Yurtsever E, Satta M, Wester R, Gianturco F A
Department of Chemistry, Koc University, Rumelifeneri Yolu, Sariyer, TR, 34450 Istanbul, Turkey.
CNR-ISMN and Department of Chemistry, The University of Rome Sapienza, P.le A. Moro 5, 00185 Rome, Italy.
J Phys Chem A. 2020 Jun 25;124(25):5098-5108. doi: 10.1021/acs.jpca.0c02412. Epub 2020 Jun 12.
We present accurate ab initio calculations on the structural properties of a gas-phase reaction of possible interest for Saturn's outer atmosphere chemistry, in which the CH molecule has been detected. In the present study, that molecule is made to react with the H anion to form the CH species, one considered as a possible intermediate in ionic processes networks. The results indicate that this reaction is markedly exothermic and proceeds with the formation of an intermediate, which occurs via only a shallow barrier below the reagents and progresses directly to the product region. The corresponding rate coefficients of reactions are also computed by making use of the variational transition state theory modeling and found to efficiently lead to the formation of the final anion even at the lower temperatures of interstellar medium conditions.
我们对土星外层大气化学中可能感兴趣的气相反应的结构性质进行了精确的从头算计算，在该反应中已检测到CH分子。在本研究中，使该分子与H阴离子反应形成CH物种，CH物种被认为是离子过程网络中的一种可能中间体。结果表明，该反应明显放热，并通过在反应物下方仅一个浅势垒形成中间体的方式进行，然后直接进入产物区域。反应的相应速率系数也通过变分过渡态理论建模进行了计算，结果发现即使在星际介质条件下的较低温度下，也能有效地导致最终阴离子的形成。
