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AIR-Manuscript-ChemRxiv.pdf (1.73 MB)

Aggregation-Induced Radical of Donor-Acceptor Organic Semiconductors

submitted on 03.05.2021, 16:08 and posted on 05.05.2021, 11:09 by Zhongxin Chen, Yuan Li, Weiya Zhu, zejun wang, Wenqiang Li, Miao Zeng, fei huang

Narrow bandgap donor-acceptor organic semiconductors are generally considered to show closed-shell singlet ground state and their radicals are reported as impurities, polarons, charge transfer state monoradical or defects. Herein, we reported the open-shell singlet diradical electronic ground state of two diketopyrrolopyrrole-based compounds Flu-TDPP and DTP-TDPP via the combination of variable temperature NMR, variable temperature electron spin spectroscopy (ESR), superconducting quantum interference device magnetometry, and theoretical calculations. It is observed that the quinoid-diradical character is significantly enhanced in aggregation state because of the limitation of intramolecular rotation. Consequently, we propose a mechanism of aggregation-induced radical to understand the driving force of the open-shell diradical formation of DTP-TDPP based on the ESR spectroscopy test in different proportions of mixed solvents. Our results demonstrate the thermally-excited triplet state for donor-acceptor organic semiconductors, providing a novel view to comprehend the intrinsic chemical structure of donor-acceptor organic semiconductors, as well as the potential electronic transition process between ground state and excited state.


Email Address of Submitting Author


State Key Laboratory of Luminescent Materials and Devices, South China University of Technology



ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest