Activity coefficients at infinite dilution gamma(infinity)(i) of alkanes, alkenes, and alkylbenzenes as well as of the linear C-1-C-6 alcohols in the paramagnetic ionic liquid 1-butyl-3-methyl-imidazolium tetrachloridoferrate(III) have been determined by gas chromatography using the ionic liquids as stationary phase. The measurements were carried out at different temperatures between (305 and 403) K. From the temperature dependence of the limiting activity coefficients partial molar excess enthalpies at infinite dilution H-i(E infinity) of the solutes in the ionic liquids have been derived. Activity coefficients at infinite dilution gamma(infinity)(i) of ionic liquid with the ionic liquids containing 1-butyl-3-methyl-imidazolium cation and different non-magnetic anions have been compared at 298 K with results for 1-butyl-3-methyl-imidazolium tetrachloridoferrate(III). No significant effects caused by the paramagnetic anion anion have been observed. (c) 2008 Elsevier Ltd. All rights reserved.