Perfect Inversion of Supramolecular Chirality by Secondary Nucleation

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K21216
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 35:Polymers, organic materials, and related fields
• Research Institution: Chiba University
• Principal Investigator: Yagai Shiki 千葉大学, 大学院工学研究院, 教授 (80344969)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: キラリティ / 超分子キラリティ / 光異性化 / 螺旋構造 / 自己集合 / 階層構造 / ナノ構造 / メゾスコピック領域

Outline of Final Research Achievements

In this study, nucleation in the self-assembly of chiral azobenzene molecules was controlled by light via photoisomerization of azobenzene to invert the chirality that occurs between molecules (supramolecular chirality). Time-dependent data on self-assembly were analyzed using a theoretical model used to analyze secondary nucleation in protein amyloid aggregation, and the contribution of secondary nucleation was demonstrated. Furthermore, we succeeded in discovering a phenomenon in which a slight asymmetry bias in the molecule is amplified via hierarchical self-assembly. These results will not only advance our understanding of the phenomenon of homochirality, in which biomolecules such as proteins and DNA in living organisms are composed of one chiral handedness of the other, but also provide new design guidelines for the development of functional materials in which helical structure is key to function.

Free Research Field

超分子化学

Academic Significance and Societal Importance of the Research Achievements

本提案では光照射による円偏光発光の反転についても視野に入れていたが、この目的を達成のためにはまず光による超分子キラリティーの完全反転を再現良く行うことが必要であると判断し、光照射条件の検討および反転メカニズムの解明を推進した。さらに、将来より安価な分子材料からキラル集合体を調製できるよう、キラル増幅に関する研究も同時に推進した。現在これらのキラル集合体への発光部位の導入を推進しており、既に高発光性のキラル集合体がいくつか得られている。今後、これらの発光性キラル集合体が示すCPL特性や、それらの光スイッチングや増幅現象の検証を行い、省エネ高機能デバイス開発の研究基盤を構築する。