Volumetric Properties of Cyclic Alanylalanine in Aqueous Solutions of MnCl2, NiCl2 and ZnCl2 at Temperatures T = (293.15 to 313.15) K

Abstract

The partial molar volumes, isentropic compressibilities, partial molar isentropic compressions and transfer molar quantities of cyclic alanylalanine in water and in aqueous solutions of MnCl2, NiCl2 and ZnCl2 were determined using the experimental density and speed of sound values. Refractive indices of all the solutions were recorded to calculate the molar refractions. The molecular interactions existing in the systems have been discussed based on the derived parameters. It has been found that M 2+ -O2H bond distances of hydrated cations influence on the volumetric properties of cyclic alanylalanine. Further, the greater effect of hydrophobic hydration has been substantiated by the Sv values of least square fits of apparent molar volume against solute molality.