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Updated: May 10, 2026

Raman and IR Spectroelectrochemical Methods as Tools to Analyze Conjugated Organic Compounds
Published on: October 12, 2018
Spectroscopy of the C-H stretching vibrational band in selected organic molecules
Jiří Šebek1, Roie Knaanie, Brian Albee
1Institute of Chemistry and The Fritz Haber Research Center, The Hebrew University, Jerusalem 91904, Israel.
Abstract:
The vibrational spectroscopy of C-H stretches in organic molecules is of considerable importance for the characterization of these systems and for exploration of their properties. These stretches are strongly anharmonic, and thus methods including anharmonicity have to be used. The vibrational self-consistent field (VSCF) is applied to the following organic compounds: acetone, dimethylacetylene, neopentane, toluene, ethylene, and cyclopropane. The computed spectra are compared to new experimental data, including Raman measurements of all molecules except cyclopropane and IR of acetone, neopentane, and ethylene. A high level of agreement is found for all of the molecules. The characteristic features of CH3 and CH2 groups are studied and analyzed in detail. A reliable, unambiguous assignment of vibrational modes to spectral peaks is provided. Several characteristic features of CH3 and CH2 vibrations in polyatomic molecules are clarified, providing easier assignments for different types of organic molecules.
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