Thermodynamic behavior of thiophene with octane, 1-hexyl-3-methylimidazolium bromide, or 1-octyl-3-methylimidazolium bromide in dilute region at TÂ =Â (288.15 to 303.15)Â K

In order to deep insight on the molecular interactions between thiophene (TS) and some imidazolium based ionic liquids, density, speed of sound and refractive index of binary liquid mixture of TS with octane, 1-hexyl-3-methylimidazolium bromide [HMIm]Br, and 1-octyl-3-methylimidazolium bromide [OMIm]Br at T = (288.15 to 303.15) K and at atmospheric pressure has been measured in dilute region of TS. Various thermophysical parameters including partial molar volumes, v¯m,i, apparent molar volumes, Vφ, standard partial molar volumes Vφ0, transfer volume of thiophene from octane to ionic liquid mixtures, ΔtrVφ0, partial molar isentropic compressibility, κφ0, excess molar volumes, VE, excess partial molar volumes, v¯m,iE, molar refractions, RD have been calculated using these data. The densitometric and refractometric non-intrinsic contribution to the partial molar volume, θd and θr have been obtained using the measured experimental data. Also, interaction volume, Vint, and cavity volume, Vcav, have been calculated from scaled particle theory (SPT). The results demonstrate that ionic liquids used in this study do not interact effectively with thiophene.