p-Benzylcalixarene (1) or p-benzylhexahomooxacalixarene (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 oxacalixarene 2 crystallises with chloroform as the 1:1 complex [CHCl3 ⊂ (2)].
|Number of pages||7|
|Journal||Chemistry - A European Journal|
|Publication status||Published - 1 Dec 1999|
- Host-guest chemistry
- Inclusion compounds
- Supramolecular chemistry