Near-infrared fluoresent dyes based on a new ESIPT skeleton

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K14614
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 33010:Structural organic chemistry and physical organic chemistry-related
• Research Institution: Osaka Metropolitan University (2022); Osaka Prefecture University (2021)
• Principal Investigator: Suzuki Naoya 大阪公立大学, 大学院工学研究科, 助教 (80823492)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: 有機色素 / 凝集有機発光 / 二重発光 / 固体発光 / ESIPT

Outline of Final Research Achievements

In this research, we newly suggested a concept, the excited-state intramolecular proton transfer (ESIPT) from the C-H bond, as a methodology to achieve intense near-infrared fluorescence. In order to realize the ESIPT from the C-H bond, we design a series of dyes by introducing various nitrogen-containing heteroaromatic rings into a highly acidic indolinone skeleton, and found that a derivative bearing the benzothiazole skeleton exhibited the dual emission in the crystal state. Although the structural analysis suggested that the dual emission behavior was due to the formation of J-aggregates in the crystal and not due to ESIPT from the C-H bond, we have achieved the development of a new dye skeleton that exhibits crystallization induced dual emission.

Free Research Field

有機化学

Academic Significance and Societal Importance of the Research Achievements

本研究で開発された色素が示す結晶化誘起二重発光は、単一分子から二つの発光が示されることから、白色発光材料やセンシング材料などの分野での応用が期待されている。これまでにも結晶化誘起二重発光を示す色素は報告されているものの、その報告数は限られている。本研究で得られた成果は、結晶化誘起二重発光性色素の新たな分子骨格を提案するものであり、分子構造の多様性を増大させることで、発光性有機材料の開発に寄与する。