Ionic Association in Hydrogen-Bonding Solvents

Studies on ionic association in hydrogen-bonding solvents including water, aliphatie alcohols, fluorinated alcohols, formamide, ethylene glycol, and propanol-aeetone mixtures are compared. Data were derived from measurements of conductivity, ultrasonic absorption, and viscosity of electrolyte solutions and diffusion of nonelectrolytes. It is concluded that electrolyte solvents can be divided into three categories according to whether they solvate effectively cations only, anions only, or both cations and anions. Water and most other hydrogen-bonding solvents constitute the third class, a group in which patterns of ionic aggregation are very similar. Fluorinated alcohols belong to the second class, showing significantly different ion-pairing behavior.