Complex Dynamical Behavior in the Oxidation of Thiocyanate by Iodate

Article abstract of DOI:10.1021/j100342a005

Complex dynamical behavior including oligooscillation (multiple extrema in concentration as a function of time) has been observed in the oxidation of thiocyanate in acidic medium.The stoichiometry of the reaction when thiocyanate is in stoichiometric excess over iodate is IO3^- + SCN^- + H2O <*> SO4^2- + CN^- + I^- + 2H⁺.In excess iodate the stoichiometry is 7IO3^- + 5SCN^- + 2H⁺ <*> I2 + 5ICN + 5SO4^2- + H2O.In high acidic concentrations the reaction initially produces iodine, and then later the iodine is consumed.In excess thiocyanate all the iodine produced is subsequently consumed, while in excess iodate some iodine is left at the end of the reaction.This behavior is explained via a network of nine reactions which are viable in acidic mixtures of iodate and thiocyanate.