Theoretical study on the atmospheric reaction of CH3O2with OH

A quantum chemical investigation on the reaction mechanism of CH3O2 with OH has been performed. Based on B3LYP and QCISD(T) calculations, seven possible singlet pathways and seven possible triplet pathways have been found. On the singlet potential energy surface (PES), the most favorable channel starts with a barrierless addition of O atom to CH3O2 leading to CH3OOOH and then the OO bond dissociates to give out CH3O + HO2. On the triplet PES, the calculations indicate that the dominant products should be 3CH2O2 + H2O with an energy barrier of 29.95 kJ/mol. The results obtained in this work enrich the theoretical information of the title reaction and provide guidance for analogous atmospheric chemistry reactions.