A compound and its application, and an organic electroluminescent device containing the same

Abstract

The present invention relates to a novel organic compound having a structure of the following formula (1): wherein: A, B and C are independently selected from a substituted or unsubstituted C6-C30 arylamino group, a substituted or unsubstituted C3-C30 heteroarylamino group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, and at least one of A and B is a group represented by formula (2). When the compound of the present invention is used as an electron transport layer material in an OLED device, it exhibits excellent device performance and stability. The present invention also protects an organic electroluminescent device using the compound of the above general formula.

Description

Technical Field

[0001] The present invention relates to an organic compound, which can be used as a charge transport material in electronic devices, in particular a hole-type charge transport material, and in particular, used as a hole injection and hole transport material in an organic electroluminescent device. The present invention also relates to the application of the compound in an organic electroluminescent device. Background Art

[0002] OLED (Organic light-Emitting diode) display technology has the advantages of self-luminescence, high contrast, fast response speed, and high color saturation. In particular, it does not contain a backlight source, has a simple device structure, a wide operating temperature range, and can achieve flexible display by bending the substrate. These characteristics make it the next generation display technology after LCD, and it has gradually shown its broad prospects for commercial applications.

[0003] Generally, the simplest OLED device structure is to evaporate an organic light-emitting material with a thickness of tens to hundreds of nanometers between two electrodes, and make the material emit light by applying a certain voltage to the two electrodes. In order to achieve higher luminous efficiency and life, it is necessary to introduce various auxiliary layers to balance the transmission of carriers, usually including hole injection layer, hole transport layer, electron blocking layer, hole blocking layer, electron transport layer, and electron injection layer. An organic electroluminescent device with good efficiency and long life is usually the result of optimized matching of device structure and various organic materials. In order to achieve higher luminous efficiency and longer working life at a lower operating voltage, researchers have been committed to researching and developing new organic electroluminescent materials, in order to obtain higher performance materials and enable OLED light-emitting devices to achieve better working conditions.

[0004] In OLED devices, hole transport materials can improve the efficiency of hole transport in the device and have an important impact on the performance of the device. The basic requirements for hole transport materials include (1) having a high hole mobility; (2) its highest molecular occupied orbital energy level (HOMO) must match the functional layer in contact with it, so as to achieve effective hole injection and transport; (3) suitable thermal stability, requiring the hole material to be able to evaporate to form a dense and uniform film to prevent the appearance of pinholes and avoid defects that affect efficiency and life. Therefore, the hole material needs to have a high glass transition temperature (T g ), which is conducive to the formation of a stable amorphous morphology.

[0005] Fluorene derivatives have a special rigid planar structure, high chemical stability, and good hole transport performance. Patent US2008000736 develops a material with a 2,7-bis-triarylamine structure of fluorene to achieve the purpose of improving efficiency; CN107641116A develops a disubstituted triarylamine material at the 2,3 position of fluorene to improve device performance. However, in practical applications, it is still necessary to continuously improve and balance the hole mobility of the device to meet low driving voltage, high current efficiency, and long service life, so the development of new hole transport materials is still one of the current urgent tasks. Summary of the invention

[0006] The purpose of the present invention is to design a fluorene derivative, and through the selection of substituents and substitution positions, ensure that the compound has a larger conjugated plane and strong intramolecular electron transfer, thereby obtaining higher thermal stability and optical stability, especially having excellent hole transport performance and high carrier mobility.

[0007] The present invention provides a compound represented by the following general formula (1):

[0008]

[0009] in,

[0010] R and R' are the same or different, and are independently selected from one of the following substituted or unsubstituted substituents: C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C1-C20 alkoxy, C6-C18 aryl, C6-C18 aryloxy or C4-C18 heteroaryl, and R and R' may be connected to form a ring;

[0011] R 1 and R 2 Each independently represents a substituent that is monosubstituted to the maximum number allowed, R 1 and R 2 Each is independently selected from hydrogen, halogen, cyano, nitro, hydroxyl or one of the following substituted or unsubstituted substituents: C1-C12 alkyl, C1-C12 thioalkyl, C2-C20 alkenyl, C2-C20 alkynyl, C1-C12 alkoxy, silane;

[0012] A, B and C are independently selected from a substituted or unsubstituted C6-C30 arylamino group, a substituted or unsubstituted C3-C30 heteroarylamino group, a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C3-C30 heteroaryl group, and at least one of A and B is a group represented by the following formula (2):

[0013]

[0014] In formula (2), Ar 1 and Ar 2 Each independently selected from a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group;

[0015] L 1 and L 2 are independently selected from a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group;

[0016] When the above groups have substituents, the substituents are selected from halogen, C1-C 10 Alkyl or cycloalkyl, C2-C 10 alkenyl, C1-C6 alkoxy or thioalkoxy group, C6-C 30 Monocyclic aromatic hydrocarbons or condensed aromatic hydrocarbon groups, C3-C 30 One of the monocyclic heteroaromatic hydrocarbon or condensed heteroaromatic hydrocarbon groups.

[0017] Furthermore, the above formula (1) of the present invention is preferably as shown in the following formula (3-1) or (3-2):

[0018]

[0019] In formula (3-1) and (3-2), A, B and C are independently selected from substituted or unsubstituted C6 to C 30 Aryl, substituted or unsubstituted C3~C 30 One of the heteroaryl groups;

[0020] R and R', R 1 and R 2 , L 1 and L 2 ,Ar 1 and Ar 2 The definitions of are the same as those in formula (1) and formula (2).

[0021] Furthermore, in formulas (3-1) and (3-2), L 1 and L 2 Each of them is independently preferably a single bond, or is preferably a substituted or unsubstituted group selected from the group consisting of phenylene, biphenylene, naphthylene, and phenanthrylene; Ar 1 and Ar 2 Each of the following groups is independently selected from substituted or unsubstituted groups: phenyl, biphenyl, naphthyl, phenanthryl, fluorene, dibenzofuran, and dibenzothiophene.

[0022] Furthermore, in formula (3-1), B and C are each independently preferably substituted or unsubstituted by the following groups: benzene, naphthalene, anthracene, benzanthracene, phenanthrene, triphenylene, pyrene, cave, perylene, fluoranthene, tetracene, pentacene, benzopyrene, biphenyl, isophenyl, terphenyl, triphenyl, tetraphenyl, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indenofluorene, trimerized indene, isotrimerized indene, spirotrimerized indene, spiroisotrimerized indene, furan, benzofuran, isobenzofuran, dibenzofuran, Furan, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthymidazole, phenanthroimidazole, pyridimidazole, pyrazinoimidazole, quinoxalinoimidazole, oxazole, benzoxazole, naphthymidazole, anthraquinone, phenanthroquinone, 1,2- Thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, 1,5-diazaanthracene, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazaperylene, pyrazine, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxathrone One of oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine and benzothiadiazole; the best choice is phenyl or naphthyl.

[0023] Furthermore, in formula (3-2), A and C are each independently preferably substituted or unsubstituted by the following groups: benzene, naphthalene, anthracene, benzanthracene, phenanthrene, triphenylene, pyrene, cave, perylene, fluoranthene, tetracene, pentacene, benzopyrene, biphenyl, isophenyl, terphenyl, triphenyl, tetraphenyl, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indenofluorene, trimerized indene, isotrimerized indene, spirotrimerized indene, spiroisotrimerized indene, furan, benzofuran, isobenzofuran, dibenzofuran, Furan, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthymidazole, phenanthroimidazole, pyridimidazole, pyrazinoimidazole, quinoxalinoimidazole, oxazole, benzoxazole, naphthymidazole, anthraquinone, phenanthroquinone, 1,2- Thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, 1,5-diazaanthracene, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazaperylene, pyrazine, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxathrone One of oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine and benzothiadiazole; the best choice is phenyl or naphthyl.

[0024] Furthermore, in formulas (3-1) and (3-2), R 1 and R 2Each of the following is preferably independently hydrogen, or is preferably one or two or more of the following groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, vinyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, methoxy, trifluoromethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, sec-pentoxy, 2-methylbutyl oxy, n-hexyloxy, cyclohexyloxy, n-heptyloxy, cycloheptyloxy, n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy, 2,2,2-trifluoroethoxy, methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio, sec-butylthio, tert-butylthio, n-pentylthio, sec-pentylthio, n-hexylthio, cyclohexylthio, n-heptylthio, cycloheptylthio, n-octylthio, cyclooctylthio, 2-ethylhexylthio, trifluoromethylthio, pentafluoroethylthio, 2,2,2-trifluoroethylthio, ethylthio, propylthio, butylthio, pentylthio, cyclopentylthio, hexylthio, cyclohexylthio, heptylthio, cycloheptylthio, octenylthio, cyclooctenylthio, ethynylthio, propynylthio, butynylthio, pentynylthio, hexynylthio, heptynylthio or octynylylthio; the most preferred is phenyl or naphthyl.

[0025] As preferred structures of the compounds involved in the present invention, the compounds with the structures shown below can be cited, but are not limited to these compounds:

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055] As another aspect of the present invention, the above-mentioned compound of the general formula of the present invention is used as a hole transport material, a hole injection material or an electron blocking material in an organic electroluminescent device.

[0056] As another aspect of the present invention, the present invention also provides an organic electroluminescent device, comprising a first electrode, a second electrode and an organic layer including at least one light-emitting layer inserted between the first electrode and the second electrode, characterized in that the organic layer contains a compound represented by the general formula (1) or formula (3-1) or formula (3-2) as described above. Preferably, the hole transport layer, the hole injection layer or the electron blocking layer contained in the organic layer contains a compound represented by the general formula (1-1) or formula (3-1) or formula (3-2) as described above.

[0057] The principle of using the above-mentioned compounds of the present invention as hole transport materials, hole injection materials or electron blocking materials in organic electroluminescent devices is still unclear, and it is speculated that the reasons may be as follows:

[0058] The general formula compound of the present invention introduces a specific substituent group at the 2nd or 3rd position of the fluorene derivative mother nucleus, so that the empty configuration of the molecule is distorted to a certain extent due to the influence of the specific substituent group, and the steric hindrance of the substituent group makes the spatial configuration of the molecule relatively stable, thereby enhancing the molecular stability. The 7th position is the reactive position of fluorene, which is easy to trigger the reaction of the molecule under special circumstances. By introducing the substituent group, the stability of the fluorene ring can be further increased, and it is also beneficial to improve the charge mobility of the molecule, so that it can meet the different use requirements of the preparation and application in the organic electroluminescent device, and can effectively achieve the beneficial effects of reducing the device driving voltage, extending the life of the device, etc.

[0059] When the novel compound obtained by structural modification and optimization of the present invention is used in the preparation and application of an organic electroluminescent device, the purpose of reducing the driving voltage of the device and increasing the life of the device can be achieved, thereby obtaining better device performance. DETAILED DESCRIPTION

[0060] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0061] The compounds of the synthesis methods not mentioned in the examples are all raw materials obtained through commercial channels. Various chemicals used in the examples such as petroleum ether, ethyl acetate, toluene, tetrahydrofuran, N,N-dimethylformamide, dichloromethane, cesium carbonate, potassium carbonate, palladium acetate, 2-dicyclohexylphosphine-2,4,6-triisopropylbiphenyl (XPhos), 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (SPhos), tetrakis(triphenylphosphine)palladium, sodium tert-butoxide and other basic chemical raw materials can be bought in the domestic chemical product market.

[0062] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The compound represented by the general formula (1) of the present invention can be obtained by the synthetic route shown below.

[0063] General synthetic route of the compounds (449-896) described in the present invention:

[0064]

[0065] Reference synthetic routes of the compounds (1-448) described in the present invention

[0066] Specific embodiments

[0068] Synthesis of intermediate M1:

[0069]

[0070] Synthesis of compound M1-1

[0071] Take 2-bromo-7-hydroxy-9,9-dimethylfluorene (18g, 62.3mmol) and dissolve it in acetic acid (400mL), add nitric acid (5.89g, 93.5mmol), heat to 60℃, then slowly add concentrated sulfuric acid (6.72g, 68.6mmol) to the above solution through a constant pressure dropping funnel, gradually solid precipitates, continue stirring for 2h after the dripping, cool down. Pour the reaction solution into 1L of ice water, stir well, filter and collect the solid, rinse the solid with water, dry to obtain 19g, and use it directly in the next step.

[0072] Synthesis of Compound M1-2

[0073] Dissolve compound M1-1 (19 g, 62.0 mmol) in dichloromethane (250 mL), add triethylamine (7.5 g, 80.6 mmol), cool to 0 ° C, add trifluoromethanesulfonyl chloride (13.5 g, 80.0 mmol), and after the addition, naturally warm to room temperature and stir for 5 hours. Pour the reaction solution into 500 mL of saturated ammonium chloride aqueous solution, extract with dichloromethane (200 mL*3), combine the organic phases, wash once with saturated brine, and dry over anhydrous sodium sulfate. Concentrate to obtain an oily substance, and purify with a silica gel column (PE / EA, 10 / 1) to obtain 23 g of a yellow solid.

[0074] Synthesis of Compound M1-3

[0075] Compound M1-2 (9.2 g, 19.7 mmol), phenylboric acid (5.8 g, 47.28 mmol) and potassium carbonate (8.2 g, 59.2 mmol) were added to a three-necked flask containing toluene (150 mL), ethanol (70 mL) and water (70 mL), and stirred thoroughly to dissolve. Then, under nitrogen protection, tetrakis(triphenylphosphine)palladium (228 mg, 0.197 mmol) was added, and the reaction system was heated to 90°C for 20 h. After cooling, the reaction solution was poured into 300 mL of saturated ammonium chloride aqueous solution for extraction. The aqueous phase was extracted twice with toluene (100 mL), the organic phases were combined, dried over anhydrous sodium sulfate, concentrated, and the crude product was purified with a silica gel column (petroleum ether / dichloromethane = 8 / 1) to obtain a yellow solid. This solid was recrystallized with toluene and methanol to obtain 8 g of a light yellow solid.

[0076] Synthesis of compound M1

[0077] The above compound M1-3 (8 g) was placed in a single-mouth bottle containing methanol (200 mL) and THF (200 mL), and Pd / C hydrate (0.5 g) was added. The air in the bottle was fully replaced with a hydrogen bag, and the hydrogen pressure was maintained and stirred for 24 hours. After the reaction was completed, the palladium carbon was removed by filtration, and the filtrate was concentrated to obtain a light yellow solid, which was purified by a silica gel column to obtain an off-white solid (7 g).

[0078] Synthesis of intermediate M2:

[0079]

[0080] Synthesis of compound M2-1

[0081] In a four-necked flask equipped with a condenser, add the raw material compound 2-bromo-7-amino-9,9-dimethylfluorene (28.7g, 0.1mol) dissolved in dichloromethane (500mL) and cool the reaction system to 0°C in an ice-water bath. Then slowly add NBS (5.6g, 0.1mmol) to the above solution in batches, control the reaction temperature, and continue stirring for 1h after NBS is completely added to the system. Monitor by TLC until the raw material disappears. Then pour the reaction solution into 500mL of ammonium chloride aqueous solution for extraction and separation. The aqueous phase is extracted with 200mL of dichloromethane, and the organic phases are combined, dried over anhydrous sodium sulfate, and concentrated to obtain a yellow solid. The crude product is further purified by silica gel chromatography to obtain 25g of light yellow solid.

[0082] Synthesis of compound M2

[0083] Compound M2-1 (20.0 g, 54.8 mmol), phenylboric acid (14.7 g, 120.6 mmol) and potassium carbonate (18.9 g, 137.0 mmol) were added to a three-necked flask containing toluene (300 mL), ethanol (150 mL) and water (1500 mL), and the mixture was stirred and dissolved. Then, under nitrogen protection, tetrakis(triphenylphosphine)palladium (630 mg, 0.548 mmol) was added, and the reaction system was heated to 90°C for 20 h. After cooling, the reaction solution was poured into 300 mL of saturated aqueous ammonium chloride solution for extraction. The aqueous phase was extracted twice with toluene (100 mL), the organic phases were combined, dried over anhydrous sodium sulfate, concentrated, and the crude product was purified by silica gel column (petroleum ether / dichloromethane = 8 / 1) to obtain 15 g of light yellow solid.

[0084] Synthesis of intermediate M3:

[0085]

[0086] The synthesis of intermediate M3 can refer to the synthesis method of M1, except that phenylboronic acid is replaced by 1-naphthaleneboronic acid.

[0087] Synthesis of intermediate M4;

[0088]

[0089] The synthesis of intermediate M4 refers to the synthesis of M1, except that phenylboronic acid is replaced by 2-naphthaleneboronic acid.

[0090] Synthesis of intermediate M5:

[0091]

[0092] The synthesis of intermediate M5 was based on the synthesis of M2, except that phenylboronic acid was replaced by 1-naphthaleneboronic acid.

[0093] Synthesis of intermediate M6:

[0094]

[0095] The synthesis of intermediate M6 was based on the synthesis of M2, except that phenylboronic acid was replaced with 2-naphthaleneboronic acid.

[0096] Synthesis Example 1:

[0097] Synthesis of compound C6:

[0098]

[0099] Synthesis of compound C6-1:

[0100] Add intermediate M1 (10g, 27.7mmol), 4-bromobiphenyl (7.1g, 30.5mmol) and sodium tert-butoxide (3.5g, 36.0mmol) to 150mL of toluene, stir to dissolve, fully replace with nitrogen, and then add Pd2(dba)3 (254mg, 0.277mmol) and SPhos (227mg, 0.554mmol). Under the protection of nitrogen, heat to reflux reaction for 20h, and monitor by TLC until the raw material reacts completely. Then cool to room temperature, extract with saturated ammonium chloride solution, extract the aqueous phase with toluene (150mL*2), combine the organic phases, wash again with saturated brine, dry with anhydrous sodium sulfate, filter, and concentrate to obtain a crude product. Continue to purify with silica gel column to obtain 12g of yellow solid.

[0101] Synthesis of compound C6:

[0102] Add intermediate C6-1 (10g, 19.5mmol), 3-bromobiphenyl (5.4g, 23.4mmol) and sodium tert-butoxide (2.4g, 25.4mmol) to 150mL of toluene, stir to dissolve, fully replace with nitrogen, and then add Pd2(dba)3 (254mg, 0.277mmol) and SPhos (227mg, 0.554mmol). Under the protection of nitrogen, heat to reflux reaction for 20h, and monitor by TLC until the raw material is completely reacted. Then cool to room temperature, extract with saturated ammonium chloride solution, extract the aqueous phase with toluene (150mL*2), combine the organic phases, wash again with saturated brine, dry with anhydrous sodium sulfate, filter, and concentrate to obtain a crude product. Continue to purify with silica gel column to obtain 10.3g of yellow solid, and the product is recrystallized twice with toluene and methanol to obtain 6.2g of light yellow solid.

[0103] Synthesis Example 2:

[0104] Synthesis of compound C454:

[0105]

[0106] Synthesis of compound C454-1:

[0107] Add intermediate M2 (10g, 27.7mmol), 4-bromobiphenyl (7.1g, 30.5mmol) and sodium tert-butoxide (3.5g, 36.0mmol) to 150mL of toluene, stir to dissolve, fully replace with nitrogen, and then add Pd2(dba)3 (254mg, 0.277mmol) and SPhos (227mg, 0.554mmol). Under the protection of nitrogen, heat to reflux reaction for 20h, and monitor by TLC until the raw material reacts completely. Then cool to room temperature, extract with saturated ammonium chloride solution, extract the aqueous phase with toluene (150mL*2), combine the organic phases, wash again with saturated brine, dry with anhydrous sodium sulfate, filter, and concentrate to obtain a crude product. Continue to purify with silica gel column to obtain 10g of yellow solid.

[0108] Synthesis of compound C454:

[0109] Add intermediate C454-1 (10g, 19.5mmol), 3-bromobiphenyl (5.4g, 23.4mmol) and sodium tert-butoxide (2.4g, 25.4mmol) to 150mL of toluene, stir to dissolve, fully replace with nitrogen, and then add Pd2(dba)3 (254mg, 0.277mmol) and SPhos (227mg, 0.554mmol). Under the protection of nitrogen, heat to reflux reaction for 20h, and monitor by TLC until the raw material is completely reacted. Then cool to room temperature, extract with saturated ammonium chloride solution, extract the aqueous phase with toluene (150mL*2), combine the organic phases, wash again with saturated brine, dry with anhydrous sodium sulfate, filter, and concentrate to obtain a crude product. Continue to purify with silica gel column to obtain 12.5g of yellow solid, and the product is recrystallized twice with toluene and methanol to obtain 7.6g of light yellow solid.

[0110] The remaining synthesis examples can be synthesized by referring to the above method, and the intermediates and raw materials used can be referred to the following Table 1:

[0111] Table 1

[0112]

[0113]

[0114]

[0115]

[0116] By replacing different Ar 1 ,Ar 2Substituents (sometimes referred to as aryl halides in the art) can obtain different target compounds. It should be noted that the Buchwald-Hartwig coupling method is used in the above-mentioned synthesis method of aromatic amines, but it is not limited to this coupling method. Those skilled in the art can also choose other methods, such as Stille coupling method, Grignard reagent method, Kumada-Tamao and other known methods, but are not limited to these methods. Any equivalent synthesis method can be used to achieve the purpose of connecting substituents A1 and A2 to the amino group, and can be selected according to needs.

[0117] Device Embodiment

[0118] Implementation

[0119] OLED includes a first electrode, a second electrode, and an organic material layer between the electrodes. The organic material can be divided into multiple regions. For example, the organic material layer can include a hole transport region, a light emitting layer, and an electron transport region.

[0120] In a specific embodiment, a substrate may be used below the first electrode or above the second electrode. The substrate is a glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, a thin film transistor (TFT) may also be provided on the substrate used as a display.

[0121] The first electrode can be formed by sputtering or depositing the material used as the first electrode on the substrate. When the first electrode is used as an anode, an oxide transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO) and any combination thereof can be used. When the first electrode is used as a cathode, a metal or alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag) and any combination thereof can be used.

[0122] The organic material layer can be formed on the electrode by vacuum thermal evaporation, spin coating, printing, etc. The compound used as the organic material layer can be organic small molecules, organic macromolecules and polymers, and combinations thereof.

[0123] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a hole transport layer (HTL) of a single-layer structure, including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport region can also be a multi-layer structure including at least one layer of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0124] In one aspect of the present invention, the hole transport region material can be selected from one or more compounds represented by formula (1) of the present invention, and can also be selected from but not limited to phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives such as the compounds shown in HT-1 to HT-34 below; or any combination thereof.

[0125]

[0126]

[0127] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can use one or more compounds represented by formula (1) of the present invention, or one or more compounds of HT-1 to HT-34, or one or more compounds of HI1 to HI3 below; or a combination of these compounds.

[0128]

[0129] The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit light of different wavelength spectra, and may also include a host material (Host). The light-emitting layer may be a monochrome light-emitting layer that emits a single color such as red, green, and blue. A plurality of monochrome light-emitting layers of different colors may be arranged in a plane according to a pixel pattern, or may be stacked together to form a color light-emitting layer. When light-emitting layers of different colors are stacked together, they may be separated from each other or may be connected to each other. The light-emitting layer may also be a single color light-emitting layer that can simultaneously emit different colors such as red, green, and blue.

[0130] According to different technologies, the light-emitting layer material can be made of different materials such as fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescent materials. In an OLED device, a single light-emitting technology can be used, or a combination of multiple different light-emitting technologies can be used. These different light-emitting materials classified by technology can emit light of the same color or different colors.

[0131] In one aspect of the present invention, the light-emitting layer adopts fluorescent electroluminescence technology. The fluorescent host material of the light-emitting layer can be selected from, but not limited to, one or more combinations of BFH-1 to BFH-16 listed below.

[0132]

[0133] In one aspect of the present invention, the light-emitting layer adopts fluorescent electroluminescence technology. The fluorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of BFD-1 to BFD-12 listed below.

[0134]

[0135] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology, and the main material of the light-emitting layer is selected from, but not limited to, one or more combinations of GPH-1 to GPH-80.

[0136]

[0137]

[0138]

[0139]

[0140] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0141]

[0142]

[0143]

[0144] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0145]

[0146]

[0147] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0148]

[0149] In one aspect of the present invention, the light-emitting layer adopts the technology of thermally activated delayed fluorescence luminescence. The fluorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of TDE1-TDE39 listed below.

[0150]

[0151]

[0152]

[0153] In one aspect of the present invention, the light-emitting layer adopts the technology of thermally activated delayed fluorescence luminescence, and the main material of the light-emitting layer is selected from, but not limited to, one or more combinations of TDH-1 to TDH-24.

[0154]

[0155]

[0156] The OLED organic material layer may further include an electron transport region between the light emitting layer and the cathode. The electron transport region may be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. The electron transport region may also be a multilayer structure including at least one layer of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0157] In one aspect of the present invention, the electron transport layer material can be selected from, but not limited to, one or more combinations of ET-1 to ET-57 listed below.

[0158]

[0159]

[0160]

[0161]

[0162] The device may further include an electron injection layer located between the electron transport layer and the cathode. Materials for the electron injection layer include, but are not limited to, one or more combinations of the following.

[0163] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca.

[0164] The cathode material can be selected from but not limited to metals, metal mixtures, and oxides such as magnesium-silver mixtures, LiF / Al, and ITO.

[0165] The preparation process of the organic electroluminescent device in Example IVD-1 is as follows:

[0166] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone:ethanol, baked in a clean environment to completely remove the water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0167] Place the glass substrate with the anode in a vacuum chamber and evacuate to a vacuum of <1×10 -5 Pa, vacuum thermally evaporate 10nm of HT-4:HIL-3 (97 / 3, w / w) mixture as a hole injection layer and 60nm of compound C6 as a hole transport layer on the above anode layer film in sequence,

[0168] HT-14 was vacuum-deposited on the hole transport layer as the electron blocking layer of the device, with a deposition rate of 0.1 nm / s and a total deposition film thickness of 35 nm.

[0169] Phosphorescent green light: 40 nm ternary mixture of compounds GPH-46:GPH-3:GPD-12 (100:100:20, w / w / w) as the light-emitting layer;

[0170] A 25nm mixture of compound ET-46:ET-57 (50 / 50, w / w) was used as the electron transport layer, 1nm of LiF was used as the electron injection layer, and 150nm of metal aluminum was used as the cathode. The total evaporation rate of all organic layers and LiF was controlled at 0.1nm / sec, and the evaporation rate of the metal electrode was controlled at 1nm / sec.

[0171] Device examples IVD-2 to IVD-12 were prepared in the same manner as IVD-1, except that C6 in the hole transport layer was replaced with compounds shown in the examples in Table 2.

[0172] Device comparison examples CCD-1 to CCD-4 were made in the same manner as device example IVD-1, except that C6 in the hole transport layer was replaced by HT-4, R-1, R-2 and R-3, respectively.

[0173] The structures of the comparative example compounds R-1, R-2 and R-3 used are as follows:

[0174]

[0175] Device testing method:

[0176] The organic electroluminescent device prepared by the above process was subjected to the following performance tests:

[0177] At the same brightness, the driving voltage and device life of the organic electroluminescent devices prepared in Examples 1 to 12 and Comparative Examples 1 to 4 were measured using a digital source meter and a brightness meter. Specifically, the voltage was increased at a rate of 0.1 V per second, and the brightness of the organic electroluminescent device was measured when it reached 10000 cd / m 2 The voltage at the initial brightness is the driving voltage; the life test of LT95 is as follows: at an initial brightness of 20000cd / m 2 Under this condition, the current is kept constant and the brightness of the organic electroluminescent device is measured by a brightness meter and drops to 19000cd / m 2 The time in hours.

[0178] The performance of organic electroluminescent devices is shown in the following table:

[0179] Table 2:

[0180]

[0181]

[0182] From the comparison results of the performance data of each comparative example and each example in Table 2 above, it can be seen that when other materials in the structure of the organic electroluminescent device prepared by the present invention are the same, the device prepared by using the general compound of the present invention as the hole transport material, compared with the device using the compound in the prior art as the hole transport material, the compound of the present invention improves the hole transport performance, thereby reducing the starting voltage of the device and improving the life.

[0183] The compounds of the embodiments of the present invention can also be used as electron blocking layers. The device structure and preparation method are the same as those of the device embodiment IVD-1, except that C6 in the hole transport layer is replaced by HT-4, and the electron blocking layer material HT-14 is replaced by the corresponding material described in the electron blocking layer of the embodiment in Table 3. The information and properties of the electron blocking layer materials of each embodiment are summarized in Table 3 below.

[0184] The driving voltage and device life of the organic electroluminescent devices prepared in Examples 13 to 20 and Comparative Examples 5 to 7 were measured according to the above device testing method. The performance of the organic electroluminescent devices is shown in Table 3 below:

[0185] Table 3

[0186]

[0187]

[0188] The above results show that when the novel organic material of the present invention is used as an electron blocking material of an organic electroluminescent device, it can effectively reduce the starting and ending voltage and increase the service life.

[0189] The compounds listed in the present invention are not limited to use as hole transport materials or electron blocking materials. For example, C111, C139, etc. can be used as an electron blocking layer as well as a hole transport layer.

[0190] Although the present invention has been described in conjunction with the embodiments, the present invention is not limited to the above embodiments. It should be understood that under the guidance of the concept of the present invention, those skilled in the art can make various modifications and improvements. The appended claims summarize the scope of the present invention.

[0191] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A compound of the general formula, as shown in the following formula (1): in, R and R' are both methyl groups; R 1 and R 2 Selected from hydrogen; A, B and C are independently selected from phenyl, naphthyl, anthracenyl, biphenyl, terphenyl or fluorenyl, and one of A and B is a group represented by the following formula (2): In formula (2), Ar 1 and Ar 2 Each independently selected from the following groups: one of phenyl, biphenyl, naphthyl, phenanthryl, fluorene, dibenzofuran, and dibenzothiophene; L 1 and L 2 Each of them is independently selected from a single bond or one of the following groups: phenylene, biphenylene, naphthylene and phenanthrylene.

2. A specific compound is selected from the following structures:

3. Use of the compound according to any one of claims 1 to 2 as a hole transport material, a hole injection material or an electron blocking material in an organic electroluminescent device.

4. An organic electroluminescent device comprising a first electrode, a second electrode and one or more organic layers inserted between the first electrode and the second electrode, characterized in that: The organic layer comprises at least one compound according to any one of claims 1 to 2.

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