Study on dynamic nuclear polarization using photo-excited triplet electron spins for versatile NMR spectroscopy

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05033
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 32010:Fundamental physical chemistry-related
• Research Institution: Osaka University
• Principal Investigator: Akinori Kagawa 大阪大学, 基礎工学研究科, 助教 (70533701)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 動的核偏極 / 核磁気共鳴 / 電子スピン共鳴 / 光励起三重項状態

Outline of Final Research Achievements

We studied the generalization of dynamic nuclear polarization using electron spins in the photo-excited triplet state (triplet DNP) for NMR application. To evaluate its electron spin properties, an electron spin resonance spectrometer was developed. We also prepared a liquid NMR probe capable of measurement in a high magnetic field and a highly uniform magnetic field to show that triplet DNP can be used for chemical analysis applications. We have succeeded in increasing the number of molecular species that can be highly polarized by triplet DNP using eutectic, which is a new sample preparation method. Rose bengal was adopted as a new highly polarization source, but we did not measure electron spin signals at near liquid nitrogen temperature.

Free Research Field

磁気共鳴、量子センシング

Academic Significance and Societal Importance of the Research Achievements

核磁気共鳴は、原子核のもつミクロな磁石の性質を利用し物質内部の情報を非破壊、非侵襲で測定できる有力な分光法である。応用幅も広く、化学解析、MRI、創薬、食料など多岐にわたっている。その最大の欠点である低感度を改善する手法が動的核偏極であり、その中でも光励起三重項状態を用いれば極低温、高磁場を必要としない動的核偏極が実現でき、安価な装置でのNMR応用が期待できる。本研究では、光励起三重項状態を用いた動的核偏極における装置開発、試料作製法、分子探索を行いNMR応用への汎用化を行った。