Article ID Journal Published Year Pages File Type
674716 Thermochimica Acta 2010 5 Pages PDF
Abstract

Heat capacity for 1-butyl-3-methylimidazolium trifluoromethanesulfonate [C4mim]OTf in the temperature range of (5–370) K has been measured in an adiabatic calorimeter. The temperature Tfus = (290.98 ± 0.01) K and the enthalpy of fusion ΔfusHm°=(19.43±0.02) kJ mol−1 were determined. A solid-phase transition was observed near T = 120 K. Thermodynamic functions for the compound in the condensed state were calculated. Trends in the solid–liquid phase change entropies, ∑ΔtrSm, for 1-alkyl-3-methylimidazolium salts [Cnmim]An were analyzed. The increment to ∑ΔtrS was shown to increase with n. It was found that ∑ΔtrSm = 66.4 ± 1.3 J K−1 mol−1 for all the studied [C4mim]An ionic liquids except [C4mim]NTf2. This difference can be partly explained by formation of two distinguishable conformers of the NTf2 anion in the liquid state.

Related Topics
Physical Sciences and Engineering Chemical Engineering Fluid Flow and Transfer Processes
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