Controlling the Confinement and Alignment of Fullerene C 70 in para ‐Substituted Calix[5]arenes

In toluene fullerene C 70 forms 2:1 complexes with p ‐benzylcalix[5]arene ( 1 ) and p ‐phenylcalix[5]arene ( 2 ), [C 70 ⊂ 1 2 ] ⋅ 6 (C 7 H 8 ) and [C 70 ⊂ 2 2 ] ⋅ 7 (C 7 H 8 ). The fullerene molecules are completely shrouded by two calix[5]arenes in addition to terminal benzyl groups from other supermolecules, [C 70 ⊂ 1 2 ], and solvent. Within the capsule‐like supermolecules the calixarenes have distinctly different arrangements relative to the principal axis of the fullerene; for [C 70 ⊂ 1 2 ] ⋅ 6 (C 7 H 8 ) the oxygen planes of the two calixarenes are skewed by 37.0 and 47.5°, whereas in [C 70 ⊂ 2 2 ] ⋅ 7 (C 7 H 8 ) the principal axes of the fullerene and the two encapsulating calixarenes are more closely aligned with the corresponding angles at 9.7 and 8.6°, and features a pentaphenyl inter‐calixarene embrace. The Hirshfeld surfaces of these two complexes have been investigated for a detailed understanding of the orientation and nature of interactions of C 70 with the cavitand‐type molecules and toluene.