Observation of shuttling on the one-second timescale in a [10]cycloparaphenylene/C <sub>60</sub> [2]catenane
[2]Catenanes comprising two identical binding sites are an excellent platform to study the kinetics of non-covalent interactions. In this work, we show that the "shuttling" of the [10]CPP nanohoop between two identical fullerene bis-adduct binding sites occurs with regioisomer-dependent rates of 1-5 s<sup>-1</sup> at room temperature, placing these among the slowest π-π and dispersion-based shuttling processes reported to date. The catenanes were accessed <i>via</i> Glaser-Eglinton macrocyclization from fullerene bis-adduct precursors, which were purified by extensive recycling chromatography, and characterized by variable-temperature <sup>1</sup>H NMR spectroscopy. Molecular dynamic simulations employing well-tempered metadynamics closely reproduce the experimental activation barrier (Δ<i>G</i> <sup>‡</sup> <i>ca.</i> 70 kJ mol<sup>-1</sup>), offering insight into the nanohoop's motion and metastable states along the shuttling pathway. The kinetic data were further complemented by thermodynamic binding studies between [10]CPP and different fullerene bis-adduct regioisomers. These findings expand our understanding of the kinetics and thermodynamics of concave/convex π-π interactions and will inform the design of future mechanically interlocked machines and 2D materials with slow response to external stimuli.
Authors
- Massimo Delle Piane (ORCID: https://orcid.org/0000-0001-8522-9047)
- Fabian M. Steudel (ORCID: https://orcid.org/0009-0005-0636-5793)
- Xavi Ribas (ORCID: https://orcid.org/0000-0002-2850-4409)
- Ferran Feixas (ORCID: https://orcid.org/0000-0001-5147-0000)
- Max von Delius (ORCID: https://orcid.org/0000-0003-1852-2969)
- Giovanni Maria Pavan (ORCID: https://orcid.org/0000-0002-3473-8471)
- Clara Sabrià (ORCID: https://orcid.org/0000-0001-8705-1457)
Institutions
- Politecnico di Torino (IT)
- Universität Ulm (DE)
- Universitat de Girona (ES)
- Center for Integrated Quantum Science and Technology (DE)
Publication Details
- Journal
- Chemical Science
- Published
- 2025-01-01
- DOI
- https://doi.org/10.1039/d5sc05734e
- Primary Topic
- Fullerene Chemistry and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.00