The reduction of ferrate(VI) to ferrate(V) by ascorbate.
The reduction of ferrate(VI) by ascorbate has been studied under anaerobic conditions in the pH range between 6.8 and 11.5 at 24 degrees C. A mechanism is proposed that is consistent with the observed rate constants k11 (HFeO4- + AH-) = (5.6 +/- 0.6) x 10(6) M-1 s-1, k12(FeO4(2-) + AH-) = (1.3 +/- 0.1) x 10(6) M-1 s-1 and the pK(HFeO4- in equilibrium with H(+) + FeO4(2-) = 7.9. Stoichiometric studies show that at high ratios of [AH-]/[FeO4(2-)], one ferrate(VI) oxidizes three molecules of ascorbate to the corresponding ascorbyl (A-) radicals.
Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973.
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Bielski
D001205:Ascorbic Acid / Q000494:pharmacology*; D005609:Free Radicals; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction / Q000187:drug effects
D005609:Free Radicals; C017311:ferrate ion; D007501:Iron; D001205:Ascorbic Acid