Catalytic Oxygen Evolution from Manganese Complexes with an Oxidation-Resistant N,N,O-Donor Ligand

There is great interest in developing Mn water-splitting catalysts due to their low cost, abundance, and relevance to the oxygen-evolving complex (OEC). Three ligands with highly donating pyridine alkoxide moieties, including 2-(pyridin-2-yl)propan-2-ol (pyalkH), 2,2-(pyridine-2,6-diyl)bis(propan-2-ol) (py-dialkH(2)), and 2-[(2,2-bipyridin)-6-yl]propan-2-ol (bipy-alkH), have been screened with Mn for oxygen-evolution catalysis. Complexes with the ligand bipy-alkH were shown to evolve O-2 when driven by Oxone (potassium peroxymonosulfate). The catalytic mixture generated from the precursor complex [Mn(bipy-alkH)Cl-2] retained activity in unbuffered solution beyond 160h.