Diarylethene-Powered Light-Induced Folding of Supramolecular Polymers

• DOI: 10.1021/jacs.1c00592
• Publication Date: 2021-03-23T16:49:50Z
• Authors: Takuya Fukushima; Kenta Tamaki; Atsushi Isobe; Takashi Hirose; Nobutaka Shimizu; Hideaki Takagi; Rie Haruki; Shin-ichi Adachi; Martin J. Hollamby; Shiki Yagai
• Keywords: Folding (DSP implementation); Diarylethene; Supramolecular Polymers

Helical folding of randomly coiled linear polymers is an essential organization process not only for biological polypeptides but also synthetic functional polymers. Realization this dynamic in supramolecular (SPs) is, however, a formidable challenge because their inherent lability main chains upon changing external environment that can drive the (e.g., solvent, concentration, and temperature). We herein report photoinduced reversible folding/unfolding rosette-based SPs driven by photoisomerization diarylethene (DAE). Temperature-controlled polymerization barbiturate-functionalized DAE (open isomer) nonpolar solvent results formation intrinsically curved, coiled, due to presence defects. Irradiation with UV light causes efficient ring-closure reaction moieties, which induces helical structures into helicoidal ones, as evidenced atomic force microscopy small-angle X-ray scattering. The internal structure ordering SP fiber repairs defects interloop interaction occurring resulting structure. In contrast, direct ring-closed monomers temperature control affords linearly extended ribbon-like lacking intrinsic curvature are thermodynamically less stable compared SPs. finding represents important concept applicable other systems; postpolymerization (photo)reaction preorganized kinetic lead more inaccessible directly through temperature-controlled protocols.