Rational molecular design toward creation of circularly polarized luminescent organic materials

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K19081
• 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: Kyushu University
• Principal Investigator: Shimizu Soji 九州大学, 工学研究院, 准教授 (70431492)
• Project Period (FY): 2018-06-29 – 2020-03-31
• Keywords: 円偏光発光 / キラリティ / 有機環状分子 / ジケトピロロピロール / BODIPY

Outline of Final Research Achievements

In this research project, a cyclic arrangement of chromophore molecules is proposed as a rational molecular design toward prominent circular polarized luminescent organic molecules. In this molecular design, small anisotropy factor (g value) of circular polarized luminescence of organic chromophores due to their inherently large transition electric dipole moments can be improved by canceling transition electric dipole moments along the circumferential direction. On the basis of this molecular design, cyclic oligomers of diketopyrrolopyrrole were synthesized and isolated using size exclusion chromatography. Due to decomposition in chiral columns, optical resolution has not been successful yet. The high theoretical g value based on the TDDFT calculations indicated potential of this molecular design toward creation of circularly polarized organic materials.

Free Research Field

有機化学

Academic Significance and Societal Importance of the Research Achievements

円偏光発光特性を示す有機色素分子は、3次元ディスプレイへの応用など、次世代の光情報技術を担う分子材料として注目されている一方で、優れた円偏光発光特性を示す分子構造についての知見はほとんど示されていない。本研究では円偏光発光の理論式に基づき、色素分子を環状に配列することを提案した。最終的な目的分子の単離には安定性の問題から達成できてはいないが、合成と理論計算の両方から、分子構造と円偏光発光特性の相関について解明し、本研究で提案した分子設計の有用性を示すことができた。