标题：Sodium chlorite-iodine-methyl acetoacetate oscillatory reaction investigated by UV-vis spectrophotometric method
作者：Shi, Laishun; Qian, Yanan; Lin, Sha; Yang, Bing; Li, Na; Liu, Jie
作者机构：[Shi, Laishun; Qian, Yanan; Lin, Sha; Yang, Bing; Li, Na; Liu, Jie] Shandong Univ, Sch Chem & Chem Engn, Jinan 250061, Peoples R China.
通讯作者地址：[Shi, LS]Shandong Univ, Sch Chem & Chem Engn, South Campus, Jinan 250061, Peoples R China.
来源：JOURNAL OF THE IRANIAN CHEMICAL SOCIETY
关键词：Sodium chlorite; Oscillation reaction; UV-vis spectrophotometry;; Apparent activation energy; Methyl acetoacetate
摘要：A new sodium chlorite-iodine-methyl acetoacetate chemical oscillatory reaction was studied using UV-vis spectrophotometric method. The initial concentrations of methyl acetoacetate, sodium chlorite, iodine, sulfuric acid, and the pH value have great influence on the oscillation observed at wavelength of 585 nm. There is a pre-oscillatory or induction period; the amplitude and the number of oscillations are associated with the initial concentration of reactants. The equations for the I-3(-)-starch complex reaction rate changing with reaction time and the initial concentrations in the oscillation stage were obtained. The time of induction period decreases with the initial concentration of methyl acetoacetate or sulfuric acid, and increases with the initial concentration of sodium chlorite. A good linear relationship exists. Oscillatory reaction can be accelerated by increasing temperature. The apparent activation energies in terms of the induction period and the oscillation period were 114.28 and 64.92 kJ/mol, respectively. It may indicate that the two stages have different reaction mechanisms. The reaction of producing enol isomer by keto-enol tautomerism is an important step to constrain the time of induction period.