A Theoretical Study on the Photodissociation of Acetone: Insight into the Slow Intersystem Crossing and Exploration of Nonadiabatic Pathways to the Ground State

摘要: Structures of transition states (TSs) and minima on seam crossing (MSXs) for potential energy surfaces (PESs) acetone the S0, S1, T1 were explored. On basis results, we propose a new mechanism, slow intersystem from S1 to without crossing, followed by CH3 dissociation via TS T1; this pathway will be overtaken more efficient higher energy. This is consistent with observed long lifetime species. Moreover, four channels, including three ones, found regenerate ground state PES, they all may involved in roaming channel that has been proposed recently as route CO generation 230 nm photolysis. There are significant differences MSX structures energies between present CASPT2 results previous CASSCF results.