Department of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi 62102, Taiwan.
J Chem Phys. 2012 Nov 21;137(19):194303. doi: 10.1063/1.4766326.
We have made high-level theoretical study on a new type of noble-gas (Ng) containing anions FNgCC(-). The calculated short Ng-CC bond lengths of 1.13, 1.77, 1.89, and 2.04 Å for Ng=He, Ar, Kr, and Xe, respectively, and the electron density distributions indicated strong covalent interactions between the Ng and CC induced by the polarizing fluoride ion. Except for FHeCC(-), the structures of all other FNgCC(-) were predicted to be linear. The intrinsic stability of the FNgCC(-) was studied by calculating the energies of the three-body dissociation reaction: FNgCC(-) → F(-) + Ng + CC and by calculating the energy barriers of the two-body dissociation reaction: FNgCC(-) → Ng + FCC(-). The results showed that FNgCC(-) (Ng=Ar, Kr, Xe) could be kinetically stable in the gas phase with the three-body dissociation energies of 17, 37, and 64 kcal/mol and two body-dissociation barriers of 22, 31, and 42 kcal/mol, respectively, at the coupled-cluster single double (triple)/aug-cc-pVQZ level of theory. The structures and the stability were also confirmed using the multi-reference CASPT2 calculation. Future experimental identification of the FNgCC(-) anions is expected under cryogenic conditions.
我们对一种新型含稀有气体（Ng）阴离子 FNgCC(-) 进行了高水平的理论研究。计算得到 Ng=He、Ar、Kr 和 Xe 时 Ng-CC 键长分别为 1.13、1.77、1.89 和 2.04 Å，电子密度分布表明，带负电荷的氟离子诱导 Ng 与 CC 之间存在强烈的共价相互作用。除了 FHeCC(-)，其他所有 FNgCC(-) 的结构都预测为线性。通过计算三体解离反应 FNgCC(-) → F(-) + Ng + CC 的能量和计算二体解离反应 FNgCC(-) → Ng + FCC(-) 的能垒，研究了 FNgCC(-) 的固有稳定性。结果表明，在气相中，FNgCC(-)（Ng=Ar、Kr、Xe）具有动力学稳定性，三体解离能分别为 17、37 和 64 kcal/mol，二体解离能垒分别为 22、31 和 42 kcal/mol，这些结果是在耦合簇单双（三）/aug-cc-pVQZ 理论水平上得到的。使用多参考 CASPT2 计算也证实了其结构和稳定性。未来有望在低温条件下对 FNgCC(-)阴离子进行实验鉴定。
