Host–guest capability of a three-dimensional heterometallic macrocycle

Abstract

A three-dimensional heterometallic coordination macrocycle is found to be capable of encapsulating planar pyrene (G₁), coronene (G₄) and non-planar corannulene (G₂) guest molecules in high yields, giving rise to 1 : 1 host–guest complexes. The bowl-shaped guest corannulene is found to be significantly flattened upon inclusion within the cavity. However, macrocyclic compounds with larger cavity sizes, which form 1 : 1 stoichiometry assemblies with a naphthalene bisimide planar molecule (G₃), are more inclined to form infinite sandwich structures. Furthermore, these heterometallic coordination macrocycles can be destroyed in the presence of a soft base to form hexanuclear triangular prism complexes. These structures are unambiguously revealed by single-crystal X-ray analysis.