In this study, the thermal decomposition mechanism of the amino acid ionic liquids (AAILs) including 1-ethyl-3-methylimidazolium ([Emim]) as the cation and Glycinate, Alaninate, Valinate, and Leucinate as the anions was investigated from the molecular approach. Different mechanisms of SN2, Hofmann elimination and alkyl rearrangement were proposed. These mechanisms were analyzed based on the steric hindrance effect of the alky groups and the nucleophilicity of the carboxylate and amine groups of the amino acid anions. SN2 and alkyl rearrangement mechanisms are the preferred routes of the reaction from the kinetic and thermodynamic viewpoints. Among all AAILs, [Emim][Ala] has the lowest thermal stability. To have an insight into the stability of the AAILs, topological properties and quantum chemistry reactivity indices (QCRI) were investigated and discussed. On the basis of QCRI analysis, low stability of [Emim][Ala] can be related to the lower electronic chemical hardness and greater positive character of the electrophilicity index in comparison with other AAILs. Moreover, the nature and energy of interactions at the transition states of decomposition reactions were evaluated by using the natural bond orbital method and atoms in molecules properties.

在这项研究中，从分子中研究了以1-乙基-3-甲基咪唑鎓（[Emim]）为阳离子，甘氨酸，铝酸，缬氨酸和亮氨酸为阴离子的氨基酸离子液体（AAIL）的热分解机理。方法。提出了SN2，霍夫曼消除和烷基重排的不同机理。基于烷基的空间位阻效应以及氨基酸阴离子的羧酸根和胺基的亲核性分析了这些机理。从动力学和热力学观点来看，SN 2和烷基重排机理是反应的优选途径。在所有AAIL中，[Emim] [Ala]具有最低的热稳定性。要了解AAIL的稳定性，研究和讨论了拓扑性质和量子化学反应性指数（QCRI）。根据QCRI分析，与其他AIL相比，[Emim] [Ala]的低稳定性可能与较低的电子化学硬度和较高的亲电性指数呈正相关。此外，通过使用自然键轨道方法和分子中的原子性质，评估了在分解反应过渡态时相互作用的性质和能量。