Cobalt(III) Complexes with Carboxamido‐N and Sulfenato‐S or Sulfinato‐S Ligands Suggest that a Coordinated Sulfenate‐S is Essential for the Catalytic Activity of Nitrile Hydratases

A bis(sulfenato-S)CoIII complex and its corresponding bis(sulfinato-S) complex were prepared. Their catalytic nitrile hydration activity was tested. Whereas the former catalyzes the hydration of CH3CN under mild acidic conditions, the latter is inactive. A mechanism for this reaction is proposed, in relation with nitrile hydratase activity.