Premium
Stability of Noble‐Gas‐Bound SiH 3 + Clusters
Author(s) -
Pan Sudip,
Moreno Diego,
Merino Gabriel,
Chattaraj Pratim K.
Publication year - 2014
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201402370
Subject(s) - chemistry , dissociation (chemistry) , covalent bond , bond dissociation energy , binding energy , bond energy , crystallography , ab initio quantum chemistry methods , population , atomic physics , noble gas , atom (system on chip) , electron localization function , computational chemistry , electron , molecule , physics , demography , organic chemistry , quantum mechanics , sociology , computer science , embedded system
The stability of noble gas (Ng)‐bound SiH 3 + clusters is explored by ab initio computations. Owing to a high positive charge (+1.53 e − ), the Si center of SiH 3 + can bind two Ng atoms. However, the SiNg dissociation energy for the first Ng atom is considerably larger than that for the second one. As we go down group 18, the dissociation energy gradually increases, and the largest value is observed for the case of Rn. For NgSiH 3 + clusters, the Ar–Rn dissociation processes are endergonic at room temperature. For He and Ne, a much lower temperature is required for it to be viable. The formation of Ng 2 SiH 3 + clusters is also feasible, particularly for the heavier members and at low temperature. To shed light on the nature of SiNg bonding, natural population analysis, Wiberg bond indices computations, electron‐density analysis, and energy‐decomposition analysis were performed. Electron transfer from the Ng centers to the electropositive Si center occurs only to a small extent for the lighter Ng atoms and to a somewhat greater extent for the heavier analogues. The SiXe/Rn bonds can be termed covalent bonds, whereas the SiHe/Ne bonds are noncovalent. The SiAr/Kr bonds possess some degree of covalent character, as they are borderline cases. Contributions from polarization and charge transfer and exchange are key terms in forming SiNg bonds. We also studied the effect of substituting the H atoms of SiH 3 + by halide groups (X) on the Ng binding ability. SiF 3 + showed enhanced Ng binding ability, whereas SiCl 3 + and SiBr 3 + showed a lower ability to bind Ng than SiH 3 + . A compromise originates from the dual play of the inductive effect of the X groups and X→Si π backbonding (p z –p z interaction).