example 1, except that Compound HI-b was used instead of Compound 59 to form a 5 nm thick film as HIL, wherein the preparation method of Compound HI-b was referenced to the preparation method of Compound 92, with the only difference being that the deuterated 2-trifluoromethylpyridine-4-boric acid was replaced with an equal molar amount of 2-trifluoromethylpyridine-4-boric acid.

[0152] Device Comparison Example 3

[0153] Device Comparative Example 1 was prepared in the same manner as Device Example 1, except that Compound HI-c was used instead of Compound 59 to form a 5 nm thick film as the HIL, wherein the preparation method of Compound HI-c was referenced to the preparation method of Compound 175, with the only difference being that (3'-(trifluoromethoxy)-[1,1'-biphenyl]-3-yl-2,2',4,4',5,5',6,6'-d8)boric acid was replaced with an equal molar amount of (3'-(trifluoromethoxy)-[1,1'-biphenyl]-3-yl-2,2',4,4',5,5',6,6'-8H)boric acid.

[0154] Device Comparison Example 4

[0155] Device Comparative Example 1 was prepared in the same manner as Device Example 1, except that Compound HI-d was used instead of Compound 59 to form a 5 nm thick film as the HIL, wherein the preparation method of Compound HI-d was referenced to the preparation method of Compound 234, with the only difference being that (2',3-bis(trifluoromethyl)-[1,1'-biphenyl]-4-yl-2,3',4',5,5',6,6'-d7)boric acid was replaced with an equal molar amount of (2',3-bis(trifluoromethyl)-[1,1'-biphenyl]-4-yl-2,3',4',5,5',6,6'-7H)boric acid.

[0156] Device Comparison Example 5

[0157] Device Comparative Example 1 was prepared in the same manner as Device Example 1, except that Compound HI-e was used instead of Compound 59 to form a 5 nm thick film as HIL, wherein the preparation method of Compound HI-e referred to the preparation method of Compound 323, the only difference being that (4-((trifluoromethyl)sulfonyl)phenyl-2,3,5,6-d4)boric acid was replaced by an equal molar amount of (4-((trifluoromethyl)sulfonyl)phenyl-2,3,5,6-4H)boric acid.

[0158] Device Comparative Example 6

[0159] Device Comparative Example 1 was prepared in the same manner as Device Example 1, except that Compound HI-f was used instead of Compound 59 to form a 5 nm thick film as HIL, wherein the preparation method of Compound HI-f was referenced to the preparation method of Compound 328, with the only difference being that (4-(perfluoroethoxy)phenyl-2,3,5,6-d4)boric acid was replaced with an equal molar amount of (4-(perfluoroethoxy)phenyl-2,3,5,6-4H)boric acid.

[0160] Device Comparison Example 7

[0161] Device Comparative Example 1 was prepared in the same manner as Device Example 1, except that Compound HI-g was used instead of Compound 59 to form a 5 nm thick film as HIL, wherein the preparation method of Compound HI-g was referenced to the preparation method of Compound 329, with the only difference being that (2,3,5,6-tetrafluorobenzene-4-d)boric acid was replaced with an equal molar amount of (2,3,5,6-tetrafluorobenzene-4H)boric acid.

[0162] Table 1 Device structure of device examples

[0163]

[0164]

[0165] The material structure used in the device is as follows:

[0166]

[0167]

[0168] For the above devices, at 100cd / cm 2 and 1000cd / cm 2 Under these conditions, the IVL characteristics were measured, and their voltage (V), lumen efficiency (cd / A), power efficiency (PE) and color coordinates are recorded in Table 2 below.

[0169] Table 2 Device data

[0170]

[0171] Table 3 Calculated values ​​of energy levels, thermal decomposition temperatures and roughness of representative materials

[0172] Compound <![CDATA[LUMO a (eV)]]> <![CDATA[T d b (℃)]]> <![CDATA[RMS c (nm)]]> 59 -6.16 406 3.80 92 -6.20 410 3.96 175 -6.25 402 3.84 234 -6.18 412 3.90 323 -6.22 418 3.92 328 -6.26 421 3.85 329 -6.21 415 3.94 HI-a -5.38 396 4.60 HI-b -5.46 390 4.55 HI-c -5.50 384 4.58 HI-d -5.42 386 4.50 HI-e -5.48 392 4.56 HI-f -5.52 388 4.62 HI-g -5.54 394 4.54

[0173] a Through theoretical calculation, we get

[0174] b Thermogravimetric analysis was performed

[0175] c Tested by atomic force microscopy

[0176] As can be seen from the above table, benzobisoxazole is used as a hole injection layer and has excellent performance in light-emitting devices. It is a type of hole injection material with excellent performance.

[0177] The various embodiments described herein are merely examples and are not intended to limit the scope of the invention. Therefore, it will be apparent to those skilled in the art that the claimed invention may include variations of the specific embodiments and preferred embodiments described in the text. Many of the materials and device structures described herein may be replaced with other materials and structures without departing from the spirit of the invention. It should be understood that the various theories about why the present invention works are not intended to be restrictive.

[0178] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A compound having a benzobisoxazole structure, characterized in that A compound having the structure of formula (I): wherein Z1 and Z2 are independently selected from CR"R"'; R" and R"' are independently selected from hydrogen, halogen, cyano, halogen-substituted alkyl, halogen-substituted aryl, halogen-substituted heteroaryl, sulfonyl-substituted aromatic, sulfonyl-substituted heteroaryl, cyano-substituted alkyl, cyano-substituted aromatic, cyano-substituted heteroaryl, cyano-and halogen-substituted aromatic, cyano-and halogen-substituted heteroaryl; R1, R2 are selected from deuterium, substituted or unsubstituted deuterated alkyl having 1-30 carbon atoms, substituted or unsubstituted deuterated alkoxy having 1-30 carbon atoms, substituted or unsubstituted deuterated aryl having 6-30 carbon atoms, substituted or unsubstituted deuterated heteroaryl having 6-30 carbon atoms, and at least one of R1 and R2 is a group containing an electron withdrawing group; wherein deuterated alkyl, deuterated alkoxy, deuterated aryl refers to deuterium replacing all hydrogens on alkyl, alkoxy, aryl or heteroaryl; substitution refers to at least one deuterium being replaced by halogen, -CF3, -C3F7, -C4F9, -C5F 11 、-C6F 13 , -OCF3, -OC2F5, -OC3F7, -OC4F9, -SF5, -SCF 3、 The alkyl group may be substituted with at least one of -SO2CF3, -SO2CD3, -NO2, an alkyl group having 1-20 carbon atoms, a cycloalkyl group having 3-20 ring carbon atoms, a heteroalkyl group having 1-20 carbon atoms, an alkoxy group having 1-20 carbon atoms, an alkenyl group having 2-20 carbon atoms, an alkynyl group having 2-20 carbon atoms, an aryl group having 6-12 carbon atoms, a heteroaryl group having 3-12 carbon atoms, an amine group having 0-20 ring carbon atoms, an acyl group having 0-20 ring carbon atoms, a carbonyl group having 0-20 ring carbon atoms, a carboxylic acid group having 0-20 ring carbon atoms, an ester group having 0-20 ring carbon atoms, a cyano group having 0-20 ring carbon atoms, an isocyano group having 0-20 ring carbon atoms, a nitro group having 0-20 ring carbon atoms, and a sulfonyl group having 0-20 ring carbon atoms.

2. The compound having a benzobisoxazole structure according to claim 1, characterized in that: The electron withdrawing group is selected from the group consisting of: halogen, nitro, acyl, carbonyl, carboxylic acid, ester, cyano, SF5, sulfonyl, deuterated nitrogen heteroaromatic ring group, alkyl group with 1-20 carbon atoms, cycloalkyl group with 3-20 ring carbon atoms, heteroalkyl group with 1-20 carbon atoms, alkoxy group with 1-20 carbon atoms, alkenyl group with 2-20 carbon atoms, alkynyl group with 2-20 carbon atoms, aryl group with 6-12 carbon atoms, heteroaryl group with 3-12 carbon atoms or a combination thereof; Preferably, the electron-withdrawing group is selected from: one or a combination of F, CF3, OCF3, SF5, SO2CF3, cyano, and pyrimidine.

3. The compound having a benzobisoxazole structure according to claim 1, characterized in that: The Z1 and Z2 are selected from the group consisting of the following structures the same or different each time they appear: wherein Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, the same or different each time it occurs; "*" indicates the position where the Z1 and Z2 groups are connected to the oxazole in the benzodioxazole in Formula I; The R1 and R2 are selected from the group consisting of the following structures the same or different each time they appear: "*" indicates the position where the R1 and R2 groups are connected to the benzene in the middle of the benzodioxazole in Formula I.

4. The compound having a benzobisoxazole structure according to claim 1, characterized in that The compound is one of the following:

5. A method for preparing a compound having a benzobisoxazole structure according to any one of claims 1 to 4, characterized in that The following steps are involved: (1) 2,5-diamino-3,6-dibromobenzene-1,4-diphenol, HC(OEt)3, and Y(OTf)3 react in a solvent to obtain an intermediate 1; (2) reacting the intermediate product 1 with R1-B(OH)2 and R2-B(OH)2 in a solvent in the presence of a base and a catalyst to obtain the intermediate product 2; (3) reacting the intermediate product 2 with n-butyl lithium and then adding elemental iodine to continue the reaction to obtain the intermediate product 3; (4) NaH is added to CR'R" to react, and then the intermediate product 3 is added to continue the reaction to obtain the intermediate product 4; (5) adding PIFA to the intermediate product 4 and reacting in a solvent to obtain a compound having a benzobisoxazole structure; The specific reaction route is as follows:

6. Use of the compound having a benzobisoxazole structure according to any one of claims 1 to 4 in an electroluminescent device.

7. An electroluminescent device, characterized in that The invention comprises an anode, a cathode, and an organic layer arranged between the anode and the cathode, wherein the organic layer comprises the compound having a benzobisoxazole structure according to any one of claims 1 to 4.

8. The electroluminescent device according to claim 7, characterized in that: The organic layer is a hole injection layer, and the hole injection layer comprises the compound having a benzobisoxazole structure as described in any one of claims 1 to 4 and a dopant, wherein the dopant comprises at least one hole transport material; the hole transport material comprises at least one of a compound having a triarylamine unit, a spirobifluorene compound, a pentacene compound, an oligothiophene compound, and an oligophenyl compound.

9. The electroluminescent device according to claim 8, characterized in that: The molar doping ratio of the compound having a benzobisoxazole structure to the hole transport material is 10000:1 to 1:10000.

10. Application of the electroluminescent device according to any one of claims 7 to 9 in flat panel displays, monitors, medical monitors, televisions, billboards, lamps for indoor or outdoor lighting and / or signaling, flat panel displays, flexible displays, smart phones, wearable devices, smart watches, smart phones, digital cameras, camcorders.

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