New interlocked molecules generated from a podand containing urea units and imidazolium salts using an anion template

A podand containing urea units (L) was found to form interlocked structures with 2,5-dihexylamide imidazolium salts (3·X), 2,5-dihexyl imidazolium salts (4·X), and 2,5-dihexyl benzoimidazolium salts (5·X), where X=Cl−, Br−, and PF6− using anions as templates. The binding ability of L and guest molecules was evaluated by 1H NMR titrations in CDCl3. It was found that L could form complexes with guest molecules in the following order, 3·X > 5·X > 4·X. Stabilities of the complexes also depended on shape of the templated anions: Cl−>Br−≫PF6−. Hydrogen bonding and π–π stacking interactions played an important role in the self-assembling of these interlocked molecules.