Visible-Light-Driven Photocatalytic CO₂ Reduction by a Ni(II) Complex Bearing a Bioinspired Tetradentate Ligand for Selective CO Production

A Ni(II) complex bearing an S₂N₂-type tetradentate ligand inspired by the active site of carbon monoxide dehydrogenase was found to selectively catalyze CO₂ reduction to produce CO in a photocatalytic system using [Ru(bpy)₃]²⁺ (bpy = 2,2'-bipyridine) as a photosensitizer and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole (BIH) as an electron donor. The Ni(II) complex shows a high turnover number over 700 with high CO selectivity of >99% and quantum yield of 1.42% in the photocatalytic system.