Control of the crytal structure and analyses of the emission mechanism of heterocyclic compounds based on the distorted conformation of their hydrogen-bonding ring

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05434
• 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 Tokyo
• Principal Investigator: Mutai Toshiki 東京大学, 生産技術研究所, 助教 (80313112)
• Co-Investigator(Kenkyū-buntansha): 重光 保博 長崎大学, 工学研究科, 教授 (50432969)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 固体発光 / 有機結晶 / ESIPT / 蛍光材料 / 超弾性 / メカノクロミック発光 / 結晶多形

Outline of Final Research Achievements

We have shown that the introduction of "distorted intramolecular hydrogen bond" led to a certain degree of conformational freedom and may have made the polymorphism easier to occur. In the course of our research, we also discovered a mechanochromic luminescence phenomenon based on a nondestructive reversible crystal-crystal phase transition called "superelastochromic luminescence," and attempted crystal structure analysis of excited states, which has been considered difficult to measure until now, and succeeded in observing the conformational change These achievements are the result of our research on organic solid-state luminescence materials. These results are important findings for mechanistic analysis and material development of organic solid-state light-emitting materials.

Free Research Field

有機光機能化学

Academic Significance and Societal Importance of the Research Achievements

有機固体発光材料は身近な材料であり、多くの場合、発光色など各種物性は合成化学的に分子構造を変えることで制御されている。近年、合成化学によらず有機分子の「集まり方」を変えることで発光特性を制御できる、という研究成果が世界各地から報告されているが、その発光機構の詳細はいまだ明らかではない。
本研究は、機構解明に向けた適切な分子群を提供し、また「超弾性発光クロミズム」という新たな発光制御方法を見出すとともに、励起状態でのX線結晶構造解析という、発光機構の解析に向けた重要な手がかりとなる成果を得ることに成功した。