title: Assembly of an Achiral Chromophore into Light-Responsive Helical Nanostructures in the Absence of Chiral Components.
abstract: The chirality found in living organisms is one of unsolved mysteries on Earth. It is crucial to understand the manner in which small achiral molecules evolve into helical superstructures in the absence of chiral components because this process can provide important insights regarding the origin of chirality in nature. 1) the uncommon helical assembly of an achiral trigonal chromophore into helical nanostructures with aggregation-induced emission enhancement (AIEE) characteristics and 2) the tunability of the helical pitch and fluorescence intensity in response to light is reported. The Rietveld refinement of X-ray diffraction (XRD) patterns and the growth process suggest that a striking transformation from an achiral to an asymmetric molecule can occur as a result of specific interactions with certain solvents, presumably leading to the unique helical assembly. More importantly, exposure to UV or visible light promoted not only the formation of irregular helical structures with a wide range of pitch lengths but also an increase in fluorescence intensity.
authors.affiliation: Department of Molecular Design & Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan. hanmin@chem.tottori-u.ac.jp.|Department of Chemistry and Biotechnology, Tottori University, 4-101 Koyama Minami, Tottori, 680-8552, Japan. hanmin@chem.tottori-u.ac.jp.
authors.forename: Mina
authors.initials: M
authors.lastname: Han
authors.affiliation: Department of Chemical Engineering, Chonnam National University, Yongbong 300, Buk-gu, Gwangju, 500-757, Korea.
authors.forename: Sung June
authors.initials: SJ
authors.lastname: Cho
authors.affiliation: Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 5, Higashi 1-1-1, Tsukuba, Ibaraki, 305-8565, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Norikane
authors.affiliation: Faculty of Molecular Chemistry and Engineering, Kyoto Institute of Technology, 1 Hashikami-cho, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Shimizu
authors.affiliation: Department of Molecular Design & Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Seki
keywords: aggregation; chromophores; fluorescence; helical structures; isomerization