SYSTEMATIC DESIGN OF CHEMICAL OSCILLATORS .74. NEWLY DESIGNED PERMANGANATE-REDUCTANT CHEMICAL OSCILLATORS

The subfamily of manganese oscillating chemical reactions containing permanganate as oxidant, plus a reductant, and phosphate to stabilize intermediate Mn oxidation states has been expanded in two ways. The ''minimal'' manganese oscillator, MnO4- + Mn2+ + H2PO4-, and several of its oscillatory derivatives give oscillation when either arsenate or vanadate replaces phosphate. Oscillatory behavior in a flow reactor has also been found for seven new reductants: arsenite, thiocyanate, thiourea, ascorbic acid, hydroxylamine, dithionite, and nitrite. A two-component permanganate oscillator is constructed using arsenite as the reductant, in which the stabilizing arsenate is generated as a reaction product. Our results yield insight into the roles of the reductant and the stabilizer in promoting oscillation.