Supramolecular double-stranded Archimedean spirals and concentric toroids

Norihiko Sasaki, Mathijs F. J. Mabesoone, Jun Kikkawa, Tomoya Fukui, Nobutaka Shioya, Takafumi Shimoaka, Takeshi Hasegawa, Hideaki Takagi, Rie Haruki, Nobutaka Shimizu, Shin-ichi Adachi, E. W. Meijer, Masayuki Takeuchi & Kazunori Sugiyasu

Published: 1 December 2020


Connecting molecular-level phenomena to larger scales and, ultimately, to sophisticated molecular systems that resemble living systems remains a considerable challenge in supramolecular chemistry. To this end, molecular self-assembly at higher hierarchical levels has to be understood and controlled. Here, we report unusual self-assembled structures formed from a simple porphyrin derivative. Unexpectedly, this formed a one-dimensional (1D) supramolecular polymer that coiled to give an Archimedean spiral. Our analysis of the supramolecular polymerization by using mass-balance models suggested that the Archimedean spiral is formed at high concentrations of the monomer, whereas other aggregation types might form at low concentrations. Gratifyingly, we discovered that our porphyrin-based monomer formed supramolecular concentric toroids at low concentrations. Moreover, a mechanistic insight into the self-assembly process permitted a controlled synthesis of these concentric toroids. This study both illustrates the richness of self-assembled structures at higher levels of hierarchy and demonstrates a topological effect in noncovalent synthesis.

Full Access Link: Nature Communications