Paramagnetic Resonance Study of Irradiated Glasses of Methanol and Ethanol

Methanol and ethanol, including some of those alcohols with deuterium substitution, have been cooled to glasses at 77°K, irradiated with gamma rays, and then examined at several temperatures in a paramagnetic resonance spectrometer. The alcohols become intensely colored and a paramagnetic resonance spectrum associated with this color has been observed superimposed on part of an underlying spectrum. The color can be bleached with incandescent illumination, and after bleaching the underlying three- or five-line spectrum (methanol and ethanol, respectively) becomes stronger showing that the bleachable species is a precursor for at least a portion of the species giving the underlying spectrum. The manner in which the five-line ethanol spectrum changes with temperature is discussed. Deuterium substitution shows that the hyperfine lines originate from four of the protons originally present on the carbon atoms of the parent alcohol and that a proton of the parent alcohol has left the α-carbon. Possible radicals that could explain the results are discussed.