Chlorine Dioxide–Iodide–Methyl Acetoacetate Oscillation Reaction Investigated by UV–Vis and an Online FTIR Spectrophotometric Method
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In order to study the chemical oscillatory behavior and mechanism of a new chlorine dioxide–iodide ion–methyl acetoacetate reaction system, a series of experiments were done by using UV–vis and an online FTIR spectrophotometric method. The initial concentrations of methyl acetoacetate, chlorine dioxide, potassium iodide, sulfuric acid, and the pH have great influences on the oscillations observed at the wavelength 350 nm. There is a pre-oscillatory or induction period, and the amplitude and number of oscillations are dependent on the initial concentration of the reactants. Equations were obtained for the variation of the triiodide ion reaction rate with the reaction time and the initial concentrations in the oscillation stage. The oscillation reaction was accelerated by increasing the temperature. The apparent activation energies for the induction period and the oscillation period are 55.65 and 33.00 kJ·mol−1, respectively. The intermediates were detected by the online FTIR analysis. Based upon the experimental data in this work and in the literature, a plausible reaction mechanism is proposed for the oscillation reaction.
KeywordsChlorine dioxide Oscillation reaction UV–vis spectrophotometry Online FTIR Apparent activation energy Methyl acetoacetate
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