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Updated: Apr 28, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Conformational Landscapes in the Ground and Excited States Dictate Circularly Polarized Excimer Emission: A
Tomohiro Kujime1, Zhe Wang1, Tadashi Mori1
1Research Center for Environmental Preservation and Department of Applied Chemistry, Graduate School of Engineering, The University of Osaka, Suita, Osaka, Japan.
Abstract:
We demonstrate that in chiral carbazole dimers, the tt conformer generates intense excimer CPL, while gauche rotamers yield only local emission. In 1a, CPL intensifies and red-shifts upon cooling due to greater tt contribution. In contrast, the tert-butyl derivative 1b shows weak, temperature-insensitive CPL owing to enhanced accessibility of non-CPL-emissive gauche conformers. This work reveals how subtle substituent and environmental effects modulate excited-state conformational dynamics and chiroptical responses through a thermodynamic-kinetic interplay.
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