【摘要】 受控分子动力学(Steered Molecular Dynamics,SMD)是一种新型的分子动力学方法。本文用SMD模拟方法研究了α-,β- 和γ-环糊精在常温下从真空穿过气液界面进入水溶液的动态水化过程。模拟发现,在垂直于水溶液气液界面方向的微小外力作用下,三种环糊精在水溶液气液界面上沿着垂直于分界面方向都呈现出窄口端取向。结合环糊精的结构特点,对动态水化过程中各种氢键作用变化的分析表明:这种一致的取向是天然环糊精的结构特性的集中体现。更多还原

【Abstract】 Steered Molecular Dynamics (SMD) simulations have been carried out to study the liquid-state hydration processes of α-, β- and γ-cyclodextrin (α-, β- and γ-CD) at constant temperature. An external force was applied to pull CD into liquid phase across the water liquid-vapor interface. The forces required to guide CDs into liquid phase were gentle and reasonable dynamic hydration processes were produced. Different natural CDs exhibit uniform narrow end orientation along the pulling path when passing the water liquid-vapor interface. This common behavior of three natural CDs at the interface was well explained by the tight interglucose hydrogen bond networks of CDs in the wide end of CDs and dynamic formation of intermolecular hydrogen bonds between CDs and water molecules in the narrow end of CD molecules as well as the hydrophobicity of CD cavity.更多还原