Host red luminous material with charge transferring structure and its prepn and application

Abstract

The present invention is host red luminous material with charge transfer structure and its preparation process. Serial red luminous materials are prepared with three kinds of excellent hole transfer radicals, carbazole, triphenylamine and phenothiazine and its substituent derivative as electron donor, with nitrile radical with strong electrophilic capacity as electron acceptor, and through double condensation reaction to form C=C double bond. The molecular structure of these red luminous materials is characterized in mass spectral analysis, nuclear magnetic resonance spectroscopy, element analysis, etc; the electrochemical property is characterized with circular volt-ampere characteristic; the physical, including optical, properties are researched in ultraviolet absorption and fluorescent spectrum; and device with the material as light emitting layer is made. Experiment shows that the material has excellent light emitting property.

Description

technical field [0001] The invention relates to an intramolecular charge transfer type red luminescent material with A-π-D-π-A symmetrical structure. [0002] The invention also relates to a method for the preparation of the aforementioned materials. [0003] The present invention also relates to the application of the above materials in organic electroluminescent devices. Background technique [0004] Organic electroluminescent devices are a new type of display technology that is gradually becoming mature in the field of optoelectronic devices and has great practical prospects. Since Kodak Corporation (Tang, C.W.; Vanslyke, S.A. Appl. Phys. Lett. 1987, 51, 913.) introduced high-efficiency organic electroluminescent devices in 1987, with its adjustable luminous color, high brightness, high efficiency, Excellent characteristics such as wide viewing angle, low power consumption, simple preparation process, and the ability to prepare curved and flexible screens, as well as po...

AI Technical Summary

Problems solved by technology

Although the doping technology solves the problem of device preparation and obtains red light-emitting devices, it also has its own insurmountable problems: (1) The energy matching between the host and guest materials is not complete, and the energy transfer is not sufficient, resulting in the device Presents impure red light emission; (2) Doping concentration limitation, under low doping concentration, incomplete energy transfer between the two causes the device to present impure red light emission; increasing the concentration of the guest can easily lead to host material The phase separation between the guest material and the guest material; the self-quenching phenomenon of the guest, the device efficiency is significantly reduced, etc.

[0008] In addition, most of the charge-transfer compounds reported in the literature and patents use 2,6-dimethyl-4-dicyanomethenyl-tetrahydropyran as the charge acceptor. The existence of a methyl group, condensation under alkali-catalyzed conditions, both methyl groups will react, resulting in condensation by-products of different structures, resulting in poor purity of the target product, and some by-products are difficult to separate and remove by normal methods (1: Chen, C.H. ; Tang, C.W.; Shi, J. Macromolecules Symp, 1998, 125, 49.2: Chen, C.H.; Klubek, K.P.; Shi, J.US Patent 5908581, 1999.)

[0009] At present, there is a shortage of non-doped host red photoluminescent materials, and there are few literature and patent reports about the application of host-type luminescent materials with A-π-D-π-A structure in organic electroluminescent devices.

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