Synthetic Support of De Novo Design: Sterically Bulky [FeFe]-Hydrogenase Models


  • We acknowledge financial support from the National Science Foundation (CHE-0616695 and CHE-0541587) and the R. A. Welch Foundation (A-0924).


original image

A twisted mimic: Upon oxidation of [(μ-SCH2C(CH3)2CH2S-){FeI(CO)2PMe3}2], rearrangement yields the mixed-valent FeIFeII cation in a square-pyramid/inverted square-pyramid geometry with a semibridging CO ligand, closely mimicking the [FeFe] hydrogenase enzyme active site. According to de novo design principles, the steric effect of bridgehead bulk in the S–S bridging ligand stabilizes this structure in the absence of the protein matrix.