LAUSR

Ionic liquid 1-ethylpyridinium bis(trifluoromethylsulfonyl)imide ([C2py][NTf2]) was synthesized and characterized by 1H NMR spectroscopy, 13C NMR spectroscopy and thermal gravity analysis. The molar heat capacities of [C2py][NTf2] were measured using a heat-flow calorimeter with “3D Calvet” calorimetric sensor from (293 to 312) K. The experiment value of molar heat capacity 502.15 J K−1 mol−1 at 298.15 K was obtained. Moreover, the estimation values of molar heat capacity were calculated by using 4 methods at 298.15 K, and the result showed the Paulechka et al.’s method was more appropriate for predicting the molar heat capacity of IL [C2py][NTf2], and the error was less than 2%. In addition, the freezing point T* was calculated by freezing point depression, which was approximately equal to experimental value 305.08 K. The molar enthalpy of fusion ΔfHm = 26.77 kJ mol−1, molar melting entropy ΔdeSm = 90.60 J mol−1 K−1 and the freezing constant Kf were also calculated.