Dissociation dynamics of CF 3C(O)X compounds (where X = H, F and Cl)

Abstract

Dissociation pathways of CF 3C(O)H, CF 3C(O)F, and CF 3C(O)Cl are studied using ab initio molecular orbital theory. Equilibrium geometries and transition state structures are fully optimized. Heats of reaction and activation energies are computed by using the Møller-Plesset perturbation theory with and without annihilation of spin contamination for molecular and free radical dissociation pathways. A new primary dissociation pathway is predicted to be the most favorable reaction route to dissociation for CF 3C(O)H, CF 3C(O)F and CF 3C(O)Cl. It is the 1,2-CF 2 molecular elimination process that forms CF 2 radicals and HFCO, F 2CO or FClCO. In the case of CF 3C(O)Cl, the extrusion of chlorine atoms to yield CF 3CO radicals is the next pathway which could compete with the 1,2-CF 2 elimination route.