Reactions of Ni(II) and its complexes with free radicals derived from thymine

Abstract

The effects of nickel (II) ions and its complexes on the products arising from the γ-radiolysis of thymine were studied. The decomposition of the pyrimidine base and formation of different radiolytic products indicate that nickel(II) ions or its complexes have little effect on the radiosensitivity of thymine. The transient hydroxyl adduct of thymine reacts with Ni(II) with the formation of a complex having a nickel–carbon bond. The rate constants for the reactions are of the order of 106 dm3 mol−1 s−1. Possible mechanisms for the formation of different products in the radiolysis of thymine in the presence of nickel(II) compounds are discussed.