Perturbations of the Briggs-Rauscher oscillating system by iron-phenanthroline complexes

摘要

Perturbations of the oscillatory regime of the Briggs-Rauscher (BR) reaction by the iron(II)-phenanthroline (ferroin) complex were observed in batch conditions. The path of the perturbation (immediate quenching of oscillations-inhibition time-resumption of oscillations) is similar to that provoked by antioxidant free-radical scavengers; however, perturbations occur in a ferroin concentration range much lower than that in which antioxidants act. To investigate this effect, reactions between the iron(II)-or iron(III)-phenanthroline (ferriin) and reagents or intermediates of the BR system were studied in detail. Results of these studies showed that the interaction of the ferroin/ferriin couple with iodine production is responsible for the observed perturbation. A mechanistic interpretation involving HOO. radical is proposed. (c) 2006 Elsevier B.V. All rights reserved.