Intramolecular Charge Transfer Controls Switching Between Room Temperature Phosphorescence and Thermally Activated Delayed Fluorescence

Chen, Chengjian; Huang, Ronjguan; Batsanov, Andrei; Pander, Piotr; Hsu, Yu-Ting; Chi, Zhenguo; Dias, Fernando; Bryce, Martin Robert

Abstract

Chemical modification of phenothiazine–benzophenone derivatives is shown to tune the emission behavior from triplet states by selecting the molecular geometry of the intramolecular charge transfer (ICT) state. A fundamental principle of planar ICT (PICT) and twisted ICT (TICT) is demonstrated to obtain selectively either room temperature phosphorescence (RTP) or highly efficient thermally activated delayed fluorescence (TADF), respectively. Time‐resolved spectroscopy and time‐dependent density functional theory (TD‐DFT) investigations on polymorphic single crystals demonstrate the roles of PICT and TICT states in the underlying photophysics. This has resulted in a RTP molecule OPM, where the triplet states contribute with 89% of the luminescence, and an isomeric TADF molecule OMP, where the triplet states contribute with 95% of the luminescence.

Citation

Chen, C., Huang, R., Batsanov, A., Pander, P., Hsu, Y.-T., Chi, Z., Dias, F., & Bryce, M. R. (2018). Intramolecular Charge Transfer Controls Switching Between Room Temperature Phosphorescence and Thermally Activated Delayed Fluorescence. Angewandte Chemie, 130(50), 16645-16649. https://doi.org/10.1002/ange.201809945

• Journal Article Type: Article
• Acceptance Date: Oct 18, 2018
• Online Publication Date: Nov 15, 2018
• Publication Date: Dec 10, 2018
• Deposit Date: Oct 29, 2018
• Publicly Available Date: Nov 15, 2019
• Journal: Angewandte Chemie
• Print ISSN: 0044-8249
• Electronic ISSN: 1521-3757
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 130
• Issue: 50
• Pages: 16645-16649
• DOI: https://doi.org/10.1002/ange.201809945
• Public URL: https://durham-repository.worktribe.com/output/1310260