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Updated: Mar 1, 2026

Direct Imaging of Laser-driven Ultrafast Molecular Rotation
Published on: February 4, 2017
Cold Snapshot of a Molecular Rotary Motor Captured by High-Resolution Rotational Spectroscopy
Sérgio R Domingos1,2, Arjen Cnossen3, Wybren J Buma4
1Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761, Hamburg, Germany.
Abstract:
We present the first high-resolution rotational spectrum of an artificial molecular rotary motor. By combining chirped-pulse Fourier transform microwave spectroscopy and supersonic expansions, we captured the vibronic ground-state conformation of a second-generation motor based on chiral, overcrowded alkenes. The rotational constants were accurately determined by fitting more than 200 rotational transitions in the 2-4 GHz frequency range. Evidence for dissociation products allowed for the unambiguous identification and characterization of the isolated motor components. Experiment and complementary quantum-chemical calculations provide accurate geometrical parameters for the C27 H20 molecular motor, the largest molecule investigated by high-resolution microwave spectroscopy to date.
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