Deuterated 1-aryl substituted carbazole compounds, methods of making and using the same

Abstract

The application discloses a deuterated 1-aryl-substituted carbazole compound and a preparation method and application thereof, and belongs to the technical field of organic optoelectronics. The 1-substituted carbazole compound containing a deuterium atom designed by the application is isotopic deuterium on a benzene ring of hydrogen. The introduction of deuterium can improve the charge transport performance of the compound and improve the thermal stability of the compound. The molecules can be used for a hole transport layer of a red, green and blue electroluminescent device. An organic electroluminescent device produced by taking the material as the hole transport layer can reduce a driving voltage, improve luminous efficiency, has excellent color purity, has a longer device life, and has great application potential. The 1-substituted carbazole compound containing the deuterium atom designed by the application is expected to be applied to a new generation of organic electronic device products such as an organic light emitting display and a quantum dot display.

Description

Technical Field

[0001] This invention relates to the field of organic optoelectronic materials technology, and more specifically, to deuterated 1-aryl-substituted carbazole compounds, their preparation methods, and applications. Background Technology

[0002] Organic light-emitting diodes (OLEDs) have attracted considerable attention from researchers due to their advantages such as active light emission without the need for a backlight, high luminous efficiency, and enormous application potential. To improve luminous efficiency and extend lifespan, the development and research of light-emitting devices are becoming increasingly active.

[0003] The brightness and performance of organic light-emitting diodes (OLEDs) are related to the energy level matching between the hole transport layer and adjacent functional layers, as well as the balance between injected electrons and holes. Hole transport materials must simultaneously possess high hole mobility, suitable highest occupied molecular orbital (HOMO) / lowest unoccupied molecular orbital (LUMO) energy levels, and thermal stability. The energy level difference between the hole transport layer and adjacent functional layers is often considered to be significantly related to device efficiency and stability. If the HOMO energy level difference between the hole transport layer and the hole injection layer is too large, it will increase the device's onset voltage and reduce its lifetime. A large difference in the HOMO energy level between the hole transport layer and the emissive layer can also prevent holes from transporting to the emissive layer. The imbalance between electron and hole injection and the difference in their mobilities prevent injected carriers from being effectively confined in the emissive layer to form excitons, causing some excess carriers to reach the electrodes, resulting in quenching of light emission at the electrodes and reducing the device's luminous efficiency. Driven by the enormous potential of the OLED display industry, high-efficiency, long-lifetime organic hole transport materials are one of the key areas of international research.

[0004] Polyvinylcarbazole (PVK) is one of the most commonly used solution-processed hole transport materials. It has good hole transport and electron blocking capabilities, and its high singlet and triplet energy levels provide effective exciton blocking capabilities. As a result, devices can achieve higher carrier and exciton utilization.

[0005] The Kido research group at Yamagata University in Japan proposed a method for crosslinking PVK at a lower temperature (Adv. Mater., 2014, 26, 7543-7546). Using dodecylmolybdate phosphate as an oxidant, PVK is blended with the PVK, and heating at 110°C for 3 minutes induces dehydrogenation at the 3,6 positions of the carbazole group to form a dicarbazole, exhibiting good crosslinking performance. The structural formula of the dicarbazole is as follows: Solution-processed blue phosphorescent OLED devices based on this cross-linked PVK interface achieve 10000 cd / m² 2An external quantum efficiency of 17% was achieved at high brightness. However, this cross-linked PVK has the drawback of uncertain molecular weight.

[0006] Therefore, designing and preparing carbazole-based branched hole transport materials with a defined molecular weight to ensure high purity while obtaining high triplet energy levels and high hole transport mobility is a technical problem that needs to be solved. Summary of the Invention

[0007] To address the problems in existing technologies, this invention proposes deuterated 1-aryl-substituted carbazole compounds, their preparation methods, and applications. Carbazole hole transport materials typically have high triplet energy levels, meeting the requirements of blue thermally assisted delayed fluorescence and phosphorescent OLEDs. Furthermore, the carbazole group exhibits good chemical stability; its 2 / 7, 3 / 6, 9, and even 1 / 8 positions can be modified, and the synthesis is simple. Therefore, this invention designs 1-substituted carbazole compounds containing deuterium atoms, with the hydrogen isotope deuterium on the benzene ring. The introduction of deuterium improves the charge transport performance and thermal stability of the compound. These molecules can be used as hole transport layers in red, green, and blue electroluminescent devices. Organic electroluminescent devices prepared using this material as the hole transport layer can reduce driving voltage, improve luminous efficiency, exhibit excellent color purity, and have longer device lifetimes, demonstrating significant application potential. The 1-substituted carbazole compounds containing deuterium atoms designed in this invention are expected to be applied to next-generation organic electronic devices such as organic light-emitting displays and quantum dot displays in the future.

[0008] One object of the present invention is to provide a deuterated 1-aryl-substituted carbazole compound having the following general structural formula 1:

[0009]

[0010] The Ar is selected from substituted or unsubstituted aryl groups, substituted or unsubstituted polycyclic aryl groups, substituted or unsubstituted heteroaryl groups, and substituted or unsubstituted aromatic amino groups.

[0011] In the deuterated 1-aryl-substituted carbazole compounds of the present invention, preferably,

[0012] The Ar is selected from substituted or unsubstituted aryl groups with 6-42 carbon atoms, substituted or unsubstituted polycyclic aryl groups with 10-22 carbon atoms, substituted or unsubstituted heteroaryl groups with 5-48 carbon atoms, and substituted or unsubstituted aromatic amino groups with 18-90 carbon atoms; and / or,

[0013] The two Ar groups in general structural formula 1 are identical;

[0014] Preferably,

[0015] The Ar is selected from substituted or unsubstituted phenyl groups with 6-30 carbon atoms, substituted or unsubstituted polycyclic aryl groups with 10-14 carbon atoms, substituted or unsubstituted heteroaryl groups with 5-36 carbon atoms, and substituted or unsubstituted triarylamine groups with 18-66 carbon atoms.

[0016] In the deuterated 1-aryl-substituted carbazole compounds of the present invention, preferably,

[0017] The Ar group selected from substituted or unsubstituted aryl groups has the following general structural formula 2:

[0018]

[0019] R1 is selected from alkyl groups having 1-10 carbon atoms and heteroaryl groups having 12-24 carbon atoms; n1 is selected from any integer from 0 to 4;

[0020] Preferably, R1 is selected from alkyl groups having 1-5 carbon atoms or heteroaryl groups containing nitrogen atoms having 12-24 carbon atoms; and / or, n1 is selected from any integer from 1 to 2;

[0021] More preferably, R1 is selected from straight-chain alkyl groups or carbazole groups having 1-3 carbon atoms.

[0022] In the deuterated 1-aryl-substituted carbazole compounds of the present invention, preferably,

[0023] The general formula 2 is selected from the following groups:

[0024]

[0025] In the deuterated 1-aryl-substituted carbazole compounds of the present invention, preferably,

[0026] The Ar group selected from substituted or unsubstituted polycyclic aryl groups is selected from naphthyl, anthraceneyl, phenanthryl, and tetraphenyl; more preferably, it is...

[0027] In the deuterated 1-aryl-substituted carbazole compounds of the present invention, preferably,

[0028] The Ar group selected from substituted or unsubstituted heteroaryl groups is pyridyl or has the following general structural formula 3:

[0029]

[0030] R2 and R3 are each independently selected from nitrogen-containing heteroaryl or aromatic amino groups;

[0031] Preferably, R2 and R3 are each independently selected from carbazole group or diarylamine group;

[0032] More preferably, R2 and R3 are selected from the same substituents.

[0033] In the deuterated 1-aryl-substituted carbazole compounds of the present invention, preferably,

[0034] The general formula 3 is selected from the following groups:

[0035] And / or,

[0036] The pyridyl group is selected from

[0037] In the deuterated 1-aryl-substituted carbazole compounds of the present invention, preferably,

[0038] The Ar group selected from substituted or unsubstituted aromatic amino groups has the following general structural formula 4:

[0039]

[0040] R4 and R5 are each independently selected from heteroaryl or aromatic amino groups containing nitrogen atoms; n4 and n5 are each independently selected from any integer from 0 to 4.

[0041] Preferably, R4 and R5 are each independently selected from carbazole group or diarylamine group; and / or,

[0042] The n4 and n5 are each independently selected from any integer between 0 and 2.

[0043] In the deuterated 1-aryl-substituted carbazole compounds of the present invention, preferably,

[0044] The general formula 4 is selected from the following groups:

[0045]

[0046] In the deuterated 1-aryl-substituted carbazole compounds of the present invention, preferably, the deuterated 1-aryl-substituted carbazole hole-transporting small molecule material has the following structural formula:

[0047]

[0048] In the formula, Ar is preferably one of the following groups:

[0049]

[0050] A second objective of this invention is to provide a method for preparing the deuterated 1-aryl-substituted carbazole compound described in one objective of this invention, comprising the following steps:

[0051] Under the action of a catalyst, the compound represented by general formula A, the compound represented by general formula B, and a base undergo a CN coupling reaction in a solvent to obtain the deuterated 1-aryl-substituted carbazole compound.

[0052] The compound represented by general formula A has the following structure:

[0053] The Ar mentioned therein corresponds to the Ar described in claims 1-9;

[0054] The compound represented by general formula B has the following structure:

[0055] X is a halogen.

[0056] In this invention, the compound represented by general formula A can be directly purchased or prepared using existing conventional preparation methods and conditions. For example, preferably...

[0057] The compound represented by general formula A can be prepared by the following two methods:

[0058] Method A:

[0059] Formulas A-1 and A-2, bases, and solvents react to produce compounds represented by general formula A;

[0060]

[0061] Method B:

[0062]

[0063] Formulas A-1 and A-3, base and catalyst react in solvent to produce compounds represented by general formula A.

[0064] In the method for preparing the deuterated 1-aryl-substituted carbazole compound of the present invention, preferably,

[0065] The catalyst is selected from at least one of CuI, Pd(OAc)2, and Pd2(dba)3; and / or,

[0066] The solvent is selected from at least one of N,N-dimethylformamide, dimethyl sulfoxide, toluene, and tetrahydrofuran; and / or,

[0067] The alkali is selected from at least one of K2CO3, NaOt-Bu, lithium bis(trimethylsilyl)amino, K3PO4, and Cs2CO3; and / or,

[0068] In general formula B, X is chlorine, bromine, or iodine, preferably bromine; and / or,

[0069] The molar ratio of the compound represented by general formula A to the compound represented by general formula B is 2.5:1 to 6:1, preferably 2.5:1 to 4:1; and / or,

[0070] The molar ratio of the compound represented by general formula B to the catalyst is 1:1 to 1:2, preferably 1:1.1 to 1:1.5; and / or,

[0071] The molar volume ratio of the compound represented by general formula A to the solvent is 1 mol: 1000–12000 mL, 1 mol: 8000–10000 mL; and / or,

[0072] The molar ratio of the compound represented by general formula B to the base is 1:1.5 to 1:4, preferably 1:2 to 1:3; and / or,

[0073] The temperature of the CN coupling reaction is 120–180°C, preferably 140–160°C; and / or,

[0074] The CN coupling reaction takes 20 to 40 hours, preferably 24 to 30 hours.

[0075] A third objective of this invention is to provide the application of the deuterated 1-aryl-substituted carbazole compound described in one objective of this invention or the deuterated 1-aryl-substituted carbazole compound prepared by the preparation method described in another objective of this invention as a hole transport layer material in flat panel displays, solar cells, and electroluminescent diodes.

[0076] In the application described in this invention, preferably,

[0077] The solar cell is selected from organic solar cells or organic perovskite cells; and / or,

[0078] The electroluminescent diode is selected from red, green, and blue electroluminescent diodes.

[0079] In the application described in this invention, preferably,

[0080] The deuterated 1-aryl-substituted carbazole compound was dissolved in an organic solvent and then prepared into a film by a wet process.

[0081] Preferably, the wet film preparation method is selected from at least one of spin coating, inkjet printing, or slot coating; and / or,

[0082] The organic solvent is selected from at least one of toluene, xylene, chlorobenzene, and o-dichlorobenzene; and / or,

[0083] The concentration of the deuterated 1-aryl-substituted carbazole compound in the organic solvent is 5–25 mg / mL, preferably 10–20 mg / mL.

[0084] Compared with the prior art, the present invention has the following advantages:

[0085] 1. In the 1-substituted carbazole compound containing deuterium atoms described in this invention, the benzene ring is occupied by the hydrogen isotope deuterium. The introduction of deuterium can improve the charge transport properties of the compound and enhance its thermal stability.

[0086] 2. In the 1-substituted carbazole compound containing deuterium atoms of the present invention, the 1-substituted carbazole compound group makes the molecular structure more distorted, which can effectively improve the triplet energy level. The present invention also introduces an Ar group on the 1-substituted carbazole compound. Due to the functionalization of the Ar group, the charge transport performance of the compound can be improved more effectively. At the same time, the molecular weight of the 1-substituted carbazole compound containing deuterium atoms is relatively large, thus significantly increasing thermal stability and film-forming properties.

[0087] 3. The present invention provides a deuterated 1-aryl-substituted carbazole hole transport small molecule material. This type of hole transport material exhibits excellent solubility and thermal stability, as well as a high triplet energy level. The deuterium-containing 1-substituted carbazole compound of the present invention can be used as the hole transport layer in red, green, and blue electroluminescent devices. Organic electroluminescent devices fabricated using this material as the hole transport layer can reduce driving voltage, improve luminous efficiency, have excellent color purity, and longer device lifetime, showing great application potential.

[0088] 4. The photothermal material described in this invention has readily available raw materials, mild synthesis conditions, a simple preparation method, and convenient purification. Attached Figure Description

[0089] Figure 1 The low-temperature phosphorescence spectrum of compound M4 in Example 1;

[0090] Figure 2 Thermogravimetric analysis (TGA) curve of compound M8 in Example 2;

[0091] Figure 3 Thermogravimetric analysis (TGA) curve of undeuterated compound M17 from Comparative Example 1. Detailed Implementation

[0092] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0093] It should also be noted that the various specific technical features described in the following embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the various possible combinations will not be described separately in this invention.

[0094] Furthermore, various embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention. The resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0095] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, such as those that can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0096] Example 1

[0097] Synthesis of compound M1:

[0098]

[0099] Under an argon atmosphere, tris(4-bromophenyl)amine (4.82 mg, 0.01 mmol) was dissolved in 100 mL of purified THF, and 1.6 mol L⁻¹ was gradually added dropwise at -78 °C. -1 5 mL of n-butyllithium was added, and the reaction was allowed to proceed for 2 hours. Then, 10 mL of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborane was added, and the reaction was continued at -78°C for 1 hour. The mixture was then slowly raised to room temperature and reacted for 24 hours. The reaction mixture was poured into water, extracted with ethyl acetate, and the organic layer was washed with brine. The solution was then dried over anhydrous magnesium sulfate. After concentration, a pale yellow, viscous crude product was obtained, which was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 15 / 1, v / v) to give a white solid. 1 ¹H NMR, MS and elemental analysis results indicate that the obtained compound is the target product (compound M1).

[0100] Synthesis of compound M2:

[0101]

[0102] Under an argon atmosphere, 4-bromo-N-(4-bromophenyl)-N-(4-(4,4,5,5-tetramethyl-1,3,2-epoxyborane-2-yl)phenyl)amine (compound M1) (5.27 mg, 0.01 mmol) was dissolved in 100 mL of purified DMSO. 2.76 mg K₂CO₃, 2 mg CuI, and 4.18 mg carbazole (0.025 mmol) were added, and the mixture was stirred. The temperature was then raised to 110 °C, and the reaction was allowed to proceed for 24 hours. The mixture was then cooled to room temperature, poured into water, and extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. After concentration, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 25 / 1, v / v) to give a white solid. 1 1H NMRMS and elemental analysis results indicate that the obtained compound is the target product (compound M2).

[0103] Synthesis of compound M3:

[0104]

[0105] In a three-necked flask, compound M2 (7.01 mg, 0.01 mmol), 1-bromo-9H-2,3,4,5,6,7,8-deuterated carbazole (7.56 mg, 0.03 mmol), and 200 mL of toluene were added and stirred to dissolve. Then, Na2CO3 (53 mg, 0.5 mmol), tetrabutylammonium bromide (0.20 mg, 0.5 μmol), and 2 mL of water were added, along with catalyst Pd(PPh3)4 (2.31 mg, 2 μmol). The mixture was then heated to 110 °C for 16 hours under argon protection, cooled to room temperature, and the reaction solution was extracted with ethyl acetate and purified by column chromatography using petroleum ether:dichloromethane = 20:1 as the eluent. 1 ¹H NMR and MS tests confirmed that it was the target product (compound M3).

[0106] Synthesis of compound M4:

[0107]

[0108] Under an argon atmosphere, m-dibromobenzene (2.34 mg, 0.01 mmol) was dissolved in 100 mL of purified DMF. 2.76 mg K₂CO₃, 2 mg CuI, and compound M3 (18.68 mg, 0.025 mmol) were added, and the mixture was stirred. The temperature was then raised to 180 °C, and the reaction was allowed to proceed for 24 hours. The mixture was then cooled to room temperature, poured into water, and extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. After concentration, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 30 / 1, v / v) to give a white solid (compound M4). 1 ¹H NMRMS and elemental analysis results indicated that the obtained compound was the target product. The molecular weight of compound M4 was determined using a Waters ACQUITY UPLC mass spectrometer with an APCI ion source. (APCI mass spectrometry) 114 H 60 D 14 N8): 1569.9.

[0109] Low-temperature phosphorescence spectroscopy was performed using a HORIBA FluoroMax-4 spectrometer. The temperature was controlled by placing the test sample solution in a long quartz tube and then using a Dewar flask filled with liquid nitrogen. The solvent used to prepare the samples was of chromatographic purity. Figure 1 The phosphorescence spectrum of compound M4 under low-temperature conditions is presented. The inflection point of the initial peak is 422 nm, and the triplet energy level of compound M4 is calculated to be 2.94 eV. Compound M4 exhibits a high triplet energy level.

[0110] Example 2

[0111] Synthesis of compound M5:

[0112]

[0113] Under an argon atmosphere, 3,6-dibromo-9-(tert-butyldimethylsilane)-9H-carbazole (4.39 g, 0.01 mmol) was dissolved in 200 mL of purified DMSO. 2.76 mg K₂CO₃, 2 mg CuI, and 4.18 mg carbazole (0.025 mmol) were added, and the mixture was stirred. The temperature was then raised to 110 °C, and the reaction was allowed to proceed for 24 hours. The mixture was then cooled to room temperature, poured into water, and extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. After concentration, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 20 / 1, v / v) to give a white solid. 1¹H NMR, MS and elemental analysis results indicate that the obtained compound is the target product (compound M5).

[0114] Synthesis of compound M6:

[0115]

[0116] M5 (6.11 mg, 0.01 mmol), tetrabutylammonium fluoride (2.62 mg, 0.01 mmol), and 100 mL of tetrahydrofuran were added to a three-necked flask. The mixture was stirred at room temperature for 5 hours and extracted with ethyl acetate. The organic phase was washed with saturated sodium chloride aqueous solution and dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporation, and the crude product was purified by column chromatography using petroleum ether as eluent to give a white solid (compound M6). 1 ¹H NMR and MS tests confirmed that it was the target product.

[0117] Synthesis of compound M7:

[0118]

[0119] Under an argon atmosphere, 1-bromo-9H-2,3,4,5,6,7,8-deuterated carbazole (2.52 mg, 0.01 mmol) was dissolved in 100 mL of purified DMSO. 2.76 mg of K₂CO₃, 2 mg of CuI, and compound M6 (12.43 mg, 0.025 mmol) were added, and the mixture was stirred. The temperature was then raised to 110 °C, and the reaction was allowed to proceed for 24 hours. The mixture was then cooled to room temperature, poured into water, and extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. After concentration, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 15 / 1, v / v) to give a white solid (compound M7). 1 HNMR, MS and elemental analysis results indicate that the obtained compound is the target product.

[0120] Synthesis of compound M8:

[0121]

[0122] Under an argon atmosphere, m-dibromobenzene (2.34 mg, 0.01 mmol) was dissolved in 100 mL of purified DMF. 2.76 mg K₂CO₃, 2 mg CuI, and compound M7 (16.73 mg, 0.025 mmol) were added, and the mixture was stirred. The temperature was then raised to 160 °C, and the reaction was allowed to proceed for 24 hours. The mixture was then cooled to room temperature, poured into water, and extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. After concentration, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 30 / 1, v / v) to give a white solid. 1 ¹H NMR, MS, and elemental analysis results indicated that the obtained compound was the target product. The elemental composition of compound M8 was determined using a Vario EL cube elemental analyzer. Elemental analysis, [C 102 H 48 D 14 Theoretical values ​​(%): C, 86.66; H, 5.42; N, 7.93. Measured values ​​(%): C, 85.39; H, 5.27; N, 7.71.

[0123] We characterized the thermal decomposition temperature of compound M8 using a thermogravimetric analyzer (TGA). The TGA analyzer model was a Netzsch TG 209, operating in a N2 atmosphere with a heating rate of 10 °C / min. Figure 2 Thermogravimetric analysis (TGA) curves for compound M8 are presented. From the vertical axis of the curve, we can see that the temperature at which 95% mass loss occurs is 433℃, indicating that the thermal decomposition temperature of compound M8 is 433℃, meaning that compound M8 has very high thermal stability.

[0124] Example 3

[0125] Synthesis of compound M9:

[0126]

[0127] Under an argon atmosphere, 1,3,5-tribromobenzene (3.12 mg, 0.01 mmol) was dissolved in 50 mL of purified DMF. 2.76 mg K₂CO₃, 2 mg CuI, and carbazole (3.34 mg, 0.02 mmol) were added, and the mixture was stirred. The temperature was then raised to 180 °C, and the reaction was allowed to proceed for 24 hours. The mixture was then cooled to room temperature, poured into water, and extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. After concentration, a white crude product was obtained, which was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 20 / 1, v / v) to give a white solid (compound M9). 1 ¹H NMR, MS and elemental analysis results indicate that the obtained compound is the target product.

[0128] Synthesis of compound M10

[0129]

[0130] Under an argon atmosphere, compound M9 (22.85 mg, 0.047 mmol), pinacol diboronate (11.9 mg, 0.047 mmol), potassium acetate (9.2 mg, 0.094 mmol), and dichloro[1,1'-bis(diphenylphosphine)ferrocene]palladium (1.7 mg, 2.35 × 10⁻⁶) were added. -3 (mmol) was dissolved in 20 mL of 1,4-dioxane and added to a 250 mL two-necked flask. The mixture was reacted at 90 °C for 6 hours. After the reaction was complete, the solid was purified by column chromatography using petroleum ether / dichloromethane as the eluent (6:1). The resulting white solid was then recrystallized in a dichloromethane / methanol system, filtered, and dried in a vacuum oven to obtain a white solid. 1 HNMR, MS and elemental analysis results confirmed it to be compound M10.

[0131] Synthesis of compound M11

[0132]

[0133] Under an argon atmosphere, compound M10 (22.44 mg, 0.042 mmol), 1-bromo-9H-2,3,4,5,6,7,8-deuterated carbazole (10.63 mg, 0.042 mmol), potassium carbonate aqueous solution (2 M, 5 mL), and tetraphenylphosphine palladium (4.9 mg, 4.2 × 10⁻⁶ mmol) were added. - 3 mmol), tetrabutylammonium bromide (1.4 mg, 4.2 × 10⁻⁶ ... -3 The solution (mmol) was dissolved in toluene (20 mL) and added to a 250 mL two-necked flask. The mixture was reacted at 110 °C for 12 hours. After the reaction was complete, the solution was purified by column chromatography using petroleum ether / dichloromethane = 10:1 as the eluent. The resulting grayish-white solid was then recrystallized in a dichloromethane / methanol system, filtered, and dried in a vacuum oven to obtain a white powder. 1 ¹H NMR, MS and elemental analysis results confirmed it to be compound M11.

[0134] Synthesis of compound M12

[0135]

[0136] Under an argon atmosphere, m-dibromobenzene (2.34 mg, 0.01 mmol) was dissolved in 100 mL of purified DMF. 2.76 mg K₂CO₃, 2 mg CuI, and compound M11 (14.51 mg, 0.025 mmol) were added, and the mixture was stirred. The temperature was then raised to 160 °C, and the reaction was allowed to proceed for 24 hours. The mixture was then cooled to room temperature, poured into water, and extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. After concentration, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 10 / 1, v / v) to give a white solid. 1 ¹H NMR, MS, and elemental analysis results indicate that the obtained compound is the target product. The elemental composition of compound M12 was determined using a Vario EL cube elemental analyzer. Elemental analysis, [C...] 90 H 42 D 14 Theoretical values ​​(%): C, 87.49; H, 5.71; N, 6.80. Measured values ​​(%): C, 84.83; H, 5.11; N, 6.04.

[0137] Example 4

[0138] Preparation of compound M13

[0139]

[0140] Under an argon atmosphere, p-bromobenzene (2.34 mg, 0.01 mmol) was dissolved in 50 mL of purified DMF. 2.76 mg K₂CO₃, 2 mg CuI, and carbazole (1.67 mg, 0.01 mmol) were added, and the mixture was stirred. The temperature was then raised to 180 °C, and the reaction was allowed to proceed for 24 hours. The mixture was then cooled to room temperature, poured into water, and extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. After concentration, a white crude product was obtained, which was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 20 / 1, v / v) to give a white solid (compound M13). 1 ¹H NMR, MS and elemental analysis results indicate that the obtained compound is the target product.

[0141] Preparation of compound M14

[0142]

[0143] Under an argon atmosphere, compound M13 (15.09 mg, 0.047 mmol), pinacol diboronate (11.9 mg, 0.047 mmol), potassium acetate (9.2 mg, 0.094 mmol), and dichloro[1,1'-bis(diphenylphosphine)ferrocene]palladium (1.7 mg, 2.35 × 10⁻⁶) were added. -3 (mmol) was dissolved in 1,4-dioxane (20 mL) and added to a 250 mL two-necked flask. The reaction was carried out at 90 °C for 6 hours. After the reaction was completed, the solid was purified by column chromatography with petroleum ether / dichloromethane as the eluent (5:1). The resulting white solid was then recrystallized in a dichloromethane / methanol system, filtered, and dried in a vacuum oven to obtain a white solid. 1 HNMR, MS and elemental analysis results confirmed it to be compound M14.

[0144] Preparation of compound M15

[0145]

[0146] Under an argon atmosphere, compound M14 (15.51 mg, 0.042 mmol), 1-bromo-9H-2,3,4,5,6,7,8-deuterated carbazole (10.63 mg, 0.042 mmol), potassium carbonate aqueous solution (2 M, 5 mL), and tetraphenylphosphine palladium (4.9 mg, 4.2 × 10⁻⁶ mmol) were added. - 3 mmol), tetrabutylammonium bromide (1.4 mg, 4.2 × 10⁻⁶ ... -3 (mmol) was dissolved in toluene (20 mL) and added to a 250 mL two-necked flask. The mixture was reacted at 110 °C for 12 hours. After the reaction was complete, the mixture was purified by column chromatography using petroleum ether / dichloromethane = 8:1 as the eluent. The resulting grayish-white solid was then recrystallized in a dichloromethane / methanol system, filtered, and dried in a vacuum oven to obtain a white powder. 1 ¹H NMR, MS and elemental analysis results confirmed it to be compound M15.

[0147] Preparation of compound M16

[0148]

[0149] Under an argon atmosphere, m-dibromobenzene (2.34 mg, 0.01 mmol) was dissolved in 100 mL of purified DMF. 2.76 mg K₂CO₃, 2 mg CuI, and compound M15 (10.38 mg, 0.025 mmol) were added, and the mixture was stirred. The temperature was then raised to 160 °C, and the reaction was allowed to proceed for 24 hours. The mixture was then cooled to room temperature, poured into water, and extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. After concentration, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 15 / 1, v / v) to give a white solid. 1 ¹H NMR, MS, and elemental analysis results indicate that the obtained compound is the target product. The elemental composition of compound M12 was determined using a Vario EL cube elemental analyzer. Elemental analysis, [C...] 66 H 28 D 14 Theoretical values ​​(%): C, 87.58; H, 6.23; N, 6.19. Measured values ​​(%): C, 84.17; H, 5.71; N, 5.56.

[0150] Comparative Example 1

[0151] Preparation of the undeuterated compound M17

[0152] Its preparation method is the same as that of M8 in Example 2. The difference between M17 and M8 is that all the deuterium atoms in M8 are replaced with hydrogen atoms.

[0153]

[0154] We used thermogravimetric analysis (TGA) to characterize the thermal decomposition temperature of the undeuterated compound M17. The TGA instrument model was Netzsch TG 209, operating in a N2 atmosphere with a heating rate of 10 °C / min. Figure 3 Thermogravimetric analysis (TGA) curves of the undeuterated compound M17 are presented. From the vertical axis of the curve, the temperature at which 95% mass loss occurs is 401℃, indicating that the thermal decomposition temperature of the undeuterated compound M17 is 401℃. This demonstrates that the thermal stability of the undeuterated M17 is worse than that of the deuterated M8.

[0155] Examples 5-9

[0156] Fabrication of electroluminescent devices

[0157] (1) Cleaning of conductive glass ITO substrate: The ITO glass substrate is placed in acetone, isopropanol, cleaning solution, deionized water and isopropanol in sequence for ultrasonic cleaning to remove any residues (such as photoresist) that may remain on the surface of the ITO glass substrate and to improve the interface contact. After cleaning, it is placed in a vacuum oven to dry.

[0158] (2) Place the ITO in an oxygen plasma etching instrument and bombard it with oxygen plasma (O2 Plasma) for twenty minutes to thoroughly remove any residual organic matter on the surface of the ITO glass substrate.

[0159] (3) A hole injection layer PEDOT:PSS (Baytron P4083) with a thickness of 40 nm was spin-coated on ITO and then dried in a vacuum oven at 80 °C for 12 hours.

[0160] (4) In a glove box under a nitrogen atmosphere, high molecular weight compound M4 (or M8, M12, M16) was dissolved in chlorobenzene to prepare solutions with a concentration of 20 mg / mL. After spin-coating a hole transport layer with a thickness of 40 nm onto the PEDOT:PSS layer, the solution was heated and annealed at 80 °C for 20 minutes on a heating stage to remove residual solvent and improve the morphology of the hole transport layer film.

[0161] (5) In a glove box under a nitrogen atmosphere, the polymer material poly(9,9-dioctylfluorene) (PFO) was dissolved in p-xylene to prepare a solution with a concentration of 20 mg / mL. A 40 nm thick light-emitting layer film was spin-coated onto the hole transport layer and then heated and annealed at 80 °C for 20 minutes on a heating stage to remove residual solvent and improve the morphology of the light-emitting layer film.

[0162] (6) In a vacuum evaporation chamber, below 3×10 -4 Under a vacuum of Pa, a 40 nm thick layer of electron transport material 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBI) is first deposited on the active layer film, followed by a 1.0 nm thick layer of cesium fluoride (CsF), and finally a 90 nm thick layer of ultrapure aluminum cathode (Al). The lithium fluoride and aluminum layers are vacuum deposited using a mask.

[0163] The effective area of ​​the device is 0.09 cm². 2The thickness of the organic layer was measured using a quartz crystal thickness gauge. After device fabrication, epoxy resin and a thin glass layer were polarly cured and encapsulated under ultraviolet light. Electroluminescence (EL) spectra were obtained using a PhotoResearch PR705 optical analyzer. The characteristics of current density and luminance versus driving voltage were measured using a Keithley 2400 source measurement unit and a Konica Minolta CS-200 colorimeter, respectively. The external quantum efficiency was calculated from luminance, current density, and EL spectra, assuming a Lambertian distribution.

[0164] The fabricated device structure is ITO / PEDOT:PSS / M4 (M8, M12, or M16).

[0165] To investigate the effect of the introduction of deuterium atoms on the performance of organic electroluminescent devices, an electroluminescent device with the structure ITO / PEDOT:PSS / M17 / PFO / TPBI / CsF / Al was also fabricated for comparative study.

[0166] The structural formula of the hole transport material polyvinylcarbazole (PVK) is as follows:

[0167]

[0168] The structural formula of the luminescent poly(9,9-dioctylfluorene) (PFO) is:

[0169]

[0170] The structural formula of the electron transport material 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBI) is:

[0171]

[0172] The photoelectric properties of the prepared electroluminescent devices were tested, and the test results are shown in Table 1.

[0173] Table 1. Photoelectric properties of electroluminescent devices

[0174]

[0175] Comparing the data in Table 1 above, it is clear that electroluminescent devices using deuterated M4, M8, M12, or M16 as the hole transport layer have higher efficiency. Compared to undeuterated M17, electroluminescent devices using deuterated M8 as the hole transport layer have lower turn-on voltage, higher luminous efficiency and maximum brightness, and better color purity. This indicates that the introduction of deuterium can improve the charge transport performance of the compound, thereby obtaining better electroluminescent performance.

[0176] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0177] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In the following, various technical solutions can, in principle, be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

Claims

1. A deuterated 1-aryl-substituted carbazole compound having the following general structural formula 1: ； Structural Formula 1 The two Ar groups in general structural formula 1 are identical; in, The Ar is selected from the structure shown in the following general formula 2: ； Structural Formula 2 In general formula 2, R1 is selected from alkyl groups with 1-10 carbon atoms and heteroaryl groups with 12-24 carbon atoms; n1 is selected from any integer from 0 to 4. Alternatively, the Ar is selected from unsubstituted polycyclic aryl groups, which are selected from naphthyl, anthracene, phenanthryl, and tetraphenyl. Alternatively, the Ar is selected from substituted or unsubstituted heteroaryl groups, wherein the unsubstituted heteroaryl group is pyridyl, and the substituted heteroaryl group has the structure shown in general formula 3: ； In general formula 3, R2 and R3 are each independently selected from a nitrogen-containing heteroaryl or aromatic amino group; Alternatively, the Ar is selected from the structure shown in general formula 4: ； Structural Formula 4 In structural formula 4, R4 and R5 are each independently selected from a heteroaryl or aromatic amino group containing a nitrogen atom; n4 and n5 are each independently selected from any integer from 0 to 4.

2. The deuterated 1-aryl-substituted carbazole compound according to claim 1, characterized in that: R1 is selected from alkyl groups having 1-5 carbon atoms, heteroaryl groups having 12-24 carbon atoms and containing nitrogen atoms; and / or n1 is selected from any integer from 1 to 2.

3. The deuterated 1-aryl-substituted carbazole compound according to claim 2, characterized in that: R1 is selected from straight-chain alkyl groups with 1-3 carbon atoms or carbazole groups.

4. The deuterated 1-aryl-substituted carbazole compound according to claim 1, characterized in that: The general formula 2 is selected from the following groups: 。 5. The deuterated 1-aryl-substituted carbazole compound according to claim 1, characterized in that: The Ar is selected from .

6. The deuterated 1-aryl-substituted carbazole compound according to claim 1, characterized in that: R2 and R3 are each independently selected from carbazole group or diarylamine group.

7. The deuterated 1-aryl-substituted carbazole compound according to claim 6, characterized in that: R2 and R3 are selected from the same substituents.

8. The deuterated 1-aryl-substituted carbazole compound according to claim 1, characterized in that: The general formula 3 is selected from the following groups: ; and / or, The pyridyl group is selected from .

9. The deuterated 1-aryl-substituted carbazole compound according to claim 1, characterized in that: R4 and R5 are each independently selected from carbazole group or diarylamine group; and / or, The n4 and n5 are each independently selected from any integer between 0 and 2.

10. The deuterated 1-aryl-substituted carbazole compound according to claim 9, characterized in that: The general formula 4 is selected from the following groups: 。 11. A method for preparing a deuterated 1-aryl-substituted carbazole compound according to any one of claims 1-10, comprising the following steps: Under the action of a catalyst, the compound represented by general formula A, the compound represented by general formula B, and a base undergo a CN coupling reaction in a solvent to obtain the deuterated 1-aryl-substituted carbazole compound. The compound represented by general formula A has the following structure: The Ar mentioned therein corresponds to the same Ar as described in any one of claims 1-10; The compound represented by general formula B has the following structure: X is a halogen.

12. The method for preparing the deuterated 1-aryl-substituted carbazole compound according to claim 11, characterized in that: The catalyst is selected from at least one of CuI, Pd(OAc)2, and Pd2(dba)3; and / or, The solvent is selected from at least one of N,N-dimethylformamide, dimethyl sulfoxide, toluene, and tetrahydrofuran; and / or, The alkali is selected from K2CO3 and NaO. t -At least one of Bu, bis(trimethylsilyl)aminolithium, K3PO4, and Cs2CO3; and / or, In general formula B, X is chlorine, bromine, iodine; and / or, The molar ratio of the compound represented by general formula A to the compound represented by general formula B is 2.5:1 to 6:1; and / or, The molar ratio of the compound represented by general formula B to the catalyst is 1:1 to 1:2; and / or, The molar volume ratio of the compound represented by general formula A to the solvent is 1 mol: 1000~12000 mL; and / or, The molar ratio of the compound represented by general formula B to the base is 1:1.5 to 1:4; and / or, The temperature for the CN coupling reaction is 120~180℃; and / or, The CN coupling reaction takes 20 to 40 hours.

13. The method for preparing the deuterated 1-aryl-substituted carbazole compound according to claim 12, characterized in that: In general formula B, X is bromine; and / or, The molar ratio of the compound represented by general formula A to the compound represented by general formula B is 2.5:1 to 4:1; and / or, The molar ratio of the compound represented by general formula B to the catalyst is 1:1.1 to 1:1.5; and / or, The molar volume ratio of the compound represented by general formula A to the solvent is 1 mol : 8000-10000 mL; and / or, The molar ratio of the compound represented by general formula B to the base is 1:2 to 1:3; and / or, The CN coupling reaction is performed at a temperature of 140~160℃; and / or, The CN coupling reaction takes 24 to 30 hours.

14. The application of the deuterated 1-aryl-substituted carbazole compound according to any one of claims 1-10 as a hole transport layer material in flat panel displays, solar cells, and electroluminescent diodes.

15. The application according to claim 14, characterized in that, The solar cell is selected from organic solar cells or organic perovskite cells; and / or, The electroluminescent diode is selected from red, green, and blue electroluminescent diodes.

16. The application according to claim 15, characterized in that, When the deuterated 1-aryl-substituted carbazole compound is used as a hole transport layer, the method for preparing the hole transport layer is as follows: The deuterated 1-aryl-substituted carbazole compound was dissolved in an organic solvent and then prepared into a film by a wet process.

17. The application according to claim 16, characterized in that, The wet film preparation method is selected from at least one of spin coating, inkjet printing, or slot coating; and / or, The organic solvent is selected from at least one of toluene, xylene, chlorobenzene, and o-dichlorobenzene; and / or, The concentration of deuterated 1-aryl-substituted carbazole compounds in organic solvents is 5~25 mg / mL.

18. The application according to claim 17, characterized in that, The concentration of deuterated 1-aryl-substituted carbazole compounds in organic solvents is 10-20 mg / mL.

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