Iodide Recognition and Sensing in Water by a Halogen-Bonding Ruthenium(II)-Based Rotaxane

authors	Langton, MJ; Marques, I; Robinson, SW; Felix, V; Beer, PD
nationality	International
journal	CHEMISTRY-A EUROPEAN JOURNAL
author keywords	anions; halogen bonding; molecular dynamics; rotaxanes; supramolecular chemistry; water
keywords	ANION RECOGNITION; AQUEOUS-MEDIA; SUPRAMOLECULAR CHEMISTRY; TRANSITION-METAL; HIGH-AFFINITY; HOST SYSTEM; RECEPTOR; FLUORESCENT; BINDING; CHLORIDE
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 beta-cyclodextrin motifs, and a luminescent tris(bipyridine) ruthenium (II)-based macrocycle component. H-1 NMR anion-binding titrations in D2O 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.
publisher	WILEY-V C H VERLAG GMBH
issn	0947-6539
year published	2016
volume	22
issue	1
beginning page	185
ending page	192
digital object identifier (doi)	10.1002/chem.201504018
web of science category	Chemistry, Multidisciplinary
subject category	Chemistry
unique article identifier	WOS:000368897600023