Metal-thiol and-thiolate interactions occur commonly and are of seminal importance in the biochemistry of life-sustaining processes. 1 Given the stability of the bond between a mercaptide ligand and various redox-active metals, it is of interest that Nature has evolved significant metalloenzymatic processes, which use key interactions of sulfur-containing functionalities with metals such as Ni, Co, Cu, and Fe (methanogenesis, 2 acetyl CoA ...