Photo-induced excitability in the tris-(bipyridyl) ruthenium(II)-catalyzed minimal bromate oscillator

The tris-(bipyridyl)-ruthenium(II) -catalyzed minimal bromate oscillator in its reduced state was found to exhibit an excitable pulse response to the pulsed light perturbation in the visible region, while the oxidized steady state did not respond to the light pulse. The oxidized steady state under the continuous illumination was also found to be insensitive to a negative light pulse perturbation. These results are successfully accounted for by the reaction scheme in which the photo-excited metal complex produces additional HBrO2 to enhance the autocatalytic process. No evidence was found to support the photo-production of Br− in the minimal bromate oscillator.