title: A metallacage encapsulating chloride as a probe for a solvation scale in ionic liquids.
abstract: With the purpose of assessing the reactivity of chloride ions dissolved in ionic liquids (ILs), a relative scale for the solvation of chloride is given for a series of ILs based on the bis(trifluoromethane)sulfonimide ([Tf(2)N]) anion and different cations, 1-butyl-3-methylimidazolium ([bmim]), 1-butyl-2,3-dimethylimidazolium ([bdmim]), 1-butyl-1-methylpyrrolidinium ([bmpy]), 1-butylpyridinium ([bpy]), 1-pentyl-1,1,1-triethylammonium ([C(5)e(3)am]), and 1-(2-hydroxy)ethyl-3-methylimidazolium ([mimeOH]). Insights into the solvation of chloride are achieved by the thermodynamic study of the reaction of dissociation of a chloride-templated nickel(II) metallacage performed at various temperatures by UV-visible spectroscopy in each IL. The order of chloride solvation [C(5)e(3)am][Tf(2)N] < [bmpy][Tf(2)N] < [bmim][Tf(2)N] <or= [bdmim][Tf(2)N] < [bpy][Tf(2)N] < [mimeOH][Tf(2)N] was ascertained from the reaction enthalpies determined in the different ILs. The reaction entropies display a concentration-dependent behavior, which has highlighted a correlated motion of the ions in these ILs.
authors.affiliation: Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: Corinne
authors.initials: C
authors.lastname: Daguenet
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Dyson