The world depends on petroleum for everything from the plastics that contain our food to the natural gas that heats our homes to the gasoline that feed our cars’ engines. With rising prices of petroleum reflecting demand for this finite resource, attention has been turned to alternative sources of energy. Biodiesel, which exhibits many of the same properties as conventional diesel but is derived from biological sources, is an attractive alternative. Fats and oils are converted to biodiesel, fatty acid methyl esters (FAMEs), by transesterification. FAMEs are subsequently thermally cracked to form more lightweight transportation fuels such as natural gas, kerosene, and possibly gasoline. We aim to further understand the thermal cracking procedure, at an atomic level, in hopes that this may aid in future engineering of viable fuels. We will present our study on the effective computational modeling of bond dissociations in the FAMEs methyl linoleate and methyl oleate, which are the most common biodiesel products of soybeans and rapeseeds (also known as canola seeds). We have employed quantum chemical methods, including the density functionals B3LYP, M06-2X, and B97D; the wave function-based MP2; and the composite CBS-QB3 method. Bond dissociation in a 44-reaction database set for which experimental energies are known is used to evaluate methods. We find that the M06-2X/6-31+G(d,p) model chemistry provides results comparable to the composite CBS-QB3 method at a much reduced cost. Last, data are compiled for possible bond dissociations in FAMEs methyl oleate and methyl linoleate.

中文翻译：

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亚油酸甲酯和油酸甲酯键解离能：明智裂解产品的电子结构捕捞

从食物所含的塑料到加热房屋的天然气，再到为汽车引擎供油的汽油，世界都依赖石油。随着石油价格上涨反映了对这种有限资源的需求，人们的注意力已转向替代能源。生物柴油具有许多与常规柴油相同的特性，但它是由生物来源衍生的，是一种有吸引力的选择。油脂通过酯交换反应转化为生物柴油，脂肪酸甲酯（FAME）。随后将FAME热裂解以形成更轻量的运输燃料，例如天然气，煤油，可能还包括汽油。我们旨在从原子的角度进一步理解热裂化程序，希望这有助于将来可行燃料的工程设计。我们将介绍有关FAME中亚油酸甲酯和油酸甲酯的键解离的有效计算模型的研究，亚油酸甲酯和油酸甲酯是大豆和油菜籽（也称为油菜籽）最常见的生物柴油产品。我们采用了量子化学方法，包括密度泛函B3LYP，M06-2X和B97D。基于波动函数的MP2；以及复合CBS-QB3方法。使用已知反应能的44反应数据库集中的键解离作用来评估方法。我们发现，M06-2X / 6-31 + G（d，p）模型化学可在大大降低的成本下提供与复合CBS-QB3方法相当的结果。最后，汇编了在FAME中油酸甲酯和亚油酸甲酯可能发生的键解离的数据。