Creation of Stable, Organic Diradicaloids with Polycyclic Conjugated Framework and Exploration of Their Function

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05089
• 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: The University of Shiga Prefecture
• Principal Investigator: Kato Shin-ichiro 滋賀県立大学, 工学部, 准教授 (70586792)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: ジラジカル / ラジカルカチオン / 酸化還元 / 複素芳香環 / 縮合多環化合物

Outline of Final Research Achievements

Open-shell singlet diradicaloids with a polycyclic π-conjugated backbone are of considerable interest due to the fascinating nature of their π-bonds and owing to their unique optical, electrochemical, and magnetic properties. In this work, we designed aromatics-fused dicyclopentanaphthalenes as well as difluorenofurans as novel diradicaloids possessing a para-quinodimethane moiety and established their efficient synthetic routes. Detailed structural and spectroscopic investigation on their physicochemical properties revealed distinctive diradical characters and electronic properties of redox species. For the development of diradicaloids including nitrogen atoms, we also designed and synthesized sulfur and carbon-bridged triphenylamine and isolated its radical cationic salt.

Free Research Field

有機化学

Academic Significance and Societal Importance of the Research Achievements

本研究により，明確なジラジカル性と高い安定性を併せ持つジラジカロイドを相次いで創出し，まずジラジカル性を精密制御する手法を確立した。次に，数百ミリグラムスケールで合成が可能な稀有なジラジカロイドを開発し，機能性物質への展開の糸口を見出した。さらに，大気下でも安定なトリアリールアミンラジカルカチオンの開発にも成功した。今後の継続的な物質開発研究により，開殻性に根ざした機能創出が期待できる。