Thermodynamic properties of 1-butyl-3-methylimidazolium salicylate as an active pharmaceutical ingredient ionic liquid (API-IL) in aqueous solutions of glycine and L-alanine at T = (288.15–318.15) K

•The novel API-IL, 1-butyl-3-methylimidazolium salicylate was synthesized.•Effect of the API-IL on the thermodynamic properties of some amino acid has been investigated.•The API-IL behaves as structure maker in the studied amino acids solutions.•Dehydration effect was observed more effective in glycine rather than l-alanine.•Dominant interaction between amino acid and API-IL are ion-hydrophilic and hydrophilic-hydrophilic interactions.

Thermodynamic properties of aqueous solutions of some amino acids, glycine and l-alanine with a novel ionic liquid containing salicylate anion, 1-butyl-3-methylimidazolium salicylate, [BMIM][SAL] as an active pharmaceutical ingredient ionic liquid (API-IL) have been investigated by volumetric, ultrasonic, refractometric and viscometric properties at T = (288.15–318.15 K). The standard partial molar volume Vϕ0, partial molar volume of transfer ΔtraVφ0, Hepler’s constant (∂2Vϕ0/∂T2)p(∂2Vϕ0/∂T2)p and apparent molar isentropic compressibility κφκφ have been calculated from density and speed of sound data. Viscosity and refractive index data were used for determination of viscosity B-coefficients (B), hydration number nH and molar refraction RD parameters. These parameters are helpful to study the structure promoting and solvation behaviour of the API-IL and various interactions present in the ternary solutions of (amino acid + [BMIM][SAL] + water).

Graphical abstractRepresentation of amino acid-API-IL interactions.Figure optionsDownload full-size imageDownload as PowerPoint slide