Photo-induced excitability in the tris-(bipyridyl)Ru(II)-catalyzed Belousov-Zhabotinsky reaction

The tris-(bipyridyl)Ru(II)-catalyzed Belousov-Zhabotinsky reaction in its steady state exhibits an excitable response to a light pulse in the visible region. The threshold light power for the excitability was determined as functions of initial concentrations of BrO3− and Br− under the flow condition. Excitable response has also been observed to a ‘negative’ light pulse (a pulsed cut-off of the steady illumination) applied to the steady state under illumination with low light power, while the system is not excitable in the steady state under illumination with high power. The photochemical reaction scheme leading to the observed photo-response is discussed.