title: Hindered fluorescence quenching in an insulated molecular wire.
abstract: A [3]rotaxane 2 within 1(2) consisting of an anionic phenylene ethynylene dumbbell 2(4-) threaded through two cationic cyclophanes 1(2+) has been prepared using aqueous Glaser coupling. Stern-Volmer analysis of the fluorescence quenching using three different electron-acceptors (methyl viologen 13(2+), dipropyl-4,4'-bipyridinium disulfonate 14 and anthraquinone-2,6-disulfonate 15(2-)) shows that the threaded cyclophanes inhibit electron-transfer from the excited state of the dumbbell by steric shielding, and by electrostatic shielding in the case of methyl viologen.
authors.affiliation: Department of Chemistry, University of Oxford, Dyson Perrins Laboratory, South Parks Road, Oxford, UK OX1 3QY.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Taylor
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Hagan
authors.forename: Harry L
authors.initials: HL
authors.lastname: Anderson