Bimetallic nickel–cobalt hydrides in H2 activation and catalytic proton reduction

The synergism of the electronic properties of nickel and cobalt enables bimetallic NiCo complexes to process H2. The nickel–cobalt hydride [(dppe)Ni(pdt)(H)CoCp*]+ ([1H]+) arising from protonation of the reduced state 1 was found to be an efficient electrocatalyst for H2 evolution with Cl2CHCOOH, and the oxidized [Ni(II)Co(III)]2+ form is capable of activating H2 to produce [1H]+. The features of stereodynamics, acid–base properties, redox chemistry and reactivity of these bimetallic NiCo complexes in processing H2 are potentially related to the active site of [NiFe]-H2ases.