Ligand Radioisotopic Exchange Reaction of Diethyldithiocarbamato Complexes of Fe (III), Co(lll) and Ni(ll) in Dioxane and Dimethylformamide

Abstract

Using radiotracer technique and extraction Separation of reactants, the kinetics of the ligand isotopic exchange reaction of diethyldithiocarbamato complexes of Fe(III), Co(III) and Ni(II) in dioxane and dimethylformamide has been studied. MCKAY's plots are linear, and no zero time exchange has been observed. The exchange reaction is very slow for the cobalt complex, whereas for the iron and nickel complexes the reaction is very fast. The ligand exchange reaction for the cobalt complex seems to be of the first order with respect to the complex, and of zero order with respect to the ligand, which suggests the S^i mechanism. Activation energy and activat'ion entropy for this reaction in dimethylformamide are 88.4±8.9 kJ/mol and 48.8±25.2 J/mol-K respectively.