A (Ni–SIr)I model for [NiFe]hydrogenase

We report the synthesis and characterization of a μ-hydroxo NiRu complex as a model for the active site of (Ni–SIr)I of [NiFe]hydrogenase. This is the first example of the (Ni–SIr)I model with a bridging hydroxo ligand between dimetal centers and an available coordination site on Ni center cis to the bridging hydroxo ligand. We have determined the structure of the (Ni–SIr)I model complex by X-ray analysis and reported reversible switching between the catalytically inactive (Ni–SIr)I and a catalytically active (Ni–SIr)II models.