Photochemical deactivation pathways of the Ã-state allyl radical

Abstract

Ab initio direct molecular dynamics with trajectory surface hopping methods simulates the photochemical deactivation pathways of the allyl radical, C₃H₅, following electronic excitation to the Ã-state. The electronically nonadiabatic dynamics mediated by two conical intersections produces predominantly hot ground state allyl radicals along both the disrotatory and conrotatory photochemical deactivation pathways with a near synchronous rotation of the terminal methylene groups. The electrocyclic transformation of the allyl radical to the cyclopropyl radical is a minor channel accounting for 8% of all trajectories with 98% of them following the disrotatory pathway.