A hole transport material and an organic electroluminescent device comprising the same

Abstract

The application discloses a kind of hole transport material and organic electroluminescent device comprising the material, it is related to organic electroluminescent material field, its structural formula is as shown in following: the organic electroluminescent device prepared by using the hole transport material described in the application is compared with control example, voltage is greatly reduced, luminous efficiency is significantly improved.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent materials, and more specifically to a hole transport material and an organic electroluminescent device containing the material. Background Technology

[0002] Organic light-emitting devices (OLEDs), also known as organic light-emitting diodes, are a type of all-solid-state flat-panel display technology developed in the 1980s. Organic electroluminescence refers to the phenomenon where organic semiconductor materials emit light under an electric field through carrier injection, transport, recombination to form excitons, and exciton decay. Displays made based on this light-emitting principle are called OLEDs.

[0003] In OLEDs, the hole transport layer plays a crucial role in improving hole transport efficiency within the device and blocking electrons within the emissive layer, thereby maximizing carrier recombination. The hole transport layer can reduce the energy barrier during hole injection, increase hole injection efficiency, and improve device brightness and lifetime. For good hole transport materials, in addition to requiring high hole mobility, the following conditions must be met: (1) the ability to form a defect-free, uniform, amorphous thin film; (2) excellent thermal stability, maintaining an amorphous morphology even under long-term operation. Although the aging mechanism of OLEDs is not yet fully understood, studies have shown that changes in the physical morphology of the organic layer are one of the influencing factors, such as melting and crystallization of the organic layer caused by heat generated during device operation; (3) having a suitable highest molecular occupied orbital (HOMO) energy level to ensure effective hole injection and transport between various interfaces; and preventing excessive Joule heating during device operation that could lead to material recrystallization. This crystallization would disrupt the uniformity of the thin film and also disrupt the good interfacial contact between the hole transport layer and the anode and organic layer, thus reducing the device's lifetime.

[0004] Currently, finding high-performance hole transport materials has become a research hotspot for engineers in the OLED field. Summary of the Invention

[0005] Objective of the invention: To address the above-mentioned technical problems, the present invention provides a hole transport material and an organic electroluminescent device containing the material.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0007] A hole transport material, the structural formula of which is shown below:

[0008]

[0009] Where a is a fused substituted or unsubstituted benzene ring;

[0010] R1, R2, R3, and R4 are each independently a substituted or unsubstituted C6-C30 aromatic group, a substituted or unsubstituted C5-C30 heteroaromatic group, or a substituted or unsubstituted C6-C30 aromatic amine group.

[0011] R5 is any one of hydrogen, deuterium, substituted or unsubstituted C1-C5 alkyl, substituted or unsubstituted C2-C5 alkenyl, substituted or unsubstituted C3-C6 cycloalkyl, substituted or unsubstituted C3-C6 heterocycloalkyl, substituted or unsubstituted C6-C30 aromatic group, or substituted or unsubstituted C5-C30 heteroaromatic group.

[0012] W represents O or S;

[0013] m and n are each independently 0 or 1.

[0014] Furthermore, R1, R2, R3, and R4 are each independently phenyl, tolyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, fluorenyl, oxofluorenyl, 9,9-dimethylfluorenyl, 9,9'-spirodifluorenyl, 9,9-diphenylfluorenyl, dibenzothiophene, carbazolyl, benzocarbazolyl, N-phenylcarbazolyl, o-diphenylphenyl, trideuterylmethylbiphenyl, methylbiphenyl, and triphenylamino.

[0015] Furthermore, R5 is selected from any one of hydrogen, deuterium, methyl, ethyl, n-propyl, isopropyl, tert-butyl, and phenyl.

[0016] Furthermore, the hole transport material is any one of the following structural compounds:

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025] Furthermore, the preparation method of the above-mentioned hole transport material is as follows:

[0026]

[0027] Raw material 1 was added to xylene and mixed to obtain a homogeneous solution. The solution was then cooled to -78°C. Under inert gas protection, a pentane solution of tert-butyllithium was added dropwise. After the addition was complete, the solution was kept warm and stirred for 10-30 minutes. The solution was then restored to room temperature. A pentane solution of n-butyllithium and AlBr3 were added sequentially, and the mixture was stirred for another 30-60 minutes. A hexane solution of raw material 2 was then added dropwise. The reaction was continued for 10-15 hours, then cooled to -78°C and quenched with water. The solution was extracted with ethyl acetate and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain the hole transport material.

[0028] The application of the aforementioned hole transport materials in the fabrication of organic electroluminescent devices.

[0029] An organic electroluminescent device includes a cathode, an anode, a light-emitting layer, and a hole transport layer, wherein the hole transport layer contains the aforementioned hole transport material.

[0030] A lighting device comprising the aforementioned organic electroluminescent device.

[0031] An electronic display device comprising the aforementioned organic electroluminescent device.

[0032] The beneficial effects of this invention are:

[0033] The hole transport material in this invention has the following core structure:

[0034]

[0035] The presence of two independent phenyl groups (a and b) in this core structure significantly reduces its planarity, increases the steric hindrance effect of the material molecules, and thus improves the amorphous film-forming properties, solubility, thermal stability, and fluorescence performance of the material. This makes the material easier to coat evenly and improves the yield of wet-process fabricated devices. Simultaneously, this structure possesses a high HOMO energy level, which is beneficial for hole transport, improves hole utilization efficiency, and consequently increases the lifespan and luminous efficiency of the light-emitting element.

[0036] The substituent R5 is a good electron-donating group, which can increase the electron delocalization range of the material molecule, improve the hole mobility of the material, and further improve the luminous efficiency of the device.

[0037] The introduction of branched amine substituents increases the overall electron cloud density of the material molecules, enhances the conformational richness of the material molecules, and can regulate the hole mobility of the material molecules. At the same time, the introduction of branched structures increases the steric hindrance of the material molecules, effectively preventing the formation of traps between adjacent material molecules, improving the hole utilization rate of the material molecules, and thus improving the lifespan and efficiency of the device. Attached Figure Description

[0038] Figure 1 This is a graph showing the relationship between the decay of the luminous intensity of the electroluminescent device in Example 6 of the present invention and the luminous time.

[0039] Depend on Figure 1 It can be seen that the lifetime (T97%) of the electroluminescent device in Application Example 6 of the present invention is 303H. Detailed Implementation

[0040] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0041] Example 1:

[0042]

[0043] The method for synthesizing hole transport material 1 is as follows:

[0044] (1)

[0045] Compound 1-a (395.85 g / mol, 10 g, 25.26 mmol), FeCl3 (0.2 eq, 162.2 g / mol, 5.05 mmol, 0.82 g), and CS2 (200 g, 20 times the mass of compound 1-a) were added to a reaction flask. Tert-butane chloride (1.1 eq, 92.57 g / mol, 27.79 mmol, 2.57 g) was added under ice bath conditions. After the addition was complete, the mixture was slowly brought to room temperature. After 10 hours, the reaction solution was poured into ice (400g, twice the mass of CS2), and hydrochloric acid was added dropwise until the pH of the system reached 2-3. Then, dichloromethane (400g, twice the mass of CS2) was added for extraction. The dichloromethane phase was separated, washed with water several times, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain crude compound 1-b. After purification by column chromatography, pure compound 1-b (8.08g, yield 70.9%) was obtained. MS (EI): 451 (M + );

[0046] (2)

[0047] Compound 1-c (20 g, 204 g / mol, 98 mmol), dichloromethane (20 times the weight of compound 1-c, 400 g), and concentrated sulfuric acid (0.05 eq, 98 g / mol, 0.48 g, 4.9 mmol) were added to a three-necked flask. After the addition was complete, N-bromosuccinimide (1.2 eq, 177.98 g / mol, 20.93 g, 117.6 mmol) was added in portions with stirring at room temperature. After the addition was complete, the reaction was stirred at room temperature for 12 hours. After the reaction was completed by HPLC, the reaction was stopped, and ethanol (50 times the weight of compound 1-c, 1000 g) was added to the reaction solution. A solid precipitated, and the solid was filtered to obtain a filter cake. The filter cake was heated in toluene for 3 hours, cooled to room temperature, and then filtered to obtain compound 1-d (23 g, yield 83.8%). MS (EI): 281 (M + ).

[0048] (3)

[0049] Under nitrogen protection, compounds 1-d (10 g, 281 g / mol, 35.59 mmol), 1-e (1 eq, 361.2 g / mol, 35.59 mmol, 12.86 g), sodium tert-butoxide (1.1 eq, 96.1 g / mol, 39.15 mmol, 3.76 g), Pd2(dba)3 (5% eq, 915.72 g / mol, 1.78 mmol, 1.63 g), and tri-tert-butylphosphine (5% eq, 202.317 g / mol, 1.78 mmol, 0.3 g) were subjected to nitrogen treatment. 6 g of toluene (100 g, 10 times the mass of compound 1-d) was added to the reaction flask. After the addition was complete, the mixture was heated to reflux and reacted for 12 h. After the reaction was completed by HPLC, the mixture was cooled to room temperature, water was added, and the mixture was stirred for 15 min. The mixture was then filtered to obtain the filtrate. The filtrate was separated to obtain the organic phase. The organic phase was dried with anhydrous magnesium sulfate and passed through a silica gel funnel to obtain the secondary filtrate. After rotary evaporation, an appropriate amount of dichloromethane was added to completely dissolve the product. Silica gel powder was then added, and the mixture was evaporated to dryness. After purification by column chromatography, high-purity compound 1-f (16.07 g, yield 80.2%) was obtained. MS (EI): 563 (M+).

[0050] (4)

[0051] Compound 1-b (8 g, 451.91 g / mol, 17.7 mmol) was added to xylene (80 g, 10 times the mass of compound 1-b) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 70.8 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 10 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 17.7 mmol) was then added sequentially. AlBr3 (1 eq, 266.69 g / mol, 17.7 mmol, 4.72 g) was added, and stirring was continued for 30 min. A hexane solution of compound 1-f (1 eq, 563.24 g / mol, 17.7 mmol, 9.97 g) was added dropwise, and the reaction was continued for 10 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain hole transport material 1 (10.57 g, yield 82.6%), MS (EI): 723 (M+).

[0052] Example 2:

[0053]

[0054] The method for synthesizing hole transport material 2 is as follows, wherein steps 1-2 are basically the same as in Example 1, and the other steps are as follows:

[0055] (3)

[0056] Under nitrogen protection, compounds 2-b (10 g, 281 g / mol, 35.59 mmol), 2-c (1 eq, 361.2 g / mol, 35.59 mmol, 12.86 g), sodium tert-butoxide (1.1 eq, 96.1 g / mol, 39.15 mmol, 3.76 g), Pd2(dba)3 (5% eq, 915.72 g / mol, 1.78 mmol, 1.63 g), and tri-tert-butylphosphine (5% eq, 202.317 g / mol, 1.78 mmol, 0.3 g) were subjected to nitrogen treatment. 6 g of toluene (100 g, 10 times the mass of compound 2-b) was added to the reaction flask. After the addition was complete, the mixture was heated to reflux and reacted for 12 h. After the reaction was completed by HPLC, the mixture was cooled to room temperature, water was added, and the mixture was stirred for 15 min. The mixture was then filtered to obtain the filtrate. The filtrate was separated to obtain the organic phase. The organic phase was dried with anhydrous magnesium sulfate and passed through a silica gel funnel to obtain the secondary filtrate. After rotary evaporation, an appropriate amount of dichloromethane was added to completely dissolve the product. Silica gel powder was then added, and the mixture was evaporated and purified by column chromatography to obtain high-purity compound 2-d (16.29 g, yield 81.3%). MS (EI) 563 (M+).

[0057] (4)

[0058] Compound 2-e (8 g, 451.91 g / mol, 17.7 mmol) was added to xylene (80 g, 10 times the mass of compound 2-e) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 70.8 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 30 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 17.7 mmol) was then added sequentially. M) and AlBr3 (1 eq, 266.69 g / mol, 17.7 mmol, 4.72 g) were added, and the mixture was stirred for 60 min. A hexane solution of compound 2-d (1 eq, 563.24 g / mol, 17.7 mmol, 9.97 g) was added dropwise, and the reaction was continued for 15 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 2 (10.39 g, yield 81.2%), MS (EI): 723 (M+).

[0059] Example 3:

[0060]

[0061] The method for synthesizing hole transport material 3 is as follows, wherein step 1 is basically the same as in Example 1, and the other steps are as follows:

[0062] (2)

[0063] Compound 3-a (20 g, 204 g / mol, 98 mmol), dichloromethane (20 times the weight of compound 3-a, 400 g), and concentrated sulfuric acid (0.05 eq, 98 g / mol, 0.48 g, 4.9 mmol) were added to a three-necked flask. After the addition was complete, N-bromosuccinimide (1.2 eq, 177.98 g / mol, 20.93 g, 117.6 mmol) was added in portions with stirring at room temperature. After the addition was complete, the reaction was stirred at room temperature for 12 hours. After the reaction was completed by HPLC monitoring, the reaction was stopped, and ethanol (50 times the weight of compound 3, 1000 g) was added to the reaction solution. A solid precipitated, and the solid was filtered to obtain a filter cake. The filter cake was heated in toluene for 3 hours, cooled to room temperature, and then filtered to obtain compound 3-b (10.11 g, yield 81.3%). MS (EI): 281 (M + ).

[0064] (3)

[0065] Under nitrogen protection, compounds 3-b (10 g, 281 g / mol, 35.59 mmol), 3-c (1 eq, 361.2 g / mol, 35.59 mmol, 12.86 g), sodium tert-butoxide (1.1 eq, 96.1 g / mol, 39.15 mmol, 3.76 g), Pd2(dba)3 (5% eq, 915.72 g / mol, 1.78 mmol, 1.63 g), and tri-tert-butylphosphine (5% eq, 202.317 g / mol, 1.78 mmol, 0.3 g) were subjected to nitrogen treatment. 6 g of toluene (100 g, 10 times the mass of compound 3-b) was added to the reaction flask. After the addition was complete, the mixture was heated to reflux and reacted for 12 h. After the reaction was completed by HPLC, the mixture was cooled to room temperature, water was added, and the mixture was stirred for 15 min. The mixture was then filtered to obtain the filtrate. The filtrate was separated to obtain the organic phase. The organic phase was dried with anhydrous magnesium sulfate and passed through a silica gel funnel to obtain the secondary filtrate. After rotary evaporation, an appropriate amount of dichloromethane was added to completely dissolve the product. Silica gel powder was then added, and the mixture was evaporated and purified by column chromatography to obtain high-purity compound 3-d (15.99 g, yield 79.8%). MS (EI) 563 (M+).

[0066] (4)

[0067] Compound 3-e (8 g, 451.91 g / mol, 17.7 mmol) was added to xylene (80 g, 10 times the mass of compound 3-e) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 70.8 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 20 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 17.7 mmol) was then added sequentially. M) and AlBr3 (1 eq, 266.69 g / mol, 17.7 mmol, 4.72 g) were added, and the mixture was stirred for 50 min. A hexane solution of compound 3-d (1 eq, 563.24 g / mol, 17.7 mmol, 9.97 g) was added dropwise, and the reaction was continued for 10 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 3 (10.89 g, yield 85.1%), MS (EI): 723 (M+).

[0068] Example 4:

[0069]

[0070] The method for synthesizing hole transport material 4 is as follows, wherein steps 1-2 are basically the same as in Example 1, and the other steps are as follows:

[0071] (3)

[0072] Under nitrogen protection, compounds 4-a (10 g, 281 g / mol, 35.59 mmol), 4-b (1 eq, 321.15 g / mol, 35.59 mmol, 11.43 g), sodium tert-butoxide (1.1 eq, 96.1 g / mol, 39.15 mmol, 3.76 g), Pd2(dba)3 (5% eq, 915.72 g / mol, 1.78 mmol, 1.63 g), and tri-tert-butylphosphine (5% eq, 202.317 g / mol, 1.78 mmol, 0. 36 g of toluene (100 g, 10 times the mass of compound 4-a) was added to the reaction flask. After the addition was complete, the mixture was heated to reflux and reacted for 12 h. After the reaction was completed by HPLC, the mixture was cooled to room temperature, water was added, and the mixture was stirred for 15 min. The mixture was then filtered to obtain the filtrate. The filtrate was separated to obtain the organic phase. The organic phase was dried with anhydrous magnesium sulfate and passed through a silica gel funnel to obtain the secondary filtrate. After rotary evaporation, an appropriate amount of dichloromethane was added to completely dissolve the product. Silica gel powder was then added, and the mixture was evaporated to dryness. After purification by column chromatography, high-purity compound 4-c (15.04 g, yield 80.8%) was obtained. MS (EI) 523 (M+).

[0073] (4)

[0074] Compound 4-d (8 g, 451.91 g / mol, 17.7 mmol) was added to xylene (80 g, 10 times the mass of compound 4-d) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 70.8 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 10 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 17.7 mmol) was then added sequentially. M) and AlBr3 (1 eq, 266.69 g / mol, 17.7 mmol, 4.72 g) were added, and the mixture was stirred for 60 min. A hexane solution of compound 4-c (1 eq, 523.21 g / mol, 17.7 mmol, 9.26 g) was added dropwise, and the reaction was continued for 10 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 4 (9.67 g, yield 80.0%), MS (EI): 683 (M+).

[0075] Example 5:

[0076]

[0077] The method for synthesizing hole transport material 5 is as follows:

[0078] (1)

[0079] Compound 5-a (445.87 g / mol, 10 g, 22.43 mmol), FeCl3 (0.2 eq, 162.2 g / mol, 4.49 mmol, 0.73 g), and CS2 (200 g, 20 times the mass of compound 5-a) were added to a reaction flask. Tert-butane chloride (1.1 eq, 92.57 g / mol, 24.67 mmol, 2.28 g) was added under ice bath conditions. After the addition was complete, the mixture was slowly brought to room temperature. After reacting for 10 hours, the reaction solution was poured into ice (400 g, twice the mass of CS2), and hydrochloric acid was added dropwise until the pH of the system reached 2-3. Then, dichloromethane (400 g, twice the mass of CS2) was added for extraction. The dichloromethane phase was separated, washed repeatedly with water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain crude compound 19. After purification by column chromatography, compound 5-b was obtained as pure compound (9.57 g, yield 85.2%). MS (EI): 501 (M + );

[0080] (2)

[0081] Compound 5-b (8 g, 501.93 g / mol, 15.94 mmol) was added to xylene (80 g, 10 times the mass of compound 5-b) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 63.76 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 20 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 15.94 mmol) was then added sequentially. M) and AlBr3 (1 eq, 266.69 g / mol, 15.94 mmol, 4.25 g) were added, and the mixture was stirred for 30 min. A hexane solution of compound 5-c (1 eq, 563.24 g / mol, 15.94 mmol, 8.98 g) was added dropwise, and the reaction was continued for 10 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 5 (10.29 g, yield 81.4%), MS (EI): 773 (M+).

[0082] Example 6:

[0083]

[0084] The method for synthesizing hole transport material 6 is as follows:

[0085] (1)

[0086] Compound 6-a (8 g, 501.93 g / mol, 15.94 mmol) was added to xylene (80 g, 10 times the mass of compound 6-a) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 63.76 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 10 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 15.94 mmol) was then added sequentially. M) and AlBr3 (1 eq, 266.69 g / mol, 15.94 mmol, 4.25 g) were added, and the mixture was stirred for 30 min. A hexane solution of compound 6-b (1 eq, 563.24 g / mol, 15.94 mmol, 8.98 g) was added dropwise, and the reaction was continued for 10 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 6 (10.09 g, yield 81.9%), MS (EI): 773 (M+).

[0087] Example 7:

[0088]

[0089] The method for synthesizing hole transport material 7 is as follows:

[0090] (1)

[0091] Compound 7-a (8 g, 501.93 g / mol, 15.94 mmol) was added to xylene (80 g, 10 times the mass of compound 7-a) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 63.76 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 30 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 15.94 mmol) was then added sequentially. M) and AlBr3 (1 eq, 266.69 g / mol, 15.94 mmol, 4.25 g) were added, and the mixture was stirred for 60 min. A hexane solution of compound 7-b (1 eq, 563.24 g / mol, 15.94 mmol, 8.98 g) was added dropwise, and the reaction was continued for 15 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 7 (10.18 g, yield 82.6%), MS (EI): 773 (M+).

[0092] Example 8:

[0093]

[0094] The method for synthesizing hole transport material 8 is as follows:

[0095] (1)

[0096] Compound 8-a (8 g, 501.93 g / mol, 15.94 mmol) was added to xylene (80 g, 10 times the mass of compound 8-a) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 63.76 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 20 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 15.94 mmol) was then added sequentially. M) and AlBr3 (1 eq, 266.69 g / mol, 15.94 mmol, 4.25 g) were added, and the mixture was stirred for 50 min. A hexane solution of compound 8-b (1 eq, 563.24 g / mol, 15.94 mmol, 8.98 g) was added dropwise, and the reaction was continued for 15 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 8 (10.25 g, yield 83.2%), MS (EI): 773 (M+).

[0097] Example 9:

[0098]

[0099] The method for synthesizing hole transport material 9 is as follows:

[0100] (1)

[0101] Compound 9-a (20 g, 204 g / mol, 98 mmol), dichloromethane (20 times the weight of compound 9-a, 400 g), and concentrated sulfuric acid (0.05 eq, 98 g / mol, 0.48 g, 4.9 mmol) were added to a three-necked flask. After the addition was complete, N-bromosuccinimide (1.2 eq, 177.98 g / mol, 20.93 g, 117.6 mmol) was added in portions with stirring at room temperature. After the addition was complete, the reaction was stirred at room temperature for 12 hours. After the reaction was completed by HPLC monitoring, the reaction was stopped, and ethanol (50 times the weight of compound 1-c, 1000 g) was added to the reaction solution. A solid precipitated, and the solid was filtered to obtain a filter cake. The filter cake was heated in toluene for 3 hours, cooled to room temperature, and then filtered to obtain compound 9-b (28 g, yield 79.6%). MS (EI): 359 (M + ).

[0102] (2)

[0103] Under nitrogen protection, compounds 9-b (10 g, 359 g / mol, 27.86 mmol), 9-c (2.1 eq, 169.09 g / mol, 58.51 mmol, 9.89 g), sodium tert-butoxide (1.1 eq, 96.1 g / mol, 30.65 mmol, 2.95 g), Pd2(dba)3 (5% eq, 915.72 g / mol, 1.39 mmol, 1.27 g), and tri-tert-butylphosphine (5% eq, 202.317 g / mol, 1.39 mmol, 0. 28 g of toluene (100 g, 10 times the mass of compound 9-b) was added to the reaction flask. After the addition was complete, the mixture was heated to reflux and reacted for 12 h. After the reaction was completed by HPLC, the mixture was cooled to room temperature, water was added, and the mixture was stirred for 15 min. The mixture was then filtered to obtain the filtrate. The filtrate was separated to obtain the organic phase. The organic phase was dried with anhydrous magnesium sulfate and passed through a silica gel funnel to obtain the secondary filtrate. After rotary evaporation, an appropriate amount of dichloromethane was added to completely dissolve the product. Silica gel powder was then added, and the mixture was evaporated to dryness. After purification by column chromatography, high-purity compound 9-d (12.31 g, yield 82.1%) was obtained. MS (EI): 538 (M+).

[0104] (3)

[0105] Compound 9-e (8 g, 451.91 g / mol, 17.7 mmol) was added to xylene (80 g, 10 times the mass of compound 9-e) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 70.8 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 30 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 17.7 mmol) was then added sequentially. M) and AlBr3 (1 eq, 266.69 g / mol, 17.7 mmol, 4.72 g) were added, and the mixture was stirred for 30 min. A hexane solution of compound 9-d (1 eq, 538.22 g / mol, 17.7 mmol, 9.53 g) was added dropwise, and the reaction was continued for 10 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 9 (10.08 g, yield 81.6%), MS (EI): 698 (M+).

[0106] Example 10:

[0107]

[0108] The method for synthesizing hole transport material 10 is basically the same as that in Example 9, except that... Replace with 10 (13.38 g, yield 82.5%) were obtained, MS (EI): 642 (M+).

[0109] Example 11:

[0110]

[0111] The method for synthesizing hole transport material 11 is basically the same as that in Example 9, except that... Replace with 11 (9.97 g, yield 83.6%) was obtained, MS (EI): 748 (M+).

[0112] Example 12:

[0113]

[0114] The method for synthesizing hole transport material 29 is basically the same as that in Example 9, except that... Replace with 29 (9.05 g, yield 82.3%) were obtained, MS (EI): 718 (M+).

[0115] Example 13:

[0116]

[0117] The method for synthesizing hole transport material 40 is as follows: (1)

[0119]

[0120] Under nitrogen protection, compounds 13-a (10 g, 359 g / mol, 27.86 mmol), 13-b (2.1 eq, 321.15 g / mol, 58.51 mmol, 18.79 g), sodium tert-butoxide (1.1 eq, 96.1 g / mol, 30.65 mmol, 2.95 g), Pd2(dba)3 (5% eq, 915.72 g / mol, 1.39 mmol, 1.27 g), and tri-tert-butylphosphine (5% eq, 202.317 g / mol, 1.39 mmol, 0. 28 g of toluene (100 g, 10 times the mass of compound 13-a) was added to the reaction flask. After the addition was complete, the mixture was heated to reflux and reacted for 12 h. After the reaction was completed by HPLC, the mixture was cooled to room temperature, water was added, and the mixture was stirred for 15 min. The mixture was then filtered to obtain the filtrate. The filtrate was separated to obtain the organic phase. The organic phase was dried with anhydrous magnesium sulfate and passed through a silica gel funnel to obtain the secondary filtrate. After rotary evaporation, an appropriate amount of dichloromethane was added to completely dissolve the product. Silica gel powder was then added, and the mixture was evaporated to dryness. After purification by column chromatography, high-purity compound 13-c (19.02 g, yield 81.1%) was obtained. MS (EI): 842 (M+). (2)

[0122]

[0123] Compound 13-d (8 g, 451.91 g / mol, 17.7 mmol) was added to xylene (80 g, 10 times the mass of compound 13-d) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 70.8 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 10 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 17.7 mmol) was then added sequentially. AlBr3 (1 eq, 266.69 g / mol, 17.7 mmol, 4.72 g) was added, and the mixture was stirred for 30 min. A hexane solution of compound 13-c (1 eq, 842.35 g / mol, 17.7 mmol, 14.91 g) was added dropwise, and the reaction was continued for 10 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 40 (14.43 g, yield 81.3%), MS (EI): 1002.45 (M+).

[0124] Example 14:

[0125]

[0126] The method for synthesizing hole transport material 52 is basically the same as that in Example 13, except that... Replace with 52 (14.21 g, yield 81.6%) were obtained, MS (EI): 1018.43 (M+).

[0127] Example 15:

[0128]

[0129] The method for synthesizing hole transport material 56 is as follows:

[0130]

[0131] Compound 15-a (8 g, 517.91 g / mol, 15.44 mmol) was added to xylene (80 g, 10 times the mass of compound 15-a) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 61.77 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 10 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 15.44 mmol) was then added sequentially. AlBr3 (1 eq, 266.69 g / mol, 15.44 mmol, 4.12 g) was added, and the mixture was stirred for 30 min. Then, a hexane solution of compound 15-b (1 eq, 842.35 g / mol, 15.44 mmol, 13.01 g) was added dropwise, and the reaction was continued for 10 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 56 (13.31 g, yield 80.7%), MS (EI): 1068.45 (M+).

[0132] Example 16:

[0133]

[0134] The method for synthesizing hole transport material 122 is as follows:

[0135]

[0136] The difference from Example 9 is that... Replace with 122 (9.78 g, yield 82.6%) was obtained, MS (EI): 683 (M+).

[0137] Example 17:

[0138]

[0139] The method for synthesizing hole transport material 123 is as follows:

[0140]

[0141] Compound 17-a (8 g, 501.93 g / mol, 15.94 mmol) was added to xylene (80 g, 10 times the mass of compound 17-a) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 63.76 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 10 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 15.94 mmol) was then added sequentially. M) and AlBr3 (1 eq, 266.69 g / mol, 15.94 mmol, 4.25 g) were added, and the mixture was stirred for 30 min. A hexane solution of compound 17-b (1 eq, 580.28 g / mol, 15.94 mmol, 9.25 g) was added dropwise, and the reaction was continued for 10 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 123 (10.38 g, yield 82.4%), MS (EI): 790 (M+).

[0142] Example 18:

[0143]

[0144] The method for synthesizing hole transport material 134 is as follows:

[0145]

[0146] Compound 18-a (8 g, 501.93 g / mol, 15.94 mmol) was added to xylene (80 g, 10 times the mass of compound 18-a) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 63.76 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 10 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 15.94 mmol) was then added sequentially. M) and AlBr3 (1 eq, 266.69 g / mol, 15.94 mmol, 4.25 g) were added, and the mixture was stirred for 30 min. A hexane solution of compound 18-b (1 eq, 523.21 g / mol, 15.94 mmol, 8.34 g) was added dropwise, and the reaction was continued for 15 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 134 (9.77 g, yield 83.6%), MS (EI): 733 (M+).

[0147] Example 19:

[0148]

[0149] The method for synthesizing hole transport material 139 is as follows:

[0150]

[0151] Compound 19-a (8 g, 501.93 g / mol, 15.94 mmol) was added to xylene (80 g, 10 times the mass of compound 19-a) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 63.76 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 10 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 15.94 mmol) was then added sequentially. M) and AlBr3 (1 eq, 266.69 g / mol, 15.94 mmol, 4.25 g) were added, and the mixture was stirred for 30 min. Then, a hexane solution of compound 19-b (1 eq, 557.22 g / mol, 15.94 mmol, 8.88 g) was added dropwise, and the reaction was continued for 10 h. The mixture was then cooled to -78 °C, quenched with water, extracted with ethyl acetate, and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain 139 (10.35 g, yield 82.5%), MS (EI): 787 (M+).

[0152] Example 20:

[0153]

[0154] The method for synthesizing hole transport material 149 is as follows:

[0155]

[0156] Compound 20-a (8 g, 451.91 g / mol, 17.7 mmol) was added to xylene (80 g, 10 times the mass of compound 20-a) and mixed thoroughly to obtain a homogeneous solution. The solution was then cooled to -78 °C. Under inert gas protection, a pentane solution (1.59 M) of tert-butyllithium (4 eq, 64.06 g / mol, 70.8 mmol) was added dropwise. After the addition was complete, the solution was kept at this temperature and stirred for 10 min. The solution was then allowed to return to room temperature. A pentane solution (1.59 M) of n-butyllithium (1 eq, 64.06 g / mol, 17.7 mmol) was then added sequentially. Add AlBr3 (1 eq, 266.69 g / mol, 17.7 mmol, 4.72 g) and continue stirring for 30 min. Add a hexane solution of compound 20-b (1 eq, 628.23 g / mol, 17.7 mmol, 11.11 g) dropwise and continue the reaction for 15 h. Then cool to -78 °C, quench with water, add ethyl acetate for extraction, separate the liquid and concentrate the ethyl acetate phase under reduced pressure, and purify by column chromatography to obtain 149 (11.40 g, yield 81.7%), MS (EI): 788 (M+).

[0157] Example 21:

[0158]

[0159] The method for synthesizing hole transport material 151 is basically the same as that in Example 20, except that... Replace with 151 (11.15 g, yield 83.5%) was obtained, MS (EI): 838 (M+).

[0160] Performance testing:

[0161] Application Example 1:

[0162] ITO was used as the anode substrate material for the reflective layer, and its surface was treated sequentially with water, acetone, and N2 ions.

[0163] A hole injection layer (HIL) with a thickness of 10 nm is deposited on top of the ITO anode substrate.

[0164] A hole transport layer (HTL) with a thickness of 120 nm is formed by vapor deposition of the hole transport material 1 in Embodiment 1 of the present invention above the hole injection layer (HIL);

[0165] 9,10-Bis(2-naphthyl)anthraces (ADN) was used as the main blue light source material and BD-1 was used as the blue light dopant material (the amount of BD-1 was 5% of the weight of ADN). The two materials were evaporated at different rates on the hole transport layer (HTL) to form a light-emitting layer with a thickness of 20 nm.

[0166] ETM and LiQ were mixed in a 1:1 ratio and vapor-deposited to obtain an electron transport layer (ETL) with a thickness of 35 nm. An electron injection layer (EIL) with a thickness of 2 nm was then vapor-deposited on top of the electron transport layer (ETL).

[0167] Subsequently, magnesium (Mg) and silver (Ag) were mixed in a 9:1 ratio and vapor-deposited to obtain a cathode with a thickness of 15 nm. A DNTPD with a thickness of 65 nm was deposited on the cathode sealing layer. In addition, the cathode surface was sealed with a UV-curable adhesive and a sealing cap containing a desiccant to protect the organic electroluminescent device from the influence of oxygen or moisture in the atmosphere. Thus, an organic electroluminescent device was prepared.

[0168]

[0169] Application Example 2-21

[0170] Using hole transport materials 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 29, 40, 52, 56, 122, 123, 134, 139, 149, and 151 from Examples 2-21 of the present invention as hole transport layer (HTL) materials, and with the other parts being the same as in Application Example 1, organic electroluminescent devices of Application Examples 2-21 were fabricated accordingly.

[0171] Compare with Examples 1, 2, 3, and 4

[0172] The difference from Application Example 1 is that compounds 151 and 118 from HTL-1, HTL-2, and prior art CN 102448926 are used instead of the compounds of the present invention as the hole transport layer; otherwise, they are the same as in Application Example 1.

[0173] The organic electroluminescent device manufactured in the above application example and the organic electroluminescent device manufactured in the comparative example have the characteristic of operating at a current density of 10 mA / cm². 2 The results were measured under the specified conditions and are shown in Table 1.

[0174] Table 1:

[0175]

[0176] As shown in Table 1 above, the experimental comparison data reveals that the organic electroluminescent device prepared using the hole transport material of this invention exhibits a significantly lower voltage and a significantly higher luminous efficiency compared to the control example. This demonstrates that the compound of this invention can greatly reduce the driving voltage of the device, thereby significantly reducing power consumption and significantly improving luminous efficiency. Furthermore, by reducing the driving voltage, the lifetime of the organic electroluminescent device is significantly improved.

Claims

1. A hole transport material, characterized in that, Its structural formula is shown below: Where a is a fused substituted or unsubstituted benzene ring; R1, R2, and R3 are each independently phenyl, tolyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, fluorenyl, oxofluorenyl, 9,9-dimethylfluorenyl, 9,9'-spirodifluorenyl, 9,9-diphenylfluorenyl, dibenzothiophene, carbazole, benzocarbazole, N-phenylcarbazole, o-diphenyl, trideuterium-methylbiphenyl, methylbiphenyl, and triphenylamino. R4 can be terphenyl, anthracene, phenanthrene, oxofluorenyl, 9,9-dimethylfluorenyl, 9,9'-spirodifluorenyl, 9,9-diphenylfluorenyl, dibenzothiophene, carbazole, benzocarbazole, N-phenylcarbazole, o-diphenyl, or triphenylamino. R5 is tert-butyl; W represents O or S; m is independent and can be 0 or 1, while n is 0.

2. The hole transport material as described in claim 1, characterized in that, The hole transport material is any one of the following compounds with the following structural formulas:

3. The hole transport material according to any one of claims 1-2, characterized in that, Its preparation method is as follows: Raw material 1 was added to xylene and mixed to obtain a homogeneous solution. The solution was then cooled to -78°C. Under inert gas protection, a pentane solution of tert-butyllithium was added dropwise. After the addition was complete, the solution was kept warm and stirred for 10-30 minutes. The solution was then restored to room temperature. A pentane solution of n-butyllithium and AlBr3 were added sequentially, and the mixture was stirred for another 30-60 minutes. A hexane solution of raw material 2 was then added dropwise. The reaction was continued for 10-15 hours, then cooled to -78°C and quenched with water. The solution was extracted with ethyl acetate and separated. The ethyl acetate phase was concentrated under reduced pressure and purified by column chromatography to obtain the hole transport material.

4. The use of the hole transport material as described in any one of claims 1-2 in the fabrication of organic electroluminescent devices.

5. An organic electroluminescent device, characterized in that, It includes a cathode, an anode, a light-emitting layer, and a hole transport layer, wherein the hole transport layer contains a hole transport material as described in any one of claims 1-2.

6. A lighting device, characterized in that, It contains the organic electroluminescent device as described in claim 5.

7. An electronic display device, characterized in that, It contains the organic electroluminescent device as described in claim 5.

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