Dipartimento di Fisica E. Amaldi, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy.
J Chem Phys. 2012 Feb 14;136(6):064520. doi: 10.1063/1.3684633.
By combining neutron diffraction and Monte Carlo simulations, we have determined the microscopic structure of the hydration ions shell in aqueous solutions of MgCl(2) and CaCl(2), along with the radial distribution functions of the solvent. In particular the hydration shell of the cations, show cation specific symmetry, due to the strong and directional interaction of ions and water oxygens. The ions and their hydration shells likely form molecular moieties and bring clear signatures in the water-water radial distribution functions. Apart from these signatures, the influence of divalent salts on the microscopic structure of water is similar to that of previously investigated monovalent solutes, and it is visible as a shift of the second peak of the oxygen-oxygen radial distribution function, caused by distortion of the hydrogen bond network of water.
通过结合中子衍射和蒙特卡罗模拟，我们确定了 MgCl(2)和 CaCl(2)水溶液中水化离子壳的微观结构，以及溶剂的径向分布函数。特别是阳离子的水化壳，由于离子和水分子氧之间的强烈和定向相互作用，表现出阳离子特定的对称性。离子及其水化壳可能形成分子部分，并在水的水分子径向分布函数中带来明显的特征。除了这些特征之外，二价盐对水的微观结构的影响与先前研究的单价溶质相似，这可以通过水分子氢键网络的扭曲导致氧-氧径向分布函数的第二个峰的移动来观察到。
