Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada.
J Chem Phys. 2012 Aug 7;137(5):054712. doi: 10.1063/1.4739928.
Molecular dynamics simulations of the pure structure II tetrahydrofuran clathrate hydrate and binary structure II tetrahydrofuran clathrate hydrate with CO(2), CH(4), H(2)S, and Xe small cage guests are performed to study the effect of the shape, size, and intermolecular forces of the small cages guests on the structure and dynamics of the hydrate. The simulations show that the number and nature of the guest in the small cage affects the probability of hydrogen bonding of the tetrahydrofuran guest with the large cage water molecules. The effect on hydrogen bonding of tetrahydrofuran occurs despite the fact that the guests in the small cage do not themselves form hydrogen bonds with water. These results indicate that nearest neighbour guest-guest interactions (mediated through the water lattice framework) can affect the clathrate structure and stability. The implications of these subtle small guest effects on clathrate hydrate stability are discussed.
采用分子动力学模拟方法研究了纯 II 型四氢呋喃笼状水合物以及与 CO2、CH4、H2S 和 Xe 等小笼体客分子形成的二元 II 型四氢呋喃笼状水合物的结构和动力学性质，探讨了小笼体客分子的形状、尺寸和分子间作用力对水合物结构和动力学的影响。模拟结果表明，小笼体中客分子的数量和种类影响四氢呋喃客分子与大笼体水分子形成氢键的概率。尽管小笼体中的客分子本身并不与水形成氢键，但对四氢呋喃氢键的影响依然存在。这些结果表明，最近邻客-客相互作用（通过水晶格框架介导）会影响笼状水合物的结构和稳定性。本文讨论了这些微小客分子效应对于笼状水合物稳定性的影响。
