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Title: ESR and spin trapping study of. gamma. -irradiated aqueous hydantoin solutions. Keto-enol equilibrium and post-radiolysis growth

Journal Article · · Radiat. Res.; (United States)
DOI:https://doi.org/10.2307/3576097· OSTI ID:5433740

An air-saturated aqueous hydantion soluton was ..gamma..-irradiated in the presence of the spin trap 2-methyl-2-nitrosopropane(MNP). The ESR spectrum of the spin adduct produced from hydantoin was assigned to the structure NH-C(=O)-NH-C(=O)-CH-N(O)-/sup t/Bu (I). When the pH was raised from 9.7 to 12.5, it was found that the structure of the spin adduct changes to N=C(O/sup -/)-N=C(OH)-CH-N(O)-/sup t/Bu and that this change is reversible. This spectral change was investigated as a function of pH, and the pK value for the equilibrium was found to be about 11.5. The post-radiolysis growth of the ESR signal was observed for the spin adduct I and di-t-butyl nitroxide, which is produced in the same solution, and was markedly pH dependent. The mechanism for this growth is the same as that previously found in a photolysis study of aqueous MNP solutions.

Research Organization:
National Inst. of Health, Bethesda, MD
OSTI ID:
5433740
Journal Information:
Radiat. Res.; (United States), Vol. 95:3
Country of Publication:
United States
Language:
English