Mechanism for OH‐Initiated Oxidation of n‐Octane in the Presence of O2 and NO: A DFT Study

Density functional theory was used to study the mechanism for the OH‐initiated atmospheric oxidation of n‐octane in the presence of O2 and NO. The geometries and frequencies of the reactants, transition states, intermediates, and products were calculated at the B3LYP/6‐31G(d) level and single‐point energy calculations were carried out with a large basis set, 6‐311+G(3df, 2p). All of the possible product channels have been studied, but only the main ones are reported. The main products obtained are hydroxynitrates and hydroxycarbonyls, which have relative low vapor pressure and are inclined to form secondary organic aerosol. The theoretical results were compared with the available experimental observations.