Reversible Molecular Topology Transformation - Creation of Transformable Macrocycles

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05417
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 33010:Structural organic chemistry and physical organic chemistry-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Nakazono Kazuko 東京工業大学, 物質理工学院, 准教授 (30467021)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: マクロサイクル / サイズ可変 / ロタキサン / 多環状高分子

Outline of Final Research Achievements

Macrocycles are expected to have various applications because they exhibit different physical and chemical properties from linear analogous molecules of the same chemical composition and molecular weight due to their closed structure. However, there are many challenges in the synthesis of macrocycles, and it is not easy to freely synthesize macrocycles with the desired structure and size. In this study, we developed a new cyclization method utilizing the dynamic structural properties of a rotaxane, a mechanically bonded molecule, and achieved the synthesis of cyclic vinyl polymer and multicyclic polymers. Normally, the synthesis of multicyclic polymers is difficult when macrocyclic monomers are used because accidental permeation occurs during polymerization, but such permeation does not occur in this method. Therefore, by introducing a stimulus-responsive functional group, the conversion from a multicyclic polymer to a linear one with a contracted cyclic structure was also achieved.

Free Research Field

構造有機化学、高分子化学

Academic Significance and Societal Importance of the Research Achievements

マクロサイクル骨格は医薬品や分子認識材料の多くに見られる骨格であり、最近では環状高分子の物性にも注目が集まっているが、マクロサイクルの研究において環化はボトルネックであり、自在な構造・サイズのマクロサイクルを高純度かつ大量に合成することは難しい。本研究を通して、ロタキサンの動的構造特性を利用したマクロサイクル合成は、従来からある鎖状分子を環化する方法や、小さな環状分子への挿入反応によって環拡大してマクロサイクルを得る方法とは本質的に異なる新しい合成概念であり、可逆的トポロジー変換という機能化も可能にすることを明らかにした。本成果をもとに多様な機能性マクロサイクルの研究の促進が期待される。