title: Aqueous solutions of divalent chlorides: ions hydration shell and water structure.
abstract: 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.
authors.affiliation: Dipartimento di Fisica E. Amaldi, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Bruni
authors.forename: S
authors.initials: S
authors.lastname: Imberti
authors.forename: R
authors.initials: R
authors.lastname: Mancinelli
authors.forename: M A
authors.initials: MA
authors.lastname: Ricci
mesh_terms: D002122:Calcium Chloride / Q000737:chemistry*; D003198:Computer Simulation; D006860:Hydrogen Bonding; D007477:Ions / Q000737:chemistry; D015636:Magnesium Chloride / Q000737:chemistry*; D008958:Models, Molecular; D009010:Monte Carlo Method; D033363:Neutron Diffraction; D014867:Water / Q000737:chemistry*
chemical_list: D007477:Ions; D015636:Magnesium Chloride; D014867:Water; D002122:Calcium Chloride