Electrode initiated proton-coupled electron transfer to promote degradation of a nickel(ii) coordination complex.

A Ni(ii) bisphosphine dithiolate compound degrades into an electrode-adsorbed film that can evolve hydrogen under reducing and protic conditions. An electrochemical study suggests that the degradation mechanism involves an initial concerted proton-electron transfer. The potential susceptibility of Ni-S bonds in molecular hydrogen evolution catalysts to degradation C-S bond cleavage is discussed.