A bis-urea naphthalenemacrocycle displaying two crystal structures with parallel ureas

Abstract

Herein we synthesized a bis-urea macrocycle from 2,7-dimethylnaphthalene that displays an unusual parallel urea conformation. The naphthalenes also adopt a bowl shape over the anticipated parallel planar orientation. Crystallization of the macrocycle from different solvent systems affords two solvated forms. 1·DMSO·(H₂O)₂ has an extended columnar structure where parallel macrocycles are linked by intervening hydrogen bonded water molecules. In 1·(MeOH)₂ direct hydrogen-bonds link the macrocycles into chains, which hydrogen-bond with methanol molecules to form a layered structure.