【摘要】 采用分子动力学模拟的方法在 2 98 1 5K及无限稀释条件下对Li+、Na+、K+、F- 、Cl- 5种单个离子的水化现象进行研究 模拟得到了离子溶液体系一幅清晰的微观物理图像 ,阳离子周围的水分子以氧来靠近阳离子 ,而阴离子周围的水分子则以其中某一个氢来逼近阴离子 提出了一个“水化因子”的新概念来定量地表征离子水化的强弱 ,阳离子水化的强弱顺序为Li+>Na+>K+ 阴离子水化强弱顺序为F- >Cl- 对于水化作用较强的Li+,其虽有第二配位圈 ,但并无水化 离子的Pauling半径大小是决定离子水化强弱的关键因素 ,这些信息将为建立相应的分子热力学模型提供基础更多还原

【Abstract】 In this paper, the ionic hydration of five ions Li~+, Na~+, K~+, F~-, Cl~- is investigated by molecular dynamics simulation at 298.15K. A clear microscopic configuration of ions in aqueous solution is obtained. The cations are surrounded by water molecules with oxygen atoms approaching them, while the anions are surrounded by water molecules with hydrogen atoms approaching them. A new hydration factor is proposed to quanti tativelycharacterize the strength of ionic hydration. The order of hydration strength for cations is Li~+>Na~+>K~+, whereas for anions F~->Cl~-. For Li~+, although there is a second coordination shell, no second hydration shell exists. These are valuable information for further establishment of molecular thermodynamic models for electrolyte solutions.更多还原