2026-05-01 九州大学
開発したキラル発光ラジカルの(左)発光写真(中)構造(右)WGM発光のスペクトルと概念図
＜関連情報＞
- https://www.kyushu-u.ac.jp/ja/researches/view/1466
- https://onlinelibrary.wiley.com/doi/full/10.1002/anie.1914320?msockid=2c4802b31d396f2425f717401cb26e4b
プロペラ型キラル性を有する発光性ドナー・アクセプターラジカル：明るく光安定性の高い赤色円偏光発光とウィスパリングギャラリーモード共鳴 Luminescent Donor-Acceptor Radical With Propeller Chirality: Bright and Photostable Red Circularly Polarized Luminescence and Whispering Gallery Mode Resonance
Kazuhiro Nakamura, Kenshiro Matsuda, Kosuke Anraku, Keiko Yamaoka, Taisuke Matsumoto, Fumitaka Ishiwari, Takeaki Zaima, Wataru Ota, Emiko Fujiwara, Tohru Sato, …
Angewandte Chemie International Edition Published: 24 April 2026
DOI:https://doi.org/10.1002/anie.1914320
ABSTRACT
Luminescent radicals are an emerging class of materials for organic electronics, bioimaging, and quantum applications. Circularly polarized luminescence (CPL) from luminescent radicals with propeller-type chirality remains challenging because it is difficult to simultaneously achieve high photoluminescence quantum yield (PLQY), high stability, and high racemization barriers. A series of brominated chiral luminescent radicals, CzTTBrM, 2CzTTBrM, and 3CzTTBrM, was obtained by attaching carbazole donors to TTBrM. The donor-acceptor-type design induces red to near-infrared (NIR) emission via charge transfer (CT) excited states with remarkably high PLQY (up to 76%) and high photostability. The new radicals possess high racemization barriers (ΔG‡(353K) = 27.9–29.1 kcal/mol), allowing the isolation of enantiopure compounds at room temperature. The enantiopure radicals exhibit CPL with broad emission across the red to NIR range (650–800 nm) and display BCPL values (0.76–1.1), nearly one order of magnitude higher than that of TTBrM (BCPL = 0.16). Moreover, doping these radicals into polystyrene microspheres produces whispering gallery mode (WGM) resonances, marking the first observation of WGM emission from luminescent radicals. This strategy establishes a versatile platform for integrating spin, chirality, and luminescence, offering new opportunities for applications in electroluminescence, bioimaging, and quantum photonics.
