Thorough mechanistic studies and DFT calculations revealed a background radical pathway latent in metal-catalyzed oxidation reactions of methane at low temperatures. Use of hydrogen peroxide with TFAA generated a trifluoromethyl radical (•CF3), which in turn reacted with methane gas to selectively yield acetic acid. It was found that the methyl carbon of the product was derived from methane, while the carbonyl carbon was derived from TFAA. Computational studies also support these findings, revealing the reaction cycle to be energetically favorable.

A computational model based on density functional calculations is presented for the hydration of acetylene to form acetaldehyde on the organotransition-metal fragment CpRu(PMe2Im′)2+ (where Me = methyl and Im′ = 1,4-dimethylimidazol-2-yl). The predicted 10-step reaction mechanism features extensive participation of the basic imidazolyl nitrogens in three distinct hydrogen transfer steps which stabilize the reaction pathway through a series of hydrogen donor–acceptor exchanges. Because several equivalents of water are present in the experiments, the impact of solvation on the activation barriers of all ten steps has been estimated by a combination of explicit solvent and semiempirical continuum methods. The results are in qualitative agreement with intermediates observed in laboratory studies of similar catalysts, forming the basis for a complete investigation of the mechanism.