Supramolecular Polymer Polymorphism: Spontaneous Helix-Helicoid Transition through Dislocation of Hydrogen-Bonded π-Rosettes.

Otsuka, Chie; Takahashi, Sho; Isobe, Atsushi; Saito, Takuho; Aizawa, Takumi; Tsuchida, Ryoma; Yamashita, Shuhei; Harano, Koji; Hanayama, Hiroki; Shimizu, Nobutaka; Takagi, Hideaki; Haruki, Rie; Liu, Luzhi; Hollamby, Martin J.; Ohkubo, Takahiro; Yagai, Shiki; Hollamby, Martin J

Abstract

Polymorphism, a phenomenon whereby disparate self-assembled products can be formed from identical molecules, has incited interest in the field of supramolecular polymers. Conventionally, the monomers that constitute supramolecular polymers are engineered to facilitate one-dimensional aggregation and, consequently, their polymorphism surfaces primarily when the states of assembly differ significantly. This engenders polymorphs of divergent dimensionalities such as one- and two-dimensional aggregates. Notwithstanding, realizing supramolecular polymer polymorphism, wherein polymorphs maintain one-dimensional aggregation, persists as a daunting challenge. In this work, we expound upon the manifestation of two formed from a large discotic supramolecular monomer (rosette), which consists of six hydrogen-bonded molecules with an extended π-conjugated core. These polymorphs are generated in mixtures of chloroform and methylcyclohexane, attributable to distinctly different disc stacking arrangements. The face-to-face (minimal displacement) and offset (large displacement) stacking arrangements can be predicated on their distinctive photophysical properties. The face-to-face stacking results in a twisted helix structure. Conversely, the offset stacking induces inherent curvature in the supramolecular fiber, thereby culminating in a hollow helical coil (helicoid). While both polymorphs exhibit bistability in nonpolar solvent compositions, the face-to-face stacking attains stability purely in a kinetic sense within a polar solvent composition and undergoes conversion into offset stacking through a dislocation of stacked rosettes. This occurs without the dissociation and nucleation of monomers, leading to unprecedented helicoidal folding of supramolecular polymers. Our findings augment our understanding of supramolecular polymer polymorphism, but they also highlight a distinctive method for achieving helicoidal folding in supramolecular polymers.

Citation

Otsuka, C., Takahashi, S., Isobe, A., Saito, T., Aizawa, T., Tsuchida, R., …Hollamby, M. J. (2023). Supramolecular Polymer Polymorphism: Spontaneous Helix-Helicoid Transition through Dislocation of Hydrogen-Bonded π-Rosettes. Journal of the American Chemical Society, 145(41), 22563-22576. https://doi.org/10.1021/jacs.3c07556

• Journal Article Type: Article
• Acceptance Date: Oct 5, 2023
• Online Publication Date: Oct 5, 2023
• Publication Date: Oct 18, 2023
• Deposit Date: Dec 22, 2023
• Publicly Available Date: Oct 6, 2024
• Journal: Journal of the American Chemical Society
• Print ISSN: 0002-7863
• Electronic ISSN: 1520-5126
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 145
• Issue: 41
• Pages: 22563-22576
• DOI: https://doi.org/10.1021/jacs.3c07556
• Keywords: Supramolecular Polymer Polymorphism
• Publisher URL: https://pubs.acs.org/doi/10.1021/jacs.3c07556
• Additional Information: This document is the Accepted Manuscript version of a Published Work that appeared in final form in JACS, Copyright © 2023 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/jacs.3c07556