Photosensitive, Bubble-free, Bromate−1,4-Cyclohexanedione Oscillating Reactions. Illumination Control of Pattern Formation

Abstract

We study the effect of visible light on chemical waves in thin layers of solution containing the bromate−1,4-cyclohexanedione bubble-free oscillating reaction with added Ru(bpy) 3 2+, ferroin, or diphenylamine as the third initial reactant. The light sensitivity was found to be much stronger in the ferroin-catalyzed system than in the Ru(bpy) 3 -catalyzed one, contrary to observations in the analogous reactions with malonic acid as the reductant. The combination of photosensitivity and absence of bubbles makes these reactions convenient tools for studying waves and patterns in reaction−diffusion systems.