Chemical origin of the sustained-like pattern formation observed in the bromate — Dual substrate — Dual catalyst oscillatory batch system

Abstract

The BrO3− — BrAc — Ru(bpy)32+ subsystem is shown to represent the core oscillator that serves as source of the long lasting temporal and spatial periodic behaviors observed in the BrO3− — H2PO2− — acetone — Mn2+ — Ru(bpy)32+ — acid “double substrate-double catalyst” oscillatory batch system. The BrAc — the substrate of the core oscillator — is formed and accumulated in the reactions taking place in the six-component system. BrAc was produced in a separate experiment with bromide, acetone, acid and excess bromate and the mixture was used for bringing about patterns in the thin solution layer after adding the Ru(bpy)32+ catalyst. The two-dimensional reaction-diffusion patterns that appear in the subsystem and its parent system are very similar in wave speed, wavelength, color and in the duration of the pattern evolution, therefore a common chemical origin is supposed to exist in their formation. The role that the BrAc may play in the mechanism of the BrO3− — reductant — acetone — catalyst type oscillators (∼ 30 variants) is also pointed out.