SEARCH

SEARCH BY CITATION

Keywords:

  • cyclic ionic receptors;
  • bis-benzimidazolium;
  • anion recognition;
  • hydrogen bond

Abstract

A series of cyclic receptors 15 based on bis-benzimidazolium group were designed and synthesized. Their anion recognition properties were investigated by UV-vis, fluorescent spectroscopy, 1H NMR and MALDI-TOF mass spectrometry. The UV-vis and fluorescent spectroscopic studies showed that the receptors 1–5 had different binding abilities for various anions such as fluoride, chloride, bromide, iodide and acetate. The high selectivity of the receptors for fluoride and acetate anions is attributed to their basicity. Job plot and MALDI-TOF mass spectrometry demonstrated that the receptors form 1:1 complex with fluoride. DFT calculation and 1H NMR studies indicated that the receptors bind anions through (C[BOND]H)+···X hydrogen bond.