Shi Laishun, Wang Xiaomei, Li Na, Liu Jie, Yan Chunying
School of Chemistry and Chemical Engineering, Shandong University, South Campus, Jinan 250061, China.
ScientificWorldJournal. 2012;2012:918620. doi: 10.1100/2012/918620. Epub 2012 Feb 1.
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 online FTIR spectrophotometric method. The initial concentrations of methyl acetoacetate, chlorine dioxide, potassium iodide, and sulfuric acid and the pH value have great influence on the oscillation observed at wavelength of 289 nm. There is a preoscillatory or induction period, and the amplitude and the number of oscillations are associated with the initial concentration of reactants. The equations for the triiodide ion reaction rate changing with reaction time and the initial concentrations in the oscillation stage were obtained. Oscillation reaction can be accelerated by increasing temperature. The apparent activation energies in terms of the induction period and the oscillation period were 26.02 KJ/mol and 17.65 KJ/mol, 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 was proposed for the oscillation reaction.
为研究新型二氧化氯-碘离子-乙酰乙酸甲酯反应体系的化学振荡行为及机理，采用紫外-可见光谱法和在线傅里叶变换红外光谱法进行了一系列实验。乙酰乙酸甲酯、二氧化氯、碘化钾、硫酸的初始浓度以及pH值对在289nm波长处观察到的振荡有很大影响。存在一个预振荡或诱导期，振荡的幅度和次数与反应物的初始浓度有关。得到了振荡阶段三碘离子反应速率随反应时间和初始浓度变化的方程。升高温度可加速振荡反应。诱导期和振荡期的表观活化能分别为26.02kJ/mol和17.65kJ/mol。通过在线傅里叶变换红外分析检测到了中间体。基于本工作及文献中的实验数据，提出了该振荡反应合理的反应机理。
