title: Electrostatic and non-covalent interactions in dicationic imidazolium-sulfonium salts with mixed anions.
abstract: A series of thioether-functionalised imidazolium salts have been prepared and characterized. Subsequent reaction of the thioether-functionalised imidazolium salts with iodomethane affords imidazolium-sulfonium salts composed of doubly charged cations and two different anions. Imidazolium-sulfonium salts containing a single anion type are obtained either by a solvent extraction method or by anion exchange. The imidazolium-sulfonium salts undergo a methyl-transfer reaction on exposure to water, giving rise to a new, singly charged imidazolium salt with iodide introduced at the 2-position of the imidazolium ring. Crystal structures of some of the imidazolium-sulfonium salts were determined by X-ray crystallography providing the topology of the interactions between the dications and the anions. Electrospray ionization mass spectrometry and quantum-chemical calculations were used to rationalise the relative strength of these interactions.
authors.affiliation: Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne (Switzerland).
authors.forename: Zhaofu
authors.initials: Z
authors.lastname: Fei
authors.forename: Dun-Ru
authors.initials: DR
authors.lastname: Zhu
authors.forename: Ning
authors.initials: N
authors.lastname: Yan
authors.forename: Rosario
authors.initials: R
authors.lastname: Scopelliti
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Katsuba
authors.forename: Gabor
authors.initials: G
authors.lastname: Laurenczy
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Chisholm
authors.forename: J Scott
authors.initials: JS
authors.lastname: McIndoe
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Seddon
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Dyson
keywords: X-ray spectroscopy; dications; electrospray ionization mass spectrometry; ionic liquids; quantum-chemical calculations