title: Iodide Recognition and Sensing in Water by a Halogen-Bonding Ruthenium(II)-Based Rotaxane.
abstract: The synthesis and anion-recognition properties of the first halogen-bonding rotaxane host to sense anions in water is described. The rotaxane features a halogen-bonding axle component, which is stoppered with water-solubilizing permethylated β-cyclodextrin motifs, and a luminescent tris(bipyridine)ruthenium(II)-based macrocycle component. (1) H NMR anion-binding titrations in D2 O reveal the halogen-bonding rotaxane to bind iodide with high affinity and with selectively over the smaller halide anions and sulfate. The binding affinity trend was explained through molecular dynamics simulations and free-energy calculations. Photo-physical investigations demonstrate the ability of the interlocked halogen-bonding host to sense iodide in water, through enhancement of the macrocycle component's Ru(II) metal-ligand charge transfer (MLCT) emission.
authors.affiliation: Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA (UK).
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Langton
authors.affiliation: Departamento de Química, iBiMED and CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal).
authors.forename: Igor
authors.initials: I
authors.lastname: Marques
authors.affiliation: Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA (UK).
authors.forename: Sean W
authors.initials: SW
authors.lastname: Robinson
authors.affiliation: Departamento de Química, iBiMED and CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal).
authors.forename: Vítor
authors.initials: V
authors.lastname: Félix
authors.affiliation: Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA (UK). paul.beer@chem.ox.ac.uk.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Beer
keywords: anions; halogen bonding; molecular dynamics; rotaxanes; supramolecular chemistry; water