ORCID
- Mikhail A. Filatov: 0000-0002-1640-841X
Abstract
Controlling the excited-state dynamics of charge-separated (CS) states in donor–acceptor (D–A) systems is challenging due to geometry changes from intramolecular rotations and vibrations. A key question is how molecular geometry governs the formation, stability, and recombination of CS states, and whether these processes can be decoupled from spin-related transitions such as intersystem crossing (ISC). Here, we investigate a rigid design strategy where BODIPY and anthracene chromophores are fused to a bicyclo[2.2.2]octane scaffold, fixing the D–A geometry and eliminating conformational flexibility. This setup enables direct evaluation of how geometric restriction affects charge-transfer dynamics. Femtosecond transient absorption spectroscopy shows efficient charge separation in polar solvents (2–9 ps), followed by rapid recombination (15–205 ps), with no detectable triplet state formation. Nanosecond transient absorption, 77 K luminescence, and singlet oxygen measurements confirm suppression of spin–orbit charge-transfer intersystem crossing (SOCT-ISC). These findings demonstrate that a rigid molecular architecture can block ISC but does not inherently extend CS state lifetimes. Our results provide new insight into the fate of CS states and emphasize that geometric rigidity alone does not ensure long-lived charge separation in D–A systems.
DOI Link
Publication Date
2026-01-01
Publication Title
Journal of Materials Chemistry C
ISSN
2050-7526
Acceptance Date
2026-01-01
Deposit Date
2026-05-13
Funding
The authors acknowledge Research Ireland award 21/FFP-A/9214 (DyeSICPhoto) for supporting this work. M. D. D. acknowledges support from the European Union's Next Generation EU Program with the I-PHOQS Infrastructure [No. IR0000016, ID D2B8D520, and CUP B53C22001750006] “Integrated infrastructure initiative in Photonic and Quantum Sciences.”
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Additional Links
Recommended Citation
Dvoracek, Metodej; Wu, Yanran; Sambucari, Greta; Newman, Craig; Twamley, Brendan; Senge, Mathias O.; Zhao, Jianzhang; Di Donato, Mariangela; and Filatov, Mikhail A., "Conformationally locked BODIPY donor–acceptor dyads: charge separation and recombination across a [2.2.2]bicyclooctane spacer" (2026). Research Outputs: 2025-Present. 35.
https://arrow.tudublin.ie/scschcpsro/35