Induction, Control and Locking of Supramolecular Chirality by Light in Self-assembled Helical Nanostructures
In a recent high profile “light-induced self-assembly process” research authored by the Department of Chemstry, light was used with π-conjugated molecules in which propeller type arrays exhibited self assembly. This is very inspiring research by the laboratory of Professor Sangyoul Kim. As written in the paper, this light driven supramolecular work is intriguing because “the entire process of induction, control and locking of supramolecular chirality can be manipulated by light,” Kim et al. intimated.
The evolution of supramolecular chirality from self-assembly of achiral compounds and control over its handedness is closely related to the evolution of life. In the research laboratory, the development of supramolecular materials with desired handedness can also be made. Here, we report a system where the entire process of induction, control, and locking of supramolecular chirality can be manipulated by light. A combination of triphenylamine and diacetylene moieties in the molecular structure allowed for photo-induced self-assembly of the molecule into helical aggregates in a chlorinated solvent by visible light, and covalent fixation of the aggregate via photopolymerization by UV, respectively. By utilizing circularly polarized light (CPL), the researchers observed that the supramolecular chirality of the resulting helical aggregates was selectively and reversibly controlled by the rotational direction of the visible CPL, and the desired supramolecular chirality could be arrested by irradiation of circular polarized ultraviolet light. This methodology opens a route to formation of supramolecular chiral conducting nanostructures from self-assembly of achiral molecules.
“Induction and control of supramolecular chirality by light in self-assembled helical nanostructures” Jisung Kim, Jinhee Lee, Woo Young Kim, Hyungjun Kim, Sanghwa Lee, Hee Chul Lee, Yoon Sup Lee, Myungeun Seo & Sang Youl Kim Nature Communications 6, Article number: 6959 doi:10.1038/ncomms7959.
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