A TPD-MS study of the interaction of coumarins and their heterocyclic derivatives with a surface of fumed silica and nanosized oxides CeO2/SiO2, TiO2/SiO2, Al2O3/SiO2
作者:Kostiantyn Kulyk、Valentyna Ishchenko、Borys Palyanytsya、Volodymyr Khylya、Mykola Borysenko、Tetiana Kulyk
DOI:10.1002/jms.1765
日期:——
The interactions between coumarins and the surface of fumed SiO2, CeO2/SiO2, TiO2/SiO2 and Al2O3/SiO2 were assessed by means of temperature-programed desorption mass spectrometry. The different stages of the thermolysis of coumarin were identified and an analysis of the underlying reactions was performed. The kinetic parameters of the involved reactions were thus obtained. The decomposition of thiazolyl-substituted coumarins was found to proceed through a ‘thiazole–thiazine’ ring expansion in the adsorbed state. A linear correlation between the sigma constants (Σσ) of the coumarin substituents and the activation energy of CO2 formation was obtained. Copyright © 2010 John Wiley & Sons, Ltd.
利用程序升温脱附质谱技术,评估了香豆素与气相二氧化硅、氧化铈/二氧化硅、二氧化钛/二氧化硅以及氧化铝/二氧化硅表面的相互作用。鉴别出香豆素热解的不同阶段,并进行了基础反应的分析。从而获得了相关反应的动力学参数。发现噻唑取代的香豆素在吸附状态下通过“噻唑-噻嗪”环扩展进行分解。获得了香豆素取代基的sigma常数(Σσ)与CO2形成活化能之间的线性关系。版权所有 © 2010 John Wiley & Sons, Ltd.