Kinetic study of the reactions of oxoiron(IV) with aromatic substrates in aqueous solutions

The kinetics of the reactions of oxoiron(IV) (FeO 2+ ) with phenol, nitrobenzene, m ‐, o ‐, and p ‐nitrophenol in 1 M HClO 4 was investigated by the stopped‐flow technique. The rate constants of these reactions decrease with increasing the one‐electron reduction potentials of the corresponding radical cations of the substrates and with the Hammett parameter of the NO 2 group in the phenol ring. A reaction mechanism is proposed, which accounts for the observed trends and for the nature of the reaction products.