A Molecular Analogue of Cu/ZSM-5 Catalyzing the Monooxygenation of Hydrocarbons via a Mono μ-Oxo Dicopper Species

The conversion of methane to methanol by the enzyme particulate methane monooxygenase (pMMO) represents an important sink in the global methane cycle. However, the exact molecular mechanism of the enzymatic reaction is unknown. An inorganic model system of pMMO is Cu/ZSM-5. There is experimental and theoretical evidence that the CH₄-to-CH₃OH conversion proceeds at a mono μ-oxo dicopper site in the latter system. We have prepared a discrete molecular complex exhibiting a Cu₂O core and found that it catalyzes the monooxygenation of aliphatic substrates with bond dissociation energies (BDEs) up to 82 kcal/mol. Herein, we show by theoretical calculations that this system exhibits an energy profile for the activation of C–H bonds that is comparable to that of Cu/ZSM-5 catalysts.