Generation and function of polarized spins in metal-organic frameworks

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K21211
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 34:Inorganic/coordination chemistry, analytical chemistry, and related fields
• Research Institution: Kyushu University
• Principal Investigator: Yanai Nobuhiro 九州大学, 工学研究院, 准教授 (90649740)
• Project Period (FY): 2020-07-30 – 2022-03-31
• Keywords: 光物性 / 金属錯体骨格 / 励起三重項 / スピン

Outline of Final Research Achievements

In this study, we focused on the fact that the excited triplet generated by photoexcitation of a molecule produces a large spin polarization at room temperature, and aimed to develop functions using this spin-polarized state. Dye molecules that form spin-polarized excited triplets after photoexcitation were introduced into the metal-organic frameworks as ligands or guest molecules. In the system in which the dye moiety is densely introduced into the metal-organic framework as a ligand, we succeeded in generating not only spin-polarized triplet but also polarized radicals. In the system in which a dye molecule was introduced into the nanopores of the metal-organic framework as a guest, we succeeded in transferring the polarization from the triplet electron spin to the nuclear spin of the drug molecule.

Free Research Field

光機能性材料

Academic Significance and Societal Importance of the Research Achievements

スピン偏極した励起三重項はこれまでの研究では材料などの評価手段として主に用いられてきたが、本研究ではスピン偏極した励起三重項のポテンシャルを最大限に引き出すことで機能創出に繋げることを試みた。金属錯体骨格中において色素分子の配列を精密に制御することにより、偏極した三重項に加えてラジカルを発生できることを見出し、これは室温における新しい偏極電子スピン生成法として有用であると考えられる。また、三重項電子スピンの偏極をモデル薬物分子の核スピンへと移すことにも成功し、今後の多様な生体分子や薬物分子の高感度NMR, MRI観測に繋がる重要な知見が得られた。