Haber- Weiss cycle

This sequence correlates quite well with the reactivity of these ions in the Haber-Weiss cycle of hydroperoxide decomposition. 

In this classical Haber-Weiss cycle iron is being reduced by superoxide anion radical (02T), ascorbic acid or glutathione and subsequently decomposes hydrogen peroxide - formed by spontaneous dismutation of 02T - in the Fenton reaction to produce 0H. This iron-driven 0H formation has a stringent requirement for an available iron coordination site, a sine qua non met not only by hexaaquoiron(III) but by most iron chelates (28). Thus, Fe-EDTA, -EGTA, and -ATP retain a reactive coordination site and catalyze the Haber-Weiss cycle. Phytic acid, however, occupies all available iron coordination sites and consequently fails to support 0H generation (Figure 6). 

Koppenol, W.H., Butler, J., and Van Leeuwen, J.W.L., The Haber-Weiss cycle, Photo-chem. Photobiol., 28, 655-660, 1978. 

Shi X, Leonard SS, Liu KJ, et al. 1998. Cr(III)-mediated hydroxyl radical generation via Haber-Weiss cycle. J Inorg Biochem 69 263-268. 

Koppenol WH. The Haber-Weiss cycle-70 years later. Redox Rep. 2001 6 229-234. 

Haber-Weiss reaction The Haber-Weiss cycle consists of the following two reactions ... 

These four reactions were terms the Haber- Weiss cycle despite two reactions being proposed by Haber and Willstadter (1931). Indeed, the only paper by Haber and Weiss (1934) was written in English and the other papers, published in German by Haber et al., were almost ignored (Koppenol 2001). Moreover, the third reaction in this cycle (5.118) was considered inefficient (George 1947, Barb et al. 1949), and... 

Koppenol, W. H. (2001) The Haber-Weiss cycle - 70 years later. Redox Report 6, 229-234 Koppmann, R., A. Khedim, J. Rudolph, D. Poppe, M.O. Andreae, G. Helas, M. Welling and... 

Scheme 9.13 The Haber-Weiss cycle for catalysis of the reactions of peroxides.

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