A phosphoramidite-based [FeFe]H2ase functional mimic displaying fast electrocatalytic proton reduction

Abstract

A phosphoramidite modified [FeFe]H₂ase mimic is studied as a model for photodriven production of H₂. On cathodic activation, the pyridyl–phosphoramidite complex exhibits a strongly enhanced rate of proton reduction over the previously reported pyridylphosphine model at the same overpotential. Analysis of the cyclic voltammograms shows an apparent H₂ evolution rate strongly influenced by the presence of both side-bound pyridyl and phosphorous-bound dimethylamino moieties at the phosphoramidite ligands. This difference is ascribed to the basic amines acting as proton relays.