Tropospheric oxidation mechanism of dimethyl ether and methyl formate

The oxidation mechanism of dimethyl ether is investigated using ab initio m ethods. The structure and energetics of reactants, products, and transition structures are determined for all pathways involved in the oxidation mecha nism. The detailed pathways leading to the experimentally observed products of dimethyl ether oxidation are presented. The energetics of over 50 speci es and transition structures involved in the oxidation process are calculat ed with G2 and G2(MP2) energies. The principal pathway following the initia l attack of dimethyl ether (CH3OCH3) by the OH radical is the formation of the methoxymethyl radical (CH2OCH3). Oxidation steps lead to the formation of methyl formate, which is consistent with the experimentally observed pro ducts. Oxidation pathways of methyl formate are also considered.