OXYHALOGEN SULFUR CHEMISTRY - OLIGOOSCILLATIONS IN THE FORMAMIDINESULFINIC ACID CHLORITE REACTION

The reaction between chlorite and formamidinesulfinic acid has been st udied in perchloric acid between pH 1 and 3. The stoichiometry of the reaction in excess chlorite is HO2SC(NH)NH2 + ClO2- + H2O --> SO42- OC (NH2)(2) + Cl- + 2H(+) (A), while the stoichiometry in excess formamid inesulfinic acid is a mixture of (A) and (B): 2HO(2)SC(NH)NH2 + ClO2- --> 2HO(3)SC(NH)NH2 + Cl- (B). In excess chlorite at the end of the ox idation of formamidinesulfinic acid ClO2 is formed from the reaction 2 ClO2- + HOCl + H+ --> 2ClO(2) + Cl- + H2O. The formation of ClO2 show s some oligooscillatory behavior in which, even in excess formamidines ulfinic acid, there is transient formation of ClO2. The reaction is au tocatalytic in HOCl via the asymmetric Cl2O2 intermediate. The dynamic s of the reaction are explained via a mechanism which is derived from the one used for the chlorite-thiourea reaction.