Alloxan-dialuric acid cycling: a complex redox mechanism
Related Experiment Video
Updated: Jun 25, 2026

Simultaneous Multi-surface Anodizations and Stair-like Reverse Biases Detachment of Anodic Aluminum Oxides in Sulfuric and Oxalic Acid Electrolyte
Published on: October 5, 2017
Janina A Rosso1, Marcos A Astorga, Daniel O Martire
1Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas, Departamento de Quimica, Universidad Nacional de La Plata, La Plata, Argentina. janina@inifta.unlp.edu.ar
Abstract:
Time-resolved kinetic studies involving the reactions of alloxan (A.H(2)O) with the reducing species superoxide and carbon dioxide radical anions and the reaction of dialuric acid (HA(-)) with sulphate radicals showed that the same radical (AH(.)) was formed either by the one-electron reduction of alloxan or by the one-electron oxidation of dialuric acid. A mechanism including several reversible reactions was proposed and validated. A detailed kinetic analysis yields the following bimolecular rate constants: k(A.H(2)O + [image omitted] ) < 10(5) m ( -1 ) s(-1), k(A.H(2)O + O(2) (-))=(3.4+/-0.5)x10(6) m ( -1 ) s(-1), k(HA(-)+[image omitted] )=(8+/-1)x10(7) m ( -1 ) s(-1) and k(AH(.)+AH(.))=(1.7+/-0.8)x10(8) m ( -1 ) s(-1). From these values, the redox potentials E degrees (A.H(2)O,H(+)/AH(.))=(-290+/-20) mV, E degrees (AH(.)/HA(-))=(277+/-20) mV and E degrees (A.H(2)O,H(+)/HA(-))=(-15+/-20) mV, were obtained.
Related Concept Videos
Redox Equilibria: Overview
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
Ladder Diagrams: Redox Equilibria
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+...
Redox Reactions
Redox Reactions
Balancing Redox Equations
