Theoretical study based on the excited state dynamical of an oxadiazole Derivative: a novel fluorescence mechanism

Excited intramolecular proton transfer (ESIPT) has been widely studied as a model system for proton transfer. In recent years, materials and biological systems containing two proton transfers have received special attention from researchers. In this work, the excited state intramolecular double-proton-transfer (ESIDPT) mechanism of a fluorescent compound based on an oxadiazole derivative, 2,5-bis-[5-(4-tert-butyl-phenyl)-[1,3,4oxadiazol-2-yl]-benzene-1,4-diol (DOX), has been comprehensively investigated through theoretical calculations. The potential energy surface curve of the reaction shows that ESIDPT can occur, and the three configurations of the compound exist simultaneously in the first excited state. This work proposes a new and reasonable fluorescence mechanism based on previous experiments, which has theoretical significance for the future research of DOX compounds in biomedicine and optoelectronics.