Establishing the mechanism of Rh-catalysed activation of O2 by H2

Abstract

Reductive activation of O₂ by H₂ with rhodium terpyridine complexes in H₂O and CH₃CN is described and the mechanism is fully elucidated. The rhodium complex extracts electrons from H₂ and reductively activates O₂ to form a peroxo active intermediate. This intermediate is able to oxidise triphenyl phosphine to triphenyl phosphine oxide. A model system constructed in CH₃CN provides isolable analogues of catalytic intermediates in H₂O, allowing a detailed look at each step in the catalytic cycle.