Pulsating Tubules from Noncovalent Macrocycles

• Published in: Science (American Association for the Advancement of Science) Vol. 337; no. 6101; pp. 1521 - 1526
• Main Authors: Huang, Zhegang, Kang, Seong-Kyun, Banno, Motonori, Yamaguchi, Tomoko, Lee, Dongseon, Seok, Chaok, Yashima, Eiji, Lee, Myongsoo
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 21.09.2012; The American Association for the Advancement of Science
• Subjects: Applied sciences; Aqueous solutions; Chirality; Contracts; Cylinders; Dendrimers; Exact sciences and technology; Fluorescence; Fullerenes; Heating; Line spectra; Macrocyclic compounds; Materials science; Molecules; Nanostructure; Nanotubes; Organic polymers; Physicochemistry of polymers; Porosity; Properties and characterization; Pyridines; Room temperature; Solution and gel properties; Stacks; Tubes; Wavelengths; Circular dichroism spectrum; Hydrodynamic radius; Nanotube; Temperature effect; Hydrophobic compound; Branched copolymer; Ethylene oxide copolymer; Experimental study; Nanoencapsulation; Absorption spectrum; Monodispersed polymer; Optically active copolymer; Toroidal shape; Dilute solution; Fullerenes; Molecular aggregation; Helical structure; Phenylene copolymer; Aqueous solution; Block copolymer; Amphiphilic polymer
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1224741

Despite recent advances in synthetic nanometer-scale tubular assembly, conferral of dynamic response characteristics to the tubules remains a challenge. Here, we report on supramolecular nanotubules that undergo a reversible contraction-expansion motion accompanied by an inversion of helical chirality. Bent-shaped aromatic amphiphiles self-assemble into hexameric macrocycles in aqueous solution, forming chiral tubules by spontaneous one-dimensional stacking with a mutual rotation in the same direction. The adjacent aromatic segments within the hexameric macrocycles reversibly slide along one another in response to external triggers, resulting in pulsating motions of the tubules accompanied by a chiral inversion. The aromatic interior of the self-assembled tubules encapsulates hydrophobic guests such as carbon-60 (C 60 ). Using a thermal trigger, we could regulate the C 60 -C 60 interactions through the pulsating motion of the tubules.