Ab initio potential energy surface for the reaction of O( [formula omitted]) with CH 2F

Abstract

The potential energy surface (PES) for the reaction of an oxygen atom with a fluorinated methyl radical has been studied using the G2MP2 level of theory. The calculations reveal an association–elimination mechanism. The addition reaction of O( 3 P ) to CH 2F produces an energy-rich intermediate OCH 2F ∗ which subsequently decomposes irreversibly. Five production channels of OCH 2F ∗ are found: H+CHFO, HF+HCO, CHFOH, F+CH 2O and H 2+FCO. CHFOH can decompose through six production channels: H+CHFO, HF+HCO, H+HCOF, H 2+FCO, F+HCOH and OH+CHF. Based on the present ab initio PES, the kinetic characteristics of the O( 3 P )+CH 2F reaction are estimated. The energy-specific rate constants for the unimolecular decomposition of OCH 2F are calculated by RRKM theory. H+CHFO are predicted to be the major products.