Effect of an Aromatic Solvent on Hydrogen-Bond-Directed Supramolecular Polymerization Leading to Distinct Topologies.

Abstract

Beyond phenomenon, self-assembly of synthetic molecules, is now becoming an essential tool to design supramolecular materials not only in the thermodynamically stable state but also in kinetically trapped states. However, an approach to design complex self-assembly processes comprising different types of self-assembled states remains elusive. Herein, an example of such systems is demonstrated based on a unique supramolecular polymer mediated by supermacrocyclization of hydrogen-bonding π-conjugated molecules. By adding an aromatic solvent into nonpolar solutions of the monomer, spontaneous nucleation triggered by supermacrocyclization was suppressed so that isothermal supramolecular polymerization could be achieved from kinetically formed topological variants and amorphous agglomerates to afford helicoidal structures hitherto obtainable only with very slow cooling of a hot solution. By increasing the proportion of aromatic solvent further, another self-assembly path was found, based on competing extended hydrogen-bonded motifs affording crystalline nanowires.