Supramolecular Self-Assembly of Monosubstituted Pillar[5]Arenes Under the Control of the Nature of the Amide Moiety

Abstract

In this study, we have shown for the first time that the introduction of a single alkylamide substituent into the macrocyclic platform of pillar[5]arene opens up the possibility to control the supramolecular properties of this macrocyclic platform. The ability of the synthesized pillar[5]arenes to form supramolecular pseudorotaxane associates both in solutions and in the crystalline state was studied by a complex of physical methods. Linear secondary amide fragments such as N,N-diethylethane-1,2-diamide, N,N-dimethylpropane-1,3-diamide, or N-aminoethylmorpholide in the structure of pillar[5]arene promote the formation of self-inclusion complexes both in solution and crystalline states. Whereas tertiary amides such as pyrrolidide or morpholide moieties favor the formation of supramolecular polymers both in solution and in crystalline states. The obtained results show the prospects for the use of amide fragments in the structures of pillar[n]arenes as customization units for controlling supramolecular self-assembly.