Electrocatalytic H2 evolution promoted by a bioinspired (N2S2)Ni(ii) complex

A bioinspired (N2S2)Ni(ii) electrocatalyst is reported that produces H2 from CF3CO2H with a turnover frequency (TOF) of ∼1250 s−1 at low acid concentration (<0.043 M) in MeCN. A mechanism for the H2 production by this electrocatalyst is proposed and its activity is benchmarked against those of other reported molecular Ni H2 evolution electrocatalysts. The involvement of a hemilabile pyridyl group of the N2S2 ligand is proposed to mimic the role of a cysteine residue involved in the biological proton reduction performed by [NiFe] hydrogenases.