STUDIES ON THE EFFECT OF WATER-DMF SOLVENT SYSTEMS ON THE THERMODYNAMIC FUNCTIONS OF AN ION-DIPOLAR SOLVOLYSIS REACTION

For studying the solvent effect of DMF, on the thermodynamic functions of alkali catalysed hydrolysis of methyl butyrate ester (Ion-dipolar reaction) the kinetics of the reaction was studied in different aqua-DMF media containing 30 to 80% DMF (v/v) at temperatures varying from 20 to 40°C. The values of Iso-composition activation energy of the reaction were found to decrease with increasing proportion of DMF in the reaction media. The plausible explanation for such depletion is due to solvation and desolation of transition and initial states of the reaction respectively. From the enhancement observed in ∆G* values with simultaneous decrease in the values of ∆H* and ∆S* of the reaction, it is inferred that the organic co-solvent DMF acts as entropy controlling solvent. The numerical value of Iso-kinetic temperature of the reaction. Which comes to be nearly 300 indicates that there is considerable solvent-solute interaction in the reaction media.