Pires W A D, Garrido J D, Nascimento M A C, Ballester M Y
Departamento de Física, Universidade Federal de Juiz de Fora-UFJF, Juiz de Fora, MG 36036-330, Brazil.
Phys Chem Chem Phys. 2014 Jul 7;16(25):12793-801. doi: 10.1039/c4cp01363h.
A study of the OH + SO → H + SO2 reaction using a quasi-classical trajectory method is presented with the aim of investigating the role of the ro-vibrational energy of the reactants in the reactivity. The calculations were carried out using a previously reported global potential energy surface for HSO2((2)A). Different initial conditions with one and both reactants ro-vibrationally excited were studied. The reactive cross sections, for each studied combination, are calculated and then fitted to a capture-like model combined with a factor accounting for the recrossing effects. The Vibrational Energy Quantum Mechanical Threshold of the Complex method was used to correct for the zero-point vibrational energy leakage of the classical calculations. State specific and averaged rate constants are reported. The reactivity is affected when ro-vibrational energy of either of the reactants is changed. The present calculations provide a theoretical support for the experimental rate constant for temperatures below 550 K, but fail to account for the significant fall in the observed rate constant upon increasing the temperature above this value.
本文采用准经典轨迹方法对OH + SO → H + SO₂反应进行了研究，旨在探究反应物的转动 - 振动能量在反应活性中的作用。计算使用了先前报道的HSO₂((²)A)全局势能面。研究了单反应物和双反应物转动 - 振动激发的不同初始条件。对于每个研究的组合，计算反应截面，然后将其拟合到一个类似捕获的模型，并结合一个考虑再交叉效应的因子。采用复合法的振动能量量子力学阈值来校正经典计算中的零点振动能量泄漏。报告了态特异性和平均速率常数。当任何一个反应物的转动 - 振动能量发生变化时，反应活性都会受到影响。目前的计算为低于550 K温度下的实验速率常数提供了理论支持，但无法解释当温度升高超过该值时观测到的速率常数显著下降的现象。
