Symmetry-aligned supramolecular encapsulation of C₆₀: [C₆₀ ⊂ (L)₂], L =p-benzylcalix[5]arene or p-benzylhexahomooxacalix[3]arene

p-Benzylcalix[5]arene (1) or p-benzylhexahomooxacalix[3]arene (2) form 2:1 complexes with C₆₀ in solutions of the fullerene or fullerite in toluene to give [C₆₀ ⊂ (1)₂] · 8toluene and [C₆₀ ⊂ (2)₂], respectively. In both structures the fullerene is shrouded by two staggered, trans-disposed, host molecules. These host calixarenes adopt a cone conformation and the benzyl groups are either dangling ([C₆₀ ⊂ (1)₂] · 8toluene) or they are positioned edge-on to the fullerene ([C₆₀ ⊂ (2)₂]). The alignment of the symmetry axis of the calixarene, C₅ or C₃, respectively, with the same symmetry element of C₆₀ highlights the importance of symmetry matching in the design of host molecules for fullerenes, as it maximises the number of points of contact and the efficiency of the π⋯π interactions. Two host-guest associations for 1 and 2 with C₆₀ are evident in solutions in toluene. The new oxacalix[3]arene 2 crystallises with chloroform as the 1:1 complex [CHCl₃ ⊂ (2)].