The gas-phase reactions of singlet oxygen atoms with methane

Abstract

The reaction of excited singlet oxygen atoms with methane has been studied by photolysis of N₂O–CH₄ mixtures with 1849 Å radiation from a low-pressure mercury lamp. The results have been explained by a mechanism involving the insertion of oxygen atoms into the C–H bonds in methane to give vibrationally excited methanol: O*+ CH₄→ CH₃OH*. A kinetic analysis of the results gave an order-of-magnitude estimate of k₁₅=ca. 3 × 10¹⁰ l mol^–1 s^–1 at room temperature. The results obtained at high methane pressures provide evidence for the nitrous oxide-photosensitized decomposition of methane.