Huynh Lam K, Violi Angela
Department of Mechanical Engineering, The University of Michigan, Ann Arbor, Michigan 48109-2125, USA.
J Org Chem. 2008 Jan 4;73(1):94-101. doi: 10.1021/jo701824n. Epub 2007 Dec 4.
In this paper, we report a detailed analysis of the breakdown kinetic mechanism for methyl butanoate (MB) using theoretical approaches. Electronic structures and structure-related molecular properties of reactants, intermediates, products, and transition states were explored at the BH&HLYP/cc-pVTZ level of theory. Rate constants for the unimolecular and bimolecular reactions in the temperature range of 300-2500 K were calculated using Rice-Ramsperger-Kassel-Marcus and transition state theories, respectively. Thirteen pathways were identified leading to the formation of small compounds such as CH(3), C(2)H(3), CO, CO(2), and H(2)CO. For the initial formation of MB radicals, H, CH(3), and OH were considered as reactive radicals participating in hydrogen abstraction reactions. Kinetic simulation results for a high temperature pyrolysis environment show that MB radicals are mainly produced through hydrogen abstraction reactions by H atoms. In addition, the C(O)OCH(3) = CO + CH(3)O reaction is found to be the main source of CO formation. The newly computed kinetic sub-model for MB breakdown is recommended as a core component to study the combustion of oxygenated species.
在本文中，我们使用理论方法报告了对丁酸甲酯（MB）分解动力学机制的详细分析。在BH&HLYP/cc-pVTZ理论水平下探索了反应物、中间体、产物和过渡态的电子结构及与结构相关的分子性质。分别使用Rice-Ramsperger-Kassel-Marcus理论和过渡态理论计算了300 - 2500 K温度范围内单分子和双分子反应的速率常数。确定了13条导致形成诸如CH(3)、C(2)H(3)、CO、CO(2)和H(2)CO等小分子化合物的途径。对于MB自由基的初始形成，H、CH(3)和OH被视为参与氢提取反应的活性自由基。高温热解环境的动力学模拟结果表明，MB自由基主要通过H原子的氢提取反应产生。此外，发现C(O)OCH(3) = CO + CH(3)O反应是CO形成的主要来源。建议将新计算的MB分解动力学子模型作为研究含氧化合物燃烧的核心组件。
