Design,Synthesis And Photoelectric Properties Study Of D-A Electroluminescent Molecules With Crossed Configuration Of Central X Shape

In recent years,the photoelectric industry has made remarkable achievements--the technology and market of organic electroluminescent devices(OLED)are becoming more and more mature.OLED has many advantages,such as high luminance,high luminous efficiency,flexible display and quick response,so that the organic electroluminescence technology is gradually replacing the traditional inorganic LED display and LCD display to become the next generation display technology.At present,the scientists usually use the vacuum evaporation process and the solution spin coating process to prepare the organic electroluminescent devices,the core part of OLED is the organic emitting layer materials.In order to achieve high efficiency and high luminance,the scientists are devoted to the use of organic D–A fluorescent materials as organic light-emitting materials.The luminescent wavelength of this sort of materials is distributed in the visible light region,and the material itself can conduct electrons and holes,and it has good chemical stability and thermodynamic stability.As scientists become more and more deep in OLED research,organic D–A fluorescent materials are varied in configuration.In this paper,we focus on constructing two pairs of central X-shape crossed structure compounds with the feature of position isomerism by transform the bonding positions of donor groups and acceptor groups on benzene bridge.The donor groups and acceptor groups of one molecular belong to the para-conjugation and meta-conjugation,and that of another molecular belong to the ortho-conjugation andmeta-conjugation.The different conjugated positions of the compounds have different conjugated structures,and the para-conjugated compounds have longer conjugation lengths,so the fluorescence quantum efficiency is higher.Meanwhile,the isomer compounds have different separated HOMO and LUMO,larger separation of HOMO and LUMO is beneficial to induce the transition of charge transfer excited state.The electroluminescent devices of two compounds were prepared by vacuum evaporation process.The basic physical properties,the excited state properties and the electroluminescent properties of compounds were compared and analyzed.The dialectical relationship between the structure and properties was explored.