REACTIONS OF COBALT(III) COMPLEXES WITH FREE-RADICALS DERIVED FROM THYMINE

The nature of interaction of Co(III) complexes such as Co(III)EDTA and Co(III)NTA with transient adducts of thymine such as TOH., T.-, and T H. formed in the gamma radiolysis of thymine were studied. The study s hows that TOH radicals do not undergo electron transfer reaction with Co(III) complexes whence no radiosensitization of thymine by Co(III) c omplexes was observed. Electron transfer however, takes place from T.- and TH. to Co(III) complexes. A plausible mechanism of radiolysis of thymine in presence of Co(III) complexes is discussed. (C) 1994 John W iley & Sons, Inc.