Periodicity and Chaos in Chemiluminescence: The Ruthenium-Catalyzed Belousov−Zhabotinsky Reaction

We investigate the chemiluminescence of the homogeneous Belousov-Zhabotinsky (BZ) reaction catalyzed by tris(2,2’-bipyridine)ruthenium (II) ([Ru(bpy) 3]) in a continuous-flow stirred tank reactor where the chemiluminescence originates from the electronically excited [Ru(bpy)3] catalyst. At high flow rates, Fareyordered as well as complex burst-like states are observed in the pure ruthenium-catalyzed reaction which we investigated using five different concentration sets. We also characterized the chemiluminescent behavior when both Ru2+ and Ce3+ were present at four different mole fractions. Under conditions of low Ru2+ concentrations, we observed two chaotic chemiluminescent states which are reached by a period-adding and a period-doubling route, respectively. Model calculations with the reaction scheme of Gao and Forsterling were performed with semiquantitative agreement with our experimental observations.