A set of structural
mimics of the [Fe]-hydrogenase active site
comprising all the group VIII metals, viz., [M(2-NHC(O)C5H4N)(CO)2(2-S-C5H4N)], has been synthesized. They exist as a mixture of
isomers in solution, and the relative stability of the isomers depends
on the nature of the metal and the substituent at the 6-position of
the pyridine ligand.