中文摘要：

针对水溶液中铝离子第三水化层（hydration shell）对Al（H2O）6^3＋动态水交换反应特性的影响,本文采用密度泛函理论（Density functional theory,DFT）在B3LYP/6-311＋G（d,p）基组水平上进行了研究.探讨了第三水化层对第一到第二水化层水交换反应速率常数kex^1-2以及第二到三水化层水交换反应速率常数kex^2-3的影响.研究结果表明,在第三水化层添加不同数目水分子时相应于kex^1-2和kex^2-3的活化能垒变化均不大,表明第三水化层对水交换反应速率常数kex^1-2和kex^2-3影响不大,采用第二水化层就可以较好处理Al（H2O）6^3＋的真实溶剂效应.

英文摘要：

The influences of the third hydration shell on the dynamic characteristics for the water-exchange reactions of Al（H2O）6^3＋（aq） complexes in aqueous solution were investigated by density functional theory（DFT） calculations on the basis of B3LYP/6-311＋G（d,p）. The effects of the third hydration shell on the water-exchange reaction rate constant between the first and second hydration shells kex^1-2 and the water exchange rate constant between the second and third hydration shells kex2-3 were examined. DFT calculation results show that the activation energy barriers for both kex^1-2 and kex^2-3 changes only slightly when different number of water molecules were considered in the third hydration shell. This indicates that the third hydration shell has little influence on the water-exchange rate constants kex^1-2 and kex^2-3. It is satisfactory to account the explicit solvent effects with two hydration shells for Al（H2O）6^3＋（aq） complexes in aqueous solution.