Nascimento Joel Leitão, Alves Tiago Vinicius, Shang Yanlei
Departamento de Físico-Química, Instituto de Química, Universidade Federal da Bahia, Rua Barão de Jeremoabo, 147, 40170-115- Salvador, Bahia, Brazil.
Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong 250014, P. R. China.
J Phys Chem A. 2025 Jun 12;129(23):5107-5117. doi: 10.1021/acs.jpca.5c02556. Epub 2025 Jun 2.
This study presents the accurate thermal rate constants for a series of hydrogen abstraction reactions involving 1- and 2-butylamine and key radicals H and OH. The potential energy surface resulting from these reactions was examined by using the M08-HX/ma-TZVP level of theory. The rate coefficients were calculated within the multistructural canonical variational theory with small-curvature tunneling correction (MS-CVT/SCT). Multistructural effects and the torsional anharmonicity corrections were evaluated through the rovibrational partition function calculated with the multistructural method based on a coupled torsional potential (MS-T). Our results demonstrated an influence of the position of the amino functional group on the kinetics. The gradual decrease in barrier heights was observed with increasing distance between the amino functional group and the reaction site. The calculated branching ratios demonstrated that the H-abstraction by the H radicals at the α-site is favored. In reactions involving OH radicals, the channel at the N-site shows a greater proportion due to its increased multistructural torsional anharmonicity and a reduced variational effect of other sites.
本研究给出了一系列涉及1-丁胺和2-丁胺以及关键自由基H和OH的氢提取反应的精确热速率常数。利用M08-HX/ma-TZVP理论水平研究了这些反应产生的势能面。速率系数是在具有小曲率隧道效应校正的多结构正则变分理论（MS-CVT/SCT）内计算的。通过基于耦合扭转势的多结构方法（MS-T）计算的振转配分函数评估了多结构效应和扭转非谐性校正。我们的结果表明了氨基官能团位置对动力学的影响。随着氨基官能团与反应位点之间距离的增加，能垒高度逐渐降低。计算得到的分支比表明，α位的H自由基进行H提取是有利的。在涉及OH自由基的反应中，N位的通道由于其多结构扭转非谐性增加以及其他位点的变分效应降低而显示出更大的比例。
