Peripheral thermal cross-linking dendritic group, thermal cross-linking dendritic thermal activation delayed fluorescence material as well as synthesis method and application of thermal cross-linking dendritic thermal activation delayed fluorescence material

Abstract

The invention discloses a peripheral thermal cross-linking dendritic group, a thermal cross-linking dendritic thermal activation delayed fluorescence material and a synthesis method and application thereof, and belongs to the field of organic photoelectric materials and organic light emitting diode devices. The molecular structure of the fluorescent material consists of three parts, wherein the first part is a luminous core with a thermal activation delayed fluorescence property; the second part is a carbazole group connected through a non-conjugated group and used as a peripheral dendritic group; and the third part is a styrene thermal crosslinking group connected to the periphery of the dendritic group. The novel material has the advantages that the steric hindrance effect of peripheraldendritic groups can effectively inhibit concentration quenching of triplet excitons, and the performance of a light-emitting device is improved; due to the introduction of alkyl chains, the solubility and the film-forming property of the material can be effectively enhanced; the introduction of the thermal crosslinking group can enhance the stability and film-forming property of a solid film. Thethermally activated delayed fluorescence material has good luminescence property and film-forming property, and is suitable for preparing organic electroluminescent devices by a wet method.

Description

technical field

[0001] The invention belongs to the field of organic photoelectric materials and organic light-emitting diode devices, and in particular relates to a peripheral thermally crosslinked dendritic group, a thermally crosslinked dendritic thermally activated delayed fluorescent material and a synthesis method and application thereof. Background technique

[0002] Thermally activated delayed fluorescence (TADF) materials are known as the latest generation of fluorescent materials because of their metal-free and 100% theoretical internal quantum efficiency, and they have attracted more and more attention in the application of organic light-emitting diodes (OLEDs). So far, a large number of evaporation-type small molecule TADF materials have been developed, and the luminous efficiency and color purity have been greatly improved. However, most of the evaporation-type OLEDs reported so far use the evaporation process, which has the disadvantages of high equipment inves...

Examples

Embodiment 1

[0041] The specific reaction process of the peripheral dendron group is as follows:

[0042]

[0043] The specific synthetic method of peripheral heat-crosslinking dendron group is:

[0044] (1) At room temperature, add 4-hydroxycarbazole (5g, 27.32mmol) and 1,6-dibromohexane (26.67g, 109.28mmol) into 50mL toluene solution and stir to dissolve, then add tetrabutylammonium bromide (1 g, 3.11 mmol) and 50% NaOH (2.73 g, 68.3 mmol) in water. The reaction temperature was 60°C, and the reaction time was 2 hours. After the reaction, the crude product was purified by column chromatography to obtain the product: 9-(6-bromohexyl)-9hydrogen-4-hydroxycarbazole, with a yield of 60%. Mass Spectrum: 345.34, Elemental Analysis: The results are as follows: C: 62.44, H: 5.82, N: 4.05.

[0045] (2) Add 9-(6-bromohexyl)-9hydro-4-hydroxycarbazole (6g, 17.34mmol) from step (1) into 50mL dry N,N-dimethylformamide and stir to dissolve, Sodium hydride (0.83g, 34.68mmol) was added, and after 20 ...

Embodiment 2

[0058] Synthesis of the target product VD2: get 9-(6-((9 hydrogen-carbazolyl-4-yl)oxyl)hexyl)-4-((4-styryl)oxyl)- in step (3) 9H-carbazole (3 g, 5.32 mmol) was dissolved in 20 mL of dry THF with stirring, and then NaH (0.26 g, 10.64 mmol) was added slowly. After reacting for 30 minutes, 2,4,6-trifluorobenzonitrile (0.21g, 1.33mmol) was added, and the reaction was carried out under the protection of nitrogen, the temperature was 60°C, and the reaction time was 24 hours; The product VD2 was purified by analytical method, yield: 78%, mass spectrum: 1791.26, elemental analysis: the results were as follows: C: 83.19, H: 6.03, N: 5.36.

[0059]

[0060] Preparation of all-wet device: The all-wet device was prepared according to the method of Example 1, except that the light-emitting layer of the device was VD2.

Embodiment 3

[0062] Synthesis of the target product VD3: get 9-(6-((9 hydrogen-carbazolyl-4-yl)oxyl)hexyl)-4-((4-styryl)oxyl)- in step (3) 9H-carbazole (3 g, 5.32 mmol) was dissolved in 20 mL of dry THF with stirring, and then NaH (0.26 g, 10.64 mmol) was added slowly. After reacting for 30 minutes, tetrafluoroisophthalonitrile (0.18g, 0.88mmol) was added, the reaction was carried out under nitrogen protection, the temperature was 60°C, and the reaction time was 24 hours; after the reaction was completed, it was purified by column chromatography to obtain Product VD3, yield: 68%, mass spectrum: 2378.89, elemental analysis: the results are as follows: C: 82.79, H: 5.93, N: 5.38.

[0063]

[0064] Preparation of all-wet device: The all-wet device was prepared according to the method of Example 1, except that the light-emitting layer of the device was VD3.

technical field

[0001] The invention belongs to the field of organic photoelectric materials and organic light-emitting diode devices, and in particular relates to a peripheral thermally crosslinked dendritic group, a thermally crosslinked dendritic thermally activated delayed fluorescent material and a synthesis method and application thereof. Background technique

[0002] Thermally activated delayed fluorescence (TADF) materials are known as the latest generation of fluorescent materials because of their metal-free and 100% theoretical internal quantum efficiency, and they have attracted more and more attention in the application of organic light-emitting diodes (OLEDs). So far, a large number of evaporation-type small molecule TADF materials have been developed, and the luminous efficiency and color purity have been greatly improved. However, most of the evaporation-type OLEDs reported so far use the evaporation process, which has the disadvantages of high equipment inves...

Examples

Embodiment 1

[0041] The specific reaction process of the peripheral dendron group is as follows:

[0042]

[0043] The specific synthetic method of peripheral heat-crosslinking dendron group is:

[0044] (1) At room temperature, add 4-hydroxycarbazole (5g, 27.32mmol) and 1,6-dibromohexane (26.67g, 109.28mmol) into 50mL toluene solution and stir to dissolve, then add tetrabutylammonium bromide (1 g, 3.11 mmol) and 50% NaOH (2.73 g, 68.3 mmol) in water. The reaction temperature was 60°C, and the reaction time was 2 hours. After the reaction, the crude product was purified by column chromatography to obtain the product: 9-(6-bromohexyl)-9hydrogen-4-hydroxycarbazole, with a yield of 60%. Mass Spectrum: 345.34, Elemental Analysis: The results are as follows: C: 62.44, H: 5.82, N: 4.05.

[0045] (2) Add 9-(6-bromohexyl)-9hydro-4-hydroxycarbazole (6g, 17.34mmol) from step (1) into 50mL dry N,N-dimethylformamide and stir to dissolve, Sodium hydride (0.83g, 34.68mmol) was added, and after 20 ...

Embodiment 2

[0058] Synthesis of the target product VD2: get 9-(6-((9 hydrogen-carbazolyl-4-yl)oxyl)hexyl)-4-((4-styryl)oxyl)- in step (3) 9H-carbazole (3 g, 5.32 mmol) was dissolved in 20 mL of dry THF with stirring, and then NaH (0.26 g, 10.64 mmol) was added slowly. After reacting for 30 minutes, 2,4,6-trifluorobenzonitrile (0.21g, 1.33mmol) was added, and the reaction was carried out under the protection of nitrogen, the temperature was 60°C, and the reaction time was 24 hours; The product VD2 was purified by analytical method, yield: 78%, mass spectrum: 1791.26, elemental analysis: the results were as follows: C: 83.19, H: 6.03, N: 5.36.

[0059]

[0060] Preparation of all-wet device: The all-wet device was prepared according to the method of Example 1, except that the light-emitting layer of the device was VD2.

Embodiment 3

[0062] Synthesis of the target product VD3: get 9-(6-((9 hydrogen-carbazolyl-4-yl)oxyl)hexyl)-4-((4-styryl)oxyl)- in step (3) 9H-carbazole (3 g, 5.32 mmol) was dissolved in 20 mL of dry THF with stirring, and then NaH (0.26 g, 10.64 mmol) was added slowly. After reacting for 30 minutes, tetrafluoroisophthalonitrile (0.18g, 0.88mmol) was added, the reaction was carried out under nitrogen protection, the temperature was 60°C, and the reaction time was 24 hours; after the reaction was completed, it was purified by column chromatography to obtain Product VD3, yield: 68%, mass spectrum: 2378.89, elemental analysis: the results are as follows: C: 82.79, H: 5.93, N: 5.38.

[0063]

[0064] Preparation of all-wet device: The all-wet device was prepared according to the method of Example 1, except that the light-emitting layer of the device was VD3.

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