Hydration of Ions in Aqueous Solution

The hydration of ions is of significant importance in understanding the properties of electrolyte solutions. Techniques such as Raman, infrared, dielectric relaxation, and nuclear magnetic resonance spectroscopy; X-ray and neutron diffraction; ultrasonic absorption; and ab initio, density functional, and molecular dynamics calculations have all contributed to the understanding of the hydration of ions over the years. In addition, mass spectrometry of sequentially hydrated ions helps us bridge the gap between gas-phase and solution phase, in the same way that crystal structure determination of aqua complexes bridges the gap between solid phase and solution phase. This collection, consisting of two reviews and eight original research articles, further advances our understanding of ions in water.