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Related Experiment Video

Updated: Jun 26, 2026

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers

Published on: August 18, 2017

Charge localization in alcohol isomers studied by Compton scattering.

M Hakala¹, K Nygård, J Vaara

¹Department of Physics, University of Helsinki, P.O. Box 64, Helsinki FI-00014, Finland. mikko.o.hakala@helsinki.fi

The Journal of Chemical Physics

|January 29, 2009

Summary

X-ray Compton scattering and DFT calculations reveal differences in electronic charge distribution between alcohol isomers. Branched alcohols exhibit narrower Compton profiles, indicating more delocalized charge compared to linear alcohols.

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Area of Science:

Physical Chemistry
Quantum Chemistry
Materials Science

Background:

Small molecule alcohols like propanol (PrOH) and butanol (BuOH) exist as various isomers.
Understanding isomeric differences is crucial for predicting molecular properties and reactivity.

Purpose of the Study:

To investigate the electronic charge density differences between alcohol isomers.
To compare experimental X-ray Compton scattering data with theoretical calculations.

Main Methods:

X-ray Compton scattering experiments using synchrotron radiation.
Density-functional theory (DFT) calculations for molecular systems (1-3 monomer units).
Analysis of Compton profiles to probe electronic momentum distributions.

Main Results:

Compton profiles of branched alcohols (iso-PrOH, iso-BuOH, sec-BuOH) were narrower than those of linear alcohols (n-PrOH, n-BuOH).
Narrower profiles indicate a more delocalized electronic charge in branched isomers.
DFT calculations reasonably reproduced experimental spectral features.

Conclusions:

Significant differences in electronic charge distribution exist between alcohol isomers.
X-ray Compton scattering provides a sensitive probe of these isomeric differences.
Quantum chemical calculations can be validated against experimental Compton scattering data.