Ravi Gajera

Determination of some thermodynamic parameters of dissociation of dihydropyrimidine derivatives

Dissociation constant of dihydropyrimidine derivatives has been determined in dimethyl forma-mide—water (60: 40 v/v) system at different temperatures. The data are discussed in terms of the electron nature of the substituents. Further, some thermodynamics parameters such as enthalpy of solution, Gibbs energy change and entropy of solution have also been evaluated for these systems.

Adiabatic compressibilities of some synthesized derivatives of dihydropyrimidines in N,N-dimethylformamide and dimethyl sulfoxide at 298.15 K

Sound velocities of solutions of some derivatives of dihydropyrimidines (DHPMs) in N,N-dimethylforamide (DMF) and dimethyl sulfoxide (DMSO) were measured at 298.15 K over a wide range of concentration. Adiabatic compressibilities, apparent adiabatic molar compressibilities and apparent adiabatic molar volumes were also evaluated. Results of sound velocity measurements provide useful information about ion-ion and ion-solvent interactions and are of significant help in understanding the behavior of electrolytes in solutions.