Electron Spin Resonance of Gamma-Irradiated Single Crystal of Cytosine Monohydrate at 77°K

Abstract

Single crystals of cytosine monohydrate have been irradiated and analyzed with electron spin resonance spectroscopy at 77°K. Two types of radicals have been observed and identified as the cytosine cation and anion radicals. The hyperfine splittings of the 14N and 1H nuclei for the cation radical are found to be in fairly good agreement with the predictions of the molecular orbital theory. The anion-radical hyperfine splittings could not be resolved in all crystal orientations. Both types of radicals rapidly disappear upon heating, probably via mutual recombination.