Synthesis of a Symmetric Cylindrical Bis(crown ether) Host and Its Complexation with Paraquat

Abstract
The first cylindrical host for paraquat derivatives was prepared and characterized by X-ray analysis. Its complex with paraquat has 1:2 stoichiometry. The complexation is statistical and strong as shown by proton NMR characterization, electrospray mass spectrometry, and X-ray analysis.