Sekhar Pooja, Ghosh Ayan, Ghanty Tapan K
Theoretical Chemistry Section, Chemistry Group, Bhabha Atomic Research Centre , Mumbai 400 085, India.
Laser and Plasma Technology Division, Beam Technology Development Group, Bhabha Atomic Research Centre , Mumbai 400 085, India.
J Phys Chem A. 2015 Nov 25;119(47):11601-13. doi: 10.1021/acs.jpca.5b09018. Epub 2015 Nov 12.
The existence of noble gas containing protonated silicon monoxide complexes have been predicted theoretically through ab initio quantum chemical methods. The predicted HNgOSi(+) ions are obtained by insertion of a noble gas atom (Ng = He, Ne, Ar, Kr, and Xe) between the H and O atoms in SiOH(+) ion. The structural parameters, energetics, harmonic vibrational frequencies, and charge distributions have been analyzed by optimizing the minima and the transition state structures using second-order Møller-Plesset perturbation theory (MP2), density functional theory (DFT), and coupled-cluster theory (CCSD(T)) based techniques. The predicted HNgOSi(+) ions are found to be stable with respect to all possible 2-body and 3-body dissociation channels, except the dissociation path leading to the respective global minimum products. However, these ions are found to be kinetically stable with respect to the global minimum dissociation process as revealed from the finite barrier heights, which in turn can prevent the transformation of these metastable species to the global minimum products. Furthermore, the computed bond lengths, vibrational frequencies, and force constant values suggest that a strong covalent bond exists between the H and Ng atoms in HNgOSi(+) ions while the Ng and O atoms share a strong van der Waals kind of interaction. Charge distributions and bonding analysis indicate that HNgOSi(+) ions can be best represented as strong complexes between the HNg ions and OSi molecule. All the computational results suggest that the predicted species, HNgOSi(+), may be prepared and characterized by suitable experimental technique at cryogenic temperature.
通过从头算量子化学方法从理论上预测了含稀有气体的质子化一氧化硅配合物的存在。预测的HNgOSi(+)离子是通过在SiOH(+)离子的H和O原子之间插入一个稀有气体原子（Ng = He、Ne、Ar、Kr和Xe）得到的。利用基于二阶Møller-Plesset微扰理论（MP2）、密度泛函理论（DFT）和耦合簇理论（CCSD(T)）的技术对极小值和过渡态结构进行优化，分析了结构参数、能量学、谐波振动频率和电荷分布。发现预测的HNgOSi(+)离子相对于所有可能的二体和三体解离通道是稳定的，但通向各自全局极小值产物的解离路径除外。然而，从有限的势垒高度可以看出，这些离子相对于全局极小值解离过程在动力学上是稳定的，这反过来又可以阻止这些亚稳物种向全局极小值产物的转变。此外，计算得到的键长、振动频率和力常数表明，HNgOSi(+)离子中H和Ng原子之间存在强共价键，而Ng和O原子之间存在强范德华相互作用。电荷分布和键合分析表明，HNgOSi(+)离子可以最好地表示为HNg离子和OSi分子之间的强配合物。所有计算结果表明，预测的物种HNgOSi(+)可以在低温下通过合适的实验技术制备和表征。
