THz-driven low-temperature photoreaction dynamics of hydrogen-bonded networks

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K05825
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Functional solid state chemistry
• Research Institution: Tohoku University
• Principal Investigator: Takahashi Masae 東北大学, 農学研究科, 准教授 (80183854)
• Co-Investigator(Kenkyū-buntansha): 松井 広志 東北大学, 理学研究科, 准教授 (30275292)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 生物物理化学 / テラヘルツ分光法 / 第一原理計算

Outline of Final Research Achievements

The purpose of this study is to elucidate the low-temperature photoreactive dynamics by terahertz waves and to develop their applications, using the formation and cleavage of hydrogen-bonded networks observed in the temperature-dependent terahertz spectral spectrum as an index. Terahertz and synchrotron infrared spectrum measurements and first-principles calculation were performed on microcrystal samples of five water-soluble vitamins, amorphous sample DMAPS showing biocompatibility, and single crystal samples of vitamins that capture hydrated salt ions. The structure of the harvested single crystal sample was determined by low-temperature X-ray crystallographic analysis. In particular, the anharmonicity evaluation, the replacement of the temperature effect by the permittivity, and the capture of liquid-like hydrated salt ions into a single crystal, which were developed in this study, provide useful information to pursue terahertz-driven low-temperature photoreactive dynamics.

Free Research Field

計算材料学

Academic Significance and Societal Importance of the Research Achievements

生体内で営まれている室温の熱エネルギーを利用した物理化学過程は、いくつかの熱振動が同時に起こることで進む。特に、水素結合ネットワークの果たす役割は見逃せない。様々な水素結合ネットワークを有する物質についての厳密な理論解析をベースにした一連の本研究成果は、テラヘルツ波による生体物質の機能発現制御という、テラヘルツ波の利点を生かした新しい応用の道の開拓につながる。また、最近26%近い効率を記録した太陽電池材料ペロブスカイトにおいて、高効率の鍵となる機構はテラヘルツ光のアップコンバージョンであり、厳密な理論解析に基づく本研究成果は新たな持続可能エネルギー材料の設計にも寄与すると期待できる。