Observation of a structural transition induced by external-field in the softcrystals using X-ray molecular movie method.

2021 Fiscal Year Final Research Report

• Project Area: Soft Crystals: Science and Photofunctions of Easy-Responsive Systems with Felxibility and Higher-Ordering
• Project/Area Number: 17H06372
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Jichi Medical University
• Principal Investigator: Sato Ayana 自治医科大学, 医学部, 講師 (50717709)
• Co-Investigator(Kenkyū-buntansha): 福本 恵紀 大学共同利用機関法人高エネルギー加速器研究機構, 物質構造科学研究所, 特任准教授 (20443559)
• Project Period (FY): 2017-06-30 – 2022-03-31
• Keywords: X線結晶構造解析 / X線吸収分光 / 時間分解測定 / 化学発光 / ベイポクロミズム / ルミノクロミズム

Outline of Final Research Achievements

The structure and electronic state of the softcrystals in the steady state and excited state, and the process of the phase transition were observed in detail by X-ray crystal structure analysis and X-ray absorption spectroscopy using synchrotron radiation. We observed changes in the powder diffraction pattern over time for two isomer molecules that exhibit chemiluminescence, which is a phenomenon in which excited molecules are generated by thermal reaction and emit light. Time-resolved single crystal X-ray crystal structure analysis of strongly luminescent softcrystals was performed, and small structural changes were unveiled. For the vapochromism complex whose color changes reversibly in response to water vapor or alcohol vapor, X-ray absorption spectroscopy was performed before and after exposure to the vapor. In addition, we conducted joint research with both inside and outside of the field, summarized each as an academic paper, and published the results.

Free Research Field

生物物理学

Academic Significance and Societal Importance of the Research Achievements

化学発光基質の粉末X線回折その場観察では、化学発光特性と速度論が結晶構造に依存することが明らかとなった。これは、分子の並び方の違い、即ち「結晶」という微視的な「場」を用いることによって、有機低分子系においても化学反応の速度を「巨視的に制御できる」ことが判明したと言え、さらなる応用研究に発展する可能性が見込まれる。強発光性ソフトクリスタルの時間分解実験では、通常の構造解析では観測できない微小な構造変化を、差フーリエ電子密度マップを用いることにより抽出しており、こちらも他の系への適用が期待される。ベイポクロミズムの系では、反応分子が水蒸気であることから、環境に配慮した系での応用が期待される。