Fluorescence of the perylene radical cation and an inaccessible D_0/D_1conical intersection: An MMVB, RASSCF, and TD-DFT computational study

摘要

The photophysics of the perylene radical cation (Pe~(+)was studied using the molecularmechanics-valence bond (MMVB) hybrid force field. Potential energy surfaces of the first three electronic states were investigated. Geometry optimizations of critical points—including conicalintersections between the relevant electronic states—were performed using the MMVB analytical energy gradient for cations. No accessible planar conical intersection between the D_0 and D_1 statesof Pe~(+) was found; this is consistent with the experimentally observed D_1 lifetimes and the observation of D I emission from this cation in the condensed phase. Benchmark RASSCF andTD-DFT calculations support the reliability of the MMVB results.