Premium
Increased Halide Recognition Strength by Enhanced Intercomponent Preorganisation in Triazolium Containing [2]Rotaxanes
Author(s) -
White Nicholas G.,
Costa Paulo J.,
Carvalho Sílvia,
Félix Vítor,
Beer Paul D.
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201303122
Subject(s) - halide , alkyl , aryl , chemistry , titration , chloride , axle , supramolecular chemistry , molecular dynamics , ion , affinities , molecular recognition , rotaxane , molecule , polymer chemistry , computational chemistry , stereochemistry , organic chemistry , thermodynamics , physics
Three triazolium‐based [2]rotaxanes containing different sized axle and macrocycle components were synthesised in good yields (40–57 %) through chloride anion templation. The anion recognition properties of the interlocked receptor systems were investigated using 1 H NMR titration experiments: all three rotaxanes display impressive selectivities for halide anions over the more basic oxoanion acetate. The rotaxanes incorporating shorter, more rigid axle components with aryl‐substituted triazolium groups display substantially higher anion binding affinities than those with longer, bis‐alkyl‐substituted heterocycles, which is attributed to the increased intercomponent preorganisation afforded by the smaller axle component. Computational DFT and molecular dynamics simulations composed of unconstrained and umbrella sampling simulations corroborate the experimental observations.