Molecular-recognition-directed self-assembly of supramolecular polymers

The first part of this paper discusses the molecular design of selected examples of structural units containing taper-shaped exo-receptors and various crown ether, oligooxyethylenic, and H-bonding-based endo-receptors, which self-assemble into cylindrical channel-like architectures via principles resembling those of tobacco mosaic virus. The ability of these structural units to self-assemble via a delicate combination of exo-and endo-recognition processes will be presented. A comparison between various supramolecular (generated via H-bonding, ionic, and electrostatic interactions) and molecular “polymer backbones” will be made. The present limitations concerning the ability to engineer the structural parameters of these supramolecular channel-like architectures and some possible novel material functions derived from them will be briefly mentioned. The second part of this paper discusses our research on the molecular design of a novel class of macrocyclics which self-assemble via intramolecular recognition processes into supramolecular “rodlike” collapsed macrocyclics which display thermotropic liquid crystalline mesophases. It is demonstrated that these macrocyclics have a higher ability to form liquid crystalline phases than the corresponding linear compounds which have identical or even higher degrees of polymerization. Therefore, they represent the ideal molecular architectures which generate mesophases.