DESIGN OF TRANSITION-METAL OSCILLATORS BASED ON THE REDUCTION OF PERMANGANATE IONS BY KETO DICARBOXYLIC-ACIDS

Permanganate chemical oscillators with some keto dicarboxylic acids in the presence of phosphoric acid in a continuously stirred tank reacto r (CSTR) are described in terms of the phase diagrams in the [ketomalo nic acid](o)-k(o), [oxalacetic acid](o)-k(o), and [alpha-ketoglutaric acid](o)-k(o) planes, and in the [H3PO4](o)-k(o), [MnO4-](o)-k(o), tem perature-k(o) planes. The results show that an optimum degree of stabi lization of the Mn(IV) colloid, which may serve as a reservoir of solv ated Mn(IV) ions participating in the elementary reaction steps, is a prerequisite for the oscillations in the MnO4--keto dicarboxylic acid system. A skeleton mechanism for permanganate oscillators with keto di carboxylic acids involving five reaction steps is proposed.