Ferrate(VI) and ferrate(V) oxidation of organic compounds: Kinetics and mechanism
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
This review presents a critical assessment of the kinetics and mechanisms of the oxidation of organic compounds, X (organosulfur compounds, amines, phenols, alcohols, hydrocarbons, ascorbate, and pharmaceuticals) by ferrate(VI) (Fe VIO 42-) and ferrate(V) (Fe VO 43-). The rate constants (k app, M -1s -1) of reactions of these compounds with ferrate(VI) and ferrate(V) usually decrease with increase in pH in alkaline media and the species-specific rate constants were evaluated from pH-dependent kinetics. The rate constants for the reactions of HFe VIO 4- and HFe VO 42- with X were correlated with 1-e - and 2-e - reduction potentials in order to understand the mechanisms of the reactions. Ferrate(V) generally oxidizes compounds by a 2-e - transfer step. The reactions of ferrate(VI) with compounds may be characterized most commonly by (i) a 1-e - transfer step from Fe(VI) to Fe(V), followed by a 2-e - transfer to Fe(III) as the reduced product (Fe VIFe VFe III), and (ii) 2-e - transfer steps (Fe VIFe IVFe II). Oxygen-atom transfer to the compounds may occur through involvement of either ferrate(VI) or ferrate(V) in the oxidations carried out by ferrate(VI). Hammett-type relationships of reactions provided additional information on intermediates involved in oxidation processes and proposed mechanisms are consistent with the oxidized products of the reactions. Oxidation of biological species by ferrate(VI) is also briefly presented. 2012 Elsevier B.V..
