Abstract
Physical properties of 4 room-temperature ionic liquids consisting of the 1-butyl-3-methylimidazolium cation
with various perfluorinated anions and the bis(trifluoromethylsulfonyl)imide (Tf2N-) anion with 12
pyrrolidinium-, ammonium-, and hydroxyl-containing cations are reported. Electronic structure methods are
used to calculate properties related to the size, shape, and dipole moment of individual ions. Experimental
measurements of phase-transition temperatures, densities, refractive indices, surface tensions, solvatochromic polarities based on absorption of Nile Red, 19F chemical shifts of the Tf2N- anion, temperature-dependent viscosities, conductivities, and cation diffusion coefficients are reported. Correlations among the measured quantities as well as the use of surface tension and molar volume for estimating Hildebrand solubility parameters of ionic liquids are also discussed.