Impact of Cα‐Chirality on Supramolecular Self‐Assembly in Cyclo‐2:1‐[α/aza]‐Hexamers (d/l‐Phe‐azaPhe‐Ala)2

Abstract

The design of new cyclic pseudopeptides of the sequence 2:1‐[α/aza]‐hexamers, which contain aza‐amino acid motifs, has gained much prominence to be involved in several potential applications. X‐ray, FTIR, and NMR spectroscopy studies showed the ability of this series to adopt β‐turn conformation in solid state, whereas in solution an equilibrium between the monomeric states (stabilized by β‐turns through intramolecular hydrogen bonds), and supramolecular construction (stabilized by intermolecular hydrogen bonds and π‐π stacking) predominates. Furthermore, both homo‐ and heterochiral 2:1‐[α/aza]‐cyclohexamers 3 and 4, respectively, can self‐assemble into organized 3D structures with increases in concentration that favor the supramolecular construction in which the macrocyles are stacking over each other and stabilized by several non‐covalent intermolecular interactions.