Efficient synthesis of thermal-stimulus responsive solid-state light-emitting molecules with various molecular geometries and evaluation of their structure-property relationship

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05212
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 35030:Organic functional materials-related
• Research Institution: Kyoto Institute of Technology
• Principal Investigator: Yamada Shigeyuki 京都工芸繊維大学, 分子化学系, 准教授 (10612252)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: フッ素 / 液晶 / 発光

Outline of Final Research Achievements

Thermally stimuli-responsive solid-state photoluminescence (PL) materials, whose luminescence behavior changes in response to heat, are expected to be used for smart windows and PL thermosensors. In this study, this researcher will establish a technology to convert easily prepared linear molecules into liquid-crystalline molecules with various geometries, such as disc-shaped, bent, and branched geometries, by converting functional groups. Namely, this researcher found that hexaarylbenzenes can be efficiently synthesized as two regiomers through the cobalt-catalyzed [2+2+2] cyclotrimerization reaction of solid state luminescent fluorinated tolane derivatives. It was also found that the thermophysical and photophysical properties varied depending on the fluorine atom on the aromatic ring and the length of the terminal alkoxy chain.

Free Research Field

有機機能分子化学

Academic Significance and Societal Importance of the Research Achievements

これまでカラムナー液晶として数多の分子が開発されてきたが，その中でメソゲンとしてヘキサアリールベンゼン骨格をもつものは限られている。本研究では，周辺位の6この芳香環のうち，3個の芳香環の分子短軸にフッ素原子を導入することで強力な分子内スルースペース相互作用を誘起し，多様な光学挙動の発現に成功した。限られて基質において液晶性発現も達成できた。これらの成果はフッ素原子導入が鍵となり，フッ素系新材料創出の一端を担う成果である。またフォトクロミズム性の発現も観察され，UV照射で色調が変化するスマート材料としての応用にも期待でき，新材料の材料設計指針を提供できる成果である。