A Heterobimetallic W–Ni Complex Containing a Redox-Active W[SNS]2 Metalloligand

The tungsten complex W­[SNS]2 ([SNS]­H3 = bis­(2-mercapto-4-methylphenyl)­amine) was bound to a Ni­(dppe) [dppe = 1,2-bis­(diphenylphosphino)­ethane] fragment to form the new heterobimetallic complex W­[SNS]2Ni­(dppe). Characterization of the complex by single-crystal X-ray diffraction revealed the presence of a short W–Ni bond, which renders the complex diamagnetic despite formal tungsten­(V) and nickel­(I) oxidation states. The W­[SNS]2 unit acts as a redox-active metalloligand in the bimetallic complex, which displays four one-electron redox processes by cyclic voltammetry. In the presence of the organic acid 4-cyanoanilinium tetrafluoroborate, W­[SNS]2Ni­(dppe) catalyzes the electrochemical reduction of protons to hydrogen coincident with the first reduction of the complex.