Electrocatalytic reduction of CO2 to CO and HCO2− with Zn(ii) complexes displaying cooperative ligand reduction

Abstract

Air-stable zinc(II) pyridyl phosphine complexes, [Zn(κ²-2,6-{Ph₂PNMe}₂(NC₅H₃))Br₂] (1) and [Zn(κ²-2-{Ph₂PNMe}(NC₅H₃))Br₂] (2) are reported and 1 was capable of electrocatalytic reduction of CO₂ at −2.3 V vs. Fc^+/0 to yield CO/HCO₂H in mixed water/acetonitrile solutions. DFT computations support a proposed mechanism involving electron transfer reactions from a species with the anionic PN³P ligand (“L⁻/Zn(II)”).