Light-Induced State Transitions in the Oscillatory ClO2--Cl--Iodomalonic Acid System in a Semibatch Reactor

Abstract

The dynamical behavior of the oscillatory ClOz--Cl--iodomalonic acid reaction in a semibatch reactor has been found to be extremely sensitive to the UV light, while the light above 420 nm does not affect the kinetics. Continuous illumination increases the amplitude and the period. Oscillations are completely extinguished beyond a critical light power. Light-induced transitions from nonoscillatory to oscillatory state and bursting-like responses upon periodic perturbations with 370 nm light have been found. The lightaccelerated formation of a reactive iodine species from iodomalonic acid and its subsequent reaction with the chlorite ion is responsible for the light sensitivity of the dynamical behavior.

Photoinduced Bifurcation and Multistability in the Oscillatory Briggs−Rauscher Reaction

“…Photoinduced bifurcations such as the photoinduction and -inhibition of chemical oscillations in well-stirred homogeneous solutions have been discovered for several systems. [1][2][3][4][5][6][7][8][9][10] The image formation and its modulation by light irradiation in unstirred solutions have also been reported. [11][12][13][14] The use of light is advantageous in the investigation of nonlinear chemical systems not only for its feasibility in changing irradiation power and wavelength, but also for its possibility in elucidating the reaction mechanism with a wider perspective.…”

“…The effects of light irradiation on the nonlinear chemical systems have been attracting much interest in recent years. Photoinduced bifurcations such as the photoinduction and -inhibition of chemical oscillations in well-stirred homogeneous solutions have been discovered for several systems. − The image formation and its modulation by light irradiation in unstirred solutions have also been reported. − The use of light is advantageous in the investigation of nonlinear chemical systems not only for its feasibility in changing irradiation power and wavelength, but also for its possibility in elucidating the reaction mechanism with a wider perspective. In order to establish the mechanism of photoirradiation effects, a unified treatment based on the concept of relative cross section has been developed and applied to several chemical oscillator systems ,, for the identification of the primary light absorber.…”

Photoinduced Reaction between Chlorine Dioxide and Iodine in Acidic Aqueous Solution

“…Intermediates of its photolysis (e.g., ClO) are expected to be involved in composite reactions in the oscillatory system. Photoinduced disproportionation of iodomalonic acid has also been investigated in details and was assumed to be responsible for the peculiar photoresponses of the iodomalonic acid−chlorite ion reaction observed in a semibatch reactor . However, according to Horváth et al, iodomalonic acid plays only a minor role, if any, in the photoresponses, but the iodine−iodide ion−chlorine dioxide subsystem is largely responsible for the response to the illumination in the CDIMA reaction.…”

“…1 The oscillatory chlorite ion-iodide ion-malonic acid reaction system (CIMA) 2 and some of its derivatives have long been known to be sensitive to the illumination by visible and UV light. Both the spatial structures 3 and exotic solution kinetics 4 exhibited by these reactions can be influenced by illumination. Recently, a related chlorine dioxide-iodine-malonic acid system (CDIMA) was also found to show sharp photoresponses both in a batch 5 and in a continuous-flow stirred tank reactor (CSTR) under illumination with light in the wavelength range of 380-620 nm.…”

Effect of Light on the Belousov−Zhabotinsky Reaction in Water-in-Oil Microemulsions of Aerosol OT in Octane

“…The effect of light on the dynamics of nonlinear chemical systems has been the subject of considerable attention of many scientists. − The use of light in controlling the system is advantageous over the other external parameters because of the feasibility of changing its intensity and wavelength. A change in the wavelength sometimes brings about a different nonlinear behavior.…”