A compound for organic light-emitting materials and its applications

Abstract

The present invention belongs to the technical field of organic light-emitting materials, and relates to a compound for organic light-emitting materials and its application. In the compound provided by the present invention, a naphtho-hexacyclic heterocycle is used as the mother nucleus, and a five-membered heterocycle is incorporated to enhance the rigidity of the mother nucleus structure. Different electron-donating groups are connected at specific positions to construct a novel compound with a relatively high glass transition temperature, good thermal stability and film-forming property, appropriate orbital energy levels and triplet energies, and effectively improved carrier mobility. It can be used as a second hole-transporting material and a light-emitting host material in organic electroluminescent devices, and can significantly improve the luminous efficiency and lifespan of the devices.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic light-emitting materials, and relates to a compound for organic light-emitting materials and its application. Background Art

[0002] The OLED material system includes key components such as hole transport materials (HTM), light-emitting materials, and electron transport materials. The hole transport material is an important part of the multi-layer composite OLED structure, which can more efficiently send the hole carriers generated by the positive electrode of the device to the light-emitting layer, effectively improve the imbalance of carrier transport, avoid energy waste, and improve the light-emitting efficiency. The hole carrier mobility, as the core index to measure the performance of the hole transport material, directly reflects the ability of the material to transport holes. In addition, when researchers design and synthesize hole transport materials, they also strive to make them have high chemical stability, excellent film-forming properties, and appropriate HOMO energy levels.

[0003] It should be noted that hole transport materials usually have a low HOMO value, which is often accompanied by a low T1 (triplet energy level) value. This characteristic may cause the excitons generated in the light-emitting layer to easily diffuse to the interface of the hole transport layer or near it, thereby causing uneven light emission or charge distribution at the interface in the light-emitting layer, and finally resulting in light emission at the interface of the hole transport layer. This will not only reduce the color purity and light-emitting efficiency of the organic electroluminescent device, but also shorten its service life. By introducing a light-emitting auxiliary layer between the light-emitting layer and the hole transport layer, the above problems can be effectively avoided.

[0004] Currently, the materials used as the light-emitting auxiliary layer are limited. Most of these materials have a high hole migration rate and a high Tl energy to block the outward diffusion of the excitons after recombination to the transport layer, improving the overall efficiency of the device. At the same time, the appropriate HOMO value reduces the transport barrier of holes from the transport layer to the light-emitting layer, resulting in a lower driving voltage of the device and an improved service life.

[0005] Therefore, in the technical field of organic electroluminescent materials, it is very important to construct a new compound that can not only improve the stability of organic electroluminescent materials but also improve the optoelectronic properties of organic electroluminescent devices. Summary of the Invention

[0006] In view of this, the object of the present invention is to provide a compound for organic light-emitting materials and its application. The present invention uses a naphtho-heterocyclic six-membered ring as the parent nucleus, and incorporates a five-membered heterocyclic ring to enhance the rigidity of the parent nucleus. By connecting different electron-donating groups at specific positions, the carrier migration ability can be effectively improved. The constructed novel organic compound has a high glass transition temperature, appropriate orbital energy levels and triplet energy. As the second hole transport material or the light-emitting host material, it can effectively improve the brightness efficiency and lifespan, and significantly improve the optoelectronic performance of the organic electroluminescent device.

[0007] In the first aspect, the present invention provides a compound having the structure shown in Formula 1,

[0008] ;

[0009] wherein, W is selected from one of N-L1-(NAr1Ar2) m , O;

[0010] X1, X2, X3, X4 are all C, and are bonded to X5 and X6 in Formula 2

[0011] ,

[0012] wherein, Y is selected from one of O, N-L2-(NAr3Ar4) n ;

[0013] At least one of W and Y is N;

[0014] Ar1, Ar2, Ar3, Ar4 in N-L1-(NAr1Ar2) m and N-L2-(NAr3Ar4) n are substituted or unsubstituted C6-C30 aryl groups, or heteroaryl groups containing N, O, S heteroatoms and having a carbon number in C3-C30;

[0015] m in N-L1-(NAr1Ar2) m is selected from one of the integers 0, 1, 2;

[0016] n in N-L2-(NAr3Ar4) n is selected from one of the integers 0, 1, 2;

[0017] L1 and L2 in N-L1-(NAr1Ar2) m and N-L2-(NAr3Ar4) n are bridging groups respectively, and L1 and L2 can be the same or different;

[0018] N-L1-(NAr1Ar2) m and N-L2-(NAr3Ar4)n The hydrogens in L1, L2, Ar1, Ar2, Ar3, and Ar4 can all be deuterated.

[0019] Furthermore, among the compounds provided by the present invention, the compound is one of Formula 3 to Formula 6,

[0020] .

[0021] Furthermore, among the compounds provided by the present invention, the bridging group is selected from one or a combination of two of benzene, naphthalene, biphenyl, terphenyl, and N-phenylcarbazole.

[0022] Furthermore, among the compounds provided by the present invention, the substituted or unsubstituted C6-C30 aryl group includes benzene, p-biphenyl, m-biphenyl, terphenyl, naphthalene, 1-phenylnaphthalene, and 2-phenylnaphthalene;

[0023] The heteroaryl group containing N, O, S heteroatoms and having a carbon number in C3-C30 includes dibenzofuran, dibenzothiophene, N-phenylcarbazole, 9,9-dimethylfluorene, and 4-phenyldibenzofuran.

[0024] Furthermore, among the compounds provided by the present invention, the compound is one of Formula 7 to Formula 18,

[0025]

[0026]

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[0028]

[0029] Furthermore, among the compounds provided by the present invention, it has the following structure:

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[0128] 。

[0129] Furthermore, among the compounds provided by the present invention, the intermediate for synthesizing the compound is selected from one of the following intermediates:

[0130]

[0131]

[0132]

[0133] 。

[0134] In a second aspect, the present invention provides an application of the compound in an organic electroluminescent device.

[0135] In a third aspect, the present invention provides an application of the compound in preparing a hole transport material or a light-emitting host material.

[0136] Fourth aspect, the present invention provides an organic electroluminescent device, comprising an anode layer, a cathode layer, and an organic thin film layer located between the anode layer and the cathode layer. The organic thin film layer includes a hole injection layer, a first hole transport layer, a second hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. The second hole blocking layer or the light-emitting layer contains the compound of the present invention.

[0137] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:

[0138] By further fusing a five-membered heterocycle to the parent nucleus of the naphtho-hexacyclic heterocycle, the present invention further enhances the rigidity of the parent nucleus. By connecting other electron-donating groups at specific positions, the constructed new compound has a high glass transition temperature, good thermal stability, good film-forming property, and can improve the lifespan of the OLED device; it has appropriate HOMO / LUMO energy levels and triplet energies. When used as a hole transport material, it has high carrier transport performance, which improves the efficiency of its application in OLED devices; when used as a light-emitting host material, it ensures energy transfer between the host and the guest, reduces the driving voltage, and can significantly improve the device performance. It is a novel organic OLED functional material with relatively promising development prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0139] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0140] Figure 1 It is a schematic structural diagram of an organic electroluminescent element. Among them, 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 OF THE EMBODIMENTS

[0141] Next, the technical solutions of the present invention will be described in conjunction with embodiments. However, the present invention is not limited to the following embodiments. The experimental methods and detection methods described in each embodiment are all conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified. The percentages in the following embodiments are all mass percentages unless otherwise specified.

[0142] The structure of the naphtho-hexacyclic heterocycle involved in the present invention is as follows:

[0143] ,

[0144] Among them, W is selected from one of N-L1-(NAr1Ar2) m , and O;

[0145] X1, X2, X3, and X4 are all C.

[0146] Preparation Example

[0147] This preparation example provides the synthesis methods of some intermediates and compounds. The synthesis methods of the remaining intermediates and compounds are all similar methods and can be easily synthesized. The specific synthesis routes are shown below.

[0148] Synthesis of Intermediate 1:

[0149]

[0150]

[0151] Synthesis of Intermediate 1-1: Under nitrogen protection, raw material 1 (224 g, 1 mol), methyl 2-hydroxybenzoate (152 g, 1 mol), cesium carbonate (390 g, 1.2 mol), and DMF solvent (1500 mL) were successively added to the reaction flask, and the mixture was heated to 147 °C and refluxed for 8 h. After the reaction was completed, it was cooled to room temperature, and the reaction solution was filtered. The filtrate was added to 3000 mL of water with stirring to form a white solid. The white solid was filtered, and the filter cake was washed successively with water and ethanol, and then recrystallized and purified with a mixed solvent of toluene and n-heptane to obtain 206.5 g of Intermediate 1 with a yield of 58%.

[0152] Synthesis of Intermediate 1-2: Under nitrogen protection, Intermediate 1-1 (178 g, 0.5 mol) and tetrahydrofuran (600 mL) were added to a three-necked flask. A 1.0 M tetrahydrofuran solution of methylmagnesium bromide (1.0 M-THF, 800 mL) was slowly added dropwise under stirring at room temperature (24 °C). After the addition was completed, the temperature was raised to 50 °C and the reaction continued for 5 h. After the reaction solution was cooled to room temperature, the reaction was quenched with an aqueous ammonium chloride solution. The pH was adjusted to 3 with dilute hydrochloric acid, and then 1000 mL of dichloroethane was added for extraction. After stirring evenly, it was washed with water repeatedly. The organic phase was dried over anhydrous magnesium sulfate, filtered and concentrated, and the solid was precipitated with ethanol and purified to obtain 142 g of Intermediate 1-2 with a yield of 80%.

[0153] Synthesis of Intermediate 1-3: Under nitrogen protection, Intermediate 1-2 (106.8 g, 0.3 mol), methanesulfonic acid (57.6 g, 0.6 mol), and toluene (600 mL) were added to a three-necked flask, and the temperature was raised to 108 °C and the reaction continued for 3 h. After the reaction solution was cooled to room temperature, it was washed with water until neutral. The organic phase was dried over anhydrous magnesium sulfate, filtered and concentrated, and recrystallized and purified with a mixed solvent of toluene and ethanol to obtain 73 g of Intermediate 1-3 with a yield of 72%.

[0154] Synthesis of Intermediate 1-4: Under nitrogen protection, add Intermediate 1-3 (67.6 g, 0.2 mol), o-nitrophenylboronic acid (33.4 g, 0.2 mol), Pd(PPh3)4 (tetrakis(triphenylphosphine)palladium, 4.6 g, 4 mmol), K2CO3 (potassium carbonate, 55.2 g, 0.4 mol), TBAB (tetrabutylammonium bromide, 6.5 g, 20 mmol), toluene (600 mL), ethanol (300 mL), and water (150 mL) into a three-necked flask. Heat to 76 °C and stir for 6 h, then cool to room temperature. Wash with water until neutral, dry the organic phase with anhydrous magnesium sulfate, pass through a silica gel column, and recrystallize and purify with a mixed solvent of toluene and n-heptane to obtain 61 g of Intermediate 1-4 with a yield of 80%.

[0155] Synthesis of Intermediate 1: Under nitrogen protection, add Intermediate 1-4 (38.1 g, 0.1 mol), PPh3 (triphenylphosphine, 52.4 g, 0.2 mol), and o-dichlorobenzene (200 mL) into a three-necked flask. Stir and heat to 160 °C for 18 h. After cooling the reaction solution to room temperature, add n-heptane to precipitate the solid product. Filter and recrystallize and purify with toluene to obtain 22 g of Intermediate 1 with a yield of 63%.

[0156] Synthesis of Intermediate 2:

[0157]

[0158]

[0159] Synthesis of Intermediate 2-1: Under nitrogen protection, add raw material 2 (192 g, 1 mol) and 800 mL of tetrahydrofuran solvent into a three-necked flask. Stir and cool the system to -50 °C with liquid nitrogen, then dropwise add butyllithium (1250 mL, 2 mol, 1.6 M) and keep the temperature for 1 h. Then dropwise add trimethyl borate (345 g, 1.5 mol), keep the temperature for 1 h, and then naturally rise to room temperature and continue the reaction for 2 h. After the reaction is completed, quench the reaction with an aqueous ammonium chloride solution, adjust the pH to 3 with dilute hydrochloric acid, then wash, dry, concentrate, add ethanol to precipitate the product, and filter to obtain 130 g of Intermediate 2-1 with a yield of 55%.

[0160] For the synthesis of Intermediate 2-2, refer to the synthesis of Intermediate 1-4, and replace Intermediate 1-3 and o-nitrophenylboronic acid with Intermediate 2-1 and 2-fluoroiodobenzene.

[0161] Synthesis of intermediate 2-3: Under nitrogen protection, add intermediate 2-2 (114.4 g, 0.4 mol) and dichloromethane (600 mL) to a dry three-necked flask, cool the reaction system to -5~0°C using an ice-salt bath, add boron tribromide (396.3 g, 1.6 mol), stir at room temperature for 6 hours, and then pour into ice water to quench the reaction. The organic phase is washed with water until neutral, dried over anhydrous magnesium sulfate, filtered, and purified by silica gel column to obtain 98 g of intermediate 2-3 with a yield of 90%.

[0162] The synthesis of intermediate 2-4 refers to the synthesis of intermediate 1-1, except that raw material 1 and methyl 2-hydroxybenzoate are replaced by intermediate 2-3.

[0163] Synthesis of intermediate 2-5: Under nitrogen protection, add intermediate 2-4 (100.8 g, 0.4 mol), methyl 2-aminobenzoate (60.4 g, 0.4 mol), Pd2(dba)3 (tri(dibenzylideneacetone)dipalladium, 3.6 g, 4 mmol), P(t-Bu)3 (tri-tert-butylphosphine, 1.6 g, 8 mmol), sodium tert-butoxide (76.8 g, 0.8 mol), toluene (600 mL) to a three-necked flask, stir and heat to 110°C for reflux reaction for 2 h. After the reaction is complete, cool to room temperature, wash with water until neutral, dry the organic phase with anhydrous magnesium sulfate and filter, pass the filtrate through a silica gel column, concentrate the column liquid and recrystallize and purify with a mixed solvent of toluene and ethanol to obtain 120.4 g of intermediate 2-5, with a yield of 82%.

[0164] The synthesis of intermediate 2-6 refers to the synthesis of intermediate 1-2, except that intermediate 1-1 is replaced by intermediate 2-5.

[0165] The synthesis of intermediate 2 refers to the synthesis of intermediate 1-3, except that intermediate 1-2 is replaced by intermediate 2-6.

[0166] Synthesis of intermediate 3:

[0167]

[0168]

[0169] Synthesis of intermediate 3-1: Under nitrogen protection, raw material 3 (224 g, 1 mol), benzamidine hydrochloride (188 g, 1.2 mol), and ethanol (2000 mL) were added to a three-necked flask. After stirring until the system was completely dissolved, 120 mL of hydrochloric acid was added dropwise, and the mixture was heated to 88 ° C for 10 h. The reaction was monitored by TCL. After the raw material 3 was completely reacted, the solvent was removed by reduced pressure distillation, 800 mL of dichloromethane was added, and the organic phase was repeatedly washed with water and extracted. It was dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated and recrystallized with a mixed solvent of ethanol and n-heptane to obtain 227 g of intermediate 3-1 with a yield of 76%.

[0170] Synthesis of Intermediate 3-2: Under nitrogen protection, add Intermediate 3-1 (179.4 g, 0.6 mol), DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone, 454 g, 2 mol), and 900 mL of toluene into a three-necked flask. Stir and heat to 90 °C for reaction for 10 h. When the volume is reduced to about 300 mL under reduced pressure, add 400 mL of n-heptane, stir evenly, let it stand, cool to room temperature, and a solid will precipitate. Filter to obtain 118.7 g of Intermediate 3-2, with a yield of 67%.

[0171] Synthesis of Intermediate 3-3: Under nitrogen protection, add Intermediate 3-2 (88.5 g, 0.3 mol), iodobenzene (67.3 g, 0.33 mol), cuprous chloride (5.9 g, 0.06 mol), K2CO3 (82.8 g, 0.6 mol), 1,10-phenanthroline (4.8 g, 0.03 mol), 18-crown-6 (2.6 g, 0.01 mol), and 600 mL of diphenyl ether into a three-necked flask. Stir and heat to 180 °C for reaction for 10 h, then distill the reaction solution under reduced pressure. After removing the solvent, add 800 mL of toluene. Wash the system repeatedly with water until neutral, separate the organic phase, dry it with anhydrous magnesium sulfate, filter, pass the filtrate through a silica gel column, concentrate the column eluent, and recrystallize with a mixed solvent of toluene and petroleum ether to obtain 89 g of Intermediate 3-3, with a yield of 80%.

[0172] For the synthesis of Intermediate 3-4, refer to the synthesis of Intermediate 2-5, and replace Intermediate 2-4 with Intermediate 3-3.

[0173] For the synthesis of Intermediate 3-5, refer to the synthesis of Intermediate 1-2, and replace Intermediate 1-1 with Intermediate 3-4.

[0174] For the synthesis of Intermediate 3, refer to the synthesis of Intermediate 1-3, and replace Intermediate 1-2 with Intermediate 3-5.

[0175] Synthesis of Intermediate 4:

[0176]

[0177]

[0178] For the synthesis of Intermediate 4-1, refer to the synthesis of Intermediate 2-5, and replace Intermediate 2-4 with Raw Material 4.

[0179] For the synthesis of Intermediate 4-2, refer to the synthesis of Intermediate 1-2, and replace Intermediate 1-1 with Intermediate 4-1.

[0180] For the synthesis of Intermediate 4-3, refer to the synthesis of Intermediate 1-3, and replace Intermediate 1-2 with Intermediate 4-2.

[0181] The synthesis of intermediate 4-4 refers to the synthesis of intermediate 3-3, replacing intermediate 3-2 with intermediate 4-3.

[0182] The synthesis of intermediate 4-5 refers to the synthesis of intermediate 1-4, replacing intermediate 1-3 with intermediate 4-4.

[0183] The synthesis of intermediate 4 refers to the synthesis of intermediate 1, replacing intermediate 1-4 with intermediate 4-5.

[0184] The synthesis of intermediate 5:

[0185]

[0186]

[0187] The synthesis of intermediate 5-1 refers to the synthesis of intermediate 1-1, replacing raw material 1 with raw material 5.

[0188] The synthesis of intermediate 5-2 refers to the synthesis of intermediate 1-2, replacing intermediate 1-1 with intermediate 5-1.

[0189] The synthesis of intermediate 5-3 refers to the synthesis of intermediate 1-3, replacing intermediate 1-2 with intermediate 5-2.

[0190] The synthesis of intermediate 5-4 refers to the synthesis of intermediate 1-4, replacing intermediate 1-3 with intermediate 5-3.

[0191] The synthesis of intermediate 5 refers to the synthesis of intermediate 1, replacing intermediate 1-4 with intermediate 5-4.

[0192] The synthesis of intermediate 6:

[0193]

[0194]

[0195] The synthesis of intermediate 6-1 refers to the synthesis of intermediate 2-1, replacing raw material 2 with raw material 6.

[0196] The synthesis of intermediate 6-2 refers to the synthesis of intermediate 2-2, replacing intermediate 2-1 with intermediate 5-1.

[0197] The synthesis of intermediate 6-3 refers to the synthesis of intermediate 2-3, replacing intermediate 2-2 with intermediate 5-2.

[0198] The synthesis of intermediate 6-4 refers to the synthesis of intermediate 2-4, replacing intermediate 2-3 with intermediate 5-3.

[0199] The synthesis of intermediate 6-5 refers to the synthesis of intermediate 2-5, replacing intermediate 2-4 with intermediate 5-4.

[0200] The synthesis of intermediate 6-6 refers to the synthesis of intermediate 2-6, replacing intermediate 2-5 with intermediate 5-5.

[0201] The synthesis of intermediate 6 refers to the synthesis of intermediate 2, replacing intermediate 2-6 with intermediate 6-6.

[0202] The synthesis of intermediate 7:

[0203]

[0204]

[0205] The synthesis of intermediate 7-1 refers to the synthesis of intermediate 3-1, replacing raw material 3 with raw material 7.

[0206] The synthesis of intermediate 7-2 refers to the synthesis of intermediate 3-2, replacing intermediate 3-1 with intermediate 7-1.

[0207] The synthesis of intermediate 7-3 refers to the synthesis of intermediate 3-3, replacing intermediate 3-2 with intermediate 7-2.

[0208] The synthesis of intermediate 7-4 refers to the synthesis of intermediate 3-4, replacing intermediate 3-3 with intermediate 7-3.

[0209] The synthesis of intermediate 7-5 refers to the synthesis of intermediate 3-5, replacing intermediate 3-4 with intermediate 7-4.

[0210] The synthesis of intermediate 7 refers to the synthesis of intermediate 3, replacing intermediate 3-5 with intermediate 7-5.

[0211] The synthesis of intermediate 8:

[0212]

[0213]

[0214] The synthesis of intermediate 8-1 refers to the synthesis of intermediate 4-1, replacing raw material 4 with raw material 8.

[0215] The synthesis of intermediate 8-2 refers to the synthesis of intermediate 4-2, replacing intermediate 4-1 with intermediate 8-1.

[0216] The synthesis of intermediate 8-3 refers to the synthesis of intermediate 4-3, replacing intermediate 4-2 with intermediate 8-2.

[0217] The synthesis of intermediate 8-4 refers to the synthesis of intermediate 4-4, except that intermediate 4-3 is replaced by intermediate 8-3.

[0218] The synthesis of intermediate 8-5 refers to the synthesis of intermediate 4-5, except that intermediate 4-4 is replaced by intermediate 8-4.

[0219] The synthesis of intermediate 8 refers to the synthesis of intermediate 4, except that intermediate 4-5 is replaced by intermediate 8-5.

[0220] Synthesis of compound 1-1:

[0221]

[0222] Under nitrogen protection, intermediate 1 (14 g, 0.04 mol), bromobenzene (6.2 g, 0.04 mol), Pd2(dba)3 (tri(dibenzylideneacetone)dipalladium, 0.4 g, 0.4 mmol), P(t-Bu)3 (tri-tert-butylphosphine, 0.3 g, 0.9 mmol), sodium tert-butoxide (7.7 g, 0.08 mol), toluene (150 mL) were added to a three-necked flask, stirred and heated to 110°C for reflux reaction for 2 h. After the reaction was complete, it was cooled to room temperature and washed with water until neutral. The organic phase was dried with 10 g of anhydrous magnesium sulfate for 1 h and then filtered. The filtrate was passed through a silica gel column. After the column liquid was concentrated, it was recrystallized with a mixed solvent of toluene and ethanol and sublimed at 300°C in high vacuum to obtain 11.4 g of white crystalline compound 1-1 with a yield of 67%. The results of mass spectrometry detection of the obtained sample were: HR-MS (APCI): m / z 425.1780 [M+H] + ; C 31 H 23 NO (%) calculated value: C, 87.5003; H, 5.4483; N, 3.2917; O, 3.7598; found value (%): C, 87.5150; H, 5.4442; N, 3.2885; O, 3.7523.

[0223] Synthesis of compound 1-4:

[0224]

[0225] The synthesis of compound 1-4 was based on the synthesis of compound 1-1, except that bromobenzene was replaced by 4-bromoterphenyl. After synthesis and purification, the compound 1-4 was sublimed under high vacuum at 315°C to obtain a white molten compound with a yield of 64%. The mass spectrometry results of the obtained sample were: HR-MS (APCI): m / z 577.2406 [M+H] + ; C 43 H 31Calculated values of NO (%) : C, 89.3974; H, 5.4088; N, 2.4245; O, 2.7693; Measured values (%) : C, 89.3998; H, 5.4120; N, 2.4223; O, 2.7659.

[0226] Synthesis of Compounds 1-6:

[0227]

[0228]

[0229] The synthesis of Intermediate A was referred to the synthesis of Intermediate 3-3, replacing Intermediate 3-2 and iodobenzene with N-phenyl-4-biphenylamine and m-bromoiodobenzene.

[0230] The synthesis of Compound 1-6 was referred to the synthesis of Compound 1-1, replacing bromobenzene with Intermediate A. After synthesis and purification, it was sublimated under high vacuum at 335 °C to obtain white molten Compound 1-6 with a yield of 70%. The results of mass spectrometry detection of the obtained sample were: HR-MS (APCI): m / z 668.2828 [M+H] + ; C 49 H 36 Calculated values of N2O (%) : C, 87.9940; H, 5.4255; N, 4.1884; O, 2.3921; Measured values (%) : C, 87.9993; H, 5.4180; N, 4.1856; O, 2.3971.

[0231] Synthesis of Compound 1-22:

[0232]

[0233]

[0234] The synthesis of Intermediate A-1 was referred to the synthesis of Intermediate A, replacing m-bromoiodobenzene with 3,5-dibromoiodobenzene.

[0235] The synthesis of Intermediate A-2 was referred to the synthesis of Compound 1-1, using Intermediate A-1 and diphenylamine as reaction raw materials.

[0236] The synthesis of Compound 1-22 was referred to the synthesis of Compound 1-1, replacing bromobenzene with Intermediate A-2. After synthesis and purification, it was sublimated under high vacuum at 340 °C to obtain white molten Compound 1-22 with a yield of 53%. The results of mass spectrometry detection of the obtained sample were: HR-MS (APCI): m / z 835.3563 [M+H] + ; C 61 H 45Calculated values of N3O (%) : C, 87.6347; H, 5.4255; N, 5.0261; O, 1.9136; Found (%) : C, 87.6422; H, 5.4211; N, 5.0271; O, 1.9096.

[0237] Synthesis of Compound 2-18:

[0238]

[0239] The synthesis of Compound 2-18 was carried out according to the synthesis method of Compound 1-1. Intermediate 1 and bromobenzene were replaced with Intermediate 2 and 9-(4-bromophenyl)carbazole. After synthesis and purification, it was sublimated under high vacuum at 350 °C to obtain Compound 2-18 in white molten state with a yield of 62%. The results of mass spectrometry detection of the obtained sample were as follows: HR-MS (APCI): m / z 590.2358 [M+H] + ; C 43 H 30 Calculated values of N2O (%) : C, 87.4302; H, 5.1191; N, 4.7423; O, 2.7084; Found (%) : C, 87.4391; H, 5.1165; N, 4.7412; O, 2.7032.

[0240] Synthesis of Compound 2-66:

[0241]

[0242] The synthesis of Compound 2-66 was carried out according to the synthesis method of Compound 1-1. Intermediate 1 and bromobenzene were replaced with Intermediate 10 and Intermediate A. After synthesis and purification, it was sublimated under high vacuum at 330 °C to obtain Compound 2-66 in white crystalline state with a yield of 61%. The results of mass spectrometry detection of the obtained sample were as follows: HR-MS (APCI): m / z 668.2828 [M+H] + ; C 49 H 36 Calculated values of N2O (%) : C, 87.9940; H, 5.4255; N, 4.1884; O, 2.3921; Found (%) : C, 87.9879; H, 5.4248; N, 4.1892; O, 2.3981.

[0243] Synthesis of Compound 3-6:

[0244]

[0245]

[0246] The synthesis of Intermediate B was carried out by referring to the synthesis of Intermediate A, with N-phenyl-4-biphenylamine replaced by bis(4-biphenyl)amine.

[0247] The synthesis of Compound 3-6 was carried out with reference to the synthesis method of Compound 1-1. Intermediate 1 and bromobenzene were replaced with Intermediate 4 and Intermediate B. After synthesis and purification, it was sublimated under high vacuum at 355 °C to obtain a white molten Compound 3-6 with a yield of 61%. The results of mass spectrometry detection of the obtained sample were as follows: HR-MS (APCI): m / z 819.3613 [M+H] + ; C 61 H 45 N3 (%) Calculated: C, 89.3445; H, 5.5314; N, 5.1242; Found (%) : C, 89.3422; H, 5.5327; N, 5.1251.

[0248] Synthesis of Compound 3-11:

[0249]

[0250]

[0251] The synthesis of Intermediate C was carried out with reference to the synthesis of Intermediate 1-1, and 4-aminobiphenyl and 4-bromodibenzofuran were used as reaction raw materials.

[0252] The synthesis of Intermediate D was carried out with reference to the synthesis of Intermediate A, and N-phenyl-4-benzidine was replaced with Intermediate C.

[0253] The synthesis of Compound 3-11 was carried out with reference to the synthesis method of Compound 1-1. Intermediate 1 and bromobenzene were replaced with Intermediate 4 and Intermediate D. After synthesis and purification, it was sublimated under high vacuum at 340 °C to obtain a white crystalline Compound 3-11 with a yield of 58%. The results of mass spectrometry detection of the obtained sample were as follows: HR-MS (APCI): m / z 833.3406 [M+H] + ; C 61 H 43 N3O (%) Calculated: C, 87.8466; H, 5.1969; N, 5.0383; O, 1.9183; Found (%) : C, 87.8425; H, 5.2089; N, 5.0293; O, 1.9193.

[0254] Synthesis of Compound 3-49:

[0255]

[0256] The synthesis of compound 3-49 refers to the synthesis method of compound 1-1. Replace intermediate 1 with intermediate 16. After synthesis and purification, it is sublimated under high vacuum at 300 °C to obtain compound 3-49 in the form of white crystals, with a yield of 68%. The results of mass spectrometry detection of the obtained sample are as follows: HR-MS (APCI): m / z 500.2252 [M+H] + ; C 37 H 28 N2 (%) Calculated value: C, 88.7669; H, 5.6375; N, 5.5956; Measured value (%): C, 88.7712; H, 5.6306; N, 5.5982.

[0257] Synthesis of compound 3-125:

[0258]

[0259] The synthesis of compound 3-125 refers to the synthesis method of compound 1-1. Replace intermediate 1 and bromobenzene with intermediate 11 and intermediate B. After synthesis and purification, it is sublimated under high vacuum at 340 °C to obtain compound 3-125 in the form of white molten state, with a yield of 68%. The results of mass spectrometry detection of the obtained sample are as follows: HR-MS (APCI): m / z 819.3613 [M+H] + ; C 61 H 45 N3 (%) Calculated value: C, 89.3445; H, 5.5314; N, 5.1242; Measured value (%): C, 89.3462; H, 5.5326; N, 5.1212.

[0260] Referring to the synthesis methods of the above compounds, all the compounds in the present invention can be synthesized. The only difference is that according to the different products, different parent nucleus intermediates and intermediates corresponding to the modifying groups need to be used for replacement, and the mass dosage of the intermediate is changed according to the different molar amounts. The replacement relationships of the parent nucleus intermediate, the intermediate corresponding to the modifying group, the reactant and the compound are shown in Table 1.

[0261] Table 1 Replacement relationships of the parent nucleus intermediate, the intermediate corresponding to the modifying group, the reactant and the compound

[0262]

[0263] The performance parameters (including Tg temperature, HOMO energy level, LUMO energy level, and triplet energy T1) of the compounds synthesized in the present invention and the existing OLED materials HT2, H1 (Comparative Example 1), and H2 (Comparative Example 2) were measured, and the results are shown in Table 2.

[0264] Table 2 Measurement Results of Performance Parameters of Compounds and Existing Materials

[0265]

[0266] Note: The highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), and the triplet energy T1 are the data obtained from simulation calculations using Gaussian 09 software. The calculation method uses the B3LYP hybrid functional and the basis set 6-31g(d). The Tg temperature is the experimentally measured value, which is measured on a DSC-60 differential scanning calorimeter (Shimadzu Corporation, Japan) with a nitrogen flow rate of 10 ml / min.

[0267] As can be seen from Table 2, the compounds provided by the present invention have a relatively high glass transition temperature and good film-forming properties, which improve the lifespan of the OLED devices made of the materials containing the compounds of the present invention; they have appropriate triplet energy, HOMO energy level, and LUMO energy level, which are conducive to the carrier transport and the energy transfer between the host and the guest in the OLED devices. The compounds of the present invention are suitable for use as the second hole transport material and the light-emitting host material.

[0268] Taking some of the compounds provided by the present invention as examples, they are applied as the second hole transport material and the light-emitting host material to the organic electroluminescent devices to verify the excellent effects achieved.

[0269] Example 1

[0270] This example provides an organic electroluminescent device, and its structure is specifically as Figure 1 shown, including 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 stacked in sequence.

[0271] Among them, the substrate 1 is a glass substrate with a thickness of 0.7 mm. The material of the anode layer 2 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 NPB with a thickness of 60 nm; the material of the second hole transport layer 5 is compound 1-4 with a thickness of 10 nm; the light-emitting layer 6 uses RD01 as the light-emitting material and H1 as the host material, with a doping mass ratio of 6% and a thickness of 30 nm; the material of the hole blocking layer 7 is HB1 with a thickness of 10 nm; the material of the electron transport layer 8 is ET1 with a thickness of 35 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.

[0272] The structural formulas of the basic materials used in each functional layer of the device are as follows:

[0273]

[0274]

[0275]

[0276] The specific preparation steps of the above organic electroluminescent device are as follows:

[0277] (1) Clean the ITO anode layer on the transparent glass or plastic substrate, ultrasonically clean it with deionized water, acetone, and ethanol for 20 minutes each, and then perform plasma treatment in an oxygen atmosphere for 5 minutes;

[0278] (2) Evaporate the hole injection layer material HAT-CN on the ITO anode layer by vacuum evaporation, with a thickness of 5 nm, and this layer serves as the hole injection layer;

[0279] (3) Evaporate the hole transport material NPB on the hole injection layer by vacuum evaporation, with a thickness of 60 nm, and this layer serves as the first hole transport layer;

[0280] (4) Evaporate the hole transport material compound 1-4 on the first hole transport layer HT1 by vacuum evaporation, with a thickness of 15 nm, and this layer serves as the second hole transport layer;

[0281] (5) Co-evaporate the light-emitting layer on the second hole transport layer by vacuum evaporation, using H1 as the host material and RD01 as the doping material, with a doping mass ratio of 6% and a thickness of 30 nm;

[0282] (6) Evaporate the hole blocking material HB1 on the light-emitting layer by vacuum evaporation, with a thickness of 10 nm, and this layer serves as the hole blocking layer;

[0283] (7) Evaporate the electron transport material ET1 on the hole blocking layer by vacuum evaporation, with a thickness of 35 nm, and this layer serves as the electron transport layer;

[0284] (8) Evaporate the electron injection material Liq on the electron transport layer by vacuum evaporation, with a thickness of 2 nm, and this layer serves as the electron injection layer;

[0285] (9) Evaporate the cathode Al on the electron injection layer by vacuum evaporation, with a thickness of 100 nm. This layer is used as the cathode conductive electrode, and this layer is the cathode layer.

[0286] The cathode conductive electrode is used, and this layer is the cathode layer.

[0287] Examples 2 to 27

[0288] The preparation processes of Examples 2 to 27 are the same as that of Example 1, except that the second hole transporting material is the compound 1-6, compound 1-13, compound 1-22, compound 1-29, compound 1-66, compound 1-81, compound 2-6, compound 2-13, compound 2-18, compound 2-28, compound 2-41, compound 2-43, compound 2-66, compound 2-91, compound 3-6, compound 3-11, compound 3-23, compound 3-25, compound 3-40, compound 3-49, compound 3-55, compound 3-81, compound 3-110, compound 3-123, compound 3-125, compound 3-147, compound 3-158 synthesized in the preparation examples of the present invention.

[0289] Examples 28 to 46

[0290] The preparation processes of Examples 28 to 46 are the same as that of Example 1, except that the second hole transporting material is replaced by HT2 for compound 1-4, and the light-emitting host material H1 is replaced by the compound 1-1, compound 1-25, compound 1-53, compound 1-73, compound 2-1, compound 2-2, compound 2-4, compound 2-29, compound 2-57, compound 2-85, compound 3-1, compound 3-2, compound 3-17, compound 3-33, compound 3-49, compound 3-76, compound 3-118, compound 3-120, compound 3-121 synthesized in the preparation examples of the present invention.

[0291] Comparative Example 1

[0292] Comparative Example 1 is the same as Example 1, except that the second hole transporting material is replaced by compound HT2 for compound 1-4.

[0293] Comparative Example 2

[0294] Comparative Example 2 is the same as Comparative Example 1, except that the light-emitting host material H2 is replaced by H1.

[0295] The constituent components of the different devices prepared in Examples 1 to 46 and Comparative Examples 1 to 2 of the device of the present invention are shown in Table 3.

[0296] Table 3 Comparative table of the constituent components of the organic electroluminescent devices of each device example

[0297]

[0298] Connect the cathodes and anodes of each group of organic electroluminescent devices with a known driving circuit, and use a Keithley 2400 power supply combined with a PR670 photometer to test the voltage-efficiency-current density relationship of the OLED devices by standard methods; the lifespan of the devices is tested by the constant current method, and the test condition is a constant current density of 10 mA / cm 2 , and the time when the test brightness decays to 95% of the initial brightness is the LT95 lifespan of the device. The results are shown in Table 4.

[0299] Table 4 Comparison of the performance results of each group of organic electroluminescent devices

[0300]

[0301] As can be seen from Table 4, when the compounds provided by the present invention are used as hole transport materials and light-emitting host materials in OLED red-light devices, the performance is improved. For example, compared with HT2 in Comparative Example 1, the compound 2-18 in Example 10 as a hole transport material has a slightly lower turn-on voltage, and the luminous efficiency and service life are significantly improved. The luminance efficiency is increased by 57%, and the service life is increased by 37%; compared with H1 and H2 in Comparative Examples 1-2, the compound 3-76 in Example 43 as a light-emitting host material also has obvious improvements in luminance efficiency and lifespan. Especially compared with H2 in Comparative Example 2, the luminance efficiency is increased by 65%, and the service life is increased by 86%.

[0302] It can be seen that when the compounds of the present invention are used as hole transport materials and light-emitting host materials, the devices have good performance in terms of efficiency and lifespan. Moreover, the synthesis process of the materials is simple, and they have great application value in the application of OLED devices and have good industrialization prospects.

[0303] As described above, the basic principles, main features and advantages of the present invention are preferably described. The above embodiments and the description are only for describing the preferred embodiments of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, various changes and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the present invention.

Claims

1. A compound, characterized in that, It has the structures shown in Formula 1 to Formula 4, ， wherein, W is selected from one of N-L1-(NAr1Ar2) m , O, Y is selected from one of O, N-L2-(NAr3Ar4) n , and W and Y are not both O at the same time; N-L1-(NAr1Ar2) m and N-L2-(NAr3Ar4) n Ar1, Ar2, Ar3, and Ar4 in are substituted or unsubstituted C6-C30 aryl groups, or heteroaryl groups containing N, O, or S heteroatoms and having a carbon number in the range of C3-C30; N-L1-(NAr1Ar2) m m in it is selected from one of the integers 0, 1, and 2; N-L2-(NAr3Ar4) n n in is selected from one of the integers 0, 1, and 2; N-L1-(NAr1Ar2) m and N-L2-(NAr3Ar4) n wherein L1 and L2 in them are bridging groups respectively, and L1 and L2 may be the same or different; N-L1-(NAr1Ar2) m and N-L2-(NAr3Ar4) n the hydrogens in L1, L2, Ar1, Ar2, Ar3, and Ar4 in The bridging group is selected from one or a combination of two of benzene, naphthalene, biphenyl, terphenyl, and N-phenylcarbazole; The substituted or unsubstituted C6-C30 aryl group is selected from one of benzene, p-biphenyl, m-biphenyl, terphenyl, naphthalene, 1-phenylnaphthalene, and 2-phenylnaphthalene; The heteroaryl group containing N, O, S heteroatoms and having a carbon number of C3-C30 is selected from one of dibenzofuran, dibenzothiophene, N-phenylcarbazole, 9,9-dimethylfluorene, and 4-phenyldibenzofuran.

2. The compound according to claim 1, wherein The compound is selected from one of Formula 5 to Formula 16, 。 3. The compound according to claim 1, wherein The compound has the structure shown below: 。 4. The compound according to claim 3, wherein The intermediate for synthesizing the compound is selected from one of the following intermediates, 。 5. Use of the compound according to any one of claims 1 to 4 in an organic electroluminescent device.

6. Use of the compound according to any one of claims 1 to 4 in the preparation of a hole transport material or a light-emitting host material.

7. An organic electroluminescent device, comprising an anode layer, a cathode layer, and an organic thin film layer located between the anode layer and the cathode layer, wherein the organic thin film layer comprises a hole injection layer, a first hole transport layer, a second hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, characterized in that, The second hole transport layer or the light-emitting layer contains the compound according to any one of claims 1 to 4.

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