Our collaborative study with Lecturer Matsuoka (Osaka University), has been published in Journal of the American Chemical Society.

In a collaborative study with Lecturer Matsuoka (Osaka University), we spectroscopically elucidated the electronic nature of the excimer-like emissive state (EX) observed in luminescent organic radical aggregates, and the results have been published in the Journal of the American Chemical Society. Using a spatially confined luminescent diradical as a model system, we showed that the EX state is a closed-shell singlet zwitterionic species generated via inter-radical charge transfer, and further demonstrated that its formation is specific to the singlet spin manifold. This work provides an important foundation for the future design of spin-photonic materials.

From our lab, Mr. Saigo (alumnus) and Mr. Ehara (D3) played central roles by performing nanosecond pump–probe transient absorption measurements, providing decisive spectroscopic evidence for both the formation pathway and the electronic-state assignment of the EX state.

“Spectroscopic Characterization of the Charge-Separated Zwitterionic State Responsible for the Excimer-like Emission of a Luminescent Diradical”
Ryota Matsuoka*, Yusuke Yoneda, Hikaru Kuramochi, Tomoaki Miura, Tadaaki Ikoma, Masaki Saigo, Takumi Ehara, Kiyoshi Miyata, Ken Onda, Tetsuro Kusamoto*
J. Am. Chem. Soc. in press (2025).