Related Experiment Video
Updated: May 17, 2026

Direct Imaging of Laser-driven Ultrafast Molecular Rotation
Published on: February 4, 2017
Laser mass spectrometry with circularly polarized light: circular dichroism of molecular ions
1Chemistry Department, Technische Universität München, 85748 Garching, Germany.
Abstract:
In recent experiments of resonance-enhanced laser ionization, large differences between circular dichroism measured for molecular and fragment ions were found by several research groups for different molecular systems. In the case of 3-methylcyclopentanone (3-MCP) we attributed this effect to a large circular dichroism of the molecular ion. In the work presented here, this effect in 3-MCP is studied by ion spectroscopy, by varying the neutral intermediate excited state involved in resonance-enhanced multiphoton ionization (REMPI) and by performing REMPI-induced measurements of circular dichroism at different laser pulse energies. It turns out that the dynamics of structural changes in the ionic ground state strongly influences the observed ionic circular dichroism.
Related Concept Videos
Matrix-Assisted Laser Desorption Ionization (MALDI)
Mass Spectrum: Interpretation
MALDI-TOF Mass Spectrometry
Mass Spectrometers
Mass Spectrometry: Overview
Raman Spectroscopy: Overview
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...

