Thermo-acoustical and optical studies of glycine and DL-alanine in aqueous furosemide solutions at different temperatures

Density (rho), speed of sound (u) and viscosity (eta) have been measured for glycine and DL-alanine in aqueous furosemide solutions (0.00, 0.001, 0.005, and 0.009 mol.kg(-1)) in the concentration range (0.02-0.20 mol.kg(-1)) at (293.15, 298.15, 303.15, 308.15, and 313.15) K. The acoustical parameters such as intermolecular free length (L-f), relative association (RA), specific acoustic impedance (Z), molar sound number ([U]), relaxation time (tau), free volume (V-f), internal pressure (pi(i)), and molar cohesive energy (MCE) have been obtained from the experimental data for glycine and DL-alanine in different solutions of furosemide at different temperature. These parameters have been further used to interpret the type and strength of intermolecular interactions present in the system investigated. The results of UV-Vis studies for ternary system corroborate with the thermo-acoustical studies. The results have been explained on the basis of competing pattern of interactions between the co-solute and solute as well as the structure making and breaking ability of amino acid in the ternary system. (C) 2016 Elsevier B.V. All rights reserved.