OXYGEN-INDUCED WAVE-FRONT INSTABILITIES AND DISORDER IN THE BELOUSOV-ZHABOTINSKY REACTION

Wavefront instabilities leading to spatiotemporal disorder in a convec tion-free and horizontally homogeneous Ru(bpy)(3)(2+)-catalyzed Belous ov-Zhabotinsky reagent had previously been measured and simulated. Nec essary conditions in a 20% O-2 atmosphere lair) were: high light inten sities (I> 150 mW/m(2)) and low catalyst concentrations (less than or equal to 1 mM). Here, we show that at sufficiently high O-2 concentrat ions, comparable instabilities and disorder appear even in the dark or at high (greater than or equal to 1 mM) catalyst concentrations. In c ontrast, in the ferroin-catalyzed reagent such dynamic processes are n ot observed at any value of I in air, although they do occur - indepen dently of I - at sufficiently high O-2 concentrations. (C) 1998 Elsevi er Science B.V. All rights reserved.