Activity coefficients at infinite dilution of alkanes and alkenes in 1-alkyl-3-methylimidazolium tetrafluoroborate

For the measurement of limiting activity coefficients different techniques are available. In this work the activity coefficients at infinite dilution γ i ∞ of alkanes and alkenes in the ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM]+[BF4]− and 1-hexyl-3-methylimidazolium tetrafluoroborate [HMIM]+[BF4]− from 303.15 K to 353.15 K were measured with the help of the dilutor technique. The new data were compared with already published experimental data measured by using gas–liquid chromatography. Furthermore, the selectivities S i j ∞ = γ i ∞ / γ j ∞ at infinite dilution for the separation problems hexane–1-hexene and octane–1-octene were determined from the experimental γ i ∞ data in the investigated ionic liquids and compared with the values obtained for other ionic liquids and conventional selective solvents.