title: [Calcium-dioxolene complexes: rate constants of pyrocatechol oxidation in the presence of Ca2+].
abstract: The effect of calcium ions on the rate of pyrocatechol autoxidation at pH 9.0 has been studied by mathematical modeling. The effect of Ca2+ on the oxygen absorption rate has been studied, and a kinetic model has been suggested, which takes different stages of interaction of pyrocatechol and its radical form with oxygen into account. It has been shown that the prooxidant action of Ca2+ is related to an abrupt increase (approximately by three orders of magnitude) in the rate constant of comproportionation (reaction of chain branching and formation of o-semiquinonates) and a marked decrease (by two orders of magnitude, from 1.4 10(7) to 0.6 10(5) M(-1)s(-1)) in the rate constant of disproportionation of o-semiquinones. The system can be used as a model for studying the prooxidant action of calcium ions.
authors.forename: A V
authors.initials: AV
authors.lastname: Lebedev
authors.forename: M V
authors.initials: MV
authors.lastname: Ivanova
authors.forename: É K
authors.initials: ÉK
authors.lastname: Ruuge
mesh_terms: D002118:Calcium / Q000737:chemistry*; D002396:Catechols / Q000737:chemistry*; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D010084:Oxidation-Reduction
chemical_list: D002396:Catechols; D006573:Heterocyclic Compounds, 1-Ring; C034221:catechol; D002118:Calcium