Physicochemical properties of ionic liquids [Cnmim][SbF6] (n=4,5,6)

Ionic liquids (1-alkyl-3-methylimidazolium hexafluoride antimonite) were designed and synthesized, namely [C(n)mim][SbF6] (n = 4,5,6). In temperature range of (293.15-343.15 +/- 0.05) K with an interval of 5 K, the density, surface tension, refractive index and conductivity of the hydrophobic ILs were measured. According to empirical and semi-empirical equations with the interstice model theory, other physicchemical properties of the ILs [C(n)mim][SbF6] (n = 4,5,6) were estimated at 298.15 K, including the standard lattice energy, surface entropy, molar entropy, the molar enthalpy of vaporization, molar surface Gibbs energy and interstitial molar surface Gibbs energy. Based on interstice model, the thermal expansion coefficient of the ILs was calculated with a good magnitude order agreement of experimental value. Then, others physic-chemical properties of the ILs [C(n)mim][SbF6] homologue were predicted with the estimated values. (C) 2018 Elsevier Ltd.