Development of organic molecular crystalline materials showing asymmetric and highly efficient circularly polarized luminescence emission

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K22180
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 33:Organic chemistry and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Sato Sota 東京大学, 大学院工学系研究科(工学部), 特任教授 (40401129)
• Project Period (FY): 2019-06-28 – 2022-03-31
• Keywords: 円偏光発光 / 大環状芳香族分子 / キラリティ / 超分子集積 / 光学物性

Outline of Final Research Achievements

According to the molecular design guideline of "chiral cylindrical aromatic molecule in which the curved π-conjugated system created by the sp2 carbon network is mounted on the same curved surface", the chiral optical properties was controlled mainly by the molecular diameter as the controlling factor. We also succeeded in preparing a crystalline solid and analyzing the single crystal X-ray structure of the supramolecular accumulation of chiral tubular aromatic molecules. Taking into consideration the molecular packing structures and the orientation of the molecules, the crystal was laser-processed into flakes, and the artifacts were removed with a specialized spectrometer capable of measuring the optical properties of chiral solids, and chiral optical properties were measured. From these experimental results, we were able to obtain design guidelines for molecules with high-performance chiral optical properties and their supramolecular integrated solids.

Free Research Field

構造有機化学

Academic Significance and Societal Importance of the Research Achievements

良好なキラル光学特性、すなわち、左右円偏光の偏りが大きく、かつ吸収・発光の効率が高い分子は、高性能な光学デバイスへの活用を念頭に熱心に開発されてきている。しかし、その分子設計の指針が無く、超分子固体として集積した際の光学特性の変化に関する基礎的知見が無く、どのようにしたら実現できるのか、という大きな課題があった。本研究では、独自にみいだした分子設計指針によって、この問に答える成果を上げることができた。分子が異方的に並ぶ結晶性固体に独特な問題を解決する結晶方位の決定と、方位に従った結晶加工法を新たに開発し、固体に対するキラル光学特性を実測するワークフローを確立することができた。