Synthesis and properties of chiral topological molecules with remarkable circular polarlized luminescence

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05043
• 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: Kitasato University
• Principal Investigator: Hasegawa Masashi 北里大学, 理学部, 教授 (20438120)
• Co-Investigator(Kenkyū-buntansha): 伊與田 正彦 東京都立大学, 理学研究科, 客員教授 (50115995)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 円偏光発光 / キラル化合物 / 円二色性スペクトル / 大環状化合物

Outline of Final Research Achievements

We synthesized several extended π-conjugated compounds with axially chiral binaphthyl and planar chiral [2.2]paracyclophane as chiral sources with high symmetry and achieved improved CPL properties. In particular, high glum values were observed for compounds that are expected to have a high symmetric structure even in the excited state. We have also synthesized molecules with high brightness with a view to light-emitting devices using circularly polarized light. Molecules consisting of [5]helicenes linked to binaphthyl were synthesized and the relationship between the structure and chiral optical properties was investigated. The C2 symmetric structure in both the ground and excited states, parallel control of the magnetic and electric transition dipole moments, and a relatively high asymmetry factor (g-value) in CPL were obtained.

Free Research Field

構造有機化学

Academic Significance and Societal Importance of the Research Achievements

キラルな分子から生じる円偏光発光(CPL)は、偏光を発する光源としてフィルターレスな液晶バックライトや情報通信技術に期待されている。これらキラル光学特性を利用した新しい技術を実現するには、十分な強度をもつCPL発光物質が必要であり、より高い円偏光度を示す材料が求められるが、キラル光学特性を支配する因子は不明瞭な点が多く、適切な分子設計の指針が存在しない。本研究では対称性の高いキラル分子を用いることで、キラル物性の鍵となる磁気および電気遷移双極子モーメントを制御し、優れた特性を導く分子の開発に成功した。これにより、傑出した特性を持つCPL発光物質の開発が加速されるものと思われる。