Ferro-Costas David, Martínez-Núñez Emilio, Rodríguez-Otero Jesús, Cabaleiro-Lago Enrique, Estévez Carlos M, Fernández Berta, Fernández-Ramos Antonio, Vázquez Saulo A
J Phys Chem A. 2018 May 31;122(21):4790-4800. doi: 10.1021/acs.jpca.8b02949. Epub 2018 May 21.
The potential energy surface involved in the thermal decomposition of 1-propanol radicals was investigated in detail using automated codes (tsscds2018 and Q2DTor). From the predicted elementary reactions, a relevant reaction network was constructed to study the decomposition at temperatures in the range 1000-2000 K. Specifically, this relevant network comprises 18 conformational reaction channels (CRCs), which in general exhibit a large wealth of conformers of reactants and transition states. Rate constants for all the CRCs were calculated using two approaches within the formulation of variational transition-state theory (VTST), as incorporated in the TheRa program. The simplest, one-well (1W) approach considers only the most stable conformer of the reactant and that of the transition state. In the second, more accurate approach, contributions from all the reactant and transition-state conformers are taken into account using the multipath (MP) formulation of VTST. In addition, kinetic Monte Carlo (KMC) simulations were performed to compute product branching ratios. The results show significant differences between the values of the rate constants calculated with the two VTST approaches. In addition, the KMC simulations carried out with the two sets of rate constants indicate that, depending on the radical considered as reactant, the 1W and the MP approaches may display different qualitative pictures of the whole decomposition process.
使用自动化程序（tsscds2018和Q2DTor）详细研究了1-丙醇自由基热分解过程中涉及的势能面。根据预测的基元反应，构建了一个相关反应网络，以研究1000 - 2000 K温度范围内的分解情况。具体而言，这个相关网络包含18个构象反应通道（CRC），这些通道通常展现出大量反应物和过渡态的构象。所有CRC的速率常数是在变分过渡态理论（VTST）的公式框架内使用两种方法计算的，该理论已纳入TheRa程序。最简单的单阱（1W）方法仅考虑反应物和过渡态的最稳定构象。在第二种更精确的方法中，使用VTST的多路径（MP）公式考虑了所有反应物和过渡态构象的贡献。此外，进行了动力学蒙特卡罗（KMC）模拟以计算产物分支比。结果表明，用两种VTST方法计算得到的速率常数数值存在显著差异。此外，用两组速率常数进行的KMC模拟表明，根据作为反应物的自由基不同，1W和MP方法可能会展现出整个分解过程不同的定性图景。
