Shape-persistent macrocycles with adaptable units:: New insights from the solid state

Shape-persistent macrocycles are described in which the orientation of the side groups is not determined by the synthesis, but can be influenced by an external parameter such as solvent polarity (adaptable side groups). In the case of amphiphilc macrocycles, a polar solvent induces a conformation in which the polar side groups point to the exterior of the molecule. Whereas in a less polar solvent in the presence of appropriate guest molecules an inverse conformation is observed where the polar side groups point to the interior of the molecule. The ability of the adaptable side groups to rotate freely lead also to the investigation of the first discotic liquid crystals with an inverse topology, namely composed of an rigid corona and a flexible core.