title: Counterion-induced translational isomerism in a bistable [2]rotaxane.
abstract: Translational isomerization can be induced by changing the anions associated with a bistable rotaxane in which the tetracationic cyclophane (blue box), cyclobis(paraquat-p-phenylene), encircles a dumbbell component containing bispyrrolotetrathiafulvalene (green) and a dioxynaphthalene (red) recognition sites. The rotaxane was isolated as both its hexafluorophosphate and tris(tetrachlorobenzenediolato)phosphate(v) (TRISPHAT(-)) salts. Photophysical measurements and NMR spectroscopy carried out in acetone (CD(3)COCD(3)) and acetonitrile (CD(3)CN) solutions reveal that the much larger TRISPHAT(-) anion favors predominantly the encirclement of the green site by the blue box.
authors.affiliation: California NanoSystems Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
authors.forename: Bo W
authors.initials: BW
authors.lastname: Laursen
authors.forename: Sune
authors.initials: S
authors.lastname: Nygaard
authors.forename: Jan O
authors.initials: JO
authors.lastname: Jeppesen
authors.forename: J Fraser
authors.initials: JF
authors.lastname: Stoddart
mesh_terms: D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D043862:Rotaxanes / Q000737:chemistry*
chemical_list: D043862:Rotaxanes