title: An all-halogen bonding rotaxane for selective sensing of halides in aqueous media.
abstract: The synthesis and anion binding properties of the first rotaxane host system to bind and sense anions purely through halogen bonding, is described. Through a combination of polarized iodotriazole and iodotriazolium halogen bond donors, a three-dimensional cavity is created for anion binding. This rotaxane incorporates a luminescent rhenium(I) bipyridyl metal sensor motif within the macrocycle component, thus enabling optical study of the anion binding properties. The rotaxane topology was confirmed by single-crystal X-ray structural analysis, demonstrating halogen bonding between the electrophilic iodine atoms and chloride anions. In 50% H2O/CH3CN solvent mixtures the rotaxane host exhibits strong binding affinity and selectivity for chloride, bromide, and iodide over a range of oxoanions.
authors.affiliation: Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford, OX1 3TA (UK).
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Mullaney
authors.forename: Amber L
authors.initials: AL
authors.lastname: Thompson
authors.forename: Paul D
authors.initials: PD
authors.lastname: Beer
keywords: anions; halogen bonding; noncovalent interactions; rotaxanes; supramolecular chemistry