Hydrogenases are iron enzymes that catalyze the reversible conversion of protons to mol. hydrogen. [Fe-Fe] hydrogenases are known for efficient prodn. of H2, at their active site (the H-cluster) thus their structure and mechanism constitute both inspiration and a target for catalyst design. Since it has been recognized that the H-cluster contains low-spin Fe(I), monovalent iron has become a focus of bio-organometallic synthetic chem. The high asymmetry of the dinuclear site stabilizes the elusive Fe(I)Fe(II) oxidized state, Hox. Oxidn. of asym. complexes [PMe3(CO)2FeI(μ-pdt)FeI(CO)2IMes] ...
