The DFT and ab initio investigations on the mechanism of CF3O2 + H reaction

The mechanisms for the reaction of CF3O2 with atomic hydrogen were studied with ab initio and DFT methods. The results reveal that the reaction could take place on the singlet and triplet potential energy surfaces (PES). For the singlet PES, addition/elimination and substitution mechanisms are determined, and the former one is dominant. The most favorable channel involves the association of CF3O2 with H atom to form CF3O2H (IM1) via a barrierless process, and then the O-O bond dissociates to give out CF3O + OH. The secondary product might be CF3OH + O, formed from the O-O bond cleavage in the initial adduct CF3O(H)O (IM2). Other products such as CF3 + O2H, HF + CF2O2 and O2 + CHF3 are of no importances because of higher barriers. On the triplet PES, only substitution mechanism is located. With higher barriers involving, the channels on the triplet PES could be negligible compared with the channels on the singlet PES.