Supramolecular [6]chochin and 'big mac' made from chiral Piedfort assemblies

摘要

Facile chemical synthesis of the natural chiral-pool-derived host I and its subsequent crystallization ("supramolecular synthesis") from different solvents yielded crystalline assemblies. Crystal structure determinations of five of the so formed solvent-inclusion compounds (1a - 1e) reveal hexagonal symmetries in four cases. The structural characteristics of these chiral host guest ensembles with varying stoichiometrics can be best described as assemblies formed through intra-pair hydrogen bridges of host molecules into Piedfort pairs of differing complexity. Hitherto undescribed, these Piedfort pairs also form even larger regular assemblies that we designate "Big Mac"-like shapes. In the only nonhexagonal case, six independent host molecules form a huge supramolecular analogue of [6]benzocyclophane, also known as [6]chochin, extending this giant supermolecule through intermolecular hydrogen bonds into macroscopic (mm-size) dimensions. As all these crystals are inherently chiral, and new model systems for solid-state applications can be envisaged. [References: 41]