abstract
A new [2]rotaxane host system containing nitro-isophthalamide macrocycle and polyether functionalised pyridinium axle components is prepared via clipping and stoppering synthetic methodologies using chloride anion templation. After removing the chloride anion template, (1)H NMR titration experiments reveal the unique interlocked host cavity to be highly selective for binding chloride and bromide in preference to basic oxoanions in competitive aqueous solvent mixtures. The rotaxane host system proved to be a superior anion complexant in comparison to the individual macrocycle and axle components. The anion binding affinity of the novel rotaxane is also investigated via molecular dynamics simulations and in general the structural data obtained corroborates the experimental solution anion recognition behaviour.
keywords
PSEUDOROTAXANE FORMATION; INTERLOCKED STRUCTURES; AQUEOUS-MEDIA; RECOGNITION; ROTAXANES; CHLORIDE; RING; METATHESIS
subject category
Chemistry
authors
Li, YT; Mullen, KM; Sardinha, J; Felix, V; Beer, PD
our authors
Vítor Félix
Associate Professor with Aggregationacknowledgements
We thank WEILUN, CGA and GBCC for scholarships (Y.L.) and the EPSRC for a post-doctoral fellowship (K.M.M.). We also thank Dr N. H. Rees for valuable NMR advice. Vitor Felix (V.F.) acknowledges the FCT for financial support under project PTDC/QUI/68582/2006 with co-participation European Community funds from the FEDER, QREN and COMPET.