Alkyl–cobalt mediation of DDT hydrolysis

Abstract

A POSSIBLE role for vitamin B12 in the detoxification of polyhalogenated hydrocarbon pesticides such as DDT has occasionally been postulated (ref 1 and references therein), and DDT has been shown to inhibit bacterial B12-dependent methanogenesis2. Although reduced cobalamins and cobaloximes will react with simpler species such as polyhalomethanes3,4, no adduct between DDT or related compounds and cobalt has previously been observed2. It has been suggested that alkyl–cobalt complexes of the ligand CR (Fig. 1) have some chemical similarities to B12 (ref. 5) and zinc complexes of CR have yielded results relevant to carbonic anhydrase6. We report the use of cobalt–CR to mediate the hydrolysis of DDT, the isolation of an alkyl–cobalt derivative of a hydrolysis product of DDT, and the formation of di(p-chlorophenyl) ketone from this compound.