Investigating the mechanism of fluorescence probe of quinoline derivatives for detecting phosgene in gas and liquid phases

Abstract

Based on density functional theory and time-dependent density functional theory, the excited state charge distribution characteristics and fluorescence mechanism of fluorescence probe Q-1 and Q-CN have been discussed. The twisting potential energy curve proves that the diethylamine group in Q-CN will be twisted in S1 state. The frontier molecular orbitals proves that Q-CN has a small degree of charge coupling and the oscillator intensity is close to zero, so it is not conducive to luminescence. The results of “hole-electron” analysis prove that the quenching of Q-CN fluorescence is caused by the delocalization of the charge in S1 state.