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 polyhalomethanes^3,4, 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.