Theoretical Chemistry Division, Institute of General, Inorganic, and Theoretical Chemistry, University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria.
Inorg Chem. 2010 Mar 1;49(5):2132-40. doi: 10.1021/ic901737y.
An ab initio quantum mechanical charge field molecular dynamics (QMCF MD) simulation was performed to investigate the behavior of the Sb(3+) ion in aqueous solution. The simulation reveals a significant influence of the residual valence shell electron density on the solvation structure and dynamics of Sb(3+). A strong hemidirectional behavior of the ligand binding pattern is observed for the first hydration shell extending up to the second hydration layer. The apparent domain partitioned structural behavior was probed by solvent reorientational kinetics and three-body distribution functions. The three-dimensional hydration space was conveniently segmented such that domains having different properties were properly resolved. The approach afforded a fair isolation of localized solvent structural and dynamical motifs that Sb(3+) seems to induce to a remarkable degree. Most intriguing is the apparent impact of the lone pair electrons on the second hydration shell, which offers insight into the mechanistic aspects of hydrogen bonding networks in water. Such electronic effects observed in the hydration of Sb(3+) can only be studied by applying a suitable quantum mechanical treatment including first and second hydration shell as provided by the QMCF ansatz.
采用从头算量子力学电荷场分子动力学（QMCF MD）模拟方法研究了 Sb(3+) 离子在水溶液中的行为。模拟结果表明，剩余价壳层电子密度对 Sb(3+) 的溶剂化结构和动力学有显著影响。对于第一水合壳层，观察到配体结合模式的强烈半各向异性行为，延伸到第二水合层。通过溶剂重取向动力学和三体分布函数探测到明显的域分区结构行为。通过三维水合空间的方便分段，适当解析了具有不同性质的区域。该方法能够很好地分离 Sb(3+) 诱导的局部溶剂结构和动力学模式，这在很大程度上是孤立的。最有趣的是孤对电子对第二水合壳层的明显影响，这为理解水中氢键网络的机制提供了线索。通过应用包括第一和第二水合壳层的合适量子力学处理，如 QMCF 假设所提供的，只能研究 Sb(3+) 水合过程中观察到的这种电子效应。
