Characterization of and Radiation Damage to Urea, Valine, and Sulfur Compounds: Report on Overall Activities

摘要

The identity and structure of the radical trapped in x-irradiated hydroxyurea have been established. A survey of ionizing irradiation damage to urea compounds as determined by ESR has been made. Five different types of radicals were found. The characteristic radical which occurred with the highest frequency was the one which is formed by the loss of an alpha -hydrogen from the substitutional group. An analysis of the irradiation damage in x-irradiated dl-valine, d-valine, and l-valine was completed. A study of the relative stability of the characteristic sulfur resonance in irradiated native proteins was made. The sulfur resonance was found to be more stable than the doublet resonance, and to remain with a measurable intensity after the disappearance of the doublet resonance. The rate of disappearance of the doublet resonance follows first order kinetics with an activation energy of 0.3 eV. The identity and structure of radicals in amide single crystals have been determined. A t-butyl radical was observed in x-irradiated pivalic acid.