Dendritic luminescent material based on space charge transfer, preparation method and application

Abstract

The invention relates to a dendritic luminescent material based on space charge transfer, and a preparation method and application thereof, and belongs to the technical field of organic luminescent materials. The technical problem that an organic electroluminescent device based on an existing dendritic fluorescent material is low in efficiency is solved. The invention designs a dendritic luminescent material based on space charge transfer, an anthrone structure is adopted as a space limiting unit, and a dendritic electron donor unit and a cyanophenyl electron acceptor unit are introduced to the 1, 9-position of the anthrone structure, so that the space charge transfer dendritic luminescent material is obtained. As the electron donor and the electron acceptor are spatially separated, the thermally activated delayed fluorescence material has a very low singlet-triplet energy level difference, further shows a significant thermally activated delayed fluorescence effect, can realize effective utilization of triplet excitons when being used as a luminescent material of a solution processing type organic electroluminescent device, and thus has high device luminescent efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic light-emitting materials, and particularly relates to a dendritic light-emitting material based on space charge transfer, a preparation method and an application thereof. Background Art

[0002] Organic light-emitting devices (OLEDs) have received extensive attention in the academic and industrial fields due to their advantages such as self-luminescence, low energy consumption, and the ability to fabricate flexible devices, and are expected to become a new generation of flat panel display and lighting technologies. Generally speaking, the structure of an OLED device is usually composed of a cathode, an anode, and an organic layer inserted between the cathode and the anode. That is, the device is composed of a transparent ITO anode, a hole injection layer (HIL), a hole transport layer (HTL), a light-emitting layer (EL), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection layer (EIL), and a cathode. One or two organic layers can be omitted as needed. Excitons are formed by the combination of holes (Hole) and electrons (Electron) injected from the positive electrode and the negative electrode on the organic thin film. When the excitons return from the excited state to the stable ground state, energy is released to achieve luminescence. The main processing techniques of OLEDs are vacuum evaporation and solution processing. Compared with vacuum-evaporated OLEDs, solution-processed OLEDs can be fabricated by wet processes such as inkjet printing, without the need for a vacuum condition, and have high material utilization rate, which is one of the mainstream directions for the development of low-cost and large-area display and lighting devices.

[0003] The OLED light-emitting materials used for solution processing mainly include two categories: polymer light-emitting materials and dendritic light-emitting materials. Among them, polymer light-emitting materials have excellent solution processing properties, but have disadvantages such as difficult purification and poor batch stability. Compared with polymer light-emitting materials, dendritic light-emitting materials have a clear chemical structure, and their molecular size and topological structure can be precisely controlled during synthesis. At the same time, dendritic light-emitting materials also have good film-forming properties and solution processing properties, and can obtain light-emitting materials with different emission wavelengths by selecting different central cores, different dendritic building units, and different peripheral modification groups. Therefore, it is one of the very promising OLED material systems.

[0004] Currently, dendritic fluorescent materials mainly focus on fluorescent materials based on the principle of chemical bond charge transfer luminescence, that is, by directly connecting an electron donor (D) and an electron acceptor (A) using a conjugated unit, and by regulating the charge transfer intensity between the electron donor and the electron acceptor, the adjustment of its emission color and the improvement of the emission efficiency are achieved. However, the problem with this type of material is that it is difficult to utilize triplet excitons through thermally activated delayed fluorescence effect, resulting in low device efficiency.

[0005] Therefore, how to find a more suitable material to solve the above-mentioned defects of dendritic fluorescent polymers in terms of material design and device performance has become one of the urgent problems to be solved by many forward-looking researchers in the field. Summary of the Invention

[0006] The present invention aims to solve the problem of low device efficiency of dendritic fluorescent polymer materials based on the principle of charge transfer luminescence through chemical bonds, and provides a dendritic fluorescent polymer compound based on spatial charge transfer, a preparation method and an application thereof. The dendritic fluorescent material with spatial charge transfer effect of the present invention has a very low singlet-triplet energy level difference, exhibits a significant thermally activated delayed fluorescence effect, can effectively utilize triplet excitons, and thus has a high device luminescence efficiency.

[0007] In order to solve the above technical problems, the technical solution of the present invention is specifically as follows:

[0008] A dendritic luminescent material based on spatial charge transfer, the structure of which is shown in formula (I):

[0009]

[0010] X and Z are independently selected from: C(R 1 R 2 ), O, S or Se; m is 0 or 1; n is 1 or 2.

[0011] p is the number of cyano groups, selected from integers from 1 to 5, specifically 1, 2, 3, 4, 5.

[0012] R, R 1 and R 2 are respectively independently selected from -H, -D, -F, substituted or unsubstituted C1-C 20 hydrocarbon groups, substituted or unsubstituted C1-C 20 haloalkane groups, substituted or unsubstituted C3-C 20 cycloalkyl groups, substituted or unsubstituted C6-C 20 aryl groups and substituted or unsubstituted C2-C 20 heteroaryl groups.

[0013] In the above technical solution, preferably, the is selected from any one of the structures shown in formula (1) to formula (2)

[0014]

[0015] In the above technical solution, preferably, the dendritic compound based on spatial charge transfer has any one of the structures shown in formula I-1 to formula I-20:

[0016]

[0017]

[0018] The present invention provides a method for preparing a dendritic fluorescent polymer compound as described in any one of the above technical solutions, comprising the following steps:

[0019] 1) Under a protective atmosphere, X-1 and o-fluorobromobenzene are subjected to a nucleophilic substitution reaction to obtain an intermediate X-2;

[0020] 2) Under a protective atmosphere, the intermediate X-2 obtained in the above step and an anthrone compound X-3 containing a benzonitrile acceptor are successively subjected to a nucleophilic addition reaction and a dehydration cyclization reaction to obtain a dendritic fluorescent polymer compound having a specific structure of formula (I).

[0021]

[0022] Preferably, the temperature of the nucleophilic substitution reaction is 100-180 °C;

[0023] The time of the nucleophilic substitution reaction is 16-48 h;

[0024] The temperature of the nucleophilic addition reaction is -100-0 °C;

[0025] The time of the nucleophilic addition reaction is 6-18 h;

[0026] The temperature of the dehydration cyclization reaction is -78-25 °C;

[0027] The time of the dehydration cyclization reaction is 1-5 h.

[0028] The present invention also provides an application of a dendritic compound based on space charge transfer, especially in an organic electroluminescent device. The organic thin film layer of the organic electroluminescent device comprises a dendritic fluorescent polymer compound as described in any one of the above technical solutions. Further, the organic thin film layer comprises a light-emitting layer; the light-emitting layer comprises the dendritic compound based on space charge transfer of the present invention.

[0029] The beneficial effects of the present invention are:

[0030] The dendritic compound based on space charge transfer provided by the present invention is as shown in formula (I). Compared with the prior art, the dendritic compound based on space charge transfer adopted by the present invention can utilize triplet excitons through thermally activated delayed fluorescence effect, thereby achieving high luminous efficiency.

[0031] The experimental results show that the dendritic fluorescent polymer compound provided by the present invention has a low singlet-triplet energy level difference, ΔE ST which is only 0.04 - 0.20 eV. Therefore, it has a significant thermally activated delayed fluorescence effect, can effectively utilize triplet excitons, has a high device luminescence efficiency, and can fabricate highly efficient electroluminescent devices. The maximum external quantum efficiency of the electroluminescent device prepared with the space charge transfer dendritic fluorescent material provided by the present invention as the luminescent material can reach 19.8%. Specific Embodiments

[0032] In order to further illustrate the present invention, the dendritic luminescent material based on space charge transfer, preparation method and application provided by the present invention are described in detail below in combination with embodiments. However, it should be understood that these embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given. It is only to further illustrate the features and advantages of the present invention, rather than a limitation on the claims of the present invention. The protection scope of the present invention is not limited to the following embodiments either.

[0033] All reagents used in the following embodiments are commercially available.

[0034] Example 1

[0035] The synthetic route of the compound of Formula I-1 is as follows:

[0036]

[0037] Under argon atmosphere, 1.61 g (1.0 mmol) of tert-butyl carbazole of the third generation, 0.16 g (0.9 mmol) of o-fluorobromobenzene and 0.59 g (1.8 mmol) of cesium carbonate were successively added to a 100 mL reaction flask, and then 10 mL of anhydrous N,N-dimethylformamide was added. The temperature was raised to 150 °C and refluxed with stirring for 24 h. After the reaction was completed, the temperature was lowered to room temperature. The reaction solution was poured into 200 mL of water, filtered, and a white precipitate was obtained and dried. The crude product was purified by column chromatography (eluent: petroleum ether / dichloromethane = 10 / 1, volume ratio), and 1.03 g of the product as a white solid (1-2) was obtained with a yield of 65.0%. Elemental analysis: theoretical values C, 83.15; H, 6.75; N, 5.56; measured values C, 83.11; H, 6.72; N, 5.50. Electrospray ionization mass spectrometry (ESI-MS): theoretical value 1762.9, experimental value 1763.0 (M + +).

[0038] Under argon atmosphere, 1-bromoxanthone (8.50 g, 31.00 mmol), bis(pinacolato)diboron (15.80 g, 62.00 mmol), dichlorobis(1,1'-bis(diphenylphosphino)ferrocene)palladium(II) (1.10 g, 1.60 mmol), potassium acetate (0.91 g, 9.3 mmol), and N,N-dimethylformamide (30 mL) were added to a 250 mL round-bottom flask and stirred at 90 °C in an oil bath for 24 h. After cooling to room temperature, the reaction mixture was poured into a beaker containing 500 mL of water, stirred for 10 min, allowed to settle, filtered, and the resulting solid was dissolved in dichloromethane and dried over anhydrous sodium sulfate. The crude product was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 15 / 1, v / v) to give 8.90 g of a white solid product (1-4) with a yield of 88.8%. Elemental analysis: calculated C, 70.84; H, 5.94; found C, 70.94; H, 6.03. ESI-MS: calculated 322.1, found 322.2 (M + ).

[0039] Under argon atmosphere, intermediate 1-4 (7.00 g, 21.7 mmol), 5-bromoisophthalonitrile (5.50 g, 26.4 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.60 g, 0.3 mmol), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (1.10 g, 1.2 mmol), methyltrioctylammonium chloride (1 mL), and 30 mL of toluene were mixed and stirred. After dissolution, 22 mL of 3 mol / L aqueous potassium carbonate solution was added, and the mixture was vigorously stirred and refluxed at 100 °C in an oil bath for 24 h. After the reaction was completed, the reaction mixture was cooled, diluted with ethanol (50 mL), allowed to settle, and then filtered by suction. The solid was dissolved in dichloromethane, concentrated to a saturated solution, and the precipitated solid was filtered to give 4.60 g of a white solid (1-5) with a yield of 66.0%. Elemental analysis: calculated C, 78.25; H, 3.13; N, 8.69; found C, 78.20; H, 3.09; N, 8.65. ESI-MS: calculated 322.1, found 322.2 (M + ).

[0040] Under argon atmosphere, intermediate 1-2 (0.88 g, 0.5 mmol) was placed in a two-necked flask, dissolved in 100 mL of anhydrous tetrahydrofuran. At -78 °C, n-butyllithium (2.5 M, 0.2 mL, 0.5 mmol) was added dropwise. After stirring at -78 °C for 1 hour, intermediate 1-5 (0.12 g, 0.375 mmol) was added. After stirring overnight, 15 mL of distilled water was added to quench the reaction. Tetrahydrofuran was removed under reduced pressure. The residue was extracted with 40 mL of dichloromethane three times, and then dichloromethane was removed under reduced pressure. The residue was recrystallized from ethanol and filtered by suction. The obtained solid was dried and placed in a 100 mL flask. 40 mL of anhydrous dichloromethane was added. After stirring in an ice-water bath for 10 minutes, 0.1 mL of 1.125 M boron trifluoride diethyl etherate was added and the reaction was carried out for 3 hours. After the reaction was completed, the reaction mixture was allowed to return to room temperature and poured into 200 mL of ice water. The product precipitated and was filtered by suction. The crude product was purified by silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether as the eluent to obtain 0.49 g of compound I-1, with a yield of 66.0%. Elemental analysis: theoretical values C, 86.41; H, 6.44; N, 6.34; measured values C, 86.39; H, 6.38; N, 6.30. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF (m / z)): theoretical value 1987.0, experimental value 1987.1 (M + ).

[0041] Example 2

[0042] The synthetic route of compound I-3 is as follows:

[0043]

[0044]

[0045] Under an inert gas atmosphere, 9-p-toluenesulfonyl-3,6-diiodocarbazole (2.80 g, 5.0 mmol), 2-1 (8.82 g, 11.0 mmol), potassium carbonate (2.00 g, 15.0 mmol), copper(I) iodide (0.20 g, 1.0 mmol), 18-crown-6 (53 mg, 0.2 mmol), and nitrobenzene (50 mL) were added to a three-necked flask, and the reaction was carried out at 170 °C for 48 h. After the reaction was completed, it was cooled to room temperature, dichloromethane was added, and the mixture was stirred for 20 min. It was filtered, and the precipitate was washed with dichloromethane. The obtained mother liquor was first concentrated to remove dichloromethane on a rotary evaporator, and then nitrobenzene was removed by distillation under reduced pressure. The obtained solid was used directly in the next step without purification. Under an inert gas atmosphere, the solid obtained in the previous step, potassium hydroxide (14.00 g, 250.0 mmol), dioxane (120 mL), and water (30 mL) were added to a three-necked flask, and the mixture was heated to reflux for 48 h. After the reaction was completed, it was poured into distilled water, and extracted with dichloromethane. The organic layer was washed with saturated brine until neutral, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to remove the solvent. Using petroleum ether / ethyl acetate = 8:1 as the eluent, separation by silica gel column chromatography gave 1.59 g of 2-2, with a yield of 18.0%.

[0046] Under argon, tris(carbazole) 2-3 (1.77 g, 1.0 mmol) with a phenyl surface group, o-fluorobromobenzene (0.16 g, 0.9 mmol), and cesium carbonate (0.59 g, 1.8 mmol) were successively added to a 100 mL reaction flask, followed by the addition of anhydrous N,N-dimethylformamide (20 mL). The temperature was raised to 150 °C, and the mixture was refluxed and stirred for 24 h. After the reaction was completed, it was cooled to room temperature, and the reaction mixture was poured into 200 mL of water and filtered to obtain a white precipitate, which was dried. The crude product was purified by column chromatography (eluent: petroleum ether / dichloromethane = 8 / 1, v / v), and the product was a white solid (2-4) with a weight of 1.06 g and a yield of 61.0%. Elemental analysis: theoretical values C, 86.23; H, 4.51; N, 5.10; measured values C, 86.19; H, 4.45; N, 5.08. Electrospray ionization mass spectrometry (ESI-MS): theoretical value 1922.6, experimental value 1922.7 (M + ).

[0047] Under argon atmosphere, intermediate 2-4 (0.96 g, 0.5 mmol) was placed in a two-necked flask, dissolved in 50 mL of anhydrous tetrahydrofuran. At -78 °C, n-butyllithium (2.5 M, 2 mL, 0.5 mmol) was added dropwise. After stirring at -78 °C for 1 hour, intermediate 1-5 (0.12 g, 0.375 mmol) was added. After stirring overnight, 15 mL of distilled water was added to quench the reaction. Tetrahydrofuran was removed under reduced pressure. The mixture was extracted with 40 mL of dichloromethane three times, and then dichloromethane was removed under reduced pressure. The residue was recrystallized from ethanol and filtered by suction. The obtained solid was dried and placed in a 100 mL flask. 40 mL of anhydrous dichloromethane was added. After stirring in an ice-water bath for 10 minutes, 0.1 mL of 1.125 M boron trifluoride diethyl etherate was added and the reaction was carried out for 3 hours. After the reaction was completed, the reaction mixture was allowed to return to room temperature and poured into 200 mL of ice water. The product precipitated and was filtered by suction. The crude product was subjected to silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether as the eluent to obtain 0.48 g of compound I-3, with a yield of 59.0%. Elemental analysis: theoretical values C, 88.93; H, 4.46; N, 5.87; measured values C, 88.87; H, 4.43; N, 5.81. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF (m / z)): theoretical value 2146.8, experimental value 2146.9 (M + ).

[0048] Example 3

[0049] The synthetic route of compound I-4 is as follows:

[0050]

[0051] Under argon atmosphere, intermediate 1-4 (7.00 g, 21.70 mmol), 4-bromobenzonitrile (4.81 g, 26.40 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.60 g, 0.30 mmol), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (1.08 g, 1.20 mmol), methyltrioctylammonium chloride (0.1 mL) and 90 mL of toluene were mixed and stirred. After dissolution, 22 mL of 3 mol / L aqueous potassium carbonate solution was added, and the mixture was vigorously stirred and refluxed in an oil bath at 100 °C for 24 h. After the reaction was completed, the reaction solution was cooled, diluted with ethanol (200 mL), allowed to stand for sedimentation, and then filtered by suction. The solid was dissolved in dichloromethane, concentrated to a saturated solution, and the solid precipitated was filtered to obtain 4.71 g of white solid (3-1), with a yield of 73.0%. Elemental analysis: theoretical values C, 80.80; H, 3.73; N, 4.71; measured values C, 80.76; H, 3.69; N, 4.68. ESI-MS: theoretical value 297.1, experimental value 297.2 (M + ).

[0052] Under argon atmosphere, intermediate 1-2 (0.88 g, 0.5 mmol) was placed in a two-necked flask, dissolved in 50 mL of anhydrous tetrahydrofuran. At -78 °C, n-butyllithium (2.5 M, 0.2 mL, 0.5 mmol) was added dropwise. After stirring at -78 °C for 1 hour, intermediate 3-1 (0.11 g, 0.375 mmol) was added. After stirring overnight, 15 mL of distilled water was added to quench the reaction. Tetrahydrofuran was removed under reduced pressure. The residue was extracted with 40 mL of dichloromethane three times, and then dichloromethane was removed under reduced pressure. The residue was recrystallized from ethanol and filtered by suction. The obtained solid was dried and placed in a 100 mL flask. 40 mL of anhydrous dichloromethane was added. After stirring in an ice-water bath for 10 minutes, 0.1 mL of 1.125 M boron trifluoride diethyl etherate was added and the reaction was carried out for 3 hours. After the reaction was completed, the reaction mixture was allowed to return to room temperature and poured into 200 mL of ice water. The product precipitated and was filtered by suction. The crude product was purified by silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether as the eluent to obtain 0.52 g of compound I-4, with a yield of 70.0%. Elemental analysis: theoretical value C, 86.90; H, 6.57; N, 5.71; measured value C, 86.84; H, 6.53; N, 5.68. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF (m / z)): theoretical value 1962.0, experimental value 1962.1 (M + ).

[0053] Example 4

[0054] The synthetic route of compound I-6 is as follows:

[0055]

[0056]

[0057] Under argon atmosphere, intermediate 1-4 (7.00 g, 21.70 mmol), 2-bromobenzene-1,3,5-tricarbonitrile (6.13 g, 26.40 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.60 g, 0.30 mmol), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (1.08 g, 1.20 mmol), methyltrioctylammonium chloride (0.1 mL) and 90 mL of toluene were mixed and stirred. After dissolution, 22 mL of 3 mol / L aqueous potassium carbonate solution was added, and the mixture was vigorously stirred and refluxed in an oil bath at 100 °C for 24 h. After the reaction was completed, the reaction solution was cooled, diluted with ethanol (200 mL), allowed to stand for sedimentation, and then filtered by suction. The solid was dissolved in dichloromethane, concentrated to a saturated solution, and the solid was precipitated and filtered to obtain 4.60 g of white solid (4-1) with a yield of 61.0%. Elemental analysis: theoretical values C, 76.08; H, 2.61; N, 12.10; measured values C, 76.02; H, 2.57; N, 12.06. ESI-MS: theoretical value 347.1, experimental value 347.2 (M + ).

[0058] Under argon atmosphere, intermediate 1-2 (0.88 g, 0.5 mmol) was placed in a two-necked flask, dissolved in 50 mL of anhydrous tetrahydrofuran, and n-butyllithium (2.5 M, 0.2 mL, 0.5 mmol) was added dropwise at -78 °C. After stirring at -78 °C for 1 h, intermediate 4-1 (0.13 g, 0.375 mmol) was added. After stirring overnight, 15 mL of distilled water was added to quench the reaction. Tetrahydrofuran was removed under reduced pressure, and the mixture was extracted with 40 mL of dichloromethane three times. Then dichloromethane was removed under reduced pressure, and recrystallization from ethanol was carried out, followed by filtration by suction. The obtained solid was dried and placed in a 100 mL flask. 40 mL of anhydrous dichloromethane was added, and after stirring in an ice-water bath for 10 minutes, 0.1 mL of 1.125 M boron trifluoride diethyl etherate was added and the reaction was carried out for 3 h. After the reaction was completed, the reaction mixture was allowed to return to room temperature, and the reaction solution was poured into 200 mL of ice water. The product was precipitated and filtered. The obtained crude product was subjected to silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether as the eluent to obtain 0.47 g of compound I-6 with a yield of 62.0%. Elemental analysis: theoretical values C, 85.94; H, 6.31; N, 6.96; measured values C, 85.90; H, 6.28; N, 6.92. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF(m / z)): theoretical value 2011.0, experimental value 2011.1 (M + ).

[0059] Example 5

[0060] The synthetic route of compound I-8 is as follows:

[0061]

[0062]

[0063] Under argon atmosphere, 1-bromothioxanthone (9.03 g, 31.00 mmol), bis(pinacolato)diboron (15.75 g, 62.00 mmol), 1,1'-bis(diphenylphosphino)ferrocene dichloropalladium(II) (1.13 g, 1.55 mmol), potassium acetate (9.13 g, 93.00 mmol), and N,N-dimethylformamide (100 mL) were added to a 250 mL round-bottom flask, and the mixture was stirred at 90 °C in an oil bath for 24 h. After cooling to room temperature, the reaction mixture was poured into a beaker containing 500 mL of water, stirred for 10 min, allowed to settle, filtered, and the resulting solid was dissolved in dichloromethane and dried over anhydrous sodium sulfate. The crude product was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 10 / 1, v / v) to obtain 8.60 g of a white solid product (5-2) with a yield of 82.0%. Elemental analysis: calculated C, 67.47; H, 5.66; S, 9.48; found C, 67.41; H, 5.63; S, 9.44. ESI-MS: calculated 338.1, found 338.2 (M + ).

[0064] Under argon atmosphere, intermediate 5-2 (7.34 g, 21.70 mmol), 5-bromoisophthalonitrile (5.47 g, 26.40 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.60 g, 0.30 mmol), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (1.08 g, 1.20 mmol), methyltrioctylammonium chloride (0.1 mL), and 90 mL of toluene were mixed and stirred. After dissolution, 22 mL of 3 mol / L aqueous potassium carbonate solution was added, and the mixture was vigorously stirred and refluxed at 100 °C in an oil bath for 24 h. After the reaction was completed, the reaction mixture was cooled, diluted with ethanol (200 mL), allowed to settle, and then filtered by suction. The solid was dissolved in dichloromethane, concentrated to a saturated solution, and the resulting solid was filtered to obtain 5.08 g of a white solid (5-3) with a yield of 69.2%. Elemental analysis: calculated C, 74.54; H, 2.98; N, 8.28; S, 9.47; found C, 74.51; H, 2.94; N, 8.23; S, 9.41. ESI-MS: calculated 338.1, found 338.2 (M + ).

[0065] Under argon atmosphere, intermediate 1-2 (0.88 g, 0.5 mmol) was placed in a two-necked flask, dissolved in 50 mL of anhydrous tetrahydrofuran. At -78 °C, n-butyllithium (2.5 M, 0.2 mL, 0.5 mmol) was added dropwise. After stirring at -78 °C for 1 hour, intermediate 5-3 (0.13 g, 0.375 mmol) was added. After stirring overnight, 15 mL of distilled water was added to quench the reaction. Tetrahydrofuran was removed under reduced pressure. The residue was extracted with 40 mL of dichloromethane three times, and then dichloromethane was removed under reduced pressure. The residue was recrystallized from ethanol and filtered by suction. The obtained solid was dried and placed in a 100 mL flask. 40 mL of anhydrous dichloromethane was added. After stirring in an ice-water bath for 10 minutes, 0.1 mL of 1.125 M boron trifluoride diethyl etherate was added and the reaction was carried out for 3 hours. After the reaction was completed, the reaction mixture was allowed to warm to room temperature and then poured into 5200 mL of ice water. The product precipitated and was filtered by suction. The crude product was purified by silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether as the eluent to obtain 0.51 g of compound I-8, with a yield of 67.5%. Elemental analysis: theoretical values C, 85.72; H, 6.39; N, 6.29; S, 1.60; measured values C, 85.66; H, 6.38; N, 6.24; S, 1.56. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF (m / z)): theoretical value 2002.0, experimental value 2002.2 (M + ).

[0066] Example 6

[0067] The synthetic route of compound I-9 is as follows:

[0068]

[0069] Under argon atmosphere, 1-bromoselenoxanthenone (10.48 g, 31.00 mmol), bis(pinacolato)diboron (15.75 g, 62.00 mmol), 1,1'-bis(diphenylphosphino)ferrocene dichloropalladium (1.13 g, 1.55 mmol), potassium acetate (9.13 g, 93.00 mmol), and N,N-dimethylformamide (100 mL) were added to a 250 mL round-bottom flask. The mixture was stirred in an oil bath at 90 °C for 24 h. After cooling to room temperature, the reaction mixture was poured into a beaker containing 500 mL of water. After stirring for 10 min, the mixture was allowed to stand for sedimentation and then filtered. The obtained solid was dissolved in dichloromethane and dried over anhydrous sodium sulfate. The crude product was separated and purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 8 / 1, v / v) to obtain 11.94 g of a white solid product (6-2), with a yield of 74.0%. Elemental analysis: theoretical values C, 59.26; H, 4.97; measured values C, 59.22; H, 4.93. ESI-MS: theoretical value 386.1, experimental value 386.2 (M + ).

[0070] Under argon atmosphere, intermediate 6-2 (8.36 g, 21.70 mmol), 5-bromoisophthalonitrile (5.47 g, 26.40 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.60 g, 0.30 mmol), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (1.08 g, 1.20 mmol), methyltrioctylammonium chloride (0.1 mL) and 90 mL of toluene were mixed and stirred. After dissolution, 22 mL of 3 mol / L aqueous potassium carbonate solution was added, and the mixture was vigorously stirred and refluxed in an oil bath at 100 °C for 24 h. After the reaction was completed, the reaction solution was cooled, diluted with ethanol (200 mL), allowed to stand for sedimentation, and then filtered by suction. The solid was dissolved in dichloromethane, concentrated to a saturated solution, and the solid was precipitated and filtered to obtain 5.50 g of white solid (6-3) with a yield of 65.8%. Elemental analysis: theoretical values C, 65.47; H, 2.62; N, 7.27; measured values C, 65.43; H, 2.57; N, 7.24. ESI-MS: theoretical value 386.0, experimental value 386.1 (M + )

[0071] Under argon atmosphere, intermediate 1-2 (0.88 g, 0.5 mmol) was placed in a two-necked flask, dissolved in 50 mL of anhydrous tetrahydrofuran, and n-butyllithium (2.5 M, 0.2 mL, 0.5 mmol) was added dropwise at -78 °C. After stirring at -78 °C for 1 h, intermediate 6-3 (0.14 g, 0.375 mmol) was added. After stirring overnight, 15 mL of distilled water was added to quench the reaction. Tetrahydrofuran was removed under reduced pressure, and the mixture was extracted with 40 mL of dichloromethane three times. Then dichloromethane was removed under reduced pressure, and the residue was recrystallized from ethanol and filtered by suction. The obtained solid was dried and placed in a 100 mL flask. 40 mL of anhydrous dichloromethane was added, and the mixture was stirred in an ice-water bath for 10 min. Then 0.1 mL of 1.125 M boron trifluoride diethyl etherate was added and the reaction was carried out for 3 h. After the reaction was completed, the reaction mixture was allowed to return to room temperature, poured into 200 mL of ice water, and the product precipitated. The product was filtered by suction, and the crude product was subjected to silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether as the eluent to obtain 0.49 g of compound I-9 with a yield of 63.8%. Elemental analysis: theoretical values C, 83.76; H, 6.24; N, 6.15; measured values C, 83.72; H, 6.21; N, 6.11. Matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF(m / z)): theoretical value 2050.0, experimental value 2050.1 (M + )

[0072] Example 7

[0073] The synthetic route of compound I-10 is as follows:

[0074]

[0075] Under an inert gas atmosphere, bis(4-bromophenyl)amine (1.64 g, 5.0 mmol), 1-1 (7.94 g, 11.0 mmol), potassium carbonate (2.00 g, 15.0 mmol), copper(I) iodide (0.20 g, 1.0 mmol), 18-crown-6 (53 mg, 0.2 mmol), and nitrobenzene (50 mL) were added to a three-necked flask, and the reaction was carried out at 170 °C for 48 h. After the reaction was completed, it was cooled to room temperature, dichloromethane was added, and the mixture was stirred for 20 min. It was filtered, and the precipitate was washed with dichloromethane. The obtained mother liquor was first evaporated to remove the solvent dichloromethane on a rotary evaporator, and then nitrobenzene was removed by vacuum distillation. The obtained crude product was separated by silica gel column chromatography using petroleum ether / ethyl acetate = 6:1 as the eluent to obtain 1.63 g of 7-1, with a yield of 20.3%.

[0076] Under argon, 7-1 (1.61 g, 1.0 mmol), o-fluorobromobenzene (0.16 g, 0.9 mmol), and cesium carbonate (0.59 g, 1.8 mmol) were successively added to a 100 mL reaction flask, and then anhydrous N,N-dimethylformamide (20 mL) was added. The temperature was raised to 150 °C, and the mixture was refluxed and stirred for 24 h. After the reaction was completed, it was cooled to room temperature, and the reaction solution was poured into 200 mL of water, filtered, and a white precipitate was obtained and dried. The crude product was purified by column separation (eluent: petroleum ether / dichloromethane = 8 / 1, volume ratio), and the product was a white solid (7-2) 1.01 g, with a yield of 63.7%. Elemental analysis: theoretical values C, 83.06; H, 6.86; N, 5.56; measured values C, 83.03; H, 6.81; N, 5.52. Electrospray ionization mass spectrometry (ESI-MS): theoretical value 1761.9, experimental value 1761.8 (M + )

[0077] Under argon atmosphere, intermediate 7-2 (0.88 g, 0.5 mmol) was placed in a two-necked flask, dissolved in 50 mL of anhydrous tetrahydrofuran. At -78 °C, n-butyllithium (2.5 M, 0.2 mL, 0.5 mmol) was added dropwise. After stirring at -78 °C for 1 hour, intermediate 1-5 (0.12 g, 0.375 mmol) was added. After stirring overnight, 15 mL of distilled water was added to quench the reaction. Tetrahydrofuran was removed under reduced pressure. The mixture was extracted with 40 mL of dichloromethane three times, and then dichloromethane was removed under reduced pressure. The residue was recrystallized from ethanol and filtered by suction. The obtained solid was dried and placed in a 100 mL flask. 40 mL of anhydrous dichloromethane was added. After stirring in an ice-water bath for 10 minutes, 0.1 mL of 1.125 M boron trifluoride diethyl etherate was added and the reaction was carried out for 3 hours. After the reaction was completed, the reaction mixture was allowed to return to room temperature and poured into 200 mL of ice water. The product precipitated and was filtered by suction. The obtained crude product was subjected to silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether as the eluent to obtain 0.49 g of compound I-10, with a yield of 66.0%. Elemental analysis: theoretical values C, 86.32; H, 6.54; N, 6.34; measured values C, 86.29; H, 6.51; N, 6.32. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF (m / z)): theoretical value 1988.0, experimental value 1988.1 (M + ).

[0078] Example 8

[0079] The synthetic route of compound I-11 is as follows:

[0080]

[0081] Under an inert gas atmosphere, 2,7-dibromo-9,9-dimethylacridine (1.84 g, 5.0 mmol), 1-1 (7.94 g, 11.0 mmol), potassium carbonate (2.00 g, 15.0 mmol), copper(I) iodide (0.20 g, 1.0 mmol), 18-crown-6 (53 mg, 0.2 mmol), and nitrobenzene (50 mL) were added to a three-necked flask and reacted at 170 °C for 48 h. After the reaction was completed, the reaction mixture was cooled to room temperature, dichloromethane was added, and the mixture was stirred for 20 min. The mixture was filtered, and the precipitate was washed with dichloromethane. The obtained mother liquor was first concentrated to remove dichloromethane on a rotary evaporator, and then nitrobenzene was removed by distillation under reduced pressure. The obtained crude product was separated by silica gel column chromatography using petroleum ether / ethyl acetate = 10:1 as the eluent to obtain 1.44 g of 8-1, with a yield of 17.5%.

[0082] Under argon atmosphere, 8-1 (1.65 g, 1.0 mmol), o-fluorobromobenzene (0.16 g, 0.9 mmol) and cesium carbonate (0.59 g, 1.8 mmol) were successively added into a 100 mL reaction flask. Subsequently, anhydrous N,N-dimethylformamide (20 mL) was added, and the temperature was raised to 150 °C. The mixture was refluxed and stirred for 24 h. After the reaction was completed, the temperature was lowered to room temperature. The reaction solution was poured into 200 mL of water, filtered to obtain a white precipitate, and dried. The crude product was purified by column chromatography (eluent: petroleum ether / dichloromethane = 10 / 1, v / v). The product was a white solid (8-2) with a yield of 61.5% (1.00 g). Elemental analysis: theoretical values C, 83.21; H, 6.93; N, 5.43; measured values C, 83.18; H, 6.89; N, 5.38. Electrospray ionization mass spectrometry (ESI-MS): theoretical value 1801.9, experimental value 1801.8 (M + ).

[0083] Under argon atmosphere, the intermediate 8-2 (0.90 g, 0.5 mmol) was placed in a two-necked flask, dissolved in 50 mL of anhydrous tetrahydrofuran. At -78 °C, n-butyllithium (2.5 M, 0.2 mL, 0.5 mmol) was added dropwise. After stirring at -78 °C for 1 h, the intermediate 1-5 (0.12 g, 0.375 mmol) was added. After stirring overnight, 15 mL of distilled water was added to quench the reaction. Tetrahydrofuran was removed under reduced pressure. The mixture was extracted with 40 mL of dichloromethane three times, and then dichloromethane was removed under reduced pressure. The residue was recrystallized from ethanol and filtered by suction. The obtained solid was dried and placed in a 100 mL flask. 40 mL of anhydrous dichloromethane was added. After stirring in an ice-water bath for 10 min, 0.1 mL of 1.125 M boron trifluoride diethyl etherate was added and the reaction was carried out for 3 h. After the reaction was completed, the temperature was restored to room temperature. The reaction solution was poured into 200 mL of ice water, and the product precipitated. The precipitate was filtered by suction. The crude product was purified by silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether as the eluent to obtain 0.53 g of compound I-11 with a yield of 69.6%. Elemental analysis: theoretical values C, 86.40; H, 6.61; N, 6.21; measured values C, 86.36; H, 6.57; N, 6.17. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF (m / z)): theoretical value 2028.1, experimental value 2028.0 (M + ).

[0084] Example 9

[0085] The synthetic route of compound I-15 is as follows:

[0086]

[0087]

[0088] Under an inert gas atmosphere, 3,7-dibromophenoxazine (1.71 g, 5.0 mmol), 1-1 (7.94 g, 11.0 mmol), potassium carbonate (2.00 g, 15.0 mmol), copper(I) iodide (0.20 g, 1.0 mmol), 18-crown-6 (53 mg, 0.2 mmol), and nitrobenzene (50 mL) were added to a three-necked flask, and the reaction was carried out at 170 °C for 48 h. After the reaction was completed, it was cooled to room temperature, dichloromethane was added, and the mixture was stirred for 20 min. It was filtered, and the precipitate was washed with dichloromethane. The obtained mother liquor was first concentrated to remove dichloromethane on a rotary evaporator, and then nitrobenzene was removed by distillation under reduced pressure. The obtained crude product was separated by silica gel column chromatography using petroleum ether / ethyl acetate = 6:1 as the eluent to obtain 1.27 g of 9-1, with a yield of 15.6%.

[0089] Under argon, 9-1 (1.62 g, 1.0 mmol), o-fluorobromobenzene (0.16 g, 0.9 mmol), and cesium carbonate (0.59 g, 1.8 mmol) were successively added to a 100 mL reaction flask, and then anhydrous N,N-dimethylformamide (20 mL) was added. The temperature was raised to 150 °C, and the mixture was refluxed and stirred for 24 h. After the reaction was completed, it was cooled to room temperature, and the reaction solution was poured into 500 mL of water, filtered to obtain a white precipitate, and dried. The crude product was purified by column chromatography (eluent: petroleum ether / dichloromethane = 6 / 1, v / v) to obtain 0.93 g of the product as a white solid (9-2), with a yield of 58.0%. Elemental analysis: theoretical values C, 82.40; H, 6.69; N, 5.51; measured values C, 82.36; H, 6.65; N, 5.47. Electrospray ionization mass spectrometry (ESI-MS): theoretical value 1775.9, experimental value 1775.8 (M + ).

[0090] Under argon, 1-bromo-10,10-dimethylanthrone (9.34 g, 31.00 mmol), bis(pinacolato)diboron (15.75 g, 62.00 mmol), 1,1'-bis(diphenylphosphino)ferrocene dichloropalladium(II) (1.13 g, 1.55 mmol), potassium acetate (9.13 g, 93.00 mmol), and N,N-dimethylformamide (100 mL) were added to a 250 mL round-bottom flask, and the mixture was stirred at 90 °C in an oil bath for 24 h. It was cooled to room temperature, and then the reaction solution was poured into a beaker containing 500 mL of water. After stirring for 10 min, it was allowed to stand for sedimentation, filtered, and the obtained solid was dissolved in dichloromethane and dried over anhydrous sodium sulfate. The crude product was separated and purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 12 / 1, v / v) to obtain 8.71 g of the white solid product (9-4), with a yield of 80.7%. Elemental analysis: theoretical values C, 75.88; H, 7.24; measured values C, 75.84; H, 7.19. ESI-MS: theoretical value 348.2, experimental value 348.3 (M+ )。

[0091] Under argon atmosphere, intermediate 9-4 (7.56 g, 21.70 mmol), 5-bromoisophthalonitrile (5.47 g, 26.40 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.60 g, 0.30 mmol), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (1.08 g, 1.20 mmol), methyltrioctylammonium chloride (0.1 mL), and 90 mL of toluene were mixed and stirred. After dissolution, 22 mL of 3 mol / L aqueous potassium carbonate solution was added, and the mixture was vigorously stirred and refluxed in an oil bath at 100 °C for 24 h. After the reaction was completed, the reaction solution was cooled, diluted with ethanol (200 mL), allowed to stand for sedimentation, and then filtered by suction. The solid was dissolved in dichloromethane, concentrated to a saturated solution, and the solid was precipitated and filtered to obtain 5.15 g of white solid (9-5) with a yield of 68.1%. Elemental analysis: theoretical values C, 82.14; H, 4.63; N, 8.04; measured values C, 82.11; H, 4.58; N, 8.02. ESI-MS: theoretical value 348.1, experimental value 348.2 (M + )。

[0092] Under argon atmosphere, intermediate 9-2 (0.89 g, 0.5 mmol) was placed in a two-necked flask, dissolved in 50 mL of anhydrous tetrahydrofuran, and n-butyllithium (2.5 M, 0.2 mL, 0.5 mmol) was added dropwise at -78 °C. After stirring at -78 °C for 1 h, intermediate 9-5 (0.13 g, 0.375 mmol) was added. After stirring overnight, 15 mL of distilled water was added to quench the reaction. Tetrahydrofuran was removed under reduced pressure, and the mixture was extracted with 40 mL of dichloromethane three times. Then dichloromethane was removed under reduced pressure, and recrystallization was carried out with ethanol, followed by filtration by suction. The obtained solid was dried and placed in a 100 mL flask. 40 mL of anhydrous dichloromethane was added, and after stirring in an ice-water bath for 10 minutes, 0.1 mL of 1.125 M boron trifluoride diethyl etherate was added and the reaction was carried out for 3 h. After the reaction was completed and the temperature was restored to room temperature, the reaction solution was poured into 200 mL of ice water, and the product was precipitated and filtered. The obtained crude product was subjected to silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether as the eluent to obtain 0.47 g of compound I-15 with a yield of 62.0%. Elemental analysis: theoretical values C, 86.40; H, 6.61; N, 6.21; measured values C, 86.37; H, 6.56; N, 6.17. Matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF(m / z)): theoretical value 2028.1, experimental value 2028.2 (M + )。

[0093] Example 10

[0094] The synthetic route of compound I-16 is as follows:

[0095]

[0096] Under an inert gas atmosphere, 3,7-dibromophenothiazine (1.79 g, 5.0 mmol), 1-1 (7.94 g, 11.0 mmol), potassium carbonate (2.00 g, 15.0 mmol), copper(I) iodide (0.20 g, 1.0 mmol), 18-crown-6 (53 mg, 0.2 mmol), and nitrobenzene (50 mL) were added to a three-necked flask and reacted at 170 °C for 48 h. After the reaction was completed, it was cooled to room temperature, dichloromethane was added, and the mixture was stirred for 20 min. It was filtered, and the precipitate was washed with dichloromethane. The obtained mother liquor was first concentrated to remove dichloromethane on a rotary evaporator, and then nitrobenzene was removed by vacuum distillation. The obtained crude product was separated by silica gel column chromatography using petroleum ether / ethyl acetate = 8 / 1 as the eluent to obtain 1.23 g of 10-1, with a yield of 15.0%.

[0097] Under argon, 10-1 (1.64 g, 1.0 mmol), o-fluorobromobenzene (0.16 g, 0.9 mmol), and cesium carbonate (0.59 g, 1.8 mmol) were successively added to a 100 mL reaction flask, and then anhydrous N,N-dimethylformamide (20 mL) was added. The temperature was raised to 150 °C, and the mixture was refluxed and stirred for 24 h. After the reaction was completed, it was cooled to room temperature, and the reaction solution was poured into 200 mL of water and filtered to obtain a white precipitate, which was dried. The crude product was purified by column chromatography (eluent: petroleum ether / dichloromethane = 9 / 1, v / v) to obtain 0.95 g of the product as a white solid (10-2), with a yield of 58.6%. Elemental analysis: theoretical values C, 81.67; H, 6.63; N, 5.46; measured values C, 81.64; H, 6.58; N, 5.42. Electrospray ionization mass spectrometry (ESI-MS): theoretical value 1791.8, experimental value 1791.7 (M + )

[0098] Under argon atmosphere, intermediate 10-2 (0.90 g, 0.5 mmol) was placed in a two-necked flask, dissolved in 50 mL of anhydrous tetrahydrofuran. At -78 °C, n-butyllithium (2.5 M, 0.2 mL, 0.5 mmol) was added dropwise. After stirring at -78 °C for 1 hour, intermediate 1-5 (0.12 g, 0.375 mmol) was added. After stirring overnight, 15 mL of distilled water was added to quench the reaction. Tetrahydrofuran was removed under reduced pressure. The residue was extracted with 40 mL of dichloromethane three times, and then dichloromethane was removed under reduced pressure. The residue was recrystallized from ethanol and filtered by suction. The obtained solid was dried and placed in a 100 mL flask. 40 mL of anhydrous dichloromethane was added. After stirring in an ice-water bath for 10 minutes, 0.1 mL of 1.125 M boron trifluoride diethyl etherate was added and the reaction was carried out for 3 hours. After the reaction was completed, the reaction mixture was allowed to return to room temperature and poured into 200 mL of ice water. The product precipitated and was filtered by suction. The crude product was subjected to silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether as the eluent to obtain 0.49 g of compound I-16 with a yield of 64.7%. Elemental analysis: theoretical values C, 85.04; H, 6.34; N, 6.24; measured values C, 84.49; H, 6.31; N, 6.18. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF (m / z)): theoretical value 2018.0, experimental value 2018.1 (M + ).

[0099] See Table 1. Table 1 shows the photophysical properties of the space charge transfer dendritic compounds prepared in the examples of the present invention.

[0100] Table 1 Photophysical properties of the space charge transfer dendritic compounds prepared in the examples of the present invention

[0101] Fluorescent material <![CDATA[λ abs (nm)]]> <![CDATA[λ em (nm)]]> <![CDATA[ΔE ST (eV)]]> I-1 268，300，380 515 0.04 I-4 263，346，363 506 0.09 I-6 261，347，363 528 0.06 I-10 268，299，351 512 0.12

[0102] As can be seen from Table 1, the dendritic fluorescent materials based on space charge transfer provided by the present invention have space charge transfer luminescence from the dendritic electron donor unit to the electron acceptor unit. The emission peak positions are all in the visible light range, and the emission wavelength can be changed by changing the chemical structure of the dendritic electron donor unit or the electron acceptor unit. On the other hand, the space charge transfer dendritic fluorescent materials provided by the present invention have a very small singlet-triplet energy level difference (0.01 eV - 0.15 eV), thus showing a significant thermally activated delayed fluorescence effect. It is beneficial to the utilization of triplet excitons when applied in organic light-emitting devices, and thus has a high luminous efficiency.

[0103] The fluorescent materials I-1, I-4, I-6 and I-10 prepared in the examples of the present invention were characterized.

[0104] See Figure 1 , Figure 1Fluorescence spectrum of the fluorescent material I-1 prepared in the embodiments of the present invention in toluene solution.

[0105] See Figure 2 , Figure 2 Fluorescence spectrum of the fluorescent material I-4 prepared in the embodiments of the present invention in toluene solution.

[0106] See Figure 3 , Figure 3 Fluorescence spectrum of the fluorescent material I-6 prepared in the embodiments of the present invention in toluene solution.

[0107] See Figure 4 , Figure 4 Fluorescence spectrum of the fluorescent material I-10 prepared in the embodiments of the present invention in toluene solution.

[0108] Device example

[0109] The preparation process of the organic electroluminescent device is as follows: Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT / PSS) is spin-coated on indium tin oxide (ITO) supported on a glass substrate and annealed at 120 °C for 60 min. Then, the dendrimer fluorescent material based on space charge transfer prepared in the present invention and the host material shown as Figure 5 are formulated into a chlorobenzene solution, and then spin-coated at a speed of 1500 revolutions per minute for 1 min and annealed at 100 °C for 30 min to form a light-emitting layer of 40 nm - 60 nm on the PEDOT / PSS; then, TSPO1, TmPyPB and LiF / Al cathodes are sequentially deposited under a vacuum of 5×10 -4 Pa to obtain an organic electroluminescent device, where TSPO1 and TmPyPB serve as a hole blocking layer and an electron transport layer respectively. The specific device structure is ITO / PEDOT:PSS(40 nm) / EML(40 nm - 60 nm) / TSPO1(8 nm) / TmPyPB(42 nm) / LiF(1 nm) / Al(100 nm).

[0110] See Figure 5 , Figure 5 Structural formulas of the host material, TSPO1 and TmPyPB in the organic electroluminescent device prepared in the present invention. Among them, Ad-4D2, m-MTDATA, TSPO1 and TmPyPB are included.

[0111] Example 11

[0112] Taking the dendrimer luminescent material I-1 based on space charge transfer as the implementation object, the obtained electroluminescent device is characterized and its performance is tested.

[0113] See Table 2, which provides the performance parameters of the electroluminescent device prepared using the dendritic light-emitting material I-1 based on space charge transfer provided by the present invention.

[0114] Example 12

[0115] Taking the dendritic luminescent material I-4 based on space charge transfer as the implementation object, the obtained electroluminescent device was characterized and the performance was tested.

[0116] See Table 2, which provides the performance parameters of the electroluminescent device prepared using the dendritic light-emitting material I-4 based on space charge transfer provided by the present invention.

[0117] Table 2 Performance parameters of electroluminescent devices prepared from dendritic luminescent materials based on space charge transfer provided by the present invention

[0118]

[0119] Note: The start voltage in the table is for a brightness of 1cd m -2 The maximum external quantum efficiency is obtained according to the current-voltage curve and electroluminescence spectrum of the device according to the calculation method described in the literature (Jpn. J. Appl. Phys. 2001, 40, L783).

[0120] The above is a detailed introduction to a dendritic luminescent material based on space charge transfer, a preparation method and an application provided by the present invention. The principle and implementation method of the present invention are explained in this article using specific examples. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the text of the claims, or if they include equivalent structural elements that are not substantially different from the text of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A dendritic luminescent material based on space charge transfer, characterized in that: Its structure is shown in formula (I): X and Z are independently selected from: C(R 1 R 2 ), O, S or Se; m is 0 or 1; n is 1 or 2; p is the number of cyano groups, selected from an integer of 1 to 5; R1, R 1 and R 2 are independently selected from -H, -D, -F, substituted or unsubstituted C1 to C 20 Hydrocarbon, substituted or unsubstituted C1~C 20 halogenated alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C6~C 20 Aryl and substituted or unsubstituted C2~C 20 One or more of the heteroaryl groups.

2. The dendritic luminescent material based on space charge transfer according to claim 1, characterized in that: Said Any one selected from formula (1) to formula (2) 3. The dendritic luminescent material based on space charge transfer according to claim 1, characterized in that: The dendritic light-emitting material based on space charge transfer has a structure shown in any one of Formulas I-1 to 20:

4. A method for preparing a dendritic luminescent compound based on space charge transfer as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: 1) Under a protective atmosphere, X-1 is subjected to a nucleophilic substitution reaction with o-fluorobromobenzene to obtain an intermediate X-2; 2) Under a protective atmosphere, the intermediate X-2 obtained in the above step and the anthrone compound X-3 containing a benzonitrile receptor are sequentially subjected to a nucleophilic addition reaction and a dehydration cyclization reaction to obtain a dendritic fluorescent polymer compound of the specific formula (I).

5. The preparation method according to claim 3, characterized in that: The temperature of the nucleophilic substitution reaction is 100-180°C; The time of the nucleophilic substitution reaction is 16 to 48 hours; The temperature of the nucleophilic addition reaction is -100 to 0°C; The time of the nucleophilic addition reaction is 6 to 18 hours; The temperature of the dehydration cyclization reaction is -78 to 25°C; The dehydration cyclization reaction time is 1 to 5 hours.

6. An organic electroluminescent device, comprising an anode, a cathode and an organic thin film layer located between the anode and the cathode; characterized in that: The organic thin film layer comprises the dendritic light-emitting material based on space charge transfer according to any one of claims 1 to 3.

7. The organic electroluminescent device according to claim 6, characterized in that: The organic thin film layer comprises a light-emitting layer; the light-emitting layer comprises the dendritic light-emitting material based on space charge transfer according to any one of claims 1 to 3.

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