Nanohoops Favour Light-Induced Energy Transfer over Charge Separation in Porphyrin/[10]CPP/Fullerene Rotaxanes

Schwer F, Zank S, Freiberger M, Steudel FM, Geue N, Ye L, Barran PE, Drewello T, Guldi DM, von Delius M (2025)

Publication Type: Journal article

Publication year: 2025

Journal

Book Volume: 64

Article Number: e202413404

Journal Issue: 1

DOI: 10.1002/anie.202413404

Abstract

[2]Rotaxanes offer unique opportunities for studying and modulating charge separation and energy transfer, because the mechanical bond allows the robust, yet spatially dynamic tethering of photoactive groups. In this work, we synthesized [2]rotaxane triads comprising a central (aza)[10]CPP⊃C60 bis-adduct complex and two zinc porphyrin stoppers to address how the movable nanohoop affects light-induced charge separation and energy transfer between the rotaxane subcomponents. We found that neither the parent nanohoop [10]CPP nor its electron-deficient analogue aza[10]CPP actively participate in charge separation. In contrast, the nanohoops completely prevented through-space charge separation. This result is likely due to supramolecular “shielding”, because charge separation was observed in the thread that acted as reference dyad. On the other hand, the suppression of electron transfer allowed the observation of energy transfer from the porphyrin triplet to the fullerene triplet state with a lifetime of ca. 25 μs. The presence of the interlocked nanohoops therefore leads to a dramatic switch between charge separation and energy transfer. We suggest that our results explain observations made by others in photovoltaic devices comprising nanohoops and may pave the way toward strategic uses of mechanically interlocked architectures in devices that feature (triplet) energy transfer.

Authors with CRIS profile

Involved external institutions

Universität Ulm Germany (DE) Henry Royce Institute United Kingdom (GB)

How to cite

APA:

Schwer, F., Zank, S., Freiberger, M., Steudel, F.M., Geue, N., Ye, L.,... von Delius, M. (2025). Nanohoops Favour Light-Induced Energy Transfer over Charge Separation in Porphyrin/[10]CPP/Fullerene Rotaxanes. Angewandte Chemie International Edition, 64(1). https://doi.org/10.1002/anie.202413404

MLA:

Schwer, Fabian, et al. "Nanohoops Favour Light-Induced Energy Transfer over Charge Separation in Porphyrin/[10]CPP/Fullerene Rotaxanes." Angewandte Chemie International Edition 64.1 (2025).

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