title: Switchable dual binding mode molecular shuttle.
abstract: [Structure: see text] Protonation controls the location of a dual binding mode macrocycle in a [2]rotaxane. In the neutral form, amide-amide hydrogen bonds hold the macrocycle over a dipeptide residue; when the thread is protonated, polyether-ammonium cation interactions dominate and the macrocycle changes position.
authors.affiliation: University of Edinburgh, School of Chemistry, The King's Buildings, West Mains Road, Edinburgh EH9 3JJ, UK. david.leigh@ed.ac.uk
authors.forename: David A
authors.initials: DA
authors.lastname: Leigh
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Thomson