Deuterated 1-aryl substituted carbazole compound as well as preparation method and application thereof

Abstract

The invention discloses a deuterated 1-aryl substituted carbazole compound as well as a preparation method and application thereof, and belongs to the technical field of organic photoelectricity. The benzene ring of the deuterium atom-containing 1-substituted carbazole compound designed by the invention is isotope deuterium 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 hole transport layers of red, green and blue electroluminescent devices, and the organic electroluminescent device manufactured by taking the material as the hole transport layer can reduce the driving voltage and improve the luminous efficiency, is excellent in color purity and longer in service life, and has huge application potential. The deuterium atom-containing 1-substituted carbazole compound designed by the invention is expected to be applied to new-generation organic electronic device products such as organic light-emitting display, quantum dot display and the like in the future.

Description

Technical Field

[0001] The invention relates to the technical field of organic photoelectric materials, and more particularly to a deuterated 1-aryl substituted carbazole compound and a preparation method and application thereof. Background Art

[0002] Organic light-emitting diodes (OLEDs) have attracted the attention of many researchers due to their advantages of active light emission without backlight, high luminous efficiency and great application prospects. In order to improve luminous efficiency and extend service life, the development and research of light-emitting devices are becoming increasingly active.

[0003] The brightness and performance of organic electroluminescent devices are related to the matching of the energy levels of the hole transport layer and the adjacent functional layer, the balance of the electrons and holes injected by the carriers, etc. The hole transport material must have high hole mobility, appropriate 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 the adjacent functional layer is also often considered to have a significant relationship with the efficiency and stability of the device. If the HOMO energy level difference between the hole transport layer and the hole injection layer is too large, the starting voltage of the device will increase and the service life of the device will be reduced. The large difference in the HOMO energy level between the hole transport layer and the light-emitting layer will also prevent the holes from being transported to the light-emitting layer. The imbalance of electron and hole injection and the difference in mobility between the two make it impossible for the carriers injected from the two poles to be effectively confined in the light-emitting layer to form excitons, resulting in some excess carriers reaching the electrode, causing quenching of light emission at the electrode and reducing the luminescence efficiency of the device. Driven by the huge prospects of the OLED display industry, high-efficiency and long-life organic hole transport materials are one of the focuses of international research.

[0004] Polyvinylcarbazole (PVK) is the most commonly used solution-processed hole transport material with good hole transport and electron blocking capabilities. Its higher singlet and triplet energy levels provide effective exciton blocking capabilities. Thanks to this, the device can achieve higher carrier and exciton utilization.

[0005] Kido's research group at Yamagata University in Japan proposed a method for cross-linking PVK at a relatively low temperature (Adv. Mater., 2014, 26, 7543-7546. Using dodecamolybdophosphoric acid as an oxidant and mixing it with PVK, heating it at 110°C for 3 minutes can cause the 3,6 positions on the carbazole group to undergo a dehydrogenation reaction to form dicarbazole, which has a good cross-linking effect. The structural formula of dicarbazole is Solution-processed blue phosphorescent OLED devices based on this cross-linked PVK interface have a power of 10,000 cd / m 2The external quantum efficiency of 17% was achieved at low brightness. However, this cross-linked PVK has the disadvantage of uncertain molecular weight.

[0006] Therefore, designing and preparing carbazole-based branched hole transport materials with a certain 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 at present. Summary of the invention

[0007] In order to solve the problems in the prior art, the present invention proposes a deuterated 1-aryl substituted carbazole compound and its preparation method and application. The triplet energy level of carbazole hole transport materials is usually high, which can meet the needs of blue thermally assisted delayed fluorescence and phosphorescent OLED. In addition, the chemical stability of the carbazole group is good, and its 2 / 7, 3 / 6, 9 or even 1 / 8 positions can be modified and the synthesis is simple. For this reason, the present invention designs a 1-substituted carbazole compound containing deuterium atoms, and the isotope of hydrogen is deuterium on its benzene ring. The introduction of deuterium can improve the charge transport performance of the compound and improve the thermal stability of the compound. This type of molecule can be used for the hole transport layer of red, green and blue electroluminescent devices. The organic electroluminescent device prepared with this material as the hole transport layer can reduce the driving voltage, improve the luminous efficiency, excellent color purity, and longer device life, and has great application potential. The 1-substituted carbazole compound containing deuterium atoms designed by the present invention is expected to be applied to a new generation of organic electronic device products such as organic light-emitting display and quantum dot display in the future.

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

[0009]

[0010] The Ar is selected from a substituted or unsubstituted aryl group, a substituted or unsubstituted polycyclic aromatic group, a substituted or unsubstituted heteroaryl group, and a substituted or unsubstituted aromatic amine group.

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

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

[0013] The substituent groups corresponding to the two Ar contained in the general structural formula 1 are the same;

[0014] Preferably,

[0015] The Ar is selected from a substituted or unsubstituted phenyl group having 6 to 30 carbon atoms, a substituted or unsubstituted polycyclic aromatic group having 10 to 14 carbon atoms, a substituted or unsubstituted heteroaromatic group having 5 to 36 carbon atoms, and a substituted or unsubstituted triarylamine group having 18 to 66 carbon atoms.

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

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

[0018]

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

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

[0021] More preferably, the R1 is selected from a linear alkyl group having 1 to 3 carbon atoms and a carbazole group.

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

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

[0024]

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

[0026] The substituted or unsubstituted polycyclic aromatic group selected from Ar is selected from naphthyl, anthracenyl, phenanthrenyl, and tetraphenylene; more preferably

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

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

[0029]

[0030] The R2 and R3 are each independently selected from a nitrogen-containing heteroaryl group or an aromatic amine group;

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

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

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

[0034] The general structural 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 compound of the present invention, preferably,

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

[0039]

[0040] The R4 and R5 are each independently selected from a nitrogen-containing heteroaryl group or an aromatic amine group; the n4 and n5 are each independently selected from any integer of 0-4;

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

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

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

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

[0045]

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

[0047]

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

[0049]

[0050] The second object of the present invention is to provide a method for preparing the deuterated 1-aryl substituted carbazole compound described in the first object of the present invention, comprising the following steps:

[0051] Under the action of a catalyst, the compound represented by the general formula A, the compound represented by the 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 structure shown in general formula A is:

[0053] The Ar is the same as Ar described in claims 1-9;

[0054] The compound structure shown in general formula B is:

[0055] The X is a halogen.

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

[0057] The compound represented by general formula A includes the following two preparation methods:

[0058] Method A:

[0059] Formula A-1, formula A-2, a base and react in a solvent to generate a compound represented by general formula A;

[0060]

[0061] Method B:

[0062]

[0063] Formula A-1, formula A-3, a base and a catalyst react in a solvent to generate a compound 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, 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 base is selected from at least one of K2CO3, NaOt-Bu, lithium bis(trimethylsilyl)amide, K3PO4, and Cs2CO3; and / or,

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

[0069] The molar ratio of the compound represented by the general formula A to the compound represented by the 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 the 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 the 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 the 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 time is 20 to 40 hours, preferably 24 to 30 hours.

[0075] The third object of the present invention is to provide the deuterated 1-aryl substituted carbazole compound described in the first object of the present invention or the deuterated 1-aryl substituted carbazole compound prepared by the preparation method described in the second object of the present invention as a hole transport layer material in flat panel displays, solar cells, and electroluminescent diodes.

[0076] In the application of the present invention, preferably,

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

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

[0079] In the application of the present invention, preferably,

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

[0081] Preferably, the wet method for preparing the film is selected from at least one of spin coating, inkjet printing or slit 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 to 25 mg / mL, preferably 10 to 20 mg / mL.

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

[0085] 1. In the 1-substituted carbazole compound containing deuterium atoms described in the present invention, the benzene ring thereof is a deuterium isotope of hydrogen. The introduction of deuterium can improve the charge transport performance of the compound and improve the thermal stability of the compound.

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

[0087] 3. The deuterated 1-aryl substituted carbazole hole transport small molecule material provided by the present invention. This type of hole transport material has excellent solubility and thermal stability, and also has a high triplet energy level. The 1-substituted carbazole compound containing deuterium atoms described in the present invention can be used for the hole transport layer of red, green, and blue electroluminescent devices. The organic electroluminescent device made with this material as the hole transport layer can reduce the driving voltage, improve the luminous efficiency, have excellent color purity, and have a longer device life, and has great application potential.

[0088] 4. The photothermal material described in the present invention has readily available raw materials, mild synthesis conditions, a simple preparation method, and convenient purification. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 is the low temperature phosphorescence spectrum of compound M4 of Example 1;

[0090] Figure 2 This is the thermogravimetric analysis diagram of compound M8 of Example 2;

[0091] Figure 3 This is the thermogravimetric analysis diagram of the undeuterated compound M17 in comparative example 1. DETAILED DESCRIPTION

[0092] The present invention is described in detail below in conjunction with specific drawings and embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the content of the present invention still fall 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 specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0094] In addition, the various embodiments of the present invention may be arbitrarily combined as long as they do not violate the concept of the present invention. The technical solutions thus formed belong to part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0095] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they 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 argon atmosphere, tri(4-bromophenyl)amine (4.82 mg, 0.01 mmol) was dissolved in 100 mL of purified THF, and 1.6 mol L -1 5 mL of n-butyl lithium was added, and the reaction was continued 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 for 1 hour at -78 ° C, and the temperature was slowly raised to room temperature for 24 hours. The reaction mixture was poured into water, extracted with ethyl acetate, and the organic layer was washed with brine, and then dried over anhydrous magnesium sulfate. After the solution was concentrated, a light yellow viscous crude product was obtained, which was purified by silica gel column chromatography (eluent selected petroleum ether / ethyl acetate = 15 / 1, v / v) to obtain a white solid. 1 H NMR, MS and elemental analysis results showed that the obtained compound was the target product (compound M1).

[0100] Synthesis of compound M2:

[0101]

[0102] Under 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 refined DMSO, K2CO3 2.76 mg, CuI 2 mg, carbazole (4.18 mg, 0.025 mmol) were added and stirred for reaction, and then the temperature was raised to 110°C and reacted for 24 hours. Then the temperature was lowered to room temperature, the reaction mixture was poured into water, extracted with ethyl acetate, the organic layer was washed with brine, and then dried over anhydrous magnesium sulfate. After the solution was concentrated, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent selected petroleum ether / ethyl acetate = 25 / 1, v / v) to obtain a white solid. 1 H NMRMS and elemental analysis results showed that the obtained compound was 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, and catalyst Pd(PPh3)4 (2.31 mg, 2 μmol) was added. Then, the mixture was heated to 110 °C under argon protection for 16 hours, 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 eluent. 1 H NMR and MS analysis showed it to be the target product (Compound M3).

[0106] Synthesis of compound M4:

[0107]

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

[0109] Low temperature phosphorescence spectra were tested using HORIBA's FluoroMax-4 spectrometer. The test sample solution was placed in a long quartz tube and the temperature was controlled using a Dewar flask filled with liquid nitrogen. The solvent purity of the sample was chromatographic grade. Figure 1 The phosphorescence spectrum of compound M4 tested under low temperature conditions is given. It can be seen from the test graph that the inflection point of the starting peak is 422nm, and the triplet energy level of compound M4 can be calculated according to the formula to be 2.94eV. Compound M4 has a high triplet energy level.

[0110] Example 2

[0111] Synthesis of compound M5:

[0112]

[0113] Under argon atmosphere, 3,6-dibromo-9-(tert-butyldimethylsilane)-9H-carbazole (4.39 g, 0.01 mmol) was dissolved in 200 mL of refined DMSO, and K2CO3 2.76 mg, CuI 2 mg, carbazole (4.18 mg, 0.025 mmol) were added to stir the reaction, and then the temperature was raised to 110 ° C and reacted for 24 hours. Then the temperature was lowered to room temperature, the reaction mixture was poured into water, extracted with ethyl acetate, the organic layer was washed with brine, and then dried over anhydrous magnesium sulfate. After the solution was concentrated, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent selected petroleum ether / ethyl acetate = 20 / 1, v / v) to obtain a white solid. 1H NMR, MS and elemental analysis results showed that the obtained compound was 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 a 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 an eluent to obtain a white solid (Compound M6). 1 H NMR and MS analysis showed that it was the target product.

[0117] Synthesis of compound M7:

[0118]

[0119] Under 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 refined DMSO, K2CO3 2.76 mg, CuI 2 mg, compound M6 (12.43 mg, 0.025 mmol) were added and stirred for reaction, and then the temperature was raised to 110 ° C and reacted for 24 hours. Then the temperature was lowered to room temperature, the reaction mixture was poured into water, extracted with ethyl acetate, the organic layer was washed with brine, and then anhydrous magnesium sulfate was added to dry. After the solution was concentrated, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent selected petroleum ether / ethyl acetate = 15 / 1, v / v) to obtain a white solid (compound M7). 1 HNMR, MS and elemental analysis results showed that the obtained compound was the target product.

[0120] Synthesis of compound M8:

[0121]

[0122] Under argon atmosphere, m-dibromobenzene (2.34 mg, 0.01 mmol) was dissolved in 100 mL of refined DMF, K2CO3 2.76 mg, CuI 2 mg, compound M7 (16.73 mg, 0.025 mmol) were added, stirred and reacted, and then the temperature was raised to 160°C and reacted for 24 hours. Then the temperature was lowered to room temperature, the reaction mixture was poured into water, extracted with ethyl acetate, the organic layer was washed with brine, and then dried over anhydrous magnesium sulfate. After the solution was concentrated, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent selected petroleum ether / ethyl acetate = 30 / 1, v / v) to obtain a white solid. 1 H NMR, MS and elemental analysis results showed that the obtained compound was the target product. The elemental composition of compound M8 was tested using Vario EL cube elemental analyzer. Elemental analysis, [C 102 H 48 D 14 N8] Theoretical value (%): C, 86.66; H, 5.42; N, 7.93. Found value (%): C, 85.39; H, 5.27; N, 7.71.

[0123] We characterized the thermal decomposition temperature of compound M8 by thermogravimetric analysis. The instrument model of the thermogravimetric analyzer is: Netzsch TG 209, N2 atmosphere, and the heating rate is 10℃ / min. Figure 2 The thermogravimetric test graph of compound M8 is given. From the ordinate of the test graph, it can be obtained that the temperature at which the mass loss is 95% is 433°C, indicating that the thermal decomposition temperature of compound M8 is 433°C, that is, compound M8 has high thermal stability.

[0124] Example 3

[0125] Synthesis of compound M9:

[0126]

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

[0128] Synthesis of compound M10

[0129]

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

[0131] Synthesis of compound M11

[0132]

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

[0134] Synthesis of compound M12

[0135]

[0136] Under argon atmosphere, m-dibromobenzene (2.34 mg, 0.01 mmol) was dissolved in 100 mL of refined DMF, K2CO3 2.76 mg, CuI 2 mg, compound M11 (14.51 mg, 0.025 mmol) were added, stirred and reacted, and then the temperature was raised to 160°C and reacted for 24 hours. Then the temperature was lowered to room temperature, the reaction mixture was poured into water, extracted with ethyl acetate, the organic layer was washed with brine, and then dried over anhydrous magnesium sulfate. After the solution was concentrated, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent selected petroleum ether / ethyl acetate = 10 / 1, v / v) to obtain a white solid. 1 H NMR, MS and elemental analysis results showed that the obtained compound was the target product. The elemental composition of compound M12 was tested using Vario EL cube elemental analyzer. Elemental analysis, [C 90 H 42 D 14 N6] Theoretical value (%): C, 87.49; H, 5.71; N, 6.80. Found value (%): C, 84.83; H, 5.11; N, 6.04.

[0137] Example 4

[0138] Preparation of compound M13

[0139]

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

[0141] Preparation of compound M14

[0142]

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

[0144] Preparation of compound M15

[0145]

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

[0147] Preparation of compound M16

[0148]

[0149] Under argon atmosphere, m-dibromobenzene (2.34 mg, 0.01 mmol) was dissolved in 100 mL of refined DMF, K2CO3 2.76 mg, CuI 2 mg, compound M15 (10.38 mg, 0.025 mmol) were added, stirred and reacted, and then the temperature was raised to 160°C and reacted for 24 hours. Then the temperature was lowered to room temperature, the reaction mixture was poured into water, extracted with ethyl acetate, the organic layer was washed with brine, and then dried over anhydrous magnesium sulfate. After the solution was concentrated, a pale yellow crude product was obtained, which was purified by silica gel column chromatography (eluent selected petroleum ether / ethyl acetate = 15 / 1, v / v) to obtain a white solid. 1 H NMR, MS and elemental analysis results showed that the obtained compound was the target product. The elemental composition of compound M12 was tested using Vario EL cube elemental analyzer. Elemental analysis, [C 66 H 28 D 14 N4] Theoretical value (%): C, 87.58; H, 6.23; N, 6.19. Found value (%): C, 84.17; H, 5.71; N, 5.56.

[0150] Comparative Example 1

[0151] Preparation of undeuterated compound M17

[0152] The 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 by hydrogen atoms.

[0153]

[0154] We characterized the thermal decomposition temperature of the undeuterated compound M17 by thermogravimetric analysis. The instrument model of the thermogravimetric analyzer is: Netzsch TG 209, N2 atmosphere, and the heating rate is 10℃ / min. Figure 3 The thermogravimetric test graph of the undeuterated compound M17 is given. From the ordinate of the test graph, it can be obtained that the temperature at which the mass loss is 95% is 401°C, indicating that the thermal decomposition temperature of the undeuterated compound M17 is 401°C, and it can be seen that the thermal stability of the undeuterated M17 is worse than that of the deuterated M8.

[0155] Embodiment 5-9

[0156] Preparation 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 for ultrasonic cleaning in sequence to remove possible stains (such as photoresist) on the surface of the ITO glass substrate and improve the interface contact. After cleaning, it is placed in a vacuum oven for drying;

[0158] (2) placing the ITO in an oxygen plasma etcher and bombarding it with oxygen plasma (O2 Plasma) for 20 minutes to completely remove any residual organic matter on the surface of the ITO glass substrate;

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

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

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

[0162] (6) Less than 3×10 -4 Pa, a 40nm thick layer of electron transport material 1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBI) is first evaporated on the active layer film, then a 1.0nm thick layer of cesium fluoride (CsF) is evaporated, and finally a 90nm thick layer of ultra-pure aluminum cathode (Al) is evaporated, where the lithium fluoride and aluminum layers are vacuum deposited through a mask plate.

[0163] The active area of ​​the device is 0.09 cm 2. The thickness of the organic layer was measured using a quartz crystal monitoring thickness gauge. After device preparation, the device was polar cured and encapsulated in UV light using epoxy resin and thin layer glass. The electroluminescence (EL) spectra were measured using a PhotoResearch PR705 optical analyzer. The current density and brightness versus drive voltage characteristics were measured using a Keithley 2400 source measurement unit and a Konica Minolta colorimeter CS-200, respectively. The external quantum efficiency was calculated from the brightness, current density, and EL spectrum assuming a Lambertian distribution.

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

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

[0166] Among them, the structural formula of the hole transport material polyvinyl carbazole (PVK) is:

[0167]

[0168] The structural formula of the light-emitting layer 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 performance of the prepared electroluminescent devices was tested respectively, 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 can be clearly seen that the electroluminescent device using deuterated M4, M8, M12 or M16 as the hole transport layer has a relatively high efficiency. Compared with the undeuterated M17, the electroluminescent device using deuterated M8 as the hole transport layer has a lower turn-on voltage, higher lumen efficiency and maximum brightness values, and better color purity. This shows 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 in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0177] The endpoints and any values ​​of the scope disclosed in the present invention are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, the endpoint values ​​of each scope, the endpoint values ​​of each scope and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this article. Hereinafter, in principle, each technical solution can be combined with each other to obtain a new technical solution, which should also be regarded as specifically disclosed in this article.

Claims

1. A deuterated 1-aryl substituted carbazole compound having the following structural formula 1: The Ar is selected from a substituted or unsubstituted aryl group, a substituted or unsubstituted polycyclic aromatic group, a substituted or unsubstituted heteroaryl group, and a substituted or unsubstituted aromatic amine group.

2. The deuterated 1-aryl substituted carbazole compound according to claim 1, characterized in that: Ar is selected from substituted or unsubstituted aryl groups having 6 to 42 carbon atoms, substituted or unsubstituted polycyclic aromatic groups having 10 to 22 carbon atoms, substituted or unsubstituted heteroaryl groups having 5 to 48 carbon atoms, and substituted or unsubstituted aromatic amine groups having 18 to 90 carbon atoms; and / or, The substituent groups corresponding to the two Ar contained in the general structural formula 1 are the same; Preferably, The Ar is selected from a substituted or unsubstituted phenyl group having 6 to 30 carbon atoms, a substituted or unsubstituted polycyclic aromatic group having 10 to 14 carbon atoms, a substituted or unsubstituted heteroaromatic group having 5 to 36 carbon atoms, and a substituted or unsubstituted triarylamine group having 18 to 66 carbon atoms.

3. The deuterated 1-aryl substituted carbazole compound according to claim 1 or 2, characterized in that: The substituted or unsubstituted aryl group selected from Ar has the following structural formula 2: R1 is selected from an alkyl group having 1 to 10 carbon atoms and a heteroaryl group having 12 to 24 carbon atoms; n1 is selected from any integer of 0 to 4; Preferably, R1 is selected from an alkyl group having 1 to 5 carbon atoms, or a nitrogen-containing heteroaryl group having 12 to 24 carbon atoms; and / or n1 is selected from any integer of 1 to 2; More preferably, the R1 is selected from a linear alkyl group having 1 to 3 carbon atoms and a carbazole group.

4. The deuterated 1-aryl substituted carbazole compound according to claim 3, characterized in that: The general structural formula 2 is selected from the following groups:

5. The deuterated 1-aryl substituted carbazole compound according to claim 1 or 2, characterized in that: The substituted or unsubstituted polycyclic aromatic group selected from Ar is selected from naphthyl, anthracenyl, phenanthrenyl, and tetraphenylene; More preferably 6. The deuterated 1-aryl substituted carbazole compound according to claim 1 or 2, characterized in that: The substituted or unsubstituted heteroaryl selected from Ar is a pyridyl group or has the following structural formula 3: In the general structural formula 3, R2 and R3 are each independently selected from a nitrogen-containing heteroaryl group or an aromatic amine group; Preferably, R2 and R3 are each independently selected from a carbazole group or a diarylamine group; More preferably, R2 and R3 are selected from the same substituent.

7. The deuterated 1-aryl substituted carbazole compound according to claim 6, characterized in that: The general structural formula 3 is selected from the following groups: and / or, The pyridyl group is selected from 8. The deuterated 1-aryl substituted carbazole compound according to claim 1 or 2, characterized in that: The substituted or unsubstituted aromatic amine group selected from Ar has the following structural formula 4: The R4 and R5 are each independently selected from a nitrogen-containing heteroaryl group or an aromatic amine group; the n4 and n5 are each independently selected from any integer of 0-4; Preferably, R4 and R5 are each independently selected from a carbazole group or a diarylamine group; and / or, The n4 and n5 are each independently selected from any integer of 0-2.

9. The deuterated 1-aryl substituted carbazole compound according to claim 8, characterized in that: The structural formula 4 is selected from the following groups:

10. A method for preparing a deuterated 1-aryl substituted carbazole compound according to any one of claims 1 to 9, comprising the following steps: Under the action of a catalyst, the compound represented by the general formula A, the compound represented by the 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 structure shown in general formula A is: The Ar is the same as Ar described in claims 1-9; The compound structure shown in general formula B is: The X is a halogen.

11. The method for preparing a deuterated 1-aryl substituted carbazole compound according to claim 10, characterized in that: The catalyst is selected from at least one of CuI, Pd(OAc)2, 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 base is selected from at least one of K2CO3, NaOt-Bu, lithium bis(trimethylsilyl)amide, K3PO4, and Cs2CO3; and / or, In the general formula B, X is chlorine, bromine, or iodine, preferably bromine; and / or, The molar ratio of the compound represented by the general formula A to the compound represented by the general formula B is 2.5:1 to 6:1, preferably 2.5:1 to 4:1; and / or, The molar ratio of the compound represented by the general formula B to the catalyst is 1:1 to 1:2, preferably 1:1.1 to 1:1.5; and / or, The molar volume ratio of the compound represented by the general formula A to the solvent is 1 mol: 1000-12000 mL, 1 mol: 8000-10000 mL; and / or, The molar ratio of the compound represented by the general formula B to the base is 1:1.5 to 1:4, preferably 1:2 to 1:3; and / or, The temperature of the CN coupling reaction is: 120-180°C, preferably 140-160°C; and / or, The CN coupling reaction time is 20 to 40 hours, preferably 24 to 30 hours.

12. Use of the deuterated 1-aryl substituted carbazole compound according to any one of claims 1 to 9 as a hole transport layer material in flat panel displays, solar cells, and electroluminescent diodes.

13. The use according to claim 12, characterized in that: The solar cell is selected from an organic solar cell or an organic perovskite cell; and / or, The electroluminescent diode is selected from red, green and blue electroluminescent diodes.

14. The use according to claim 13, characterized in that When the deuterated 1-aryl substituted carbazole compound is used as a hole transport layer, the preparation method of the hole transport layer is: The deuterated 1-aryl substituted carbazole compound is dissolved in an organic solvent and then prepared into a film by a wet method; Preferably, the wet method for preparing the film is selected from at least one of spin coating, inkjet printing or slit coating; and / or, The organic solvent is selected from at least one of toluene, xylene, chlorobenzene and o-dichlorobenzene; and / or, The concentration of the deuterated 1-aryl-substituted carbazole compound in the organic solvent is 5 to 25 mg / mL, preferably 10 to 20 mg / mL.

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