Search results for "hybrid receptors"

Cooperatively Enhanced Ion Pair Binding with a Hybrid Receptor

2015

A simple 18-crown-6-based bis-urea receptor R(1) was synthesized in three steps from a commercial starting material. The receptor's behavior toward anions, cations, and ion pairs was studied in solution with (1)H NMR, in solid state with single-crystal X-ray diffraction, and in gas phase with mass spectrometry. In 4:1 CDCl3/dimethyl sulfoxide solution the receptor's binding preference of halide anions is I(-) < Br(-) < Cl(-) following the trend of the hydrogen-bonding acceptor ability of the anions. The receptor shows a remarkable positive cooperativity toward halide anions Cl(-), Br(-), and I(-) when complexed with Na(+), K(+), or Rb(+). The solid-state binding modes of R(1) with alkali an…