Selective catalytic oxidation of hydrocarbons. New prospects

Methods for enhancing the catalytic activity of transition metal complexes in hydrocarbon (particularly, alkylarene) oxidation with dioxygen are briefly discussed. Attention is focused on the original method of controlling the catalytic activity of complexes ML¹_n [M=Ni(II), Fe(II,III); L=acac, enamac, n=2, 3] in the alkylarene oxidation to hydroperoxides by introducing additional electron-donating mono- or polydentate modifying ligands L². The role played by H-bonds in the mechanisms of homogeneous catalysis is discussed. A strategy of controlling the catalytic activity of Fe(II,III)(acac)_n·L² complexes (L²=R₄NBr or 18-crown-6) by adding H₂O to small concentrations is proposed. The activity of Ni and Fe catalysts in microsteps of chain initiation and propagation in the radical chain process of ethylbenzene oxidation is assessed.