title: Ion pairing in ethanol/water solution probed by electrophoretic and diffusion NMR.
abstract: We demonstrate that a combination of electrophoretic NMR and diffusion NMR experiments can measure the average charge carried by ions in solution. This average charge is used as a quantitative indicator of ion pairing. Our results show that there is a Hofmeister relation in the ion pairing between monovalent anions and the tetramethylammonium cation in 95% ethanol/water solution. The ion pairing of the divalent sulfate ion was larger than that shown by any of the monovalent anions.
authors.affiliation: Division of Physical Chemistry and Industrial NMR Centre, Department of Chemistry, Royal Institute of Technology, SE-10044 Stockholm, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Hallberg
authors.forename: István
authors.initials: I
authors.lastname: Furó
authors.forename: Peter
authors.initials: P
authors.lastname: Stilbs
mesh_terms: D000838:Anions / Q000737:chemistry*; D002412:Cations / Q000737:chemistry*; D004058:Diffusion; D004586:Electrophoresis; D000431:Ethanol; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012996:Solutions
chemical_list: D000838:Anions; D002412:Cations; D000644:Quaternary Ammonium Compounds; D012996:Solutions; D000431:Ethanol; C027917:tetramethylammonium