Spin trapping of the short-lived free radicals formed in γ-irradiated alcohols

Short-lived free radicals formed in γ-irradiated methanol, ethanol and 2-propanol have been detected by E.S.R. combined with spin trapping method using 2,4,6-tri-t-buthylnitrosobenzene (BNB) as a spin trap. The observed spectra could be identified clearly by the help of deuterated alcohols. The hydrogen spin adduct, which had not been clearly identified in earlier works, was observed together with alkoxy radicals and other radicals. It was revealed that a part of the hydrogen adduct could come from proton transfer to the anion radical of BNB, which was produced by electron capture during irradiation. From the change of ^∗CH₂OH/CH₃O^∗ ratio with that of added spin trap concentration one may conclude that the methoxy radical and hydrogen atom are primary radicals in radiolysis of liquid phase methanol. This conclusion is also supported by both the change of the ratio with irradiation temperature and the isotope effect on the spin adduct yields.