Molecular interactions in glycylglycine-mncl2 aqueous solutions at (288.15, 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) k

Abstract

The viscosities, ultrasonic velocities, densities, and refractive indices of glycylglycine and MnCl2in water have been studied at different temperatures and concentrations. Excess thermodynamic parameters such as adiabatic compressibility (?ad), apparent molar volume (?V), apparent molar compressibility (?K),intermolecular free length (Lf), specific acoustic impedance (Z), relative association (RA), and salvation number (Sn) have been calculated. The variations in apparent molar volume were confirmed by Scaled particle theory, and the changes in apparent molar compressibilities were interpreted using the Kirkwood model. The variations in apparent molar volumes were fitted with Masson's equation. The viscosity data have been fitted using the Jones-Dole empirical equation. The molecular relaxation of MnCl2and glycylglycine in water gives an idea about solute-solute interactions. The interactions also suggest the formation of H-bonding in the system. The tructure forming tendency of the solute has also been indicated by the solvation number. Copyright& copy; 2009 American Chemical Society.