الفهرس 
Ion association and solvent effectOnly 14 pages are availabe for public view
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Abstract
Ion-association is a chemical reaction whereby ions of opposite electrical charge come together in solution to form a distinct chemical entity. Ion-associates are classified, according to the number of ions that associate with each other, as ion-pairs ion-triplets, etc. Ion-pairs are also classified according to the nature of the interaction as contact, solvent-shared or solvent-separated. The most important factor to determine the extent of ion-association is the dielectric constant of the solvent. Ionassociates have been characterized by means of vibrational spectroscopy.In the schematic representation above, the circles represent spheres. The sizes are arbitrary and not necessarily similar as illustrated. The cation is considered as (A) and the anion is considered as (B). The green area represents solvent molecules in a primary solvation shell: secondary solvation is ignored. When both ions have a complete primary solvation sphere the ion-pair may be termed fully solvated. When there is about one solvent molecule between cation and anion, the ion-pair may be termed solvent-shared. Lastly when the ions are in contact with each other the ion-pair is termed a contact ion-pair. Even in a contact ion-pair, however, the ions retain most of their solvation shell. The nature of this solvation shell is generally not known with any certainty. In aqueous solution and in other donor solvents, metal cations are surrounded by between four and nine solvent molecules in the primary solvation shell, but the nature of solvation of anions is mostly unknown.