ESR Spectroscopic Detection of Methoxyl Radicals Formed in the Photochemical Gas-Phase Reaction of Methane and Water

Article abstract of DOI:10.1021/j100354a020

During the photolysis of methane-water gas mixtures, a radical has been trapped by both α-phenyl-N-tert-butylnitrone and 5,5-dimethyl-1-pyrroline 1-oxide.The analysis of the ESR parameters along with the control experiments and the determination of reaction products strongly suggests the detection of methoxyl radical.It is revealed that the yield of methanol and methoxyl radical depends on the initial concentration of methane and the reaction temperature, and the observed difference between their yields is mainly ascribed to the reaction CH3O^. + CH4 --> CH3OH + ^.CH3, which is favorable at higher concentration of initial methane and at higher reaction temperature.Furthermore, the preferential trapping of the methoxyl radical by the spin traps is discussed.