What can be learnt from dielectric relaxation spectroscopy about ion solvation and association?

Ion solvation and ion association are key features of ion-solvent interactions, and their balance largely determines structure, thermodynamics, and dynamics of electrolyte solutions. Despite being studied for many years with various techniques, these effects are still intriguing because too often results obtained with different methods-each having its individual merits and limitations-cannot be connected properly due to lacking information. In this contribution, we would like to bring dielectric relaxation spectroscopy (DRS) as a further tool for solution studies to the attention of the audience. The principles of DRS and the required instrumentation are briefly introduced. The major focus will be on the kind of results obtained with this technique regarding ion solvation and association and how this information compares with results obtained from other techniques.