A carbazole-imidazole material, its preparation method and application

Abstract

The present invention relates to the technical field of OLED luminescent materials, and specifically relates to a carbazole-imidazole-based material, a preparation method thereof and an application thereof. The structure of the carbazole-imidazole-based material is shown in the following formula [I]:; R is any one of 2-phenyl-4-phenyl-d5-quinazolinyl, 9-phenyl-d5-phenanthrolinyl, 2,3-diphenylquinoxalinyl, 2,4,6-triphenyl-1,3,5-triazinyl, 6'-(pyridin-2-yl)-2,2':4',2''-terpyridinyl, 2,4,6-triphenylpyrimidinyl, 1,2-diphenyl-1H-benzo[d]imidazolyl, 2,7-diphenylbenzoxazolyl. The carbazole-imidazole-based material is used in the electron transport layer and / or the light-emitting layer of an OLED device, and can significantly improve the luminous efficiency and service life of the device.

Description

Technical Field

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

[0002] An organic light-emitting diode (OLED) is a light-emitting device based on organic materials. In recent years, due to the breakthroughs in OLED technology, this technology has been widely applied in the fields of display technology and lighting. Because of its characteristics of being light, thin, fast-responsive, transparently displayable, and flexible and foldable, OLED is the most popular organic optoelectronic material at present. The OLED panel not only has a huge market demand at the present stage, but also has great market prospects in the future for some time, and the demand will increase significantly globally.

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

[0004] In view of the problems existing in current OLED materials, the present invention provides a carbazole-imidazole material, a preparation method and an application thereof. The carbazole-imidazole material is used in the electron transport layer and / or the light-emitting layer of an OLED device, and can significantly improve the luminous efficiency and service life of the device.

[0005] The technical solution for the present invention to solve the above technical problems is as follows: A carbazole-imidazole material, the structure of the carbazole-imidazole material is shown in the following formula [I]:

[0006] Formula [I];

[0007] The R is any one of 2-phenyl-4-phenyl-d5-quinazolinyl, 9-phenyl-d5-phenanthrolinyl, 2,3-diphenylquinoxalinyl, 2,4,6-triphenyl-1,3,5-triazinyl, 6'-(pyridin-2-yl)-2,2':4',2''-terpyridinyl, 2,4,6-triphenylpyrimidinyl, 1,2-diphenyl-1H-benzo[d]imidazolyl, 2,7-diphenylbenzoxazolyl.

[0008] Further, R is any one of the following structural formulas:

[0009] .

[0010] Further, the structural formula of the carbazole imidazole material is any one of the following structural formulas:

[0011] .

[0012] The present invention also discloses a preparation method of a carbazole imidazole material, and the preparation method is as follows:

[0013] ;

[0014] S1. Under the protection of inert gas, add 2-bromo-4-chlorophenylhydrazine hydrochloride, 4-tert-butylcyclohexanone and glacial acetic acid to the reactor, stir and heat up, keep the temperature for reaction, and after the reaction is completed, obtain compound A through post-treatment;

[0015] S2. Under the protection of inert gas, add compound A, manganese dioxide and a solvent to the reactor, stir and keep the temperature for reaction, and after the reaction is completed, obtain compound B through post-treatment;

[0016] Add 3-fluorobenzene-1,2-diamine, 4-pyridinecarboxaldehyde and a solvent to another reactor, heat, introduce air into the system, keep the temperature for reaction, and after the reaction is completed, obtain compound C through post-treatment;

[0017] S3. Under the protection of inert gas, add compound B, compound C, cesium carbonate and a solvent to the reactor, heat and keep the temperature for reaction, and after the reaction is completed, obtain compound D through post-treatment;

[0018] S4. Under the protection of inert gas, add compound D, potassium carbonate, copper iodide, 1,10-phenanthroline and a solvent to the reactor, heat and keep the temperature for reaction, and after the reaction is completed, obtain compound E through post-treatment;

[0019] S5. Under the protection of inert gas, add compound E, potassium carbonate, tetrahydrofuran and water to the reactor, add palladium acetate and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl under stirring, heat, then add a tetrahydrofuran solution of o-nitrophenylboronic acid, and after adding, keep the temperature for reaction, and after the reaction is completed, obtain compound F through post-treatment;

[0020] S6. Under the protection of inert gas, add compound F, triphenylphosphine and a solvent to the reactor, heat and keep the temperature for reaction, and after the reaction is completed, obtain compound G through post-treatment;

[0021] Under the protection of inert gas, compound G reacts with X-R under alkaline conditions. After the reaction is completed, the carbazole imidazole-based material is obtained through post-treatment, where X is any one of Cl, Br, I, and F.

[0022] Furthermore, in step S1, the temperature for the heat preservation reaction is 90 - 95 °C;

[0023] In step S2, the temperature for the heat preservation reaction when preparing compound B is 20 - 30 °C, and the temperature for the heat preservation reaction when preparing compound C is 80 - 85 °C;

[0024] In step S3, the temperature for the heat preservation reaction is 100 - 110 °C;

[0025] In step S4, the temperature for the heat preservation reaction when preparing the compound is 140 - 145 °C;

[0026] In step S5, the temperature for the heat preservation reaction when preparing the compound is 60 - 65 °C;

[0027] In step S6, the temperature for the heat preservation reaction when preparing the compound is 175 - 180 °C.

[0028] Even further, in step S2, the solvent used when preparing compound B is toluene, and the solvent used when preparing compound C is DMF;

[0029] In steps S3 and S4, the solvent used is DMF;

[0030] In step S6, the solvent used is ODB.

[0031] The present invention also discloses an application of the carbazole imidazole-based material, and the carbazole imidazole-based material is applied to an organic electroluminescent device.

[0032] Furthermore, the carbazole imidazole-based material is applied to the electron transport layer and / or the light-emitting layer of the organic electroluminescent device.

[0033] Further, the carbazole imidazole-based material is applied as an electron transport material to the electron transport layer of the organic electroluminescent device.

[0034] Further, the carbazole imidazole-based material is applied as a host light-emitting material to the light-emitting layer of the organic electroluminescent device.

[0035] The carbazole imidazole-based material is applied as an electron transport layer material and / or a host light-emitting material to the organic electroluminescent device. The prepared organic electroluminescent device can improve the light-emitting performance of the light-emitting device; the light-emitting performance can be current efficiency, driving voltage magnitude, and the light-emitting lifetime of the device, etc.

[0036] 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.

[0037] The beneficial effects of the present invention are as follows:

[0038] For the carbazole-imidazole-based material of the present invention, by introducing N-containing groups such as imidazole and pyridine into the parent structure, the local electron cloud density is enhanced, and the n-type conductivity of the material is enhanced, thereby effectively improving the electron transport efficiency and deepening the HOME energy level; in addition, the introduction of tert-butyl groups gives the whole molecule a unique non-planar conformation, which not only endows the material with good rigidity and stability during film formation, but also increases the glass transition temperature of the material, thus significantly improving the thermal stability of the material and greatly increasing the service life of the device; the introduction of the carbazole structure utilizes the interaction between the SP 3 hybridization and SP 2 hybridization of N atoms to weaken the conjugation effect of the whole molecule, thereby increasing the triplet energy level of the molecule and realizing the idealization of the material energy level.

[0039] The organic light-emitting device made of the carbazole-imidazole-based material of the present invention has high luminous efficiency, good thermal stability and a long service life. It is an electroluminescent material with excellent comprehensive performance and has good application prospects in the rapidly developing OLED industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic structural diagram of the organic electroluminescent device described in the application example;

[0041] In the figure, 1 is a transparent substrate layer; 2 is a transparent anode electrode layer; 3 is a hole injection layer; 4 is a hole transport layer; 5 is an electron blocking layer; 6 is a light-emitting layer; 7 is a hole blocking layer; 8 is an electron transport layer; 9 is an electron injection layer; 10 is a cathode reflective electrode layer. DETAILED DESCRIPTION OF THE INVENTION

[0042] The following is a detailed description of the specific embodiments of the present invention. The present invention can be implemented in many other ways different from those described herein. Those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used are only for describing specific embodiments and do not limit the present invention.

[0044] I. Preparation Example

[0045] Prepare the common intermediate compound G, and the specific synthesis method is as follows:

[0046] ;

[0047] The preparation of compound G includes the following steps:

[0048] (1) Under the protection of inert gas, add 2-bromo-4-chlorophenylhydrazine hydrochloride, 4-tert-butylcyclohexanone and glacial acetic acid into a three-necked flask in sequence. The reaction material ratio is 2-bromo-4-chlorophenylhydrazine hydrochloride: 4-tert-butylcyclohexanone = 1.0eq: 1.2eq. After adding the materials, start stirring and heat up to 90-95 °C, keep the temperature for 10 h until the reaction is complete. After post-treatment by hydrolysis, extraction, washing with water, column chromatography, desolvation and recrystallization, a white solid compound A is obtained. The total yield is 72.7%, GC≥98%, the theoretical value of GC-MS is 342.70, and the measured value is 342.80.

[0049] The NMR data of compound A are as follows:

[0050] 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).

[0051] 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).

[0052] (2)Under the protection of inert gas, compound A, manganese dioxide and toluene were successively added into a three-necked flask. The reaction material ratio was compound A: manganese dioxide = 1.0 eq: 8.0 eq. After the addition, stirring was started, and the temperature was raised to 20 - 30 °C and kept warm for 20 h. After the reaction was complete, the post-treatment was carried out by hydrolysis, extraction, washing with water, column chromatography, solvent removal, and recrystallization to obtain a off-white solid compound B. 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.

[0053] The NMR data of compound B are as follows:

[0054] 1 H 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).

[0055] 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).

[0056] (3)3-Fluorobenzene-1,2-diamine, 4-pyridinecarboxaldehyde and DMF were successively added into a three-necked flask. The reaction material ratio was 3-fluoro-1,2-diamine: 4-pyridinecarboxaldehyde = 1.0 eq: 1.0 eq. After the addition, the temperature was raised to 80 - 85 °C, and air was introduced into the system. The mixture was kept warm for 20 h. After the reaction was complete, the post-treatment was carried out by extraction, washing with water, column chromatography, solvent removal, and recrystallization to obtain a off-white solid compound C. The total yield was 85.5%, and the GC was ≥99.5%. The theoretical value of GC-MS was 213.21, and the measured value was 213.32.

[0057] The NMR data of compound C are as follows:

[0058] 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).

[0059] 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).

[0060] (4)Under inert gas protection, compound B, compound C, potassium carbonate and DMF were successively added into a three-necked flask, and the reaction material ratio was compound B: compound C and cesium carbonate = 1.0 eq: 1.0 eq: 3.0 eq. After the addition was completed, the temperature was raised to 105.0 °C and the reaction was kept at this temperature for 5.0 h. After the reaction was qualified, through extraction, washing with water, column chromatography, solvent removal, and recrystallization, light yellow solid compound D was obtained with an overall yield of 80.2% and HPLC: ≥99.0%. The theoretical value of HPLC-MS: 529.86, the measured value: 530.56.

[0061] The NMR data of compound D are as follows:

[0062] 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).

[0063] 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).

[0064] Under the protection of inert gas, compound D, potassium carbonate, copper(I) iodide, 1,10-phenanthroline and DMF were successively added into a three-necked flask. The reaction material ratio was compound D: potassium carbonate: copper(I) iodide: 1,10-phenanthroline = 1.0 eq: 3.0 eq: 0.1 eq: 0.2 eq. After the addition was completed, the temperature was raised to 140 - 145 °C and kept warm for 20 h until the reaction was complete. The post-treatment involved hydrolysis, extraction, washing with water, column chromatography, and recrystallization to obtain a light yellow solid compound E. The total yield was 84.0%, and HPLC ≥ 99.5%. The theoretical value of HPLC-MS was 448.95, and the measured value was 449.86.

[0065] The NMR data of compound E are as follows:

[0066] 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).

[0067] 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).

[0068] Under the protection of inert gas, compound E, potassium carbonate, toluene, purified water, palladium acetate, and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl were successively added into a three-necked flask. After the addition was completed, stirring was started, and the temperature was raised to 60 - 65 °C. A tetrahydrofuran solution of o-nitrophenylboronic acid was added dropwise thereto. After the addition was completed, the mixture was kept at 60 - 65 °C for 10 h to complete the reaction. The reaction material ratio was compound E: potassium carbonate: palladium acetate: 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl: o-nitrophenylboronic acid = 1.0 eq: 3.0 eq: 0.01 eq: 0.02 eq: 1.2 eq. The post-treatment was carried out by washing with water, column chromatography, and recrystallization to obtain a light yellow solid compound F. The total yield was 73.2%, and HPLC ≥ 99.5%. The theoretical value of HPLC-MS was 535.59, and the measured value was 536.36.

[0069] The NMR data of compound F are as follows:

[0070] 1 H 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).

[0071] 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(1C),129.91(1C),129.74(1C),129.45(1C),129.32(1C),129.09(1C),125.91(1C),125.42(1C),124.11(1C),123.69(1C),122.62(1C),121.96(1C),121.59(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).

[0072] Under the protection of inert gas, compound F, triphenylphosphine and ODB were successively added into a three-necked flask. After the addition, stirring was started, and the temperature was raised to 175 - 180 °C and kept warm for 20 h until the reaction was complete. The reaction material ratio was compound F:triphenylphosphine = 1.0 eq:3.0 eq. After treatment by washing with water, column chromatography and recrystallization, a light yellow solid compound G was obtained. The total yield was 66.3%, and HPLC ≥ 99.9%. The theoretical value of HPLC-MS was 503.60, and the measured value was 504.32.

[0073] The NMR data of compound G are as follows:

[0074] 1 H 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).

[0075] 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).

[0076] Example 1

[0077] Synthesis of compound A-1:

[0078] ;

[0079] Under the protection of inert gas, 50.3 g (0.1 mol) of compound G, 36.6 g (0.1 mol) of 2-(3-bromophenyl)-4-(phenyl-2,3,4,5,6-d5) quinazoline, 19.2 g (0.2 mol) of sodium tert-butoxide, 0.915 g (1.0 mmol) of tris(dibenzylideneacetone) dipalladium, and 0.952 g (2.0 mmol) of 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl were successively weighed in a 2 L three-necked flask. Then, 1006.0 g of xylene was added, and the temperature was raised to 125.0 °C. After holding the temperature for 10 h, the reaction was qualified, HPLC: 94.2%. After washing with water, column chromatography, and solvent removal, recrystallization from toluene gave 66.3 g of light yellow solid compound A-1, with an overall yield of 84.0% and HPLC: 99.9%. The theoretical value of HPLC-MS was 788.95, and the measured value was 789.35.

[0080] The NMR data of compound A-1 are as follows:

[0081] 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).

[0082] 1313C 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).

[0083] Example 2

[0084] Synthesis of Compound A-5:

[0085] ;

[0086] Under the protection of inert gas, 50.3 g (0.1 mol) of compound G, 34.0 g (0.1 mol) of 2-bromo-9-(phenyl-2,3,4,5,6-d5)-1,10-phenanthroline, 19.2 g (0.2 mol) of sodium tert-butoxide, 0.915 g (1.0 mmol) of tris(dibenzylideneacetone)dipalladium, and 0.952 g (2.0 mmol) of 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl were successively weighed into a 2 L three-necked flask. Then 1006.0 g of xylene was added, and the temperature was raised to 125.0 °C. After holding the temperature for reaction for 10 h, the reaction was qualified, HPLC: 93.1%. After washing with water, column chromatography, and solvent removal, recrystallization from toluene gave 62.6 g of a light yellow solid compound A-5, with an overall yield of 82.1% and HPLC: 99.9%. The theoretical value of HPLC-MS: 762.91, the measured value: 763.31.

[0087] The NMR data of compound A-5 are as follows:

[0088] 1 1H-NMR (500 MHz, 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).

[0089] 1313C 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).

[0090] Example 3

[0091] Synthesis of Compound A-9:

[0092] ;

[0093] Under the protection of inert gas, 50.3 g (0.1 mol) of Compound G, 36.1 g (0.1 mol) of 5-bromo-2,3-diphenylquinoxaline, 19.2 g (0.2 mol) of sodium tert-butoxide, 0.915 g (1.0 mmol) of tris(dibenzylideneacetone)dipalladium, and 0.952 g (2.0 mmol) of 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl were successively weighed into a 2 L three-necked flask. Then 1006.0 g of xylene was added, and the temperature was raised to 125.0 °C and kept for 10 h. The reaction was qualified by HPLC: 97.2%. After washing with water, column chromatography, and solvent removal, recrystallization from toluene gave 68.5 g of a light yellow solid compound A-9 with an overall yield of 87.4% and HPLC: 99.9%. The theoretical value of HPLC-MS was 783.92, and the measured value was: 784.56.

[0094] The NMR data of Compound A-9 are as follows:

[0095] 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).

[0096] 13 C 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).

[0097] Example 4

[0098] Synthesis of Compound A-14:

[0099] ;

[0100] Under the protection of inert gas, 50.3 g (0.1 mol) of Compound G, 32.7 g (0.1 mol) of 2-(3-fluorophenyl)-4,6-diphenyl-1,3,5-triazine, and 97.5 g (0.3 mol) of cesium carbonate were successively weighed into a 2 L three-necked flask. Then, 754.5 g of N,N-dimethylformamide (DMF) was added. The mixture was stirred and heated to 125.0 °C and kept at this temperature for 20.0 h until the reaction was qualified (HPLC: 96.3%). After extraction, washing with water, column chromatography, and recrystallization from o-dichlorobenzene, 73.2 g of a white solid Compound A-14 was obtained, with an overall yield of 90.3% and HPLC purity of 99.9%. The theoretical value of HPLC-MS was 810.94, and the measured value was 811.86.

[0101] The NMR data of Compound A-14 are as follows:

[0102] 1 H 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).

[0103] 1313C 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).

[0104] Example 5

[0105] Synthesis of Compound A-17:

[0106] ;

[0107] Under the protection of inert gas, 50.3 g (0.1 mol) of Compound G, 38.9 g (0.1 mol) of 6''-bromo-6'-(pyridin-2-yl)-2,2':4',2''-terpyridine, 19.2 g (0.2 mol) of sodium tert-butoxide, 0.915 g (1.0 mmol) of tris(dibenzylideneacetone) dipalladium, and 0.952 g (2.0 mmol) of 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl were successively weighed in a 2 L three-necked flask. Then 1006.0 g of xylene was added, and the temperature was raised to 130.0 °C and kept for reaction for 10 h. The reaction was qualified, HPLC: 95.2%. After washing with water, column chromatography, and solvent removal, recrystallization from toluene gave 73.1 g of a light yellow solid Compound A-17, with an overall yield of 90.0%, HPLC: 99.9%. The theoretical value of HPLC-MS was 811.93, and the measured value was 812.69.

[0108] The NMR data of Compound A-17 are as follows:

[0109] 1 1H 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).

[0110] 13 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).

[0111] Example 6

[0112] Synthesis of Compound A-20:

[0113] ;

[0114] Under the protection of inert gas, 50.3 g (0.1 mol) of compound G, 43.4 g (0.1 mol) of 2-(3-iodophenyl)-4,6-diphenylpyrimidine, 19.2 g (0.2 mol) of sodium tert-butoxide, 0.915 g (1.0 mmol) of tris(dibenzylideneacetone)dipalladium, and 0.952 g (2.0 mmol) of 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl were successively weighed into a 2 L three-necked flask. Then, 1006.0 g of xylene was added, and the temperature was raised to 125.0 °C. After holding the temperature for 5 h, the reaction was qualified, HPLC: 94.2%. After extraction, washing with water, column chromatography, and recrystallization from o-dichlorobenzene, 73.2 g of a white solid compound A-20 was obtained, with an overall yield of 90.4% and HPLC: 99.9%. The theoretical value of HPLC-MS was 809.96, and the measured value was 810.86.

[0115] The NMR data of compound A-20 are as follows:

[0116] 1 H 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).

[0117] 1313C 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).

[0118] Example 7

[0119] Synthesis of Compound A-24:

[0120] ;

[0121] Under the protection of inert gas, 50.3 g (0.1 mol) of Compound G, 30.5 g (0.1 mol) of 2-(3-iodophenyl)-4,6-diphenylpyrimidine, 19.2 g (0.2 mol) of sodium tert-butoxide, 0.915 g (1.0 mmol) of tris(dibenzylideneacetone)dipalladium, and 0.952 g (2.0 mmol) of 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl were successively weighed into a 2 L three-necked flask. Then 1006.0 g of xylene was added, and the temperature was raised to 130.0 °C. After holding the temperature for 10 h, the reaction was qualified by HPLC: 92.3%. After extraction, washing with water, column chromatography, and recrystallization from o-dichlorobenzene, 61.5 g of a white solid compound A-24 was obtained, with an overall yield of 79.7% and HPLC: 99.9%. The theoretical value of HPLC-MS was 771.91, and the measured value was 772.86.

[0122] The NMR data of Compound A-24 are as follows:

[0123] 1 1H 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).

[0124] 13 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).

[0125] Example 8

[0126] Synthesis of Compound A-25:

[0127] ;

[0128] Under the protection of inert gas, 50.3 g (0.1 mol) of Compound G, 30.6 g (0.1 mol) of 7-(3-chlorophenyl)-2-phenylbenzo[d]oxazole, 19.2 g (0.2 mol) of sodium tert-butoxide, 0.915 g (1.0 mmol) of tris(dibenzylideneacetone)dipalladium, and 0.952 g (2.0 mmol) of 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl were successively weighed in a 2 L three-necked flask. Then, 1006.0 g of xylene was added, and the temperature was raised to 135.0 °C. After maintaining the temperature for 10 h, the reaction was qualified by HPLC: 92.8%. After extraction, washing with water, column chromatography, and recrystallization with o-dichlorobenzene, 68.5 g of a white solid compound A-25 was obtained, with an overall yield of 88.6% and HPLC: 99.9%. The theoretical value of HPLC-MS was 772.89, and the measured value was 773.68.

[0129] The NMR data of Compound A-25 are as follows:

[0130] 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).

[0131] 1313C 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).

[0132] The synthesis methods of other compounds included in the present invention are the same as or similar to the specific implementation cases, and will not be listed one by one. The mass-to-charge ratios of the synthesized compounds are shown in Table 1 below; the main raw materials and some auxiliary materials used for synthesizing the compounds in the specific implementation cases are all known compounds, and the specific information CAS numbers are shown in Table 2.

[0133] Table 1 Mass-to-charge ratios of compounds

[0134]

[0135] Table 2 CAS numbers of related main raw materials and auxiliary materials

[0136]

[0137] II. Preparation and evaluation of organic electroluminescent devices

[0138] Through the following Comparative Example 1 and Application Examples 1 - 24, the application effects of the OLED luminescent materials synthesized by the present invention on devices are described in detail. The specific implementation methods are as follows:

[0139] Comparative Example 1

[0140] The structure of the organic electroluminescent device is as Figure 1 shown. The transparent anode electrode layer 2 (with a film thickness of 208 nm, indium tin oxide) having a transparent substrate layer 1 is processed as follows: First, photolithography and etching are performed to form the required regular transparent anode electrode layer 2. Immediately afterwards, the glass transparent substrate layer 1 is washed, that is, alkali washing, deionized water washing, acetone ultrasonic cleaning, ethanol ultrasonic cleaning, ultrapure water cleaning, and drying are carried out in sequence, and then ultraviolet-ozone washing is performed on the transparent anode electrode layer 2 to ensure the removal of organic residues on the surface of the transparent anode electrode layer 2. After the above treatment, a hole injection layer 3 is evaporated on the transparent anode electrode layer 2. Using a vacuum evaporation device, a material of Structural Formula I (α-NPB) is evaporated (evaporation conditions: using a molybdenum crucible, evaporation rate 0.1 nm / s, vacuum degree 4.0×10 -5 Pa), and its film thickness is 56 nm. This organic material is used as the hole injection layer 3. Immediately after the hole injection layer 3, a material of Structural Formula II (CCP) with a thickness of 23 nm is evaporated as the hole transport layer 4. Immediately after the hole transport layer 4, a material of Structural Formula III (TAPC) with a thickness of 21 nm is evaporated as the electron blocking layer 5.

[0141] After the evaporation of the electron blocking layer 5 is completed, a material of Structural Formula IV (MNBPA) and [2-(4,6-difluorophenyl)pyridine-C2,N](pyridine)iridium (Firpic) are mixed in a doping weight ratio of 95:5 and then evaporated onto the electron blocking layer 5 (evaporation conditions: using a molybdenum crucible, evaporation rate 0.1 nm / s, vacuum degree 4.0×10 -5 Pa) to obtain the light-emitting layer 6, and the film thickness of the light-emitting layer 6 is 32 nm.

[0142] The preparation of the hole blocking layer 7 is carried out after the light-emitting layer 6. The material of the hole blocking layer 7 (the material shown in Structural Formula V (TmPyPB)) is continuously vacuum-evaporated onto the light-emitting layer 6 (evaporation conditions: using a molybdenum crucible, evaporation rate 0.1 nm / s, vacuum degree 4.0*10-5Pa), and the vacuum evaporation film thickness of this material is 21 nm. After the evaporation is completed, immediately a material shown in Structural Formula VI (DPyPA) is evaporated to obtain the electron transport layer 8, and the evaporation film thickness is 78 nm. The electron injection layer 9 is a 0.8-nm-thick lithium fluoride (LiF) layer fabricated on the electron transport layer 8 through a vacuum evaporation device as the electron injection layer 9.

[0143] A cathode reflective electrode layer 10 is formed on the electron injection layer 9 by vacuum evaporation. The cathode reflective electrode layer 10 is an aluminum (Al) layer with a film thickness of 148 nm.

[0144] The structural formulas of the raw materials involved in the preparation process of the organic electroluminescent device are as follows:

[0145] .

[0146] After completing the organic OLED electroluminescent device as described above, the anode and the cathode are connected by a known driving circuit, and then the current-voltage performance, luminous efficiency, and device emission spectrum of the device are measured.

[0147] Comparative Example 2

[0148] An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that: the electron transport material (structural formula six) used in the electron transport layer 8 of the organic electroluminescent device was changed to structural formula four.

[0149] Comparative Example 3

[0150] An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that: the main luminescent material (structural formula four) used in the light-emitting layer 6 of the organic electroluminescent device was changed to structural formula six.

[0151] Application Example 1

[0152] An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that: the electron transport material (structural formula six) used in the electron transport layer 8 of the organic electroluminescent device was changed to the compound A-1 of the present invention.

[0153] Application Example 2

[0154] An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that: the main luminescent material (structural formula four) used in the light-emitting layer 6 of the organic electroluminescent device was changed to the compound A-1 of the present invention.

[0155] Application Example 3

[0156] An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that: the electron transport material (structural formula six) used in the electron transport layer 8 and the main luminescent material (structural formula four) used in the light-emitting layer 6 of the organic electroluminescent device were changed to the compound A-1 of the present invention.

[0157] Application Example 4

[0158] An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that: the electron transport material (structural formula six) used in the electron transport layer 8 of the organic electroluminescent device was changed to the compound A-5 of the present invention.

[0159] Application Example 5

[0160] An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the host luminescent material (structural formula IV) used in the luminescent layer 6 of the organic electroluminescent device was changed to Compound A-5 of the present invention.

[0161] Application Example 6

[0162] 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 and the host luminescent material (structural formula IV) used in the luminescent layer 6 were changed to Compound A-5 of the present invention.

[0163] Application Example 7

[0164] 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 Compound A-9 of the present invention.

[0165] Application Example 8

[0166] An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the host luminescent material (structural formula IV) used in the luminescent layer 6 of the organic electroluminescent device was changed to Compound A-9 of the present invention.

[0167] Application Example 9

[0168] 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 and the host luminescent material (structural formula IV) used in the luminescent layer 6 were changed to Compound A-9 of the present invention.

[0169] Application Example 10

[0170] 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 Compound A-14 of the present invention.

[0171] Application Example 11

[0172] An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the host luminescent material (structural formula IV) used in the luminescent layer 6 of the organic electroluminescent device was changed to Compound A-14 of the present invention.

[0173] Application Example 12

[0174] 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 and the host luminescent material (Structural Formula IV) used in the luminescent layer 6 of the organic electroluminescent device were changed to Compound A-14 of the present invention.

[0175] Application Example 13

[0176] 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 Compound A-17 of the present invention.

[0177] Application Example 14

[0178] An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the host luminescent material (Structural Formula IV) used in the luminescent layer 6 of the organic electroluminescent device was changed to Compound A-17 of the present invention.

[0179] Application Example 15

[0180] 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 and the host luminescent material (Structural Formula IV) used in the luminescent layer 6 of the organic electroluminescent device were changed to Compound A-17 of the present invention.

[0181] Application Example 16

[0182] 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 Compound A-20 of the present invention.

[0183] Application Example 17

[0184] An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the host luminescent material (Structural Formula IV) used in the luminescent layer 6 of the organic electroluminescent device was changed to Compound A-20 of the present invention.

[0185] Application Example 18

[0186] 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 and the host luminescent material (Structural Formula IV) used in the luminescent layer 6 of the organic electroluminescent device were changed to Compound A-20 of the present invention.

[0187] Application Example 19

[0188] 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 Compound A-24 of the present invention.

[0189] Application Example 20

[0190] An organic electroluminescent device was prepared by the same method as in Comparative Example 1, except that the host luminescent material (Structural Formula IV) used in the luminescent layer 6 of the organic electroluminescent device was changed to Compound A-24 of the present invention.

[0191] Application Example 21

[0192] 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 and the host luminescent material (Structural Formula IV) used in the luminescent layer 6 of the organic electroluminescent device were changed to Compound A-24 of the present invention.

[0193] Application Example 22

[0194] 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 Compound A-25 of the present invention.

[0195] Application Example 23

[0196] 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 Compound A-25 of the present invention.

[0197] Application Example 24

[0198] 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 Compound A-25 of the present invention.

[0199] The test results of Application Examples 1-24 and Comparative Examples 1-3 are shown in Table 3 under the conditions of the same brightness (1000 cd / m 2 ), the same temperature (22.0 °C) and the same humidity (35.0%) of the external environment.

[0200] Table 3 Test Results

[0201]

[0202] According to the data comparison in Table 3, when the compounds obtained by the present invention (Application Examples A-1 to A-24) are applied to the electron transport layer, their current efficiency is significantly improved; when they are applied to the light-emitting layer, their service life is significantly increased; when they are simultaneously applied to the electron transport layer and the light layer, both their current efficiency and service life are significantly improved. For the electroluminescent device using this material, its thermal stability, service life, and luminous efficiency are all significantly improved, its color purity is more pure, and it has great potential for commercial promotion and application.

[0203] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, all possible combinations of the technical features in the above-described embodiments are not exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0204] For those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. The protection scope of the present invention shall be subject to the appended claims.

Claims

1. A carbazole imidazole-based material, characterized in that, The structure of the dibenzocarbazole imidazole material is shown as the following formula [I]: Formula [I]; R is any one of the following structural formulas: 。 2. A carbazole-imidazole-based material, characterized in that, The structural formula of the dibenzocarbazole imidazole material is any one of the following structural formulas: 。 3. A preparation method of a carbazole-imidazole-based material according to claim 1, characterized in that, The preparation method is as follows: ； S1. Under the protection of an inert gas, add 2-bromo-4-chlorophenylhydrazine hydrochloride, 4-tert-butylcyclohexanone and glacial acetic acid to a reactor, stir and heat up, keep the temperature for reaction, and after the reaction is completed, obtain compound A through post-treatment; S2. Under the protection of an inert gas, add compound A, manganese dioxide and a solvent to a reactor, stir and keep the temperature for reaction, and after the reaction is completed, obtain compound B through post-treatment; Add 3-fluorobenzene-1,2-diamine, 4-pyridinecarboxaldehyde and a solvent to another reactor, heat, introduce air into the system, keep the temperature for reaction, and after the reaction is completed, obtain compound C through post-treatment; S3. Under the protection of an inert gas, add compound B, compound C, cesium carbonate and a solvent to a reactor, heat and keep the temperature for reaction, and after the reaction is completed, obtain compound D through post-treatment; S4. Under the protection of an inert gas, add compound D, potassium carbonate, copper iodide, 1,10-phenanthroline and a solvent to a reactor, heat and keep the temperature for reaction, and after the reaction is completed, obtain compound E through post-treatment; S5. Under the protection of an inert gas, add compound E, potassium carbonate, tetrahydrofuran and water to a reactor, add palladium acetate and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl under stirring, heat, then add a tetrahydrofuran solution of o-nitrophenylboronic acid, after addition, keep the temperature for reaction, and after the reaction is completed, obtain compound F through post-treatment; S6. Under the protection of an inert gas, add compound F, triphenylphosphine and a solvent to a reactor, heat and keep the temperature for reaction, and after the reaction is completed, obtain compound G through post-treatment; S7. Under the protection of an inert gas, react compound G with X-R under alkaline conditions, and after the reaction is completed, obtain the dibenzocarbazole imidazole material through post-treatment, where X is any one of Cl, Br, I, F, and R is the group defined in claim 1.

4. The preparation method of a carbazole imidazole-based material according to claim 3, characterized in that, In step S1, the temperature for the reaction with temperature maintained is 90 - 95 °C; In step S2, the temperature for the reaction with temperature maintained for preparing compound B is 20 - 30 °C, and the temperature for the reaction with temperature maintained for preparing compound C is 80 - 85 °C; In step S3, the temperature for the reaction with temperature maintained is 100 - 110 °C; In step S4, the temperature for the reaction with temperature maintained for preparing the compound is 140 - 145 °C; In step S5, the temperature for the reaction with temperature maintained for preparing the compound is 60 - 65 °C; In step S6, the temperature for the reaction with temperature maintained for preparing the compound is 175 - 180 °C.

5. Use of a carbazole imidazole material according to any one of claims 1-2, characterized in that The dibenzocarbazole imidazole material is applied to the electron transport layer and / or the light-emitting layer of an organic electroluminescent device.

6. The application of a carbazole imidazole material according to claim 5, characterized in that, The dibenzocarbazole imidazole material is applied to the electron transport layer of an organic electroluminescent device as an electron transport material.

7. The application of a carbazole imidazole material according to claim 5, characterized in that The dibenzocarbazole imidazole material is applied to the light-emitting layer of an organic electroluminescent device as a host light-emitting material.

8. The application of a carbazole imidazole material according to claim 5, wherein 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.

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