Ghosh Ayan, Manna Debashree, Ghanty Tapan K
†Laser and Plasma Technology Division, Beam Technology Development Group, and ‡Theoretical Chemistry Section, Chemistry Group, Bhabha Atomic Research Centre, Mumbai 400 085, India.
J Phys Chem A. 2015 Mar 19;119(11):2233-43. doi: 10.1021/jp5042266. Epub 2014 Jul 10.
The existence of new interesting insertion compounds, HNgCS(+) (Ng = He-Xe), have been predicted theoretically through insertion of a noble gas atom into the thioformyl cation, HCS(+). Second-order Møller-Plesset perturbation theory (MP2), density functional theory (DFT), and coupled-cluster theory (CCSD(T)) based techniques have been used to explore the structure, energetics, charge distribution, and harmonic vibrational frequencies of these compounds. These predicted ions are found to be energetically stable with respect to all the possible 2-body and 3-body dissociation pathways, except the 2-body channel leading to the global minimum products (HCS(+) + Ng). Nevertheless, all these ions are found to be kinetically stable with a finite barrier height corresponding to their transition states, which are connected to their respective global minima products. The results obtained from charge distribution as well as atoms in molecules (AIM) analysis suggest that these ions can be best described as HNgCS. Strong covalent character in the H-Ng bond is supported by the high positive energy value corresponding to the 3-body dissociation pathways. Thus, it might be possible to prepare the HNgCS(+) ions in a glow discharge containing H2S, CO, and noble gas under cryogenic conditions through matrix isolation technique.
理论上通过将稀有气体原子插入硫代甲酰阳离子HCS(+)中，预测了新的有趣插入化合物HNgCS(+)（Ng = He - Xe）的存在。基于二阶Møller - Plesset微扰理论（MP2）、密度泛函理论（DFT）和耦合簇理论（CCSD(T)）的技术已被用于探索这些化合物的结构、能量、电荷分布和谐波振动频率。发现这些预测的离子相对于所有可能的二体和三体解离途径在能量上是稳定的，但导致全局最小产物（HCS(+) + Ng）的二体通道除外。然而，发现所有这些离子在动力学上是稳定的，具有对应于其过渡态的有限势垒高度，这些过渡态与其各自的全局最小产物相连。从电荷分布以及分子中的原子（AIM）分析获得的结果表明，这些离子可以最好地描述为HNgCS。H - Ng键中的强共价特性由对应于三体解离途径的高正能量值支持。因此，通过基质隔离技术在低温条件下在含有H2S、CO和稀有气体的辉光放电中制备HNgCS(+)离子可能是可行的。
