Lim Len Herald V, Hofer Thomas S, Pribil Andreas B, Rode Bernd M
Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Austria.
J Phys Chem B. 2009 Apr 2;113(13):4372-8. doi: 10.1021/jp809937h.
The structural properties of the hydrated Sn(2+) ion have been investigated using ab initio quantum mechanical charge field molecular dynamics (QMCF MD) simulations at double-xi HF quantum mechanical level. The results from the work significantly extend previous study using QM/MM MD simulation and are in good agreement with X-Ray and EXAFS diffraction experiments. The data indicate a set of characteristics for the first hydration shell uncommon among metal ions. Although frequent ligand exchange prevents the formation of a well defined structure, more detailed analyses reveal an asymmetric distribution of ligands around Sn(II). An average of eight water molecules coordinate with the Sn(2+) ion and are distributed at proximal and distal positions that are distinguishable from the second hydration shell and manifest dissimilar degrees of lability.
利用双ζHF量子力学水平的从头算量子力学电荷场分子动力学（QMCF MD）模拟研究了水合Sn(2+)离子的结构性质。该工作的结果显著扩展了先前使用QM/MM MD模拟的研究，并且与X射线和EXAFS衍射实验结果高度吻合。数据表明了第一水合层的一组特征，这在金属离子中并不常见。尽管频繁的配体交换阻止了明确结构的形成，但更详细的分析揭示了Sn(II)周围配体的不对称分布。平均有八个水分子与Sn(2+)离子配位，并分布在近端和远端位置，这些位置与第二水合层不同，且表现出不同程度的活性。
