Deuterated carbazole derivative and organic electroluminescent device thereof

Abstract

The invention belongs to the technical field of photoelectric materials, and particularly relates to a deuterated carbazole derivative and an organic electroluminescent device thereof. According to the invention, hydrogen atoms in alkyl carbazole molecules are subjected to deuteration, such that intermolecular interaction is enhanced, and molecular structure stability is improved. Due to the enhanced molecular stability, the energy level structure of the material is more beneficial to migration of electrons and holes, the energy loss of current carriers in the transmission process is reduced, and therefore the electric energy needed by the device in the light emitting process is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of photoelectric materials, and in particular relates to a deuterated carbazole derivative and an organic electroluminescent device thereof. Background Art

[0002] Organic light-emitting diodes (OLEDs) can not only promote the innovation of new display products, but also promote the development of new lighting products. Currently, OLED display technology has found applications in many fields such as smartphones and tablets. However, in order to better meet the needs of product applications, OLED technology still needs to be further optimized and improved in terms of luminous efficiency and lifespan.

[0003] OLEDs are composed of multiple layers of electrode materials and organic functional materials sandwiched between them. When a voltage is applied to the electrodes at both ends of the OLED, the electric field causes the positive and negative charges in the organic material layer to separate and recombine in the light-emitting layer, thereby generating light. The triplet exciton radiative transition of most organic molecules is limited, resulting in low luminescence efficiency. To this end, the efficiency is improved by adding organic metal compounds containing elements such as platinum, iridium, and osmium. These compounds can effectively transfer and utilize the energy of triplet excitons. However, triplet-triplet annihilation (TTA) may occur during the energy transfer process, resulting in energy loss, especially at high brightness, which can lead to a decrease in efficiency or "efficiency roll-off". Optimizing the material combination in the light-emitting layer can alleviate this problem.

[0004] By carefully adjusting the ratio of host and guest materials in the light-emitting layer, the triplet-triplet annihilation (TTA) phenomenon can be effectively reduced, thereby improving the performance of OLEDs. Currently, the main challenges facing OLED technology include high driving voltage, insufficient luminous efficiency, and short service life, which limit the widespread application of OLED technology in more fields. Therefore, the development of efficient organic electroluminescent materials and devices with longer service life and lower driving voltage has become a key technical problem that technicians in this field need to overcome. Summary of the invention

[0005] In order to solve the deficiencies of the prior art, the present invention provides a deuterated carbazole derivative and an organic electroluminescent device thereof. The deuterated carbazole group in the derivative provided by the present invention has a larger conjugated system, and still maintains planar characteristics when combined with anthracene or phenanthrene groups. The derivative provided by the present invention has enhanced the stereoregularity of the molecule by introducing deuterium atoms at specific positions, avoiding the aggregation quenching effect caused by planar stacking during the evaporation process, thereby extending the service life of the device. In addition, the regular molecular structure reduces the evaporation temperature of the material and improves the thermal stability. The HOMO and LOMO energy level difference of the organic electroluminescent device provided by the present invention conforms to the energy difference range of the organic electroluminescent device, can promote the recombination of electrons and holes, form efficient excitons, improve the charge injection efficiency, thereby improving the luminous efficiency and the working voltage, luminous efficiency, and the service life of the device.

[0006] The technical solution provided by the present invention is as follows:

[0007] A deuterated carbazole derivative having a structure shown in Formula 1:

[0008]

[0009] The A ring, the B ring, and the C ring are each independently empty, a substituted phenyl group, or an unsubstituted phenyl group, and at least one of A, B, and C is a substituted phenyl group or an unsubstituted phenyl group.

[0010] Further, one of A and B is a substituted phenyl group or an unsubstituted phenyl group, or A and C are both substituted phenyl groups or unsubstituted phenyl groups.

[0011] Furthermore, the substituted phenyl group is selected from: a phenyl group substituted by a tert-butyl group and a phenyl group.

[0012] Further, A is a substituted or unsubstituted phenyl group, and the B ring and the C ring are each empty, or, B is a substituted or unsubstituted phenyl group, and the A ring and the C ring are each empty, or, the A ring and the C ring are substituted or unsubstituted phenyl groups, and the B ring is empty.

[0013] R1-R6 are the same or different and are selected from: hydrogen, deuterium, cyano, C1-C 10 Alkyl, C1-C 10 Alkylsilyl, C6-C 15 The aromatic group.

[0014] Furthermore, the C6-C 15 The aryl group is deuterium, cyano, or phenyl substituted by a C1-C4 alkyl group.

[0015] Furthermore, one of R1-R6 is a C1-C4 alkyl group, or a phenyl group substituted with deuterium, cyano, or a C1-C4 alkyl group, and the rest are hydrogen.

[0016] L1-L2 are the same or different and are selected from: single bond, C6-C 15 Aryl, C6-C 15 deuterated aryl;

[0017] R7 is selected from the group consisting of: hydrogen, deuterium, N(R9)(R 10 )、C1-C 10 Alkyl, C1-C 10 Deuterated alkyl, C6-C 20 Aryl, C6-C 20 Deuterated aryl, C6-C 20 Heteroaryl, C6-C 20 deuterated heteroaryl;

[0018] R9-R 10 The same or different selected from: C6-C 20 Aryl, C6-C 20 Deuterated aryl, C6-C 20 Heteroaryl, C6-C 20 deuterated heteroaryl;

[0019] R8 is a structure shown in Formula 2:

[0020]

[0021] is the linking site;

[0022] R 11 -R 16 , R 17a , R 17b The same or different ones are selected from: hydrogen, deuterium or C1-C 10 deuterated alkyl, 1 to 2 of which are C1-C 10 deuterated alkyl;

[0023] That is: R 11 , R 13 , R 14 , R 16 The same or different ones are selected from: hydrogen or deuterium;

[0024] R 12 , R 15 The same or different ones are selected from: hydrogen, deuterium or C1-C 10 of a deuterated alkyl group.

[0025] According to the above technical features, the structure of Formula 1 is selected from:

[0026]

[0027] Among them, R1-R6, R18a -R 18d The same or different ones are selected from: hydrogen, deuterium;

[0028] or R3-R4, R 18b -R 18c The same or different selected from: C1-C 10 Alkyl, C1-C 10 Alkylsilyl, hexamembered aryl, deuterated hexamembered aryl.

[0029] Furthermore, R1, R 18d Connect to L1 and L2 respectively.

[0030] Or the structure of Formula 1 is selected from:

[0031]

[0032] Among them, R1-R6, R 19a -R 19d The same or different ones are selected from: hydrogen, deuterium;

[0033] or R 19b Selected from: hydrogen, deuterium, C1-C 10 Alkyl, C1-C 10 Alkylsilyl, hexamembered aryl, deuterated hexamembered aryl.

[0034] Furthermore, L1 is connected to one of R1-R6, and L2 is connected to R 19a -R 19d One connection.

[0035] Or the structure of Formula 1 is selected from:

[0036]

[0037] Among them, R1-R4, R 5a -R 5e , R6 are the same or different and are selected from: hydrogen, deuterium;

[0038] Or, R1 or R6 are the same or different and are selected from: hydrogen, deuterium, C1-C 10 Alkyl, C1-C 10 Alkylsilyl, hexamembered aryl, deuterated hexamembered aryl.

[0039] Furthermore, L1 is connected to one of R2-R4, and L2 is connected to R 5c -R 5e One connection.

[0040] According to the above technical features, L1-L2 is C6-C 15 When the aromatic group is , it is a structure shown in Formula 3:

[0041]

[0042] Where R 20a -R 20b , R 21a -R 21b The same or different ones are selected from: hydrogen, deuterium, cyano, or form a condensed ring structure with a six-membered aryl or a deuterated six-membered aryl through a shared chemical bond;

[0043] R 22 Selected from: hydrogen, deuterium, C1-C 10 Alkyl, C1-C 10 of a deuterated alkyl group.

[0044] L1-L2 is preferably phenyl, naphthyl, anthracenyl, or phenyl, naphthyl, anthracenyl substituted with a C1-C4 alkyl or a C1-C4 deuterated alkyl.

[0045] When R7 is selected from: C6-C 20 Aryl, C6-C 20 Deuterated aryl, C6-C 20 Heteroaryl, C6-C 20 A deuterated heteroaryl group having a structure shown in Formula 4, or a structure of Formula 4 and A condensed ring structure is formed by sharing chemical bonds, and * is the linking site:

[0046]

[0047] X 1a -X 1c Selected from: CH or N;

[0048] R 23 -R 24 The same or different ones are selected from: hydrogen, cyano, C1-C 10 Alkyl, C1-C 10 deuterated alkyl, phenyl, naphthyl, deuterated, cyano, C1-C 10 Alkyl, C1-C 10 Phenyl and naphthyl substituted with deuterated alkyl;

[0049] X2 is selected from: O, S, C(CH3, CH3), NR 26 ;

[0050] R 25 Selected from: hydrogen, cyano, C1-C 10 Alkyl, C1-C 10 Deuterated alkyl, C6-C 20 Aryl, C6-C 20 deuterated aryl;

[0051] Further, R 25Medium C6-C 20 Aryl, C6-C 20 The deuterated aryl group is selected from the group consisting of phenyl, biphenyl, and naphthyl;

[0052] R 26 Selected from: C6-C 20 Aryl, C6-C 20 deuterated aryl; R 26 Preferred are: phenyl and biphenyl.

[0053] Preferred are:

[0054] According to the above technical features, the structure of L1-L2 is further selected from:

[0055]

[0056] The hydrogen atoms on L1-L2 are not deuterated or substituted with at least one D.

[0057] When R7 is selected from C6-C 20 Aryl, C6-C 20 When the deuterated aryl is selected from: phenyl, naphthyl, 9,9-dimethylfluorene, or, deuterated, cyano, C1-C 10 Alkyl, deuterated C1-C 10 Phenyl and naphthyl substituted with alkyl.

[0058] When R7 is selected from C6-C 20 Heteroaryl, C6-C 20 When the deuterated heteroaryl group is

[0059]

[0060] Where R 32 -R 34 Selected from: hydrogen, deuterium, phenyl, biphenyl, naphthyl, or deuterated, cyano, C1-C 10 Alkyl, deuterated C1-C 10 Alkyl substituted phenyl, biphenyl, naphthyl;

[0061] or R 32 -R 33 Selected from:

[0062] X3 is selected from: O, S, NR 35 ;

[0063] R 35 Selected from: phenyl.

[0064] According to the above technical features, R7 is selected from C6-C 20 Heteroaryl, C6-C 20 The deuterated heteroaryl group is further selected from:

[0065]

[0066] When R7 is selected from N(R9, R 10 ), the structure shown in Formula 6:

[0067]

[0068] Where R 36 -R 41 Selected from: hydrogen, deuterium, cyano, C1-C 10 Alkyl, six-membered aromatic group;

[0069] Further, R 36 -R 41 Contains at least 1, 2, 3, 4, or 5 hydrogens or deuteriums; or R 36 -R 41 , wherein two adjacent substituents are connected to —CH═CH—CH═CH— through a common chemical bond to form a condensed ring structure;

[0070] or R 36 -R 41 , where two adjacent substituents are bonded to each other through a shared chemical bond Connected to form a condensed ring structure;

[0071] X4 is selected from: O, S, NR 26 .

[0072] further, Selected from:

[0073] According to the above technical features, R7 is selected from N(R9, R 10 ) is further selected from:

[0074]

[0075] According to the above technical features, R8 is selected from:

[0076]

[0077] According to the above technical features, C1-C 10 The alkyl group is selected from: a C1-C5 alkyl group, wherein the hydrogen on the alkyl group is not deuterated or is replaced by at least one deuterium;

[0078] C1-C 10 The alkyl group is preferably: methyl, ethyl, propyl, tert-butyl;

[0079] C1-C 10 The alkylsilyl group is selected from: C1-C5 alkylsilyl group;

[0080] The six-membered aryl group is selected from: phenyl;

[0081] All H groups on the above-mentioned aryl and heteroaryl groups can be replaced by D.

[0082] According to the above technical features, a deuterated carbazole derivative has a structure selected from:

[0083]

[0084]

[0085]

[0086]

[0087] The deuterated carbazole derivatives are organic electroluminescent materials.

[0088] In the present invention, the organic electroluminescent device comprises an anode, a hole transport region, a light emitting layer, an electron transport region and a cathode. Specifically:

[0089] The anode material preferably has a material with a large work function so that holes can be smoothly injected into the organic material layer. The anode material includes: metals (such as vanadium, chromium, copper, zinc and gold), metal alloys, metal oxides (such as zinc oxide, indium oxide, indium tin oxide (ITO) and indium zinc oxide (IZO)), combinations of metals and oxides (such as ZnO:Al or SnO2:Sb), conductive polymers (such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrrole and polyaniline), but is not limited thereto.

[0090] The cathode material preferably has a material with a small work function so that electrons can be smoothly injected into the organic material layer. The cathode material includes: metals (such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin and lead), metal alloys or multilayer structure materials (such as LiF / Al or LiO2 / Al); but is not limited to these.

[0091] The hole transport region includes a hole injection layer, a hole transport layer, an electron blocking layer and a hole blocking layer, and the light emitting layer is located between the electron blocking layer and the hole blocking layer.

[0092] Wherein, the hole injection layer material is a material that receives holes from the anode at a low voltage, and the highest occupied molecular orbital (HOMO) of the hole injection material is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer. The hole injection material includes metal porphyrin, oligothiophene, organic material based on arylamine, organic material based on hexanitrile hexaazatriphenylene, organic material based on quinacridone, organic material based on perylene, anthraquinone, and conductive polymers based on polyaniline and polythiophene.

[0093] The hole transport layer material is a material that can receive holes from the anode or the hole injection layer and transport the holes to the light-emitting layer and has high hole mobility. The hole transport layer material includes an organic material based on arylamine, a conductive polymer, and a block copolymer having both a conjugated part and a non-conjugated part, but is not limited thereto.

[0094] The electron blocking layer is disposed between the hole transport layer and the light emitting layer, and the electron blocking layer material includes an arylamine-based organic material.

[0095] The hole blocking layer is disposed between the hole transport layer and the light emitting layer, and the hole blocking layer material includes a triazine-based compound.

[0096] The electron transport region includes an electron transport layer and an electron injection layer.

[0097] The electron transport layer has the function of promoting electron transport. The electron transport material is a material with high electron mobility that receives electrons from the cathode and transports the electrons to the light-emitting layer. The electron transport material includes an Al complex of 8-hydroxyquinoline, a complex of Alq3, an organic free radical compound, and a hydroxyflavone-metal complex, but is not limited thereto. The thickness of the electron transport layer is 1 nm to 50 nm, which can prevent the electron transport characteristics from decreasing and prevent the driving voltage from increasing.

[0098] The electron injection layer has the function of promoting electron injection, and the electron injection material is a material that has the ability to transport electrons, has excellent electron injection effect on the light-emitting layer or the light-emitting material, prevents the excitons generated in the light-emitting layer from migrating to the hole injection layer, and has excellent thin film forming ability. The electron injection layer material includes fluorenone, anthraquinone dimethane, diphenoquinone, thiopyran dioxide, azole, diazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenyl methane, anthrone, etc. and their derivatives, metal complexes, nitrogen-containing five-membered ring derivatives, but is not limited thereto.

[0099] In the present invention, the organic electroluminescent device may be a top emission type, a bottom emission type or a double-side emission type.

[0100] The organic electroluminescent device can be used in a display panel, an organic solar cell, an electronic paper, an organic photoreceptor or an organic thin film transistor.

[0101] Compared with the prior art, the present invention has the following beneficial effects:

[0102] Electron transport and hole blocking: By replacing hydrogen atoms with deuterium atoms, the interaction between molecules and structural stability are enhanced. The energy level structure of the material is optimized, which is conducive to the migration of carriers (electrons and holes), reduces energy loss, and thus reduces the driving voltage of the device;

[0103] Improved luminescence efficiency: The modified deuterated alkyl carbazole has improved thermal stability and reduced vibration frequency, reducing energy loss in the excited state, so that more energy is converted into light energy rather than heat energy. Therefore, at the same current, the device has higher luminescence efficiency and significantly improved current efficiency;

[0104] Extended device life: High thermal stability and low vibration frequency not only enhance the long-term stability of the material, but also improve its heat resistance and reduce performance degradation in high temperature environments. The increase in glass transition temperature ensures that the device can still maintain excellent mechanical and electrical properties at higher temperatures, extending the working life;

[0105] Improved blue light purity: The stable molecular structure and ordered energy level arrangement reduce non-radiative transitions and energy losses. At the same time, the enhanced thermal stability ensures that high luminous efficiency and color purity can be maintained at high temperatures and high voltages, achieving efficient and pure blue light emission and avoiding unnecessary color pollution. DETAILED DESCRIPTION

[0106] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0107] The reagents or instruments used in the present invention, if the manufacturer is not specified, are all conventional products that can be purchased from the market. For process parameters not specifically specified, conventional techniques can be used.

[0108] Synthesis of intermediate 1:

[0109]

[0110] Feeding: Add 200 ml of a mixed solution of toluene (2V) / ethanol (1V) / water (1V) into a three-necked flask, flush with nitrogen for 5 minutes to replace the air in the system, add A1-1 (20 g), A1-2 (11.46 g), sodium carbonate (12.48 g) and tetrakistriphenylphosphine palladium (906.90 mg), react at 85°C for 12 hours under a nitrogen environment, monitor the reaction by TLC, and perform post-treatment after the reaction is completed;

[0111] Post-treatment: After the reaction is completed, 0.1 mol / L HCl is added to adjust the pH of the system to 6-7, water is added to separate, the organic phase is retained, the organic phase is spin-dried, ethanol is added and refluxed for 1 h, and after cooling to room temperature, the intermediate 1-A1-3 (18.96 g, HPLC shows a purity of 99%) is obtained by filtration and drying;

[0112] The sample was sent to MS, and MS showed: 298.5142 (MS+1);

[0113] According to the synthesis and post-treatment methods of intermediate 1, intermediates 2 to intermediate 5 can be synthesized. The catalysts, Lewis bases, feeding methods, post-treatments, etc. of intermediates 2 to intermediate 5 are the same, but A1-1 and A1-2 are different. The specific structures of A1-1, A1-2, intermediates 2 to intermediate 5 (A1-3), and test data are shown in the following table:

[0114]

[0115] Synthesis of intermediate 6:

[0116]

[0117] Feeding: Add 200 ml of dry dioxane to a three-necked flask, flush with nitrogen for 5 minutes to replace the air in the system, add A2-1 (20 g), A2-2 (13.50 g), dry sodium tert-butoxide (9.69 g), tri-tert-butylphosphine (20.40 g), PD2(DBA)3 (0.6 g), react at 100 ° C for 12 hours under nitrogen environment, monitor the reaction by TLC, and perform post-treatment after the reaction is completed;

[0118] Post-treatment: After the reaction is completed, add 0.1 mol / L HCl to adjust the pH of the system to 6-7, add water to split, retain the organic phase, spin dry the organic phase, add ethanol and reflux for 1 h, cool to room temperature, filter, and dry to obtain intermediate 1-A2-3 (21.57 g);

[0119] Feed: A2-3 (21.57 g) was dissolved in 200 mL of anhydrous THF, 3.36 g of n-butyl lithium was injected at -78°C, and after reacting for 1 hour, 11.94 g of anhydrous trimethyl borate was injected and reacted for 12 hours.

[0120] Post-treatment: add water to quench the reaction, extract with dichloromethane, dry, and recrystallize with n-hexane to obtain 15.81 g of intermediate A2-4. HPLC shows that the product has a purity of 99%.

[0121] The sample was sent to MS, and MS showed: 418.1200 (MS+1);

[0122] According to the synthesis and post-treatment methods of intermediate 6, intermediate 7 can be synthesized. The catalyst, Lewis base, feeding method, post-treatment, etc. of intermediate 7 are the same, but A2-1 and A2-2 are different. The specific structures of A2-1, A2-2, intermediate 7 (A2-3), and test data are shown in the following table:

[0123]

[0124] Synthesis of intermediate 8:

[0125]

[0126] Step 1: Add 200 ml of a mixed solution of toluene (2V) / ethanol (1V) / water (1V) into a three-necked flask, flush with nitrogen for 5 minutes to replace the air in the system, add A3-1 (20 g), A3-2 (43.00 g), sodium tert-butoxide (12.98 g) and tetrakistriphenylphosphine palladium (1.04 g), react at 85° C. for 12 hours under a nitrogen environment, monitor the reaction by TLC, and perform post-treatment after the reaction is completed;

[0127] Post-treatment: After the reaction is completed, 0.1 mol / L HCl is added to adjust the pH of the system to 6-7, water is added to separate, the organic phase is retained, the organic phase is spin-dried, ethanol is added and refluxed for 1 h, and after cooling to room temperature, the intermediate 1-A3-3 (42.81 g, HPLC shows a purity of 99%) is obtained by filtration and drying;

[0128] Step 2: Add A3-3 (42.81 g) to 200 ml THF, stir to dissolve, add 1,3-dibromo-5,5-dimethylhydantoin (11.71 g), stir for 12 h, and after the reaction is complete, add water to the reaction system for extraction, retain the organic phase, dry the organic phase with anhydrous magnesium sulfate, spin dry, pass through a silica gel column, and elute with petroleum ether: ethyl acetate = 10:1, and spin dry to obtain 43.49 g of intermediate 8 (A3-4).

[0129] The sample was sent to MS, and MS showed: 653.2641 (MS+1);

[0130] According to the synthesis and post-treatment methods of intermediate 8, intermediate 9 can be synthesized. The catalyst, Lewis base, feeding method, post-treatment, etc. of intermediate 9 are the same, but A3-1 and A3-2 are different. The specific structures of A3-1, A3-2, intermediate 7 (A3-4), and test data are shown in the following table:

[0131]

[0132] Synthesis of Example 1

[0133]

[0134] Feeding: Add 200 ml of dry dioxane to a three-necked flask, flush with nitrogen for 5 minutes to replace the air in the system, add B1-1 (20 g), B1-2 (intermediate 1, 17.86 g), sodium tert-butoxide (8.65 g), tri-tert-butylphosphine (18.21 g), PD2(DBA)3 (0.5 g), react at 100 ° C for 12 hours under nitrogen environment, monitor the reaction by TLC, and perform post-treatment after the reaction is completed;

[0135] Post-treatment: After the reaction is completed, 0.1 mol / L HCl is added to adjust the pH of the system to 6-7, water is added to separate, the organic phase is retained, the organic phase is spin-dried, ethanol is added and refluxed for 1 h, and after cooling to room temperature, filtered and dried to obtain Example 1-B1-3 (27.10 g, HPLC shows a purity of 99%);

[0136] The sample was sent for MS, and MS showed: 550.5110 (MS+1).

[0137] According to the synthesis and post-treatment methods of Example 1, Examples 2 to 14 can be synthesized. The catalysts, Lewis bases, feeding methods, post-treatments, etc. of Examples 2 to 14 are the same, but B1-1 and B1-2 are different. The specific structures (B1-3) and test data of B1-1, B1-2, Examples 2 to 14 are shown in the following table:

[0138]

[0139]

[0140]

[0141] Synthesis of Example 15:

[0142]

[0143] Feeding: Add 200 ml of a mixed solution of toluene (2V) / ethanol (1V) / water (1V) into a three-necked flask, flush with nitrogen for 5 minutes to replace the air in the system, add B2-1 (20 g), B2-2 (intermediate 6, 25.05 g), sodium carbonate (9.54 g) and tetrakistriphenylphosphine palladium (693.57 mg), react at 85°C for 12 hours under a nitrogen environment, monitor the reaction by TLC, and perform post-treatment after the reaction is completed;

[0144] Post-treatment: After the reaction is completed, 0.1 mol / L HCl is added to adjust the pH of the system to 6-7, water is added to separate, the organic phase is retained, the organic phase is spin-dried, ethanol is added and refluxed for 1 h, and after cooling to room temperature, it is filtered, dried, and passed through a silica gel column, and eluted with petroleum ether: ethyl acetate = 10:1, and the organic solution on the silica gel column is dried to obtain Example 15-B2-3 (30.69 g, HPLC shows a purity of 99%);

[0145] The sample was sent to MS, and MS showed: 626.3005 (MS+1);

[0146] According to the synthesis and post-treatment methods of Example 15, Examples 16 to 20 can be synthesized. The catalysts, Lewis bases, feeding methods, post-treatments, etc. of Examples 16 to 20 are the same, but B2-1 and B2-2 are different. The specific structures (B2-3) of B2-1, B2-2, Examples 16 to 20, and the test data are shown in the following table:

[0147]

[0148]

[0149] Synthesis of Example 21:

[0150]

[0151] Feeding: Add 300 ml of dry dioxane to a three-necked flask, flush with nitrogen for 5 minutes to replace the air in the system, add B3-1 (20 g), B3-2 (intermediate 1, 24.38 g), sodium carbonate (13.03 g), tri-tert-butylphosphine (24.86 g), PD2(DBA)3 (0.7 g), react at 100 ° C for 12 hours under nitrogen environment, monitor the reaction by TLC, and perform post-treatment after the reaction is completed;

[0152] Post-treatment: After the reaction is completed, 0.1 mol / L HCl is added to adjust the pH of the system to 6-7, water is added to separate, the organic phase is retained, the organic phase is spin-dried, ethanol is added and refluxed for 1 h, and after cooling to room temperature, it is filtered, dried, and passed through a silica gel column, and eluted with petroleum ether: ethyl acetate = 10:1, and the organic solution on the silica gel column is dried to obtain Example 21-B3-3 (28.10 g, HPLC shows a purity of 99%);

[0153] The sample was sent to MS, and MS showed: 922.0037 (MS+1);

[0154] According to the synthesis and post-treatment methods of Example 21, Example 22 can be synthesized. The catalyst, Lewis base, feeding method, post-treatment, etc. of Example 22 are the same, but B3-1 and B3-2 are different. The specific structures of B3-1, B3-2, Example 22 (B3-3), and test data are shown in the following table:

[0155]

[0156]

[0157] Device Example 1

[0158] The glass substrate with 120nm ITO transparent film was ultrasonically cleaned with acetone, isopropanol and deionized water for 10min each, vacuum dried at 105°C for 2h, and then UV ozone cleaned for 15min, and then the ITO glass substrate was transferred to a vacuum evaporator.

[0159] On the surface where the ITO film is formed, molybdenum trioxide (MoO3) is vacuum-deposited to form a 10 nm thick hole injection layer;

[0160] Next, 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] (TAPC) was vacuum-deposited on the hole injection layer to form a 70 nm thick hole transport layer;

[0161] Next, on the hole transport layer, the compound prepared in the above-mentioned Synthesis Example 1 (as a light-emitting host material, 90 wt%) and 4,4'-bis(9-ethyl-3-carbazole vinyl)-1,1'-biphenyl (BCzVBi, as a light-emitting guest material, 10 wt%) were co-vacuum-deposited to form a light-emitting layer with a thickness of 30 nm;

[0162] Next, on the light-emitting layer, 3,3'-[5'-[3-(3-pyridyl)phenyl][1,1':3',1"-terphenyl]-3,3"-diyl]bipyridine (TmPyPB) was vacuum-deposited to form an electron transport layer with a thickness of 40 nm.

[0163] Next, lithium fluoride (LiF) is vacuum-deposited on the electron transport layer to form an electron injection layer with a thickness of 1 nm;

[0164] Finally, aluminum (Al) was vacuum-deposited on the electron injection layer to form a cathode with a thickness of 100 nm.

[0165] Device Example 2 to Device Example 22

[0166] An organic electroluminescent device was prepared in the same manner as in Device Example 1, except that the compounds synthesized in Synthesis Example 2 to Synthesis Example 22 were used to replace the compound prepared in Synthesis Example 1.

[0167]

[0168] Device Comparative Example 1 to Device Comparative Example 2

[0169] An organic electroluminescent device was prepared in the same manner as in Device Example 1, except that the following compounds (C-1) to (C-2) were used to replace the compounds prepared in Synthesis Example 1 respectively:

[0170]

[0171] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A deuterated carbazole derivative, characterized in that: The structure is shown in formula 1: Ring A, Ring B, and Ring C are each independently empty, substituted phenyl, or unsubstituted phenyl, and at least one of A, B, and C is substituted phenyl or unsubstituted phenyl; R1-R6 are the same or different and are selected from: hydrogen, deuterium, cyano, C1-C 10 Alkyl, C1-C 10 Alkylsilyl, C6-C 15 The aromatic group; L1-L2 are the same or different and are selected from: single bond, C6-C 15 Aryl, C6-C 15 deuterated aryl; R7 is selected from the group consisting of: hydrogen, deuterium, N(R9)(R 10 )、C1-C 10 Alkyl, C1-C 10 Deuterated alkyl, C6-C 20 Aryl, C6-C 20 Deuterated aryl, C6-C 20 Heteroaryl, C6-C 20 deuterated heteroaryl; R9-R 10 The same or different selected from: C6-C 20 Aryl, C6-C 20 Deuterated aryl, C6-C 20 Heteroaryl, C6-C 20 deuterated heteroaryl; R8 is the structure shown in Formula 2; The structure of Formula 2 is as follows: is the linking site; R 11 -R 16 , R 17a , R 17b The same or different ones are selected from: hydrogen, deuterium or C1-C 10 deuterated alkyl, 1 to 2 of which are C1-C 10 of a deuterated alkyl group.

2. The deuterated carbazole derivative according to claim 1, characterized in that The structure of Formula 1 is selected from: Among them, R1-R6, R 18a -R 18d The same or different ones are selected from: hydrogen, deuterium; or R3-R4, R 18b -R 18c The same or different selected from: C1-C 10 Alkyl, C1-C 10 Alkylsilyl, hexaaryl, deuterated hexaaryl; Or the structure of Formula 1 is selected from: Among them, R1-R6, R 19a -R 19d The same or different ones are selected from: hydrogen, deuterium; or R 19b Selected from: hydrogen, deuterium, C1-C 10 Alkyl, C1-C 10 Alkylsilyl, hexaaryl, deuterated hexaaryl; Or the structure of Formula 1 is selected from: Among them, R1-R4, R 5a -R 5e , R6 are the same or different and are selected from: hydrogen, deuterium; or R1, R6, R 5b , R 5a The same or different ones are selected from: hydrogen, deuterium, C1-C 10 Alkyl, C1-C 10 Alkylsilyl, hexamembered aryl, deuterated hexamembered aryl.

3. The deuterated carbazole derivative according to claim 1, characterized in that: L1 or L2 is C6-C 15 When the aromatic group is , it is a structure shown in Formula 3: Where R 20a -R 20b , R 21a -R 21b , R 22 The same or different ones are selected from: hydrogen, deuterium, cyano, C1-C4 alkyl, C1-C 10 or a deuterated alkyl group, or a hexamembered aryl group or a deuterated hexamembered aryl group to form a condensed ring structure through a shared chemical bond; When R7 is selected from: C6-C 20 Aryl, C6-C 20 Deuterated aryl, C6-C 20 Heteroaryl, C6-C 20 A deuterated heteroaryl group having a structure shown in Formula 4, or a structure of Formula 4 and A condensed ring structure is formed by sharing chemical bonds, and * is the connection site: * is the linking site; X 1a -X 1c Selected from: CH or N; R 23 -R 24 The same or different ones are selected from: hydrogen, cyano, C1-C 10 Alkyl, C1-C 10 deuterated alkyl, phenyl, naphthyl, deuterated, cyano, C1-C 10 Alkyl, C1-C 10 Phenyl and naphthyl substituted with deuterated alkyl; X2 is selected from: O, S, C(CH3, CH3), NR 26 ; R 26 Selected from: C6-C 20 Aryl, C6-C 20 Deuterated aryl.

4. The deuterated carbazole derivative according to claim 3, characterized in that: The structure of L1-L2 is selected from: The hydrogen atoms on L1 or L2 are not deuterated or replaced by at least one D; When R7 is selected from C6-C 20 Aryl, C6-C 20 When the deuterated aryl is selected from: phenyl, naphthyl, 9,9-dimethylfluorenyl, or, deuterated, cyano, C1-C 10 Alkyl, deuterated C1-C 10 Alkyl substituted phenyl, naphthyl; When R7 is selected from C6-C 20 Heteroaryl, C6-C 20 When the deuterated heteroaryl group is Where R 32 -R 34 Selected from: hydrogen, deuterium, phenyl, biphenyl, naphthyl, or deuterated, cyano, C1-C 10 Alkyl, deuterated C1-C 10 Alkyl-substituted phenyl, biphenyl, naphthyl; or R 32 -R 33 Selected from: X3 is selected from: O, S, NR 35 ; R 35 Selected from: phenyl; When R7 is selected from N(R9, R 10 ), it is the structure shown in Formula 6: Where R 36 -R 41 Selected from: hydrogen, deuterium, cyano, C1-C 10 Alkyl, six-membered aromatic group; or R 36 -R 41 , wherein two adjacent substituents are connected to —CH═CH—CH═CH— through a common chemical bond to form a condensed ring structure; or R 36 -R 41 , where two adjacent substituents are bonded to each other through a shared chemical bond Connected to form a condensed ring structure; X4 is selected from: O, S, NR 35 .

5. The deuterated carbazole derivative according to claim 1, characterized in that R8 is selected from:

6. The deuterated carbazole derivative according to claim 1, characterized in that: C1-C 10 The alkyl group is selected from: a C1-C5 alkyl group, wherein the hydrogen on the alkyl group is not deuterated or is replaced by at least one deuterium; C1-C 10 The alkylsilyl group is selected from: C1-C5 alkylsilyl group; The six-membered aryl group is selected from: phenyl; All H groups on the above-mentioned aryl and heteroaryl groups can be replaced by D.

7. The deuterated carbazole derivative according to claim 1, characterized in that Selected from the following compounds:

8. An organic electroluminescent device, characterized in that: Contains at least the deuterated carbazole derivative according to any one of claims 1 to 7.

9. The organic electroluminescent device according to claim 8, characterized in that: The organic electroluminescent device comprises an anode, an organic electroluminescent material layer and a cathode. The organic electroluminescent material layer comprises a light-emitting layer. The light-emitting layer comprises a doping material and the deuterated carbazole derivative according to any one of claims 1 to 7.

10. The organic electroluminescent device according to claim 9, characterized in that ； The mass ratio of the organic electroluminescent material to the doping material is (1-99):(99-1); The organic electroluminescent material layer further comprises a hole transport region and an electron transport region; The hole transport region includes a hole injection layer, a hole transport layer, an electron blocking layer and a hole blocking layer, and the light emitting layer is located between the electron blocking layer and the hole blocking layer; The electron transport region includes an electron transport layer and an electron injection layer.

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