A pyridine-based macrocyclic host for urea and acetone

A pyridine-based macrocycle with a polyether chain has been designed and synthesized. The macrocycle shows strong binding for acetone involving both conventional and unconventional hydrogen bonds. The acetone in the cavity is exchangeable in CHCl3 by urea. This has been studied thoroughly by 1H NMR, 13C NMR, mass and X-ray analyses.