Mechanism of reaction of alkyl radicals with (Ni(II)L)2+ complexes in aqueous solutions.

The reactions of methyl radicals, *CH3, with the macrocyclic complexes Ni(II)L(1-5) (L(1-5) = cyclam derivatives, vide infra) and Ni(II)edta in aqueous solutions were studied. Methyl radicals react with all these nickel complexes, forming intermediates with Ni(III)-C sigma-bonds. The L(m)Ni(III)-CH3 complexes are formed in equilibria processes with relatively fast forward rate constants of k(f) > 1 x 10(8) M(-1) s(-1) (except in the case of NiL2-trans I cyclam, where the reaction is slower).