Solvation

Solvation or solvation takes place in mostly liquid solutions. It is based on an attraction or association of molecules of solvent with molecules or ions of the solute. An interaction of the solute with the solvent leads to the stabilization of the solute in the solution. These interaction forces also lead to an ordered structure of the solvent molecules around the solute and one also speaks of a solvation shell around the solute.

Solvent and intermolecular interactions

Solvation can in principle be carried out by different types of intermolecular ( also in ion interatomic ) interactions, such as ion-dipole, dipole -dipole, hydrogen bonds and van der Waals forces. Ion-ion interactions can occur in ionic solvents.

Particularly good solvents are polar solvents which have an electric dipole due to their molecular structure. If, for example, Ions are located in a polar solvent, they exercise due to their electric charge forces on the Lösungsmitteldipole. In the vicinity of positive ions ( cations), then the dipoles of the solvent judge usually made so that its negative pole is directed toward the cation and its positive pole of the cation away. In the vicinity of the negative ions (anions ) of the positive pole to the negative pole of the anion back and is directed away from the anion. In the special case of water is referred to as the solvation hydration and solvation shell as a hydration shell. Since the water structure is dominated by hydrogen bonds, the structures of the hydration shells around dissolved ions are often more complex than using the simple ion-dipole interaction, would be as described above and shown in the figure expected.

An important source of information in the experimental study of ion solvation is the nuclear magnetic relaxation, in particular the relaxation of nuclei within the ions of interest.