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

Abstract

The present invention relates to a novel organic compound having the structure of the following formula (1): wherein one of A and B is of formula Y 1 As shown, the other is as shown in formula Y 2 As shown. 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 a novel triarylamine compound and its application, and an organic electroluminescent device containing the same. The compound can be used as a hole transport layer material in an organic electroluminescent device, including hole injection, hole transport, and electron blocking layers. Devices using the novel triarylamine compound have significantly improved driving voltage, luminous efficiency, and device life. Background Art

[0002] OLED (organic light-emitting diode) refers to the phenomenon that organic functional materials emit light under the action of electric field and are stimulated by current and voltage. It is a process that directly converts electrical energy into light energy. In 1979, Dr. Deng Qingyun, the "Father of OLED", accidentally discovered the electroluminescent properties of organic thin film devices in the laboratory; in 1987, Dr. Deng Qingyun and others produced a double-layer OLED device using TPD as a hole transport material and Alq3 as a luminescent material. The device can achieve a brightness of 1000nit at 10V and a life span of more than 100 hours, making the practical application of OLED technology possible. OLED devices are all-solid-state self-luminous devices with the characteristics of fast response speed, wide viewing angle, and wide operating temperature range. Organic light-emitting materials can be structurally designed and improved according to the requirements of use, and full-color output can be achieved in theory. Compared with other display technologies, OLED display technology has a simpler structure and can realize ultra-thin large-area flat-panel display. The OLED display screen with the characteristics of lightness, flexibility, and foldability makes people full of endless imagination about its application in real life.

[0003] Nowadays, the structure of OLED devices is usually composed of different functional materials added in a certain order between the cathode and the anode. These materials can be roughly divided into luminescent materials, hole injection materials, hole transport materials, electron transport materials, etc. according to their functions. The core part of the device is the luminescent layer that allows the positively charged carriers from the anode and the negatively charged carriers from the cathode to recombine to produce excitons. In order to effectively alleviate the aggregation of excitons in the luminescent material, avoid concentration quenching, and improve the luminescence efficiency, the luminescent layer generally adopts a host-guest doping system, and the excitons generated by the host are transmitted to the dopant, thereby emitting high-efficiency light. In the process of electrical excitation, according to the quantum spin statistics theory, one-quarter of these generated excitons are in the singlet excited state and three-quarters are in the triplet excited state. The luminescence phenomenon of deexcitation from the singlet excited state to the ground state is called fluorescence; the luminescence phenomenon of deexcitation from the triplet excited state to the ground state is called phosphorescence. In general organic luminescent materials, triplet excitons cannot be used to radiate light because the radiative transition of triplet excitons to the ground state is spin-forbidden. Therefore, the theoretical value of the quantum efficiency of fluorescent materials does not exceed 25%, and the low efficiency seriously restricts the development of OLED. However, scientists have found that transition metals such as Ir 3+ , Pt 2+ 、Ru 2+ , Os 2+ The complex material can make the OLED device obtain 100% internal quantum efficiency through the spin-orbit coupling of heavy metal atoms. The emergence of phosphorescent materials has accelerated the process of OLED practical application.

[0004] At present, OLED display technology still has the problems of high driving voltage and short display life, which seriously affect the further practical application of this technology. Therefore, it is necessary to continue to work hard to develop organic light-emitting devices with low voltage driving, high brightness and long life.

[0005] As mentioned above, the hole transport layer plays a very important role in OLED devices. Hole transport materials with excellent hole mobility are conducive to the rapid transfer of positive charge carriers to the light-emitting layer. By adjusting the reasonable barrier energy level, the carrier injection balance is achieved, thereby reducing the device driving voltage. On the other hand, in order to make the excitons generated in the light-emitting layer completely captured by the light-emitting material to produce light, avoid the excitons from being transferred to the transport layer, and ultimately lead to light emission at the interface between the hole transport layer and the light-emitting layer, resulting in color cast and reduced luminescence efficiency. This requires that the hole transport material also needs to have the ability to block the diffusion of excitons to the hole transport layer, prevent efficiency roll-off and improve the stability of the device. Summary of the invention

[0006] In order to solve the above problems, the present invention aims to provide a novel compound having excellent hole mobility and electron blocking ability. When used as a hole transport layer, the hole transport speed can be increased, which is beneficial to the injection balance of carriers; when used as an electron blocking layer, the transfer of excitons to the hole transport layer can be blocked, the efficiency roll-off phenomenon can be suppressed, and a stable organic light-emitting device with low voltage and long life can be realized.

[0007] The present invention provides a new type of compound of general formula, which can be represented by the following chemical formula (1):

[0008]

[0009] in:

[0010] R and R' are the same or different and are independently selected from C1 to C 20 Alkyl, alkenyl, alkynyl, C1~C 20 Alkoxy, substituted or unsubstituted C6~C 18 Aryl, substituted or unsubstituted C4~C 18 One of the heteroaryl groups, R and R' can be connected to form a ring;

[0011] L 1 ~L 5 are independently selected from a single bond, a substituted or unsubstituted C6-C 30 arylene, substituted or unsubstituted C3~C 30 A heteroarylene group;

[0012] R 1 Selected from C1~C 12 Alkyl, C3~C 12 Cycloalkyl, C1~C 12 Alkoxy, substituted or unsubstituted C6~C 30 Arylamine, substituted or unsubstituted C3~C 30 Heteroarylamine, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 One of the heteroaryl groups;

[0013] P is an integer selected from 1 to 4;

[0014] Ar 1 ~Ar 4 are independently selected from substituted or unsubstituted C6 to C 30 aryl or substituted or unsubstituted C4~C 30 heteroaryl;

[0015] When the above groups have substituents, the substituents are selected from hydrogen, deuterium, halogen, C1-C10 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 or a combination of at least two of the monocyclic heteroaromatic hydrocarbon groups or condensed-ring heteroaromatic hydrocarbon groups.

[0016] Furthermore, the above formula (1) of the present invention is represented by the following formula (1-1) or formula (1-2):

[0017]

[0018] Where: R, R', L 1 ~L 5 , R 1 , p and Ar 1 ~Ar 4 The definitions of are the same as those in the general formula (1).

[0019] Furthermore, the above formula (1) of the present invention is represented by the following formula (2-1) or formula (2-2):

[0020]

[0021] Where: R, R', L 1 ~L 5 , R 1 , P and Ar 1 ~Ar 4 The definitions of are the same as those in the general formula (1).

[0022] Furthermore, the present invention is preferably as shown in formula (2-2):

[0023]

[0024] Where: R, R', L 1 ~L 5 , R 1 , P and Ar 1 ~Ar 4 The definitions of are the same as those in the general formula (1).

[0025] Furthermore, the present invention is preferably as shown in formula (3):

[0026]

[0027] In formula (3), R, R', L 1 ~L 5 and Ar 1 ~Ar 4The definitions of are the same as those in the general formula (1);

[0028] R 1 Selected from C1~C 12 Alkyl, C3~C 12 Cycloalkyl, C1~C 12 Alkoxy, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 One of the heteroaryl groups, or R 1 A substituent selected from the group described in the above formula Y;

[0029] In formula Y, L 6 ~L 8 are independently selected from a single bond, a substituted or unsubstituted C6 to C 30 arylene, substituted or unsubstituted C3~C 30 A heteroarylene group;

[0030] Ar 5～ Ar 6 are independently selected from substituted or unsubstituted C6 to C 30 aryl, substituted or unsubstituted C4~C 30 One of the heteroaryl groups;

[0031] When the above groups have substituents, the substituents are selected from hydrogen, deuterium, 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 or a combination of at least two of the monocyclic heteroaromatic hydrocarbon groups or condensed-ring heteroaromatic hydrocarbon groups.

[0032] Furthermore, in formula (3) and formula Y:

[0033] L 1 ~L 4 and L 6 ~L 7 Preferably a single bond;

[0034] L 5 It is preferably a single bond, or preferably a substituted or unsubstituted group: one of phenylene, biphenylene, naphthylene, and phenanthrylene;

[0035] L 8 It is preferably a single bond, or preferably a substituted or unsubstituted one of the following groups: phenylene, biphenylene, naphthylene, and phenanthrylene.

[0036] Furthermore, in formula (3) and formula Y:

[0037] Ar 1～ Ar 6 are independently selected from substituted or unsubstituted C6 to C 30 aryl, or selected from substituted or unsubstituted C4~C 30 Electron donating heteroaryl;

[0038] Furthermore, in formula (3) and formula Y:

[0039] Ar 1～ Ar 6 Each of the following groups is independently selected from substituted or unsubstituted groups: one of phenyl, biphenyl, naphthyl, phenanthryl, fluorene, dibenzofuran and dibenzothiophene;

[0040] Furthermore, among the general formula compounds of the present invention, the following specific structural compounds can be preferably selected, but are not limited to the compounds shown below:

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055] As another aspect of the present invention, the compound of the above general formula of the present invention is used as a hole transport 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 the compound represented by the general formula (1) as described above. Preferably, the hole transport layer contained in the organic layer contains the compound represented by the general formula (1) as described above.

[0057] The specific reason why the above-mentioned compounds of the present invention have excellent performance as hole transport materials in organic electroluminescent devices is still unclear, but it is speculated that the reasons may be as follows:

[0058] The general formula compound of the present invention introduces an aromatic amine substituent at the 3-position of the fluorene derivative mother core, and in the novel structural design of the present invention, an aromatic amine substituent is introduced at the 2-position of the mother core, thereby forming a fluorene derivative containing a diaromatic amine structure as a whole, which can further enhance the hole migration ability of the entire molecule. In addition, a substituent that can increase the molecular stability is preferably further introduced at the 7-position of the mother core. Through the combination and optimization design of different substituent groups, the highest occupied orbital energy level and triplet energy level of the compound molecule can be effectively adjusted, so that different use requirements for the preparation and application in organic electroluminescent devices can be met, and the beneficial effects of reducing the device driving voltage and extending the life of the device can be effectively achieved. Therefore, the organic electroluminescent device prepared by using the compound of the present invention as a hole transport material has the advantages of low voltage, high efficiency and long life. DETAILED DESCRIPTION

[0059] 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.

[0060] The compounds of the synthetic method not mentioned in the present invention are all raw materials obtained by commercial channels. Solvent used and reagent in the present invention, such as dichloromethane, petroleum ether, ethanol, tetrahydrofuran, N, N-dimethylacetamide, quinazoline, triazine, quinoxaline and the like chemical reagents, can all be purchased from the domestic chemical product market, such as purchased from Sinopharm Group Reagent Company, TCI Company, Shanghai Bi De Pharmaceutical Company, Bailingwei Reagent Company, etc. In addition, those skilled in the art can also synthesize by known methods.

[0061] The synthesis method of the compound of the present invention is briefly described below.

[0062] It should be noted that obtaining the compound is not limited to the method and route used in the present invention, and those skilled in the art may also select other methods or routes to obtain the novel compound proposed in the present invention.

[0063] Synthesis Example 1

[0064] Synthesis of compound C1

[0065] The synthetic route of compound C1 is as follows:

[0066]

[0067] Synthesis of intermediate C1-1:

[0068] Dissolve the raw material 2-bromo-9,9-dimethylfluorene (81.9g, 0.3mol) in acetic acid (270g) and stir well. Then add nitric acid (113.4g, 1.8mol) to precipitate a white solid. Heat to 60°C and the solid will dissolve. Then slowly add sulfuric acid to the above reaction solution, a yellow solid will precipitate and the solution will be brown-red. After the addition is complete, continue the reaction for 5 hours. Until the raw materials are completely reacted. Cool down, pour the reaction solution into cold water, stir well to obtain a yellow solid. Collect the solid, stir in methanol and petroleum ether to obtain a yellow solid (81g).

[0069] Synthesis of intermediate C1-2:

[0070] The obtained C1-1 (81 g, 255 mmol) was placed in a three-necked flask (2 L), and ammonium chloride (136 g, 2.6 mol) and 95% ethanol (1.5 L) were added. The mixture was stirred thoroughly and heated to 80 °C. Iron powder was then added in batches. The reaction was exothermic and the system was kept at a gentle reflux. The solution was black. After the iron powder was added, the reaction was continued for 2 hours.

[0071] After the reaction solution was allowed to stand for a while to cool, it was filtered through a suction funnel filled with diatomaceous earth while hot, and the filter residue was rinsed with ethyl acetate until no product was eluted. The filtrate was concentrated to obtain a light brown solid, which was fully stirred in 1L of water, filtered, and then rinsed with methanol and petroleum ether to obtain a light yellow solid, which was dried for later use. 75g of the product was obtained.

[0072] Synthesis of intermediate C1-3:

[0073] The raw material compound C1-2 (40g, 138.8mmol) was dissolved in DMF (250mL) and cooled to 0°C. NBS (24.7g, 138.8mmol) was dissolved in DMF (150mL), placed in a constant pressure dropping funnel, and slowly added dropwise to the above reaction system. The solution was brown and dripped in about 1 hour. TLC monitoring showed that the raw material reaction was complete. 500mL of cold water was poured into the reaction solution, extracted with EA (300mL, twice), and the organic phase was washed with saturated brine and dried with sodium sulfate. Filtered and concentrated, the crude product was a brown oil. Purified by chromatography column (petroleum ether / ethyl acetate, 8 / 1) to obtain a brown solid (30g)

[0074] Synthesis of intermediate C1-4:

[0075] Dissolve C1-3 (20 g, 54.8 mmol) in 300 mL of dichloromethane, add triethylamine (8.27 g, 81.7 mmol), cool to 0°C, add acetyl chloride (6.4 g, 81.7 mmol) dropwise to the reaction flask, warm to room temperature after completion of the addition, and stir overnight. Pour the reaction solution into 300 mL of water, extract with ethyl acetate (200 mL, twice), dry the organic phase with anhydrous sodium sulfate, concentrate, and purify with a chromatography column (petroleum ether / ethyl acetate, 50 / 1) to obtain a light yellow solid (18 g).

[0076] Synthesis of intermediate C1-5:

[0077] The above-synthesized compound C1-4 (15.0 g, 36.6 mmol) and 4-diphenylaminophenylboronic acid (23.2 g, 80.7 mmol) were placed in a 500 mL three-necked flask, and then potassium carbonate (15.2 g, 109.9 mmol) and toluene (200 mL), ethanol (80 mL) and water (80 mL) were added. After sufficient stirring, the air in the flask was replaced by nitrogen, and then the catalyst tetrakistriphenylphosphine palladium (0.847 g, 0.733 mmol) was added, and the temperature was raised to 100 ° C for reaction for 18 h. After cooling, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (200 mL, three times), the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brown-black oil. The crude product was purified by silica gel layer column (petroleum ether / dichloromethane, 20 / 1) to obtain a light yellow solid. The solid was recrystallized twice in toluene and methanol to obtain 22 g of a light yellow solid.

[0078] Synthesis of intermediate C1-6:

[0079] The above compound was added to a mixed solvent of methanol (150 mL) and tetrahydrofuran (100 mL), potassium carbonate (6 g) was added, and the mixture was stirred at room temperature for 24 hours. The reaction was extracted with ethyl acetate and dried over anhydrous sodium sulfate. The crude product was purified by chromatography (petroleum ether / dichloromethane, 6 / 1) to obtain a light yellow solid (19 g).

[0080] Synthesis of compound C1:

[0081] The above-synthesized compound C1-6 (12.0 g, 17.2 mmol) and bromobenzene (8.7 g, 55.3 mmol) were placed in a 500 mL three-necked flask, and then sodium tert-butoxide (6.38 g, 66.3 mmol) and toluene (250 mL) were added. After sufficient stirring, the air in the flask was replaced with nitrogen, and then the catalyst tri(dibenzylideneacetone)dipalladium (607 mg, 0.663 mmol) and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (544 mg, 1.33 mmol) were added, and the temperature was raised and refluxed for 16 h. After cooling, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (200 mL, three times), the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brown-black oil. The crude product was purified by silica gel column (petroleum ether / dichloromethane, 5 / 1) to obtain a light yellow solid. The solid was recrystallized twice from toluene and methanol to obtain 7 g of light yellow solid.

[0082] Synthesis Example 2 Synthesis of Compound C2

[0083]

[0084] Synthesis of intermediate C2-1:

[0085] The above-synthesized compound C1-6 (12.0 g, 22.0 mmol) and bromobenzene (4.2 g, 26.5 mmol) were placed in a 500 mL three-necked flask, and then sodium tert-butoxide (3.2 g, 33.2 mmol) and toluene (150 mL) were added. After sufficient stirring, the air in the flask was replaced by nitrogen, and then the catalyst tri(dibenzylideneacetone)dipalladium (202 mg, 0.221 mmol) and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (182 mg, 0.442 mmol) were added, and the temperature was raised and refluxed for 16 h. After cooling, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (200 mL, three times), the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brown-black oil. The crude product was purified by silica gel column (petroleum ether / dichloromethane, 5 / 1) to obtain a light yellow solid (12 g).

[0086] Synthesis of compound C2:

[0087] The above-synthesized compound C2-1 (12.0 g, 19.4 mmol) and 1-bromonaphthalene (4.82 g, 23.3 mmol) were placed in a 250 mL three-necked flask, and then sodium tert-butoxide (2.8 g, 29.1 mmol) and toluene (150 mL) were added. After sufficient stirring, the air in the flask was replaced with nitrogen, and then the catalyst tri(dibenzylideneacetone)dipalladium (177 mg, 0.194 mmol) and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (159 mg, 0.388 mmol) were added, and the temperature was raised and refluxed for 16 h. After cooling, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (200 mL, three times), the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brown-black oil. The crude product was purified by silica gel column (petroleum ether / dichloromethane, 5 / 1) to obtain a light yellow solid, which was then recrystallized twice from toluene and ethanol to obtain a light yellow solid (6 g).

[0088] Synthesis Example 3 Synthesis of Compound C4:

[0089] The synthesis of compound C4 can refer to the synthesis method of compound C2, except that 1-bromonaphthalene is replaced by 2-bromo-9,9-dimethylfluorene.

[0090] Synthesis Example 4 Synthesis of Compound C8:

[0091] The synthesis of compound C8 can refer to the synthesis method of compound C2, except that 1-bromonaphthalene is replaced by m-bromobiphenyl.

[0092] Synthesis Example 5 Synthesis of Compound C18:

[0093] The synthesis of compound C18 can refer to the synthesis method of compound C2, except that bromobenzene is replaced by m-bromobiphenyl.

[0094] Synthesis Example 6 Synthesis of Compound C19:

[0095] The synthesis of compound C19 can refer to the synthesis method of compound C2, except that p-bromobenzene is replaced by o-bromobiphenyl.

[0096] Synthesis Example 7 Synthesis of Compound C24:

[0097] The synthesis of compound C24 can refer to the synthesis method of compound C2, except that bromobenzene is replaced by 1-bromonaphthalene; and 1-bromonaphthalene is replaced by 2-bromonaphthalene. Synthesis Example 8 Synthesis of compound C36:

[0098] The synthesis of compound C36 can refer to the synthesis method of compound C2, except that bromobenzene is replaced by 4-methylbromobenzene; and 1-bromonaphthalene is replaced by 4-cyclohexylbromobenzene.

[0099] Synthesis Example 9 Synthesis of Compound C48:

[0100]

[0101] Synthesis of C48-1

[0102] The raw material compound C1-2 (40g, 138.8mmol) was dissolved in N, N-dimethylformamide (250mL) and cooled to 0°C. N-iodosuccinimide (31.2g, 138.8mmol) was dissolved in DMF (150mL), placed in a constant pressure dropping funnel, and slowly added dropwise to the above reaction system. The solution was brown and dripped in about 1 hour. TLC monitoring showed that the raw material reaction was complete. 500mL of cold water was poured into the reaction solution, extracted with EA (300mL, twice), and the organic phase was washed with saturated brine and dried with sodium sulfate. Filtered and concentrated, the crude product was a brown oil. Purified by chromatography column (petroleum ether / ethyl acetate, 8 / 1) to obtain 48g of brown solid.

[0103] Synthesis of C48-2

[0104] C48-1 (20 g, 48.4 mmol) was dissolved in 300 mL of dichloromethane, triethylamine (8.27 g, 81.7 mmol) was added, and after cooling to 0°C, acetyl chloride (5.67 g, 72.6 mmol) was added dropwise to the reaction flask. After the addition was complete, the mixture was warmed to room temperature and stirred overnight. The reaction solution was poured into 300 mL of water, extracted with ethyl acetate (200 mL, twice), the organic phase was dried over anhydrous sodium sulfate, concentrated, and purified by chromatography column (petroleum ether / ethyl acetate, 50 / 1) to obtain 18 g of a light yellow solid.

[0105] Synthesis of C48-3

[0106] 2-Amino-9,9-dimethylfluorene (12.0 g, 57.3 mmol) and 2-bromonaphthalene (14.3 g, 68.8 mmol) were placed in a 250 mL three-necked flask, and then sodium tert-butoxide (8.27 g, 86.0 mmol) and toluene (250 mL) were added. After sufficient stirring, the air in the flask was replaced by nitrogen, and then the catalyst [1,1'-bis(diphenylphosphino)ferrocene] palladium dichloride (420 mg, 0.573 mmol) and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (470 mg, 1.15 mmol) were added, and the temperature was raised to 80°C for reaction for 16 h. After cooling to room temperature, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (150 mL, three times), the organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated to obtain a brown oil. The crude product was purified by silica gel column chromatography (petroleum ether / dichloromethane, 5 / 1) to obtain 18 g of a white solid.

[0107] Synthesis of C48-4

[0108] The above-synthesized compound C48-3 (12.0 g, 35.8 mmol) and p-bromoiodobenzene (12.1 g, 42.9 mmol) were placed in a 500 mL three-necked flask, and then sodium tert-butoxide (5.16 g, 53.6 mmol) and toluene (250 mL) were added. After sufficient stirring, the air in the flask was replaced with nitrogen, and then the catalyst tri(dibenzylideneacetone)dipalladium (328 mg, 0.358 mmol) and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (294 mg, 0.716 mmol) were added, and the temperature was raised and refluxed for 16 h. After cooling, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (200 mL, three times), the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brown-black oil. The crude product was purified by silica gel column (petroleum ether / dichloromethane, 10 / 1) to obtain a light yellow solid. The solid was recrystallized twice from toluene and methanol to obtain 17 g of a light yellow solid.

[0109] Synthesis of C48-5

[0110] Dissolve the dried C48-4 (17 g, 34.7 mmol) in dry anhydrous tetrahydrofuran (250 mL) and cool to -78 ° C. Then add n-butyl lithium (15.3 mL, 2.5 M in hexane) dropwise to the reaction solution, control the temperature not to exceed -60 ° C, and after the addition is complete, keep the temperature at -60 ° C for half an hour. Cool it again to -78 ° C, then dissolve trimethyl borate (5.4 g, 51.9 mmol) in anhydrous tetrahydrofuran (15 mL) and add it dropwise to the above solution. After the addition is complete, slowly warm it to room temperature and continue stirring for 16 hours. Then add dilute hydrochloric acid dropwise to the above solution and stir for half an hour until it is completely hydrolyzed. Pour the reaction solution into a saturated aqueous ammonium chloride solution, extract it with ethyl acetate, dry it over anhydrous sodium sulfate, and concentrate it to obtain a white solid (13 g).

[0111] Synthesis of C48-6

[0112] The above-synthesized compounds C48-2 (13.0 g, 28.5 mmol) and C48-5 (14.3 g, 31.4 mmol) were placed in a 500 mL three-necked flask, and potassium carbonate (11.8 g, 85.5 mmol) and toluene (200 mL), ethanol (80 mL) and water (80 mL) were added. After sufficient stirring, the air in the flask was replaced by nitrogen, and then the catalyst tetrakistriphenylphosphine palladium (0.658 g, 0.570 mmol) was added, and the temperature was raised to 100 ° C for reaction for 18 h. After cooling, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (200 mL, three times), the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brown-black oil. The crude product was purified by silica gel column (petroleum ether / dichloromethane, 20 / 1) to obtain a light yellow solid. The solid was recrystallized twice in toluene and methanol to obtain 17 g of a light yellow solid.

[0113] Synthesis of C48-7

[0114] The above-synthesized compound C48-6 (17.0 g, 23.0 mmol) and 4-diphenylaminophenylboronic acid (6.6 g, 23.0 mmol) were placed in a 500 mL three-necked flask, and then potassium carbonate (3.45 g, 25.0 mmol) and toluene (200 mL), ethanol (80 mL) and water (80 mL) were added. After sufficient stirring, the air in the flask was replaced by nitrogen, and then the catalyst tetrakistriphenylphosphine palladium (0.658 g, 0.570 mmol) was added, and the temperature was raised to 100 ° C for reaction for 18 h. After cooling, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (200 mL, three times), the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brown-black oil. The crude product was purified by silica gel layer column (petroleum ether / dichloromethane, 20 / 1) to obtain a light yellow solid. The solid was recrystallized twice in toluene and methanol to obtain 20 g of a light yellow solid.

[0115] Synthesis of C48-8

[0116] The above compound was added to a mixed solvent of methanol (150 mL) and tetrahydrofuran (100 mL), potassium carbonate (6 g) was added, and the mixture was stirred at room temperature for 24 hours. The reaction was extracted with ethyl acetate and dried over anhydrous sodium sulfate. The crude product was purified by chromatography (petroleum ether / dichloromethane, 6 / 1) to obtain 18 g of a light yellow solid.

[0117] Synthesis of C48

[0118] The above-synthesized compound C48-8 (12.0 g, 13.9 mmol) and bromobenzene (4.81 g, 30.62 mmol) were placed in a 500 mL three-necked flask, and then sodium tert-butoxide (4.01 g, 41.8 mmol) and toluene (250 mL) were added. After sufficient stirring, the air in the flask was replaced by nitrogen, and then the catalyst tri(dibenzylideneacetone)dipalladium (382 mg, 0.418 mmol) and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (343 mg, 0.835 mmol) were added, and the temperature was raised and refluxed for 16 h. After cooling, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (200 mL, three times), the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brown-black oil. The crude product was purified by silica gel column (petroleum ether / dichloromethane, 5 / 1) to obtain a light yellow solid. The solid was recrystallized twice from toluene and methanol to obtain 5 g of a light yellow solid.

[0119] Synthesis Example 10 Synthesis of Compound C49:

[0120] The synthesis of compound C49 was based on the synthesis of C48, except that 2-amino-9,9-dimethylfluorene was replaced by 3-amino-9,9-dimethylfluorene.

[0121] Synthesis Example 11 Synthesis of Compound C53:

[0122] The synthesis of compound C53 was based on the synthesis of C48, except that 2-amino-9,9-dimethylfluorene was replaced by 4-aminobiphenyl and 2-bromonaphthalene was replaced by bromobenzene.

[0123] Synthesis Example 12 Synthesis of Compound C148:

[0124]

[0125] Synthesis of intermediate C148-1:

[0126] Referring to the synthesis of C48-6, Replace

[0127] The synthesis of intermediate C48-7 Replace

[0128] Synthesis of compound C148:

[0129] Refer to the synthesis of C2, and replace bromobenzene with 2-bromo-9,9-dimethylfluorene.

[0130] Synthesis Example 13 Synthesis of Compound C154:

[0131] Refer to the synthesis of C148 and replace 2-bromo-9,9-dimethylfluorene with

[0132] Synthesis Example 14 Synthesis of Compound C163:

[0133] Referring to the synthesis of 148, bromobenzene was replaced by 1-bromonaphthalene; 2-bromo-9,9-dimethylfluorene was replaced by 2-bromobiphenyl.

[0134] Synthesis Example 15 Synthesis of Compound C167:

[0135] Referring to the synthesis of 148, bromobenzene and 2-bromo-9,9-dimethylfluorene were replaced with 2-bromonaphthalene.

[0136] Synthesis Example 16 Synthesis of Compound C181:

[0137] Referring to the synthesis of 148, bromobenzene was replaced by p-methylbromobenzene, and 2-bromo-9,9-dimethylfluorene was replaced by p-cyclohexylbromobenzene.

[0138] Synthesis Example 17 Synthesis of Compound C193:

[0139] Reference 148 synthesis,

[0140] Will Replace

[0141] Replace 2-bromo-9,9-dimethylfluorene with bromobenzene.

[0142] Synthesis Example 18 Synthesis of Compound C229:

[0143] Referring to the synthesis of 148, 2-bromo-9,9-dimethylfluorene was replaced by 4-(4-bromophenyl)dibenzofuran.

[0144] Synthesis Example 19 Synthesis of Compound C230:

[0145] Referring to the synthesis of 148, 2-bromo-9,9-dimethylfluorene was replaced by 4-(4-bromophenyl)dibenzothiophene.

[0146] Synthesis Example 20 Synthesis of Compound C235:

[0147] Referring to the synthesis of 148, 2-bromo-9,9-dimethylfluorene was replaced by 2-(3-bromophenyl)dibenzothiophene.

[0148] Synthesis Example 21 Synthesis of Compound C236:

[0149] Referring to the synthesis of 148, 2-bromo-9,9-dimethylfluorene was replaced by 2-(3-bromophenyl)dibenzofuran.

[0150] Synthesis Example 21 Synthesis of Compound C241:

[0151]

[0152] Synthesis of intermediate C241-1

[0153] The above-synthesized compound C48-2 (12.0 g, 26.3 mmol) and di(4-biphenyl)amine (9.30 g, 28.9 mmol) were placed in a 250 mL three-necked flask, and then sodium tert-butoxide (3.29 g, 34.2 mmol) and toluene (200 mL) were added. After sufficient stirring, the air in the flask was replaced with nitrogen, and then the catalyst [1,1'-bis(diphenylphosphino)ferrocene] palladium dichloride (193 mg, 0.263 mmol) and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (108 mg, 0.263 mmol) were added, and the temperature was raised to 80°C for reaction for 16 h. After cooling to room temperature, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (150 mL, three times), the organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated to obtain a brown oil. The crude product was purified by silica gel column chromatography (petroleum ether / dichloromethane, 15 / 1) to obtain 13 g of white solid. Synthesis of Intermediate C241-2

[0154] C241-1 (12.0 g, 18.5 mmol), phenylboric acid (2.48 g, 20.3 mol), potassium carbonate (3.06 g, 22.2 mmol) were placed in a three-necked flask containing toluene (150 mL), ethanol (80 mL), and water (80 mL), and stirred thoroughly. The air on the flask was then replaced with nitrogen three times. Tetrakistriphenylphosphine palladium (213 mg, 0.184 mmol) was added to the reaction solution under nitrogen protection, and then the temperature was raised to 100 ° C and reacted for 18 hours. After cooling, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (200 mL, three times), the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brown oil. The crude product was purified by silica gel chromatography (petroleum ether / ethyl acetate, 40 / 1) to obtain 10 g of a white solid.

[0155] Synthesis of intermediate C241-3

[0156] The above compound C241-2 was added to a mixed solvent of methanol (150 mL) and tetrahydrofuran (100 mL), and NaOH (1 g) was added, and stirred at room temperature for 24 hours. The reaction was extracted with ethyl acetate and dried over anhydrous sodium sulfate. The obtained crude product was purified by chromatography column (petroleum ether / dichloromethane, 6 / 1) to obtain a light yellow solid (8 g).

[0157] Synthesis of intermediate C241-4

[0158] The above-synthesized compound C241-3 (8.0 g, 13.3 mmol) and bromobenzene (2.28 g, 14.6 mmol) were placed in a 250 mL three-necked flask, and then sodium tert-butoxide (1.65 g, 17.2 mmol) and toluene (200 mL) were added. After sufficient stirring, the air in the flask was replaced by nitrogen, and then the catalyst [1,1'-bis(diphenylphosphino)ferrocene] palladium dichloride (100 mg, 0.132 mmol) and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (108 mg, 0.263 mmol) were added, and the temperature was raised to 80 ° C for 16 h. After cooling to room temperature, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (150 mL, three times), the organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated to obtain a brown oil. The crude product was purified by silica gel column chromatography (petroleum ether / dichloromethane, 15 / 1) to obtain 8 g of a white solid.

[0159] Synthesis of compound C241

[0160] The above-synthesized compound C241-4 (8.0 g, 11.8 mmol) and 4-(4-bromophenyl)dibenzofuran (4.18 g, 12.9 mmol) were placed in a 250 mL three-necked flask, and then sodium tert-butoxide (1.47 g, 15.3 mmol) and toluene (100 mL) were added. After sufficient stirring, the air in the flask was replaced with nitrogen, and then the catalyst tri(dibenzylideneacetone)dipalladium (107 mg, 0.118 mmol) and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (96 mg, 0.234 mmol) were added, and the temperature was raised and refluxed for 16 h. After cooling, the reaction solution was poured into a saturated aqueous ammonium chloride solution, extracted with ethyl acetate (200 mL, three times), the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brown-black oil. The crude product was purified by silica gel column (petroleum ether / dichloromethane, 5 / 1) to obtain a light yellow solid, which was then recrystallized twice from toluene and ethanol to obtain 5 g of a light yellow solid.

[0161] Device Embodiment

[0162] Implementation

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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.

[0167] 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).

[0168] 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.

[0169]

[0170]

[0171] 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.

[0172]

[0173] 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.

[0174] 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.

[0175] 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-17 listed below.

[0176]

[0177] 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.

[0178]

[0179]

[0180] 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.

[0181]

[0182]

[0183]

[0184]

[0185] 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.

[0186]

[0187]

[0188] 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.

[0189]

[0190]

[0191] 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.

[0192]

[0193]

[0194] 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.

[0195]

[0196]

[0197] 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.

[0198]

[0199]

[0200]

[0201] 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).

[0202] 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.

[0203]

[0204]

[0205]

[0206] 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.

[0207] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca.

[0208] The preparation process of the organic electroluminescent device in Example IVD-1 is as follows:

[0209] 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;

[0210] Place the glass substrate with the anode in a vacuum chamber and evacuate to a vacuum of <1×10 -5 Pa, vacuum thermally deposited 10 nm of HT-4:HIL-3 (97 / 3, w / w) mixture as a hole injection layer and 60 nm of compound C1 as a hole transport layer on the above anode layer film in sequence,

[0211] 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.

[0212] 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;

[0213] 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.

[0214] Device examples IVD-2 to IVD-9 were made in the same way as IVD-1, except that C1 of the hole transport layer was replaced by C2, C18, C36, C48, C148, C154, C181, and C193, respectively;

[0215] Device comparison examples CCD-1 to CCD-3 were made in the same manner as device example IVD-1, except that C1 of the hole transport layer was replaced by HT-30, R1 and R2, respectively.

[0216] In the present invention, the structures of the comparative compounds R1 and R2 used in the device comparative examples are as follows:

[0217]

[0218] Device test method (including equipment and test conditions):

[0219] The organic electroluminescent device prepared by the above process was subjected to the following performance tests:

[0220] At the same brightness, the driving voltage and current efficiency of the organic electroluminescent devices prepared in Examples 1 to 9 and Comparative Examples 1 to 3 and the life of the devices 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 this time is the driving voltage. The life test of LT95 is as follows: Use a brightness meter at 5000cd / m 2 At the same brightness, the current is kept constant and the brightness of the organic electroluminescent device is measured to drop to 4850cd / m 2 The time in hours.

[0221] Table 1:

[0222]

[0223] The above results show that the novel organic material of the present invention can be used in organic electroluminescent devices to effectively reduce the starting voltage and increase the life of the device, and is a hole transport material with good performance.

[0224] When the novel compounds of the present invention can also be used as electron blocking layers, device embodiments IVD-10 to IVD-17 are prepared using the same method as IVD-1, replacing C1 in the hole transport layer with HT-4, and replacing the electron blocking material HT-14 with the corresponding material described in the electron blocking layer in the embodiment in Table 2.

[0225] The material information and properties of each electron blocking layer in the examples are summarized in Table 2 below, where the electron blocking layer material HT-14 is replaced with the corresponding material described in the electron blocking layer in the examples in Table 2. The material information and properties of each electron blocking layer in the examples are summarized in Table 2 below.

[0226] The driving voltage and device life of the organic electroluminescent devices prepared in Examples 10 to 17 and Comparative Examples 4 to 6 were measured according to the above device testing method. The device organic electroluminescent device performance is shown in Table 2 below:

[0227] Table 2:

[0228]

[0229]

[0230] When used as an electron blocking material, the novel organic material of the present invention also has a significant effect on reducing the starting voltage and increasing the life of the device. The novel compound of the present invention is also an electron blocking layer material with good performance.

[0231] 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 may make various modifications and improvements. The appended claims summarize the scope of the present invention.

[0232] 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 (3): in: R and R' are each independently selected from methyl; L 1 ~L 4 and L 6 ~L 7 is a single bond; L 5 is selected from a single bond or from the following substituted or unsubstituted groups: one of phenylene and biphenylene; L 8 is selected from a single bond or from the following substituted or unsubstituted groups: one of phenylene and biphenylene; R 1 Selected from substituted or unsubstituted C6~C 30 Aryl, or R 1 A substituent selected from the group described in the above formula Y; Ar 1～ Ar 6 are independently selected from substituted or unsubstituted C6 to C 30 aryl, substituted or unsubstituted C4~C 30 One of the electron donating heteroaryl groups; When the above groups have substituents, the substituents are selected from C1-C 10 Alkyl or cycloalkyl, 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.

2. The compound of the general formula according to claim 1, wherein in formula (3) and formula Y: Ar 1～ Ar 6 Each of the following groups is independently selected from substituted or unsubstituted groups: phenyl, biphenyl, naphthyl, phenanthryl, fluorene, dibenzofuran, and dibenzothiophene.

3. A compound selected from the following specific structural compounds:

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

5. 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 3.

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