Beyond Common Energy Transfer: Intramolecular Electron Transfer Cascade Controls Triplet Population of a Long-Lived Iron-Anthracene Molecular Dyad
Glaser F, Beneventi GM, Cadranel A, Troian-Gautier L (2025)
Publication Type: Journal article
Publication year: 2025
Journal
Book Volume: 11
Pages Range: 1870-1881
Journal Issue: 10
DOI: 10.1021/acscentsci.5c01040
Abstract
An iron-anthracene dyad was recently used to populate a microsecond-lived nonluminescent (dark) triplet state, but with a surprisingly low triplet population yield. In-depth spectroscopic experiments highlight that direct energy transfer does not take place, but rather an intramolecular electron-transfer occurs, generating the corresponding reduced iron center and oxidized anthracene moiety, and the final triplet dark state is populated following charge recombination. This electron-transfer cascade reaction mechanism provided the unique opportunity to control the energy level of the charge-separated state relative to the energy of the triplet state by changing the solvent polarity. As such, the triplet formation yield increased from 5% in acetonitrile to 75% in dichloromethane. This outlines an unreported mechanistic pathway for first-row transition metal complexes to populate long-lived excited states and provides design guidelines that differ between d5and prototypical d6photosensitizers. The d5electronic configuration enables population of the final triplet energy acceptor via a cascade of electron transfer that does not formally require intersystem crossing or spin-flip transitions, thus also minimizing energy loss channels. Although the energy of the final triplet state is important, our findings highlight that the redox potentials of the excited photosensitizer and final energy acceptor moiety are pivotal to efficiently populate dark triplet states.
Authors with CRIS profile
Giovanni Mariano Beneventi
Lehrstuhl für Physikalische Chemie I
Alejandro Cadranel
Professur für Physikalische Chemie
Involved external institutions
Belgium (BE)How to cite
APA:
Glaser, F., Beneventi, G.M., Cadranel, A., & Troian-Gautier, L. (2025). Beyond Common Energy Transfer: Intramolecular Electron Transfer Cascade Controls Triplet Population of a Long-Lived Iron-Anthracene Molecular Dyad. ACS Central Science, 11(10), 1870-1881. https://doi.org/10.1021/acscentsci.5c01040
MLA:
Glaser, Felix, et al. "Beyond Common Energy Transfer: Intramolecular Electron Transfer Cascade Controls Triplet Population of a Long-Lived Iron-Anthracene Molecular Dyad." ACS Central Science 11.10 (2025): 1870-1881.
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