Synthesis And Optical Properties Investigation Of Branched Fluorescent Dyes Containing Different Electron Donor-acceptor Groups

Two-photon absorption materials is widely applied in optical limiting,two-photon upconversion lasing,two-photon fluorescence microscopy,three-dimensional optical data storage and microfabrication. Therefore,how to improve two-photon absorption cross-section of two-photon materials has gained wide-spread popularity in the field of materials research.In this article, seven triphenylamine-core stilbene fluorescence derivatives were synthesized, which could be divided into as two series following:â‘ Novel triphenylamine-core fluorescence derivatives containing electron donor-acceptor groups: 4-(3,4,5-Trimethoxyphenylethylene)yl-triphenylamine (C6), 4-(p-Nitro-phenylethylene)yl- triphenylamine (C7), 4-(3,4,5-Trimethoxyl-phenylethylene)yl-4'-formyl-triphenylamine (C8) and 4-(p-Nitro-phenylethylene)yl-4'-formyl-triphenylamine (C9);â‘¡Novel triphenylamine-core fluorescence derivatives bearing benzophenone part with different substituents: 4-(p-benzoylstyrene)yl-4'-(styrene)yl-triphenylamine (C13), 4-(p-benzoylstyrene)yl-4'-3,4,5- trimethoxylstyrene)yl-triphenylamine (C14) and 4-(p-benzoylstyrene)yl-4'-(p'-nitrostyrene)yl- triphenylamine (C15).These synthesized molecules were detested by a few methods. such as UV-visible spectrum, one- and two-photon fluorescence spectra, the fluorescent life time and TPA cross-sections. On the one- and two-photon absorption as well as fluorescence behavior were used to analyse these band-gap charge, stocks shift displacement, cyclic voltammetry, thermal stability and intermolecular charge density. The results obtained are as following :1. The molecules with triphenylamine as the core and containing electron donor-acceptor, which showed increasing charge transfer and reducing band gap, exhibited different luminscence properties with the increasing electron withdrawing ability of electron acceptor. Therefore, we could choose different types of electron donor-acceptor to modify the compounds with the indentical structure so as to measure its charge transfer and band-gap and regulate its color. So it could be able to be used to prepare suitable organic photo materials with matched energy band and improve the luminous efficiency. TPA cross-sections were widly improved by the increasing electron withdrawing ability.2. The different substituents impacted the two-photon absorption for the fluorescene dyes with triphenylamine as the core bearing benzophenone part. TPA cross-sections were distinctly improved with the increasing electron withdrawing ability of the substituents and intramolecular charge transfer. Aslo, two-photon absorption of the molecules with the co-conjugated chain length was compared. Due to the increasing length of the co-conjugated chain, the molecular TPA cross-section also showed the trend increasing. And this relationship could be served as a useful field in increasing TPA cross-section and improving the application of the two-photon materials.