Electrostriction of Several Nonaqueous Solvents under Ambient Conditions and Solvation Numbers of Ions in Them

The diminution of the mean molar volume on electrostriction, Δ_elV_S, in the large electrical field of ions solvated by several solvents that are useful for the dissolution of electrolytes is presented. The solvents dealt with are ethanol, trifluoroethanol, 1,2- and 1,3-propanediols, glycerol, 2-butanone, 1,1- and 1,2-dichloroethane, pyridine, benzonitrile, nitromethane, nitrobenzene, formamide, and dimethylformamide. The inverse dependence of the relative molar electrostriction volume on the dipole moment of the solvents is suggestive of the fact that the larger the polarity of the solvents, the more they are able to withstand the compressive effect of the electrical field. The implications of this decrease in solvent volume with regard to the solvation number of ions in these solvents have been dealt with.