Construction of chiral macromolecular structure through controlled chemical bond rotation by circularly polarized light irradiation

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02759
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 35010:Polymer chemistry-related
• Research Institution: Hokkaido University
• Principal Investigator: Nakano Tamaki 北海道大学, 触媒科学研究所, 教授 (40227856)
• Co-Investigator(Kenkyū-buntansha): 宋 志毅 北海道大学, 触媒科学研究所, 准教授 (80600981)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 円偏光 / らせん / ねじれ構造 / 励起状態 / 有機構造体

Outline of Final Research Achievements

The chirality induction method based on chirality of circularly polarized light (CPL) was applied for linear polymers, covalent organic framework (COF) with regular, inner branching, and functional small molecules. A polynaphthalene derivative, a linear polymer, was found to be induced different types of chiral structure through the asymmetric polymerization method and through the CPL irradiation method. Also, the CPL irradiation method led COFs composed of benzene rings to optically active materials with preferred-handed twist around single bonds connecting benzene rings. Furthermore, a series of blue-light emitting small molecules were induced chirality at high efficiency through the CPL irradiation method, and the resulting optically active materials were found to emit circularly polarized luminescence at high anisotropy in blue color, which make them good candidates of blue-CPL-emitting OLED.

Free Research Field

高分子化学

Academic Significance and Societal Importance of the Research Achievements

物質のキラリティーは人の生活に極めて重要な役割を果たし、光学活性物質の合成手法開発は重要である。医薬品等を含む光学活性物質は、従来、基底状態での化学（主に不斉配位子等の不斉源とする合成および光学異性体の分割）により調製されてきたが、本研究では、光のキラリティー（円偏光）を用いる新手法を開発した。本手法はキラル源となる化学物質を必要とせず、副生成物もほぼ発生せず、光エネルギーと非対称性のみに基づいて光学活性物質の調製を可能にするものであり、持続可能な社会形成の観点から社会的な意義は大きい。加えて、従来の基底状態化学とは全く異なる原理による物質の構造制御を探求するものであり学術的意義も深い。