Product vibrational state distributions of F+CH3OH reaction on full-dimensional accurate potential energy surface

Abstract

The hydrogen abstraction reaction of methanol with fluorine atoms can produce HF and CH3O or CH2OH radicals, which are important in the environment, combustion, radiation, and interstellar chemistry. In this work, the dynamics of this typical reaction is investigated by the quasi-classical trajectory method based on a recently developed globally accurate full-dimensional potential energy surface. Particularly, the vibrational state distributions of the polyatomic products CH3O and CH2OH are determined by using the normal mode analysis method. It is found that CH3O and CH2OH are dominantly populated in the ground state when the reactants are at the ground ro-vibrational state. The OH stretching mode, torsional mode, H2CO out-of-plane bending mode and their combination bands in the CH2OH product can be effectively excited once the OH stretching mode of the reactant CH3OH is excited to the first vibrationally excited state. Most of the available energy flows into the HF vibrational energy and the translational energy in both channels, while the radical products, CH3O or CH2OH, receive a small amount of energy, consistent with experiment, which is an indication of its spectator nature.