Carbazole imidazole material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of OLED (Organic Light Emitting Diode) luminescent materials, in particular to a carbazole imidazole material as well as a preparation method and application thereof, and the structure of the carbazole imidazole material is as shown in the following formula [I]: # imgabs0 #, r is any one of a 2-phenyl-4-phenyl-d5-quinazolinyl group, a 9-phenyl-d5-phenanthroline group, a 2, 3-diphenyl quinoxalinyl group, a 2, 4, 6-triphenyl-1, 3, 5-triazinyl group, a 6 '-(pyridine-2-yl)-2, 2': 4 ', 2 ''-tetrapyridyl group, a 2, 4, 6-triphenylpyrimidyl group, a 1, 2-diphenyl-1H-benzo [d] imidazolyl group and a 2, 7-diphenyl benzoxazolyl group. When the carbazole imidazole material is used in an electron transport layer and / or a light-emitting layer of an OLED device, the light-emitting efficiency of the device can be remarkably improved, and the service life of the device can be remarkably prolonged.

Description

Technical Field

[0001] The invention relates to a carbazole imidazole material and a preparation method and application thereof, belonging to the technical field of OLED luminescent materials. Background Art

[0002] Organic light-emitting diode (OLED) is a light-emitting device based on organic materials. Thanks to the breakthrough of OLED technology in recent years, this technology has been widely used in display technology and lighting fields. Due to its light, thin, fast response, transparent display, flexible and foldable characteristics, OLED is the hottest organic optoelectronic material at present. OLED panels not only have great market demand at this stage, but also have great market prospects in the future. The demand worldwide will be greatly increased.

[0003] The continuous popularization of OLED display technology and the expansion of its application fields have led to an increasing market demand for the industry, which has also promoted the continuous upgrading of OLED. In this environment, only OLEDs with excellent performance can stand out. The main problems facing OLED at this stage are still poor stability, low luminous efficiency and insufficient life. In OLED, electroluminescent materials play a decisive role in its luminous performance. An electroluminescent material with excellent performance is the key to solving the problems faced by OLED. Therefore, how to develop electroluminescent materials with excellent performance, especially electron-transmitting luminescent materials, is the focus of research at this stage. Summary of the invention

[0004] The present invention aims at the problems existing in OLED materials at this stage and provides a polycarbazole imidazole material and a preparation method and application thereof. The polycarbazole imidazole material is used in the electron transport layer and / or the light-emitting layer of the OLED device, which can significantly improve the light-emitting efficiency and service life of the device.

[0005] The technical solution of the present invention to solve the above technical problem is as follows: a carbazole imidazole material, the structure of the carbazole imidazole material is shown in the following formula [I]: Formula[I]; The R is any one of 2-phenyl-4-phenyl-d5-quinazolinyl, 9-phenyl-d5-phenanthroline, 2,3-diphenylquinoxalinyl, 2,4,6-triphenyl-1,3,5-triazine, 6'-(pyridin-2-yl)-2,2':4',2''-tetrapyridyl, 2,4,6-triphenylpyrimidinyl, 1,2-diphenyl-1H-benzo[d]imidazolyl, and 2,7-diphenylbenzoxazolyl.

[0006] Furthermore, the R is any one of the following structural formulas: .

[0007] Furthermore, the structural formula of the carbazole imidazole material is any one of the following structural formulas: .

[0008] The present invention also discloses a method for preparing a carbazole imidazole material, the preparation method comprising: ; S1. Under the protection of inert gas, 2-bromo-4-chlorophenylhydrazine hydrochloride, 4-tert-butylcyclohexanone and glacial acetic acid are added to the reactor, the temperature is raised with stirring, and the temperature is kept for reaction. After the reaction is completed, compound A is obtained by post-treatment; S2, under the protection of inert gas, adding compound A, manganese dioxide and solvent into the reactor, stirring and keeping warm for reaction, and after the reaction is completed, post-treatment is performed to obtain compound B; Add 3-fluorobenzene-1,2-diamine, 4-pyridinecarboxaldehyde and a solvent into another reactor, heat, pass air into the system, and keep the temperature to react. After the reaction is completed, post-treatment is performed to obtain compound C; S3, under the protection of inert gas, adding compound B, compound C, cesium carbonate and solvent into the reactor, heating and keeping warm for reaction, after the reaction is completed, obtaining compound D through post-treatment; S4, under the protection of inert gas, adding compound D, potassium carbonate, cuprous iodide, 1,10-phenanthroline and solvent into the reactor, heating and keeping warm for reaction, after the reaction is completed, post-treatment to obtain compound E; S5. Under the protection of inert gas, compound E, potassium carbonate, tetrahydrofuran and water are added to the reactor, palladium acetate and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl are added under stirring, and after heating, a tetrahydrofuran solution of o-nitrophenylboric acid is added. After the addition is completed, the mixture is kept warm for reaction. After the reaction is completed, compound F is obtained by post-treatment. S6. Under the protection of inert gas, compound F, triphenylphosphine and solvent are added into the reactor, and the mixture is heated and kept warm for reaction. After the reaction is completed, compound G is obtained by post-treatment; S7. Under the protection of inert gas, compound G reacts with XR under alkaline conditions. After the reaction, post-treatment is performed to obtain the polycarbazole imidazole material, wherein X is any one of Cl, Br, I, and F.

[0009] Further, in step S1, the insulation reaction temperature is 90-95°C; In step S2, the temperature of the heat preservation reaction is 20-30°C when preparing compound B, and the temperature of the heat preservation reaction is 80-85°C when preparing compound C; In step S3, the reaction temperature is kept at 100-110°C; In step S4, the preparation compound is kept at a reaction temperature of 140-145°C; In step S5, the preparation compound is kept at a reaction temperature of 60-65°C; In step S6, the preparation compound is kept at a reaction temperature of 175-180°C.

[0010] Furthermore, in step S2, the solvent used in preparing compound B is toluene, and the solvent used in preparing compound C is DMF; In step S3 and step S4, the solvent used is DMF; In step S6, the solvent used is ODB.

[0011] The invention also discloses an application of a carbazole imidazole material, and the carbazole imidazole material is applied to an organic electroluminescent device.

[0012] Furthermore, the carbazole imidazole material is applied to the electron transport layer and / or the light emitting layer of an organic electroluminescent device.

[0013] Furthermore, the carbazole imidazole material is used as an electron transport material in an electron transport layer of an organic electroluminescent device.

[0014] Furthermore, the carbazole imidazole material is used as a main light-emitting material in the light-emitting layer of an organic electroluminescent device.

[0015] The carbazole imidazole material is used as an electron transport layer material and / or a main luminescent material in an organic electroluminescent device. The prepared organic electroluminescent device can improve the luminescent performance of the luminescent device; the luminescent performance can be current efficiency, driving voltage size and luminescent life of the device.

[0016] Furthermore, the organic electroluminescent device includes a substrate layer, an anode electrode layer, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer and a cathode reflective electrode layer.

[0017] The beneficial effects of the present invention are: The carbazole imidazole material of the present invention introduces N-containing groups such as imidazole and pyridine into the parent structure to enhance the local electron cloud density and the n-type conductivity of the material, thereby effectively improving the electron transmission efficiency and deepening the HOME energy level; in addition, the introduction of the tert-butyl group makes the entire molecule have a unique non-planar conformation, which not only makes the material have good rigidity and stability in the film forming process, but also increases the glass transition temperature of the material, thereby significantly improving the thermal stability of the material and greatly improving the service life of the device; the introduction of the carbazole structure utilizes the SP 3 Hybridization and SP 2 The hybrid interaction weakens the conjugation effect of the entire molecule, thereby increasing the triplet energy level of the molecule and achieving the idealization of the material energy level.

[0018] The organic light-emitting device made of the carbazole imidazole material of the present invention has high luminous efficiency, good thermal stability and long service life, is an electroluminescent material with excellent comprehensive performance, and can have good application prospects in the rapidly developing OLED industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of the organic electroluminescent device described in the application example; In the figure, 1, transparent substrate layer; 2, transparent anode electrode layer; 3, hole injection layer; 4, hole transport layer; 5, electron blocking layer; 6, light-emitting layer; 7, hole blocking layer; 8, electron transport layer; 9, electron injection layer; 10, cathode reflective electrode layer. DETAILED DESCRIPTION

[0020] The specific implementation of the present invention is described in detail below. The present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.

[0022] 1. Preparation Example The common intermediate compound G is prepared by the following specific synthesis method: ; The preparation of compound G comprises the following steps: (1) Under the protection of inert gas, 2-bromo-4-chlorophenylhydrazine hydrochloride, 4-tert-butylcyclohexanone and glacial acetic acid were added to a three-necked flask in sequence. The reaction material ratio was 2-bromo-4-chlorophenylhydrazine hydrochloride: 4-tert-butylcyclohexanone = 1.0 eq: 1.2 eq. After the addition of the materials, stirring was started and the temperature was raised to 90-95°C. The temperature was kept for 10 hours until the reaction was complete. After post-treatment, hydrolysis, extraction, water washing, column chromatography, solvent removal and recrystallization were performed to obtain an off-white solid compound A. The total yield was 72.7%, GC ≥ 98%, the theoretical value of GC-MS was 342.70, and the measured value was 342.80.

[0023] The NMR data of compound A is: 1 H NMR (500 MHz, Chloroform-d) δ 7.50 (d, 1H), 7.37 (d, 1H), 4.54 (d,1H), 4.27 (dq, 1H), 3.05 (q, 1H), 1.95 (dt, 1H), 1.85(m, 2H), 1.68 (dq, 1H), 1.52 (m, 2H), 1.46 (m, 1H), 0.88 (d, 9H).

[0024] 13 C NMR (125 MHz, Chloroform-d) δ 145.64(1C), 133.14(1C), 128.62(1C), 123.10(1C), 122.99(1C), 105.42(1C), 60.97(1C), 46.10(1C), 43.25(1C), 32.32(1C), 31.30(1C), 29.49(1C), 27.58(3C), 25.48(1C).

[0025] (2) Under the protection of inert gas, compound A, manganese dioxide and toluene were added to a three-necked flask in sequence, with the reaction material ratio of compound A: manganese dioxide = 1.0eq: 8.0eq. After the addition of the materials, stirring was started, and the temperature was raised to 20-30°C and kept for 20 hours. The reaction was complete, and the off-white solid compound B was obtained through post-treatment such as hydrolysis, extraction, water washing, column chromatography, solvent removal and recrystallization. The total yield was 83.2%, and the GC was ≥99.0%. The theoretical value of GC-MS was 336.65, and the measured value was 336.51.

[0026] The NMR data of compound B are: 1H NMR (500 MHz, Chloroform-d) δ 9.03 (s, 1H), 8.25 (d,1H), 7.48 (s,2H), 7.43 (dd, 1H), 7.38 (d, 1H), 1.38 (s, 9H).

[0027] 13 C NMR (125 MHz, Chloroform-d) δ 144.88(1C), 140.20(1C), 136.86(1C),131.57(1C), 128.82(1C), 125.26(1C), 124.26(1C), 122.81(1C), 120.60(1C), 117.14(1C), 111.90(1C), 99.43(1C), 35.80(1C), 31.14(3C).

[0028] (3) 3-fluorobenzene-1,2-diamine, 4-pyridinecarboxaldehyde and DMF were added to a three-necked flask in sequence, with a reaction material ratio of 3-fluoro-1,2-diamine:4-pyridinecarboxaldehyde=1.0eq:1.0eq. After the addition of the materials, the temperature was raised to 80-85°C, the system was ventilated with air, and the temperature was kept for 20 hours. The reaction was completed, and after post-treatment, an off-white solid compound C was obtained by extraction, water washing, column chromatography, solvent removal and recrystallization. The total yield was 85.5%, and GC: ≥99.5%. The theoretical value of GC-MS: 213.21, and the measured value: 213.32.

[0029] The NMR data of compound C are: 1 H NMR (500 MHz, Chloroform-d) δ 8.78 (m, 2H), 8.25 (m, 2H), 7.57(dd, 1H), 7.42 (td,1H), 7.20 (td, 1H), 5.10(S, 1H).

[0030] 13 C NMR (125 MHz, Chloroform-d) δ 152.91(1C), 149.83(2C), 149.10(1C),144.77(1C), 140.55(1C), 124.87(1C), 124.35(1C), 121.34(2C), 110.95(1C),109.95(1C).

[0031] (4) Under the protection of inert gas, compound B, compound C, potassium carbonate and DMF were added to the three-necked flask in sequence, and the reaction material ratio of compound B: compound C and cesium carbonate was 1.0eq: 1.0eq: 3.0eq. After the addition of the materials, the temperature was raised to 105.0℃ and the reaction was kept at this temperature for 5.0h. After the reaction was qualified, a light yellow solid compound D was obtained after extraction, washing, column column, solvent removal and recrystallization, with a total yield of 80.2%, HPLC: ≥99.0%. The theoretical value of HPLC-MS: 529.86, the measured value: 530.56.

[0032] The NMR data of compound D are: 1 H NMR (500 MHz, Chloroform-d) δ 8.69 (m, 2H), 8.19 (d, 1H), 8.12 (m,2H), 7.67 (dd, 1H), 7.53 (m, 2H), 7.49 (m, 2H), 7.46 (d, 1H), 7.36 (dd, 1H),5.34(S,1H)1.37(s,9H).

[0033] 13 C NMR (125 MHz, Chloroform-d) δ 152.14(1C),149.37(2C), 145.50(1C),139.27(1C), 138.96(1C), 137.86(1C), 137.05(1C), 131.82(1C), 131.38(1C),127.78(1C), 125.46(1C), 125.82(1C), 124.52(1C), 123.24(1C), 123.14(1C),122.38(1C), 122.16(1C), 122.06(1C), 121.01(2C), 117.20(1C), 110.81(1C), 100.16(1C), 35.80(1C), 31.20(3C).

[0034] (5) Under the protection of inert gas, compound D, potassium carbonate, cuprous iodide, 1,10-phenanthroline and DMF were added to a three-necked flask in sequence. The reaction material ratio was compound D: potassium carbonate: cuprous iodide: 1,10-phenanthroline = 1.0eq: 3.0eq: 0.1eq: 0.2eq. After the addition of the materials, the temperature was raised to 140-145°C and kept for 20 hours to complete the reaction. After post-treatment, light yellow solid compound E was obtained through hydrolysis, extraction, water washing, column chromatography and recrystallization. The total yield was 84.0%, HPLC ≥ 99.5%. The theoretical value of HPLC-MS was 448.95, and the measured value was 449.86.

[0035] The NMR data of compound E are: 1 H NMR (500 MHz, Chloroform-d) δ 8.71 (m, 2H), 8.29 (d, 1H), 8.04(dd, 1H), 7.92 (m, 2H), 7.78 (dd, 2H), 7.62 (d, 1H), 7.59 (t, 1H), 7.52 (d,1H), 7.49 (dd,1H), 1.36 (s, 9H).

[0036] 13 C NMR (125 MHz, Chloroform-d) δ 149.74(2C), 144.87(1C), 138.02(1C), 137.36(1C), 136.51(1C), 129.45(1C), 128.36(1C), 126.97(1C), 125.52(1C),124.77(1C), 123.96(1C), 122.05(1C), 121.78(1C), 121.32(2C), 120.62(1C),120.20(1C), 118.74(1C), 118.25(1C), 118.01(1C), 117.97(1C), 115.69(1C), 111.24(1C), 35.81(1C), 31.22(3C).

[0037] (6) Under the protection of inert gas, compound E, potassium carbonate, toluene, purified water, palladium acetate, and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl were added to a three-necked flask in sequence. After the addition of the materials, stirring was started, and the temperature was raised to 60-65°C. A tetrahydrofuran solution of o-nitrobenzeneboric acid was added dropwise thereto. After the addition, the temperature was kept at 60-65°C for 10 hours until the reaction was complete. The reaction material ratio was compound E: potassium carbonate: palladium acetate: 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl: o-nitrobenzeneboric acid = 1.0eq: 3.0eq: 0.01eq: 0.02eq: 1.2eq. After post-treatment, light yellow solid compound F was obtained by washing with water, column chromatography, and recrystallization. The total yield was 73.2%, and the HPLC was ≥99.5%. The theoretical value of HPLC-MS was 535.59, and the measured value was 536.36.

[0038] The NMR data of compound F are: 1H NMR (500 MHz, Chloroform-d) δ 8.72 (m, 2H), 8.31 (d, 1H), 8.09(dd, 1H), 8.04 (d, 1H), 7.96 (d, 1H), 7.92 (m, 2H), 7.80 (dd, 2H), 7.76 (dd,1H), 7.66(m, 1H), 7.63 (dd, 1H), 7.57 (td, 1H), 7.50 (dd, 1H), 7.33 (d, 1H),1.37 (s, 9H).

[0039] 13 C NMR (125 MHz, Chloroform-d) δ 149.08(2C), 148.94(1C), 146.69(1C),146.12(1C), 138.05(1C),137.79(1C),137.57(1C),132.85(1C),130.03(1C),129.97(1 C),129.91(1C),129.74(1C),129.45(1C),129.32(1C),129.09(1C),125.9 1(1C),125.42(1C),124.11(1C),123.69(1C),122.62(1C),121.96(1C),12 1.59(2C),120.72(1C),118.67(1C),118.09(1C),117.85(1C),112.77(1C), 111.17(1C), 35.79(1C), 31.15(3C).

[0040] (7) Under the protection of inert gas, compound F, triphenylphosphine and ODB were added to the three-necked flask in sequence. After the addition of the materials, stirring was started, and the temperature was raised to 175-180°C and kept for 20 hours to complete the reaction. The reaction material ratio was compound F: triphenylphosphine: = 1.0eq: 3.0eq. After post-treatment, light yellow solid compound G was obtained by washing with water, column chromatography and recrystallization. The total yield was 66.3%, HPLC ≥ 99.9%. The theoretical value of HPLC-MS was 503.60, and the measured value was 504.32.

[0041] The NMR data of compound G are: 1H NMR (500 MHz, Chloroform-d) δ 10.02 (s,1H), 8.86 (dd, 1H), 8.72(m, 2H), 8.38 (d, 1H), 8.10 (s, 1H), 7.92 (m, 2H), 7.85 (dd, 1H), 7.75 (dd,1H), 7.66 (t,1H), 7.52(dd, 1H), 7.46 (td,1H), 7.42 (dd,1H), 7.36 (d, 1H),7.29 (td, 1H), 1.37 (s, 9H).

[0042] 13 C NMR (125 MHz, Chloroform-d) δ 148.95(2C), 148.72(1C), 145.36(1C), 139.13(1C), 137.96(1C), 137.58(1C), 131.27(1C), 129.08(1C), 125.88(1C),125.84(1C), 125.78(1C), 125.29(1C), 124.15(1C), 123.61(1C), 123.51(1C),121.96(1C), 121.90(1C), 121.75(2C), 120.89(1C), 120.58(1C), 119.58(1C), 118.70(1C),118.16(1C), 116.80(1C), 116.11(1C), 111.23(1C), 111.15(1C), 107.37(1C),35.79(1C), 31.17(3C).

[0043] Example 1 Synthesis of compound A-1: ; Under the protection of inert gas, 50.3g (0.1mol) of compound G, 36.6g (0.1mol) of 2-(3-bromophenyl)-4-(phenyl-2,3,4,5,6-d5)quinazoline, 19.2g (0.2mol) of sodium tert-butoxide, 0.915g (1.0mmol) of tris(dibenzylideneacetone)dipalladium, 0.952g (2.0mmol) of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl were weighed in a 2L three-necked flask, and then 1006.0g of xylene was added, the temperature was raised to 125.0℃, and the reaction was kept warm for 10h. The reaction was qualified, HPLC: 94.2%. After washing with water, column, desolventizing, and recrystallization from toluene, 66.3g of light yellow solid compound A-1 was obtained, with a total yield of 84.0%, HPLC: 99.9%. Theoretical value of HPLC-MS: 788.95, measured value: 789.35.

[0044] The NMR data of compound A-1 are: 1 H NMR (500 MHz, Chloroform-d) δ 8.71 (m, 2H), 8.35 (t, 1H), 8.32 (t,1H), 8.28 (s, 1H), 8.18 (dt, 1H), 8.14 (dd, 1H), 8.11 (dd,1H), 7.97(dd,1H),7.89 (m, 3H),7.81 (td, 1H), 7.74 (dd, 1H), 7.65 (t, 1H), 7.62 (m, 1H), 7.59(m, 2H), 7.49 (d, 2H), 7.41 (dt, 1H), 7.33 (td, 1H), 7.25 (td, 1H), 1.40 (s,9H).

[0045] 13C NMR (125 MHz, Chloroform-d) δ 168.68(1C), 162.06(1C), 150.57(1C), 148.90(2C), 148.21(1C), 145.08(1C), 142.72(1C), 139.97(1C), 138.94(1C),137.30(1C), 135.49(1C), 134.38(1C), 133.80(1C), 131.75(1C), 131.03(1C),130.56(1C), 130.49(1C), 129.11(1C), 128.83(1C), 128.81(2C), 128.71(2C), 128.38(1C),128.18(1C), 127.96(1C), 127.87(1C), 127.86(1C), 127.40(1C),126.82(1C), 125.85(1C), 125.35(1C), 123.46(1C), 123.25(1C), 122.72(1C), 122.51(2C), 122.47(1C),122.27(1C), 121.86(1C), 121.56(1C), 121.32(1C), 120.71(1C),119.62(1C), 118.52(1C), 118.35(1C), 115.99(1C), 111.32(1C), 105.55(1C), 34.66(1C), 31.62(3C).

[0046] Example 2 Synthesis of compound A-5: ; Under the protection of inert gas, 50.3g (0.1mol) of compound G, 34.0g (0.1mol) of 2-bromo-9-(phenyl-2,3,4,5,6-d5)-1,10-phenanthroline, 19.2g (0.2mol) of sodium tert-butoxide, 0.915g (1.0mmol) of tris(dibenzylideneacetone)dipalladium, and 0.952g (2.0mmol) of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl were weighed into a 2L three-necked flask in sequence, and then 1006.0g of xylene was added, the temperature was raised to 125.0℃, and the reaction was kept warm for 10h. The reaction was qualified, HPLC: 93.1%. After washing with water, column, desolventizing, and recrystallization from toluene, 62.6g of light yellow solid compound A-5 was obtained, with a total yield of 82.1%, HPLC: 99.9%. Theoretical value of HPLC-MS: 762.91, measured value: 763.31.

[0047] The NMR data of compound A-5 are: 1 H-NMR(500MHz, Chloroform-d) δ 8.71 (m, 2H), 8.36 (s, 1H), 8.34 (dd,1H), 8.32 (t, 1H), 8.27 (dd, 1H), 8.20 (d, 1H), 8.01 (m, 1H), 7.92 (m, 1H), 7.90 (m, 3H), 7.75 (m,2H), 7.66 (m, 1H), 7.52 (m, 1H), 7.49 (m, 3H), 7.31 (m,2H), 1.41 (s, 9H).

[0048] 13 C NMR (125 MHz, Chloroform-d) δ 152.63(1C), 152.13(1C), 150.57(1C),148.90(2C), 146.97(1C), 145.50(1C), 145.08(1C), 139.38(1C), 138.94(1C),137.04(1C), 134.99(1C), 133.80(1C), 133.68(1C), 132.77(1C), 132.14(1C),130.57(1C), 129.97(1C), 129.61(2C), 128.98(1C), 128.83(1C), 128.53(1C), 128.22(1C),128.11(1C), 127.78(1C), 127.35(2C), 126.95(1C), 126.61(1C), 125.69(1C),125.61(1C), 123.46(1C), 122.65(1C), 122.15(1C), 122.10(2C), 121.86(1C), 121.50(1C),121.43(1C), 120.59(1C), 120.23(1C), 119.62(1C), 118.35(1C),115.99(1C), 113.73(1C), 113.70(1C), 105.21(1C), 34.66(1C), 31.62(3C).

[0049] Example 3 Synthesis of compound A-9: ; Under the protection of inert gas, 50.3g (0.1mol) of compound G, 36.1g (0.1mol) of 5-bromo-2,3-diphenylquinoxaline, 19.2g (0.2mol) of sodium tert-butoxide, 0.915g (1.0mmol) of tris(dibenzylideneacetone)dipalladium, and 0.952g (2.0mmol) of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl were weighed into a 2L three-necked flask in turn, and then 1006.0g of xylene was added, the temperature was raised to 125.0℃, and the reaction was kept warm for 10h. The reaction was qualified, HPLC: 97.2%. After washing with water, column, desolventizing, and recrystallization from toluene, 68.5g of light yellow solid compound A-9 was obtained, with a total yield of 87.4%, HPLC: 99.9%. The theoretical value of HPLC-MS is 783.92, and the measured value is: 784.56.

[0050] The NMR data of compound A-9 are: 1 H NMR (500 MHz, Chloroform-d) δ 8.70 (m, 2H), 8.40 (s, 1H), 8.31 (t,1H), 8.03 (dd, 1H), 7.95 (dd, 1H), 7.89 (m, 3H), 7.84 (m, 4H), 7.80 (t, 1H),7.75 (dd, 1H), 7.66(d, 1H), 7.60 (dd, 1H), 7.57 (dd, 1H), 7.49 (d, 2H), 7.36(m, 2H),7.32 (td, 1H), 7.30(m, 4H), 7.28(td, 1H), 1.41 (s, 9H).

[0051] 13C NMR (125 MHz, Chloroform-d) δ 151.26(1C), 150.57(1C), 148.90(2C),148.73(1C), 145.08(1C), 142.67(1C), 139.11(1C), 138.94(1C), 138.71(1C),137.75(1C), 137.04(1C), 134.99(1C), 134.28(1C), 133.06(1C), 133.01(1C),130.57(1C), 129.85(1C), 129.81(1C), 129.30(1C), 128.83(1C), 128.66(1C), 128.62(1C),128.58(2C), 128.40(1C), 128.38(2C), 128.27(1C), 128.26(2C), 127.82(1C),127.11(1C), 126.61(1C), 126.18(1C), 123.46(1C), 122.99(1C), 122.79(1C), 122.40(1C),122.38(2C), 121.82(1C), 121.68(1C), 121.47(1C), 120.77(1C),119.62(1C), 118.35(1C), 115.99(1C), 111.18(1C), 105.32(1C), 34.66(1C), 31.62(3C).

[0052] Example 4 Synthesis of compound A-14: ; Under the protection of inert gas, 50.3g (0.1mol) of compound G, 32.7g (0.1mol) of 2-(3-fluorophenyl)-4,6-diphenyl-1,3,5-triazine, and 97.5g (0.3mol) of cesium carbonate were weighed in a 2L three-necked flask, and then 754.5g of N,N-dimethylformamide (DMF) was added. Stirring was started and the temperature was raised to 125.0℃. The reaction was kept warm for 20.0h and the result was qualified. HPLC: 96.3%. After extraction, washing, column column, and recrystallization from o-dichlorobenzene, 73.2g of off-white solid compound A-14 was obtained, with a total yield of 90.3% and HPLC: 99.9%. The theoretical value of HPLC-MS was 810.94, and the measured value was 811.86.

[0053] The NMR data of compound A-14 are: 1H NMR (500 MHz, Chloroform-d) δ 8.71 (m, 2H), 8.56 (m, 4H), 8.41 (t,1H), 8.32 (t, 1H), 8.31 (m, 2H), 7.98 (dd, 1H), 7.89 (m, 3H), 7.74 (dd, 1H), 7.66 (dt, 2H), 7.58 (dd, 1H), 7.48 (m, 9H), 7.32 (td, 1H), 7.25 (td, 1H), 1.41 (s, 9H).

[0054] 13 C NMR (125 MHz, Chloroform-d) δ 168.97(1C), 167.43(2C), 150.57(1C),148.90(2C), 145.08(1C), 142.72(1C), 139.92(1C), 138.94(1C), 137.31(1C),134.99(1C), 133.80(1C), 132.62(1C), 131.79(2C), 131.26(2C), 130.57(1C),128.83(1C), 128.71(1C), 128.69(4C), 128.42(4C), 128.38(1C), 128.33(1C), 128.29(1C),127.96(1C), 127.86(1C), 126.82(1C), 123.46(1C), 123.23(1C), 122.72(1C),122.33(1C), 122.27(1C), 122.19(2C), 121.68(1C), 121.56(1C), 120.71(1C), 119.59(1C),118.46(1C), 118.35(1C), 115.99(1C), 111.32(1C), 105.55(1C), 34.66(1C), 31.62(3C).

[0055] Example 5 Synthesis of compound A-17: ; Under the protection of inert gas, 50.3g (0.1mol) of compound G, 38.9g (0.1mol) of 6''-bromo-6'-(pyridin-2-yl)-2,2':4',2''-tetrapyridine, 19.2g (0.2mol) of sodium tert-butoxide, 0.915g (1.0mmol) of tris(dibenzylideneacetone)dipalladium, 0.952g (2.0mmol) of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl were weighed into a 2L three-necked flask, and then 1006.0g of xylene was added, the temperature was raised to 130.0℃, and the reaction was kept warm for 10h. The reaction was qualified, HPLC: 95.2%. After washing with water, column, desolvation, and recrystallization from toluene, 73.1g of light yellow solid compound A-17 was obtained, with a total yield of 90.0%, HPLC: 99.9%. The theoretical value of HPLC-MS is 811.93, the measured value is 812.69.

[0056] The NMR data of compound A-17 are: 1 H NMR (500 MHz, Chloroform-d) δ 8.78 (dd, 2H), 8.70 (m, 2H), 8.65(dd, 2H), 8.52 (s, 2H), 8.35 (s, 1H), 8.32 (t, 1H), 8.12 (dd, 1H), 8.02 (m,1H), 7.88 (m, 5H),7.81 (m, 2H), 7.75 (dd, 1H), 7.66 (m, 1H), 7.54 (m, 1H),7.48 (d, 2H), 7.30 (m, 2H), 7.19 (td, 2H), 1.41 (s, 9H).

[0057] 13C NMR (125 MHz, Chloroform-d) δ 154.41(2C), 152.77(1C), 152.75(1C),152.73(2C), 151.74(1C), 150.57(1C), 148.90(2C), 148.09(2C), 145.08(1C),139.66(1C), 139.48(2C), 138.94(1C), 137.31(1C), 136.73(1C), 134.99(1C),133.86(1C), 133.78(1C), 130.57(1C), 130.06(1C), 128.98(1C), 128.83(1C), 126.95(1C),126.82(1C), 124.64(2C), 123.46(1C), 122.66(2C), 122.43(1C), 122.37(2C),122.19(2C), 121.68(1C), 121.66(1C), 121.61(1C), 121.43(1C), 120.59(1C), 120.37(1C),119.59(1C), 118.35(1C), 115.99(1C), 113.40(1C), 113.26(1C),105.21(1C), 34.66(1C), 31.62(3C).

[0058] Example 6 Synthesis of compound A-20: ; Under the protection of inert gas, 50.3g (0.1mol) of compound G, 43.4g (0.1mol) of 2-(3-iodophenyl)-4,6-diphenylpyrimidine, 19.2g (0.2mol) of sodium tert-butoxide, 0.915g (1.0mmol) of tris(dibenzylideneacetone)dipalladium, and 0.952g (2.0mmol) of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl were weighed into a 2L three-necked flask in turn, and then 1006.0g of xylene was added, the temperature was raised to 125.0℃, and the reaction was kept warm for 5h. The reaction was qualified, HPLC: 94.2%. After extraction, washing, column, and recrystallization from o-dichlorobenzene, 73.2g of off-white solid compound A-20 was obtained, with a total yield of 90.4%, HPLC: 99.9%. The theoretical value of HPLC-MS is 809.96, and the measured value is: 810.86.

[0059] The NMR data of compound A-20 are: 1H NMR (500 MHz, Chloroform-d) δ 8.71 (m, 2H), 8.34 (t, 1H), 8.32 (t,1H), 8.26 (s, 1H), 8.18 (m, 4H), 8.17(dt,1H), 8.15 (s, 1H), 7.97 (dd, 1H),7.89 (m, 2H),7.87(dd, 1H), 7.74 (dd, 1H), 7.65 (t, 1H), 7.62 (t, 1H), 7.58(dd, 1H), 7.50 (m, 6H), 7.41(dt, 1H), 7.40 (m,2H), 7.32 (td, 1H), 7.26 (td,1H), 1.41 (s, 9H).

[0060] 13 C NMR (125 MHz, Chloroform-d) δ 167.88(1C), 153.73(2C), 150.57(1C),148.90(2C), 145.08(1C), 142.72(1C), 139.92(1C), 138.94(1C), 137.54(2C),137.31(1C), 134.99(1C), 133.80(1C), 131.74(1C), 130.57(1C), 129.60(2C),128.83(1C), 128.71(1C), 128.60(4C), 128.38(1C), 128.33(1C), 128.29(1C), 128.19(4C),127.87(1C), 127.86(1C), 126.82(1C), 123.46(1C), 123.23(1C),122.72(1C), 122.33(1C), 122.27(1C), 122.19(2C), 121.68(1C), 121.56(1C), 120.71(1C), 119.59(1C),118.35(1C), 117.83(1C), 115.99(1C), 111.60(1C), 111.32(1C),105.55(1C), 34.66(1C), 31.62(3C).

[0061] Example 7 Synthesis of compound A-24: ; Under the protection of inert gas, 50.3g (0.1mol) of compound G, 30.5g (0.1mol) of 2-(3-iodophenyl)-4,6-diphenylpyrimidine, 19.2g (0.2mol) of sodium tert-butoxide, 0.915g (1.0mmol) of tris(dibenzylideneacetone)dipalladium, and 0.952g (2.0mmol) of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl were weighed into a 2L three-necked flask in turn, and then 1006.0g of xylene was added, the temperature was raised to 130.0℃, and the reaction was kept warm for 10h. The reaction was qualified, HPLC: 92.3%. After extraction, water washing, column column, and o-dichlorobenzene recrystallization, 61.5g of off-white solid compound A-24 was obtained, with a total yield of 79.7%, HPLC: 99.9%. The theoretical value of HPLC-MS is 771.91, and the measured value is: 772.86.

[0062] The NMR data of compound A-24 are: 1 H NMR (500 MHz, Chloroform-d) δ 8.71 (m, 2H), 8.34 (t, 1H), 8.26 (s,1H), 8.01 (m, 2H), 7.96 (dd, 1H), 7.89 (m, 2H), 7.88(dd, 1H), 7.79 (dd, 1H),7.75 (dd, 1H),7.66(t, 1H), 7.64 (dd, 1H), 7.60 (m, 3H), 7.49 (m, 4H), 7.45(td, 1H), 7.39 (m, 3H), 7.34(td, 1H), 7.32(td, 1H), 7.26 (td, 1H), 1.41 (s,9H).

[0063] 13C NMR (125 MHz, Chloroform-d) δ 150.57(1C), 150.53(1C), 149.33(2C), 145.08(1C), 143.05(1C), 140.22(1C), 139.60(1C), 138.94(1C), 137.04(1C),136.40(1C), 135.06(1C), 134.99(1C), 134.28(1C), 130.57(1C), 129.34(2C),128.91(2C), 128.83(1C), 128.72(1C), 128.43(1C), 128.27(1C), 127.86(1C), 127.49(1C),126.61(1C), 126.24(1C), 126.10(1C), 124.96(2C), 123.46(1C), 123.25(1C),122.98(1C), 122.72(1C), 122.55(1C), 122.10(2C), 121.68(1C), 121.34(1C), 120.71(1C),120.58(2C), 119.62(1C), 119.57(1C), 118.35(1C), 115.99(1C),115.84(1C), 111.32(1C), 105.55(1C), 34.66(1C), 31.62(3C).

[0064] Example 8 Synthesis of compound A-25: ; Under the protection of inert gas, 50.3g (0.1mol) of compound G, 30.6g (0.1mol) of 7-(3-chlorophenyl)-2-phenylbenzo[d]oxazole, 19.2g (0.2mol) of sodium tert-butoxide, 0.915g (1.0mmol) of tris(dibenzylideneacetone)dipalladium, and 0.952g (2.0mmol) of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl were weighed into a 2L three-necked flask in sequence, and then 1006.0g of xylene was added, the temperature was raised to 135.0℃, and the reaction was kept warm for 10h. The reaction was qualified, HPLC: 92.8%. After extraction, washing, column column, and recrystallization from o-dichlorobenzene, 68.5g of off-white solid compound A-25 was obtained, with a total yield of 88.6%, HPLC: 99.9%. The theoretical value of HPLC-MS is 772.89, the measured value is 773.68.

[0065] The NMR data of compound A-25 are: 1 H NMR (500 MHz, Chloroform-d) δ 8.71 (m, 2H), 8.33 (t, 1H), 8.27 (s,1H), 8.12 (m, 2H), 7.98 (dd, 1H), 7.90 (m, 3H), 7.88 (dd, 1H), 7.74 (dd, 1H),7.66 (t, 1H),7.64 (dd, 1H), 7.60 (dd, 1H), 7.53 (dd, 1H), 7.49 (d, 2H), 7.44(m, 6H), 7.39 (t, 1H), 7.33 (td, 1H), 7.25 (td, 1H), 1.40 (s, 9H)。

[0066] 13 C NMR (125 MHz, Chloroform-d) δ 160.82(1C), 150.57(1C), 149.33(2C),146.40(1C), 145.08(1C), 142.74(1C), 140.09(1C), 139.92(1C), 138.94(1C),137.04(1C), 135.44(1C), 134.99(1C), 134.28(1C), 131.08(1C), 130.57(1C), 129.47(1C),128.83(1C), 128.72(1C), 128.49(1C), 128.43(1C), 128.42(2C),127.86(1C), 127.38(1C), 127.32(1C), 127.13(2C), 126.61(1C), 126.24(1C), 125.85(1C), 123.46(1C),123.25(1C), 122.72(1C), 122.55(1C), 122.10(2C),121.68(1C), 121.34(1C), 120.71(1C), 120.35(1C), 119.62(1C), 119.57(1C), 119.48(1C), 118.35(1C), 117.91(1C),115.99(1C), 111.32(1C), 105.55(1C), 34.66(1C),31.62(3C)。

[0067] The synthesis methods of other compounds included in the present invention are the same or similar to those of the specific implementation examples, and are not listed one by one. The mass-to-core ratios of the synthesized compounds are shown in Table 1 below; the main raw materials and some auxiliary materials used to synthesize the compounds of the specific implementation examples are all known compounds, and the specific CAS numbers are shown in Table 2.

[0068] Table 1 Mass-to-nuclear ratio of compounds

[0069] Table 2 CAS numbers of relevant main raw materials and auxiliary materials

[0070] 2. Preparation and evaluation of organic electroluminescent devices The following comparative example 1 and application examples 1-24 illustrate in detail the application effect of the synthesized OLED light-emitting material of the present invention on the device, and the specific implementation method is as follows: Comparative Example 1 The structure of organic electroluminescent devices is as follows Figure 1 As shown, the transparent anode electrode layer 2 (film thickness of 208nm, indium tin oxide) with a transparent substrate layer 1 is processed: first, photolithography and etching are performed to form the required regular transparent anode electrode layer 2, and then the glass transparent substrate layer 1 is washed, that is, alkaline washing, deionized water washing, acetone ultrasonic cleaning, ethanol ultrasonic cleaning, ultrapure water cleaning, drying, and then ultraviolet-ozone washing of the transparent anode electrode layer 2 is performed to ensure that the organic residues on the surface of the transparent anode electrode layer 2 are removed. After the above treatment, the hole injection layer 3 is evaporated on the transparent anode electrode layer 2, and the material of the structural formula (α-NPB) is evaporated using a vacuum evaporation device (the evaporation conditions are: using a molybdenum crucible, the evaporation rate is 0.1nm / s, and the vacuum degree is 4.0×10 -5 Pa), with a film thickness of 56nm. This layer of organic material is used as a hole injection layer 3. A 23nm thick structural formula II (CCP) material is evaporated immediately after the hole injection layer 3 as a hole transport layer 4. A 21nm thick structural formula III (TAPC) material is evaporated immediately after the hole transport layer 4 as an electron blocking layer 5.

[0071] After the electron blocking layer 5 is evaporated, the structural formula tetrakis (MNBPA) material and [2-(4,6-difluorophenyl)pyridine-C2,N] (pyridine) iridium (Firpic) are mixed at a doping weight ratio of 95:5 and then evaporated onto the empty electron blocking layer 5 (evaporation conditions: using a molybdenum crucible, evaporation speed 0.1nm / s, vacuum degree 4.0×10 -5 Pa) to obtain the light-emitting layer 6, the light-emitting layer 6 has a film thickness of 32 nm.

[0072] The preparation of the hole blocking layer 7 is to continue to vacuum-evaporate the hole blocking layer 7 material (the material shown in structural formula five (TmPyPB)) onto the light-emitting layer 6 after the light-emitting layer 6 (evaporation conditions are: using a molybdenum crucible, evaporation rate 0.1nm / s, vacuum degree 4.0*10-5Pa), and the vacuum-evaporated film thickness of the material is 21nm. After the evaporation is completed, the material shown in structural formula six (DPyPA) is evaporated to obtain the electron transport layer 8, and the evaporated film thickness is 78nm. The electron injection layer 9 is formed on the electron transport layer 8 by a vacuum evaporation device to form a lithium fluoride (LiF) layer with a film thickness of 0.8nm as the electron injection layer 9.

[0073] On the electron injection layer 9, a cathode reflective electrode layer 10 is formed by vacuum deposition. The cathode reflective electrode layer 10 is an aluminum (Al) layer having a film thickness of 148 nm.

[0074] The structural formulas of the raw materials involved in the preparation of organic electroluminescent devices are as follows: .

[0075] After the organic OLED electroluminescent device is completed as described above, the anode and cathode are connected using a known driving circuit, and then the current-voltage performance, luminous efficiency and luminous spectrum of the device are measured.

[0076] Comparative Example 2 The organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the electron transport material (Structural Formula 6) used in the electron transport layer 8 of the organic electroluminescent device was changed to Structural Formula 4.

[0077] Comparative Example 3 The organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the main luminescent material (Structural Formula 4) used in the luminescent layer 6 of the organic electroluminescent device was changed to Structural Formula 6.

[0078] Application Example 1 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the electron transport material (Structural Formula VI) used in the electron transport layer 8 of the organic electroluminescent device was changed to the compound A-1 of the present invention.

[0079] Application Example 2 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the main light-emitting material (Structural Formula 4) used in the light-emitting layer 6 of the organic electroluminescent device was changed to the compound A-1 of the present invention.

[0080] Application Example 3 An organic electroluminescent device is prepared by the same method as in Comparative Example 1, except that the electron transport material (structural formula 6) used in the electron transport layer 8 of the organic electroluminescent device and the main light-emitting material (structural formula 4) used in the light-emitting layer 6 are changed to the compound A-1 of the present invention.

[0081] Application Example 4 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the electron transport material (Structural Formula VI) used in the electron transport layer 8 of the organic electroluminescent device was changed to the compound A-5 of the present invention.

[0082] Application Example 5 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the main light-emitting material (Structural Formula 4) used in the light-emitting layer 6 of the organic electroluminescent device was changed to the compound A-5 of the present invention.

[0083] Application Example 6 An organic electroluminescent device is prepared by the same method as in Comparative Example 1, except that the electron transport material (structural formula 6) used in the electron transport layer 8 of the organic electroluminescent device and the main light-emitting material (structural formula 4) used in the light-emitting layer 6 are changed to the compound A-5 of the present invention.

[0084] Application Example 7 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the electron transport material (Structural Formula VI) used in the electron transport layer 8 of the organic electroluminescent device was changed to the compound A-9 of the present invention.

[0085] Application Example 8 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the main light-emitting material (Structural Formula 4) used in the light-emitting layer 6 of the organic electroluminescent device was changed to the compound A-9 of the present invention.

[0086] Application Example 9 An organic electroluminescent device is prepared by the same method as in Comparative Example 1, except that the electron transport material (structural formula 6) used in the electron transport layer 8 of the organic electroluminescent device and the main light-emitting material (structural formula 4) used in the light-emitting layer 6 are changed to the compound A-9 of the present invention.

[0087] Application Example 10 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the electron transport material (Structural Formula VI) used in the electron transport layer 8 of the organic electroluminescent device was changed to the compound A-14 of the present invention.

[0088] Application Example 11 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the main light-emitting material (Structural Formula 4) used in the light-emitting layer 6 of the organic electroluminescent device was changed to the compound A-14 of the present invention.

[0089] Application Example 12 An organic electroluminescent device is prepared by the same method as in Comparative Example 1, except that the electron transport material (structural formula 6) used in the electron transport layer 8 of the organic electroluminescent device and the main light-emitting material (structural formula 4) used in the light-emitting layer 6 are changed to the compound A-14 of the present invention.

[0090] Application Example 13 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the electron transport material (Structural Formula VI) used in the electron transport layer 8 of the organic electroluminescent device was changed to the compound A-17 of the present invention.

[0091] Application Example 14 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the main light-emitting material (Structural Formula 4) used in the light-emitting layer 6 of the organic electroluminescent device was changed to the compound A-17 of the present invention.

[0092] Application Example 15 An organic electroluminescent device is prepared by the same method as in Comparative Example 1, except that the electron transport material (structural formula 6) used in the electron transport layer 8 of the organic electroluminescent device and the main light-emitting material (structural formula 4) used in the light-emitting layer 6 are changed to the compound A-17 of the present invention.

[0093] Application Example 16 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the electron transport material (Structural Formula VI) used in the electron transport layer 8 of the organic electroluminescent device was changed to the compound A-20 of the present invention.

[0094] Application Example 17 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the main light-emitting material (Structural Formula 4) used in the light-emitting layer 6 of the organic electroluminescent device was changed to the compound A-20 of the present invention.

[0095] Application Example 18 An organic electroluminescent device is prepared by the same method as in Comparative Example 1, except that the electron transport material (structural formula 6) used in the electron transport layer 8 of the organic electroluminescent device and the main light-emitting material (structural formula 4) used in the light-emitting layer 6 are changed to the compound A-20 of the present invention.

[0096] Application Example 19 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the electron transport material (Structural Formula VI) used in the electron transport layer 8 of the organic electroluminescent device was changed to the compound A-24 of the present invention.

[0097] Application Example 20 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the main light-emitting material (Structural Formula 4) used in the light-emitting layer 6 of the organic electroluminescent device was changed to the compound A-24 of the present invention.

[0098] Application Example 21 An organic electroluminescent device is prepared by the same method as in Comparative Example 1, except that the electron transport material (structural formula 6) used in the electron transport layer 8 of the organic electroluminescent device and the main light-emitting material (structural formula 4) used in the light-emitting layer 6 are changed to the compound A-24 of the present invention.

[0099] Application Example 22 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the electron transport material (Structural Formula VI) used in the electron transport layer 8 of the organic electroluminescent device was changed to the compound A-25 of the present invention.

[0100] Application Example 23 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the electron transport material (Structural Formula VI) used in the electron transport layer 8 of the organic electroluminescent device was changed to the compound A-25 of the present invention.

[0101] Application Example 24 An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the electron transport material (Structural Formula VI) used in the electron transport layer 8 of the organic electroluminescent device was changed to the compound A-25 of the present invention.

[0102] Application Example 1-24 and Comparative Example 1-3 have the same brightness (1000cd / m 2 ), the test results under the same external environment temperature (22.0℃) and the same humidity (35.0%) are shown in Table 3.

[0103] Table 3 Test results

[0104] According to the data comparison in Table 3, when the compounds obtained in the present invention (Application Examples A-1 to A-24) are used in the electron transport layer, their current efficiency is significantly improved; when they are used in the light-emitting layer, their service life is significantly improved; when they are used in the electron transport layer and the light layer at the same time, their current efficiency and service life are significantly improved. The electroluminescent device using this material has significantly improved thermal stability, service life and luminous efficiency, and its color purity is purer, which has great potential for commercial promotion and application.

[0105] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0106] For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, all of which belong to the protection scope of the present invention. The protection scope of the present invention shall be based on the attached claims.

Claims

1. A carbazole imidazole material, characterized in that: The structure of the polycarbazole imidazole material is shown in the following formula [I]: Formula [I]; The R is any one of 2-phenyl-4-phenyl-d5-quinazolinyl, 9-phenyl-d5-phenanthroline, 2,3-diphenylquinoxalinyl, 2,4,6-triphenyl-1,3,5-triazine, 6'-(pyridin-2-yl)-2,2':4',2''-tetrapyridyl, 2,4,6-triphenylpyrimidinyl, 1,2-diphenyl-1H-benzo[d]imidazolyl, and 2,7-diphenylbenzoxazolyl.

2. The carbazole imidazole material according to claim 1, characterized in that: The R is any one of the following structural formulas: 。 3. The carbazole imidazole material according to claim 1, characterized in that: The structural formula of the carbazole imidazole material is any one of the following structural formulas: 。 4. A method for preparing a carbazole imidazole material according to any one of claims 1 to 3, characterized in that: The preparation method is: ； S1. Under the protection of inert gas, 2-bromo-4-chlorophenylhydrazine hydrochloride, 4-tert-butylcyclohexanone and glacial acetic acid are added to the reactor, the temperature is raised with stirring, and the temperature is kept for reaction. After the reaction is completed, compound A is obtained by post-treatment; S2, under the protection of inert gas, adding compound A, manganese dioxide and solvent into the reactor, stirring and keeping warm for reaction, and after the reaction is completed, post-treatment is performed to obtain compound B; Add 3-fluorobenzene-1,2-diamine, 4-pyridinecarboxaldehyde and a solvent into another reactor, heat, pass air into the system, and keep the temperature to react. After the reaction is completed, post-treatment is performed to obtain compound C; S3, under the protection of inert gas, adding compound B, compound C, cesium carbonate and solvent into the reactor, heating and keeping warm for reaction, after the reaction is completed, obtaining compound D through post-treatment; S4, under the protection of inert gas, adding compound D, potassium carbonate, cuprous iodide, 1,10-phenanthroline and solvent into the reactor, heating and keeping warm for reaction, after the reaction is completed, post-treatment is performed to obtain compound E; S5. Under the protection of inert gas, compound E, potassium carbonate, tetrahydrofuran and water are added to the reactor, palladium acetate and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl are added under stirring, and after heating, a tetrahydrofuran solution of o-nitrophenylboric acid is added. After the addition is completed, the mixture is kept warm for reaction. After the reaction is completed, compound F is obtained by post-treatment. S6. Under the protection of inert gas, compound F, triphenylphosphine and solvent are added into the reactor, and the mixture is heated and kept warm for reaction. After the reaction is completed, compound G is obtained by post-treatment; S7. Under the protection of inert gas, compound G reacts with XR under alkaline conditions. After the reaction, post-treatment is performed to obtain the polycarbazole imidazole material, wherein X is any one of Cl, Br, I, and F, and R is the group defined in claim 1.

5. The method for preparing a carbazole imidazole material according to claim 4, characterized in that: In step S1, the reaction temperature is kept at 90-95°C; In step S2, the temperature of the heat preservation reaction is 20-30°C when preparing compound B, and the temperature of the heat preservation reaction is 80-85°C when preparing compound C; In step S3, the reaction temperature is kept at 100-110°C; In step S4, the preparation compound is kept at a reaction temperature of 140-145°C; In step S5, the preparation compound is kept at a reaction temperature of 60-65°C; In step S6, the preparation compound is kept at a reaction temperature of 175-180°C.

6. An application of a carbazole imidazole material according to any one of claims 1 to 3, characterized in that: The carbazole imidazole material is applied in organic electroluminescent devices.

7. The use of a carbazole imidazole material according to claim 6, characterized in that: The carbazole imidazole material is used in the electron transport layer and / or the light emitting layer of an organic electroluminescent device.

8. The use of a carbazole imidazole material according to claim 6, characterized in that: The carbazole imidazole material is used as an electron transport material in an electron transport layer of an organic electroluminescent device.

9. The use of a carbazole imidazole material according to claim 6, characterized in that: The carbazole imidazole material is used as a main luminescent material in a luminescent layer of an organic electroluminescent device.

10. The use of a carbazole imidazole material according to claim 6, characterized in that: The organic electroluminescent device comprises a substrate layer, an anode electrode layer, a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer and a cathode reflective electrode layer.

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