The Absorption And Fluorescence Emission Spectra Of The Molecules Containing Azo And/or Oxadiazole Units

The ground state structures of a series of organic molecules containing azo and/oroxadiazole units were obtained by using density functional theory B3LYP/6-31G (d) Method.The first singlet excited state structures were optimized by using singlet-excitation configurationinteraction CIS/6-31G (d) Method. The absorption and fluorescence emission spectra are thenevaluated using the time-dependent density functional theory B3LYP and PBE1PBE Methodswith6-311++G (3df,2p) basis set. The calculation results show that compared with their parentmolecules A-H， the absorption and fluorescence emission wavelength values of all thederivatives show red shifts. The derivatives containing both oxadiazole unit and methoxyl unitare good candidates for longer absorption and fluorescence emission wavelength materials. Theeffects of azo, oxadiazole, and methoxyle units and other electron-withdrawing group orelectron-donating group on the absorption and emission wavelength are discussed. Thecalculation results show that the absorption and fluorescence emission wavelength values of allthe derivatives of Me-OXD-A-N=N-Ph-R show red shifts.