title: Ionic liquids and solids with paramagnetic anions.
abstract: Four paramagnetic ionic compounds have been prepared and their magnetic, structural and thermal properties have been investigated. The four compounds are methylbutylpyrrolidinium tetrachloroferrate(III) ([Pyrr(14)](+)/[FeCl(4)](-)), methyltributylammonium tetrachloroferrate(III) ([N(1444)](+)/[FeCl(4)](-)), butylmethylimidazolium tetrachloroferrate(III) ([bmim](+)/[FeCl(4)](-)) and tetrabutylammonium bromotrichloroferrate(III) ([N(4444)](+)/[FeBrCl(3)](-)). Temperature-dependent studies of their magnetic behaviors show that all four compounds are paramagnetic at ambient temperatures. Glass transitions are observed for only two of the four compounds, [Pyrr(14)](+)/[FeCl(4)](-) and [bmim](+)/[FeCl(4)](-). Crystal structures for [Pyrr(14)](+)/[FeCl(4)](-) and [N(1444)](+)/[FeCl(4)](-) are compared with the previously reported [N(4444)](+)/[FeBrCl(3)](-).
authors.affiliation: Department of Chemistry and Chemical Biology Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8087, USA.
authors.forename: Brenna M
authors.initials: BM
authors.lastname: Krieger
authors.forename: Heather Y
authors.initials: HY
authors.lastname: Lee
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Emge
authors.forename: James F
authors.initials: JF
authors.lastname: Wishart
authors.forename: Edward W
authors.initials: EW
authors.lastname: Castner