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Updated: Jun 20, 2026

Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
Conformational flexibility of a rotaxane thread probed by electronic spectroscopy in helium nanodroplets
Szymon Smolarek1, Anouk M Rijs, Jeffrey S Hannam
1University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands.
Abstract:
Ultrahigh-resolution spectroscopic studies have been performed to elucidate the conformational landscape of the succinamide-based thread 1 that is frequently employed in mechanically interlocked molecular assemblies. We show how dissolving single molecules into a helium nanodroplet enables us to resolve the broad absorption spectrum--which is normally observed--into the separate contributions of individual conformers that are populated under the employed experimental conditions. Excellent agreement is obtained with the results of molecular dynamics calculations. The absorption spectrum of each conformer reveals a splitting of the zero-phonon resonance that is different for each conformer and could thus serve as a spectral signature.
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