Cerium(IV)-driven water oxidation catalyzed by a manganese(V)-nitrido complex

The study of manganese complexes as water-oxidation catalysts (WOCs) is of great interest because they can serve as models for the oxygen-evolving complex of photosystem II. In most of the reported Mn-based WOCs, manganese exists in the oxidation states III or IV, and the catalysts generally give low turnovers, especially with one-electron oxidants such as Ce^IV. Now, a different class of Mn-based catalysts, namely manganese(V)-nitrido complexes, were explored. The complex [Mn^V(N)(CN)₄]^2- turned out to be an active homogeneous WOC using (NH₄)₂[Ce(NO₃)₆] as the terminal oxidant, with a turnover number of higher than 180 and a maximum turnover frequency of 6 min^-1. The study suggests that active WOCs may be constructed based on the Mn^V(N) platform. High turnover: The study of manganese complexes as catalysts for the oxidation of water is of great interest as they can serve as models for the oxygen-evolving complex of photosystem II. The manganese(V)-nitrido complex [Mn(N)(CN)₄]^2- was now shown to catalyze the oxidation of water by cerium(IV) with a turnover number (TON) of higher than 180.