Complexation of C60 with hexahomooxacalix[3]arenes and supramolecular structures of complexes in the solid state

Hexahomooxacalix[3]arenes 1–5, which possess a variety of substituents on their upper rim, have captured fullerene C60 in toluene with association constants of Ka = 9.1–35.6 dm3 mol–1; X-ray analysis of the complex of C60 and 4 indicated that a van der Waals attractive interaction is the dominant driving force which brings the hexagonal faces of the C60 close to both the aromatic rings and the dibenzyl ether oxygen of 4.