73133-33-2Relevant articles and documents
Pulse Radiolytic Studies of the Reactions of HO2/O2- with Fe(II)/Fe(III) Ions. The Reactivity of HO2/O2- with Ferric Ions and Its Implication of the Occurrence of the Haber-Weiss Reaction
Rush, James D.,Bielski, Benon H. J.
, p. 5062 - 5066 (2007/10/02)
The reactions between ferrous ion, Fe2+, and the simple complexes of Fe(III), FeOH2+, and FeSO4+ with superoxide and perhydroxyl radicals O2-/HO2 have been studied as a function of pH (1-7) in aqueous sulfate and formate media.The measured rate constants for the various reactions are k17(HO2 + Fe2+) = (1.2 +/- 0.2) X 106 M-1 s-1 (in good agreement with earlier reported values6d); k18(O2- + Fe2+) = (1.0 +/- 0.1) X 107 M-1 s-1; k20(O2- + FeSO4+) ca. k22(O2- + FeOH2+) = (1.5 +/- 0.2) X 108 M-1 s-1.The reduction of FeSO4+ by HO2 is relatively slow, k19(HO2 + FeSO4+) 3 M-1 s-1.At neutral pH the superoxide radical is catlytically decomposed to dioxygen and hydrogen peroxide by trace amounts of Fe(II)/Fe(III), if the overall reaction is completed before Fe(III) can polymerize/precipitate.The corresponding second-order rate constant is kcat = (1.3 +/- 0.2) X 107 M-1 s-1.The results from the kinetic studies of reactions 20 and 22 corroborate the mechanism for the catalytic decomposition of hydrogen peroxide by Fe(II)/Fe(III) advanced by Barb, Baxendale, George, and Hargrave in 1951.2,3
