Targeting synthetic analogues of the metallo-sulfur active sites of nickel enzymes capable of important catalysis

The nickel containing enzymes NiFe-hydrogenase, carbon monoxide dehydrogenase and acetyl-CoA synthase are able to catalyse environmentally, and potentially industrially, important reactions: hydrogen uptake; carbon dioxide/carbon monoxide interconversion; and incorporation of carbon monoxide to form acetyl-CoA, respectively. Progress toward the synthesis of nickel–iron complexes with structural features related to the active sites of these enzymes are described, together with the synthesis, properties and crystal structure of the first methylated-nickel–iron diheterometallic complex, [{Fe(NS3)(NO)-S}Ni(CH3)(dppe)] (NS3 = N(CH2CH2S)33−), relevant to a proposed mechanistic intermediate in the acetyl-CoA synthase mechanism.