CINBIO, Dpto. de Física Aplicada, Univ. de Vigo, Vigo, Spain.
J Chem Phys. 2023 Jan 28;158(4):044503. doi: 10.1063/5.0137734.
In the present work, we study the behavior of the noble gases He, Ne, Ar, and Kr inside a hydroquinone clathrate (HQC) by using all-atom molecular dynamics. Larger elements of the same group were not considered due to their inability to fit inside the HQC cavities. By using the umbrella sampling technique, we have obtained the following inter-cage transition barriers-which are arguably the main factor determining the type of diffusion of the gases-at 310 K and 0.1 MPa: 1192; 2204; 6450; 10 730 kJ mol for the guests He, Ne, Ar, and Kr, respectively. These energy barriers were found to have a linear relation with atomic radii (σ). We have tested this tendency with CH, due to its intermediate size between Ar and Kr, obtaining a barrier of 8926 kJ mol, in excellent agreement with the results for noble gases.
在本工作中，我们使用全原子分子动力学研究了氦（He）、氖（Ne）、氩（Ar）和氪（Kr）等稀有气体在对苯二酚笼合物（HQC）中的行为。由于同组的较大元素无法装入 HQC 腔，因此未考虑它们。通过使用伞形采样技术，我们在 310 K 和 0.1 MPa 下获得了以下笼间跃迁势垒-这可以说是决定气体扩散类型的主要因素：对于客体 He、Ne、Ar 和 Kr，分别为 1192；2204；6450；10730 kJ/mol。这些能垒与原子半径（σ）呈线性关系。由于 CH 的尺寸介于 Ar 和 Kr 之间，我们用它对此趋势进行了测试，得到了 8926 kJ/mol 的势垒，与稀有气体的结果非常吻合。
