Tracking the FeIV(O) intermediate and O-O bond formation of a nonheme iron catalyst for water oxidation

To identify the short-lived, highly-active iron intermediate generated in situ for water oxidation, we describe here a new complex 1 by subtle modulation of the TPA ligand and succeed in capturing the high-valent Fe-IV(O) species, which is responsible for the O-O bond formation and oxygen evolution with higher efficiency.