Thermo-acoustical study of biologically active 1,1’-bis(3-methyl-4-carboxyethylphenoxy) cyclohexane at four different temperatures

Density (ρ), viscosity (η), ultrasonic speed (U), and thermo-acoustical parameters such as specific acoustical impedance (Z), adiabatic compressibility (κa), internal pressure (π), free volume (Vf), inter molecular free path length (Lf), Van der Waals constant (b), viscous relaxation time (τ), classical absorption coefficient (α/f2)cl, Rao’s molar sound function (Rm), solvation number (Sn), Gibbs free energy of activation (ΔG*), enthalpy of activation (ΔH*) and entropy of activation (ΔS*) of biologically active 1,1’-bis(3-methyl-4-carboxyethylphenoxy)cyclohexane (BMCPC) in 1,4-dioxane (DO), ethyl acetate (EA), tetrahydrofuran (THF) have been studied at four different temperatures: 298, 303, 308 and 313 K to understand the molecular interactions in the solutions. A good to excellent correlation between a given parameter and concentration is observed at all temperatures and solvent systems studied. Linear increase or decrease [except (α/f2)cl ] of acoustical parameters with concentration and temperature indicated the existence of strong molecular interactions. ΔG* decreased linearly with increasing concentration and temperature in DO and EA systems and increased with temperature in THF system. ΔH* and ΔS* are found practically concentration independent in case of DO and EA system but both are found concentration dependent in THF system.