Reaction mechanisms of methanol oxidation by FeIVO biomimetic complex

Density functional theory calculations were carried out to investigate the reaction mechanism of methanol oxidation mediated by [(bpg)FeIVO]+ (A). Two models (CH3CN-bound ferryl model B and CH3OH-bound ferryl model C) were also studied in this work to probe ligand effect. Mechanistically, both direct and concerted hydrogen transfer (DHT and CHT) pathways were explored. It is found that the initial step of methanol oxidation by A is CH bond activation via a DHT pathway. Addition of different equatorial ligands has considerable influence on the reaction mechanisms. Methanol oxidation mediated by B commences via OH bond activation; in sharp contrast, the oxidation mediated by C stems from CH bond activation. Frontier molecular orbital analysis showed that the initial CH bond activation by all these model complexes follows a hydrogen atom transfer (HAT) mechanism, whereas OH bond activation proceeds via an HAT or proton transfer. © 2016 Wiley Periodicals, Inc.