Pure and Applied Chemistry

Abstract: Water is a highly structured liquid, as indicated by its stiffness (cohesive energy density) and being ordered (large entropy of vaporization), its three-dimensional hydrogen-bonded network being its most outstanding feature. The extent of this network depends on the definition of the hydrogen bond, and both computer simulation and thermodynamic data yield a consistent picture. The effects of ions on this network in dilute aqueous solutions have been studied from dynamic, thermodynamic, spectroscopic, and computer simulation aspects. A classification of ions from those that are highly water-structure-breaking ions through borderline cases to those that are highly water-structure-making ions results from such studies.