Anion Influence on Thermophysical Properties of Ionic Liquids: 1-Butylpyridinium Tetrafluoroborate and 1-Butylpyridinium Triflate.

The thermophysical properties of two pryidinium-based ionic liquids, 1-butylpyridinium tetrafluoroborate and 1-butylpyridinium triflate, have been measured. Thus, densities, refractive Indices, speeds Of Sound, Viscosities, surface tensions, isobaric molar heat capacities, and thermal properties have been experimentally determined over I wide range of temperatures. The comparison of the properties of the two ionic liquids has allowed LIS to analyze in detail the anion influence. Moreover, useful derived properties have been calculated from the results. Oil the other hand, the influence of the lack of a substituent in the cation has been evaluated when properties of 1-butylpyridinium tetrafluoroborate have been contrasted to those of 1-butyl-n-methylpyridinium tetrafluoroborate, (n = 2, 3, or 4). The Study has been carried Out paying special attention to interactions between ions ill order to elucidate the desired relationship between properties and Structural characteristics of ionic liquids.