Basel B, Zirzlmeier J, Hetzer C, Seelam RR, Phelan BT, Krzyaniak MD, Volland M, Brana Coto P, Young RM, Clark T, Thoss M, Tykwinski R, Wasielewski MR, Guldi DM (2018)
Publication Status: Published
Publication Type: Journal article
Publication year: 2018
Publisher: CELL PRESS
Book Volume: 4
Pages Range: 1092-1111
Journal Issue: 5
DOI: 10.1016/j.chempr.2018.04.006
Singlet fission (SF) is a process that converts one singlet excited state into two triplet states. The mechanism of SF is still not well understood. Here, we report on the use of a combination of transient absorption and electron paramagnetic resonance spectroscopies in conjunction with theoretical calculations to probe SF in a pentacene dimer linked by a non-conjugated, 1,4-diethynylbicyclo[2.2.2]octane spacer. Next to observing the key intermediates in solution-based SF, including the formation and decay of a quintet state that precedes formation of the pentacene triplet excitons, we demonstrate that the coupling is sufficiently weak that SF is essentially inoperative in non-polar media. Transitioning to a polar medium, however, amplifies the coupling strength such that SF becomes operative and supports long triplet lifetimes. Our results offer strong evidence for a charge-transfer mediation and, in turn, provide a solid framework for decoding the complete mechanism of SF in systems beyond pentacene.
APA:
Basel, B., Zirzlmeier, J., Hetzer, C., Seelam, R.R., Phelan, B.T., Krzyaniak, M.D.,... Guldi, D.M. (2018). Evidence for Charge-Transfer Mediation in the Primary Events of Singlet Fission in a Weakly Coupled Pentacene Dimer. Chem, 4(5), 1092-1111. https://doi.org/10.1016/j.chempr.2018.04.006
MLA:
Basel, Bettina, et al. "Evidence for Charge-Transfer Mediation in the Primary Events of Singlet Fission in a Weakly Coupled Pentacene Dimer." Chem 4.5 (2018): 1092-1111.
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