abstract
A new rotaxane containing the 3-amido-phenyl-triazolium group incorporated into the interlocked structure's axle component has been prepared by a chloride anion templated clipping strategy. Proton NMR titration experiments reveal that the interlocked host displays a high degree of halide anion recognition in competitive 1:1 CDCl3-CD3OD solvent mixture. Chloride and bromide anions are bound strongly and selectively, with negligible complexation of the larger, more basic oxoanions, acetate and dihydrogen phosphate being observed. Density functional theory calculations on the related axle motifs 3-amido-phenyl-triazolium, pyridinium bis-triazole and pyridinium bis-amide were performed, and indicate that the new rotaxane axle motif displays much weaker oxoanion binding than the pyridinium based systems.
keywords
SURFACE-ELECTROSTATIC POTENTIALS; MACROCYCLIC RECEPTOR; CHLORIDE BINDING; DONOR GROUPS; ROTAXANE; CH; TRIAZOLOPHANES; COMPLEXATION; PROGRAM; SULFATE
subject category
Chemistry
authors
White, NG; Colaco, AR; Marques, I; Felix, V; Beer, PD
our authors
acknowledgements
NGW thanks the Clarendon. Fund, Trinity College Oxford and the Vice-Chancellors' Fund for financial support. We thank Diamond Lightsource for an award of beamtime on Beamline I19. ARC, IM and VF acknowledge the financial support from FCT under the project PEst-C/CTM/LA0011/2013 with co-participation of the European Community funds FEDER, QREN and COMPETE. IM thanks the FCT for the PhD scholarship SFRH/BD/87520/2012.