The influence of visible light on the formation of revival waves in the 1,4-cyclohexanedione–bromate–ferroin reaction

Abstract

Revival waves, which emerge spontaneously long after the oscillatory bromate–1,4-cyclohexanedione–ferroin reactions become quiescent, are found susceptible to the illumination of visible light. Depending on the intensity and the duration of the light perturbation, an illumination can drive the system either to a reduced reaction state with a high concentration of ferroin, or to an oxidized state with a high concentration of ferriin. When hydroquinone, a main product from 1,4-cyclohexanedione oxidation, is used to gradually replace 1,4-cyclohexanedione as the reductants, the induction period of the formation of revival waves is shortened significantly; however, there is no clear difference in their photosensitivity. These new experimental results suggest that the observed photosensitivity is determined by the photochemistry of the products of hydroquinone.