Study of solvation consequences of glycine, L-alanine and L-valine in aqueous 1-butyl-4-methyl pyridinium chloride ionic liquid solutions probed by physicochemical approach in the temperature interval (288.15–308.15) K

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The apparent molar volume (V∅) and isentropic compression (K∅,s) of glycine, L-alanine and L-valine have been studied in (0.025, 0.05, 0.075 and 0.1)mol·kg−1 aqueous 1-butyl-4-methyl pyridinium chloride ([C4mpy]Cl) solutions over a range of temperatures (288.15, 293.15, 298.15, 303.15 and 308.15)K from the values of densities (ρ) and ultrasonic speed (c), repectively. The standard partial molar volumes (V∅0), standard partial molar isentropic compression (K∅,s0), and experimental slopes (SV and SK) have been determined for these amino acid solutions from the Masson equation and have been interpreted in terms of solute-solvent and solute-solute interactions, respectively. The hydrophilic-hydrophilic, hydrophilic-hydrophobic and hydrophobic-hydrophobic interactions are involved in the studied systems of [C4mpy]Cl+amino acids+H2O by calculating the corresponding transfer functions (ΔV∅0andΔK∅,s0). The contribution of the charged end groups (NH3+,COO-), (-CH2) group and other alkyl chains of the amino acids were estimated using V∅0 values. Hydration number (nH) for studied amino acids in aqueous [C4mpy]Cl solutions are positive, which suggest a strong dehydration effect of [C4mpy]Cl. The obtained parameters will be helpful to understand mixing effects and other complex biological processes between head and side chain group of amino acids and ionic liquid [C4mpy]Cl in aqueous solution.