Department of Chemical Engineering, Al-Hussein Bin Talal University, Ma'an, Jordan.
J Phys Chem A. 2011 Dec 8;115(48):14092-9. doi: 10.1021/jp2067765. Epub 2011 Nov 10.
Motivated by the necessity to understand the pyrolysis of alkylated amines, unimolecular decomposition of acetamide is investigated herein as a model compound. Standard heats of formation, entropies, and heat capacities, are calculated for all products and transition structures using several accurate theoretical levels. The potential energy surface is mapped out for all possible channels encountered in the pyrolysis of acetamide. The formation of acetamedic acid and 1-aminoethenol and their subsequent decomposition pathways are found to afford the two most energetically favored pathways. However, RRKM analysis shows that the fate of acetamedic acid and 1-aminoethenol at all temperatures and pressures is to reisomerize to the parent acetamide. 1-Aminoethenol, in particular, is predicted to be a long-lived species enabling its participation in bimolecular reactions that lead to the formation of the major experimental products. Results presented herein reflect the importance of bimolecular reactions involving acetamide and 1-aminoethenol in building a robust model for the pyrolysis of N-alkylated amides.
受理解烷基胺热解必要性的驱动，本文选择乙酰胺作为模型化合物来研究其单分子分解。使用几种精确的理论水平，为所有产物和过渡态计算了标准生成焓、熵和热容。绘制了乙酰胺热解中可能遇到的所有通道的势能面。发现乙酰胺酸和 1-氨基乙醇的形成及其随后的分解途径提供了两种最有利的能量途径。然而，RRKM 分析表明，在所有温度和压力下，乙酰胺酸和 1-氨基乙醇的命运都是重排回母体乙酰胺。特别是 1-氨基乙醇被预测为长寿命物质，使其能够参与导致主要实验产物形成的双分子反应。本文的结果反映了涉及乙酰胺和 1-氨基乙醇的双分子反应在构建 N-烷基化酰胺热解的稳健模型中的重要性。
