Protonation and Alkylation of a Dinuclear Nickel Thiolate Complex

Protonation of transition metal ligand donor atoms is often invoked in metallobiochemical redox mechanisms. However, examples of complexes with thiol ligands are rare. The authors report the synthesis and characterization of a novel protonated dithiolato-bridged dinickel(II) complex that features a terminal thiol ligand and the crystal structure of an analogous complex featuring an alkylated thiolate ligand. These dinuclear complexes may serve as models in exploring the chemistry of the cysteinate-bridged dimetallic active site of Ni,Fe hydrogenases (H{sub 2}ases).