Study of solute–solute and solute–solvent interactions of N-acetyl glycine in aqueous d-fructose solutions at different temperatures

• Densities and speeds of sound of AcGly in aqueous fructose solutions.
• Partial molar volumes and compressibility of transfer are determined.
• Molar hydration number is calculated.
• Hydrophilic–hydrophilic interactions are present.
• Pair-wise and triplet interaction coefficients are calculated.

Densities (ρ) and ultrasonic speeds (u) for N-acetyl glycine (AG) in (0.05, 0.15, 0.25 and 0.35 mol kg−1) aqueous d-fructose (FR) solutions have been measured at temperatures (288.15, 293.15, 298.15, 303.15 and 308.15) K and at pressure 101 kPa. These data have been used to calculate apparent molar volume (Vϕ) and acoustical parameters, coefficient of isentropic compression (βs), molal hydration number (nH) and apparent molar isentropic compression (Kϕ,s). Partial molar volumes (Vϕ0) and partial molar isentropic compression (Kϕ,s0) of AG at infinite dilutions were also evaluated. The partial molar volumes of transfer (ΔVϕ0) and partial molar isentropic compression of transfer (ΔKϕ,s0) of AG from aqueous to aqueous FR solutions have been calculated and interpreted in terms of solute-co-solute interactions. Pair and triplet interaction coefficients have also been calculated. The results have been used to investigate the solute–solute and solute–solvent interactions as well as the effect of the concentration of FR on these interactions. It is observed that there exist strong solute–solvent interactions in these systems. The data of transfer parameters suggest that the type of interactions present in these systems are complex depending both on the nature of side group as well as on temperature.