B. S. N. V. Degree College, Lucknow Manuscript received 3 July 1975 ; revised 10 January 1976 ; accepted 19 February 1976. Ion-dipole interaction energy, ∆EID, of some cations and anions in five solvents namely H2O, DMA, DMSO, EC and PC** and dipole-dipole interaction energy, ∆EDD of these five solvents have been calculated. The ratio ∆EID/∆EDD has also been calculated for the R4N+ ions in these solvents. The calculated values of ion-dipole interaction energy have been found to be exception ally high for the common and compact cations like Li+, Na +, etc. and appreciably high for the anions like F-,Cl-,Br- etc., whereas in case of tetraalkylammonium ions (R4N+), these values have been found to be quite low but slightly greater than the corresponding dipolar interaction energy of the solvents except in H2O for larger R4N+ ions. The dipole-dipole interaction energy value decreases with increasing size of the solvent molecule. The ratio ∆EID/∆EDD has been found to be greater than unity in all cases except for larger R4N+ ions in water which appear to be solvated, specially the smaller ones in EC, PC, DMSO and DMA ; however in case of water only (CH3)4N+ and (C2H5)4N+ ions are supposed to bo solvated. Solvation of ion has been found to be directly related to the dielectric constant of the medium.