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Updated: May 27, 2026

Raman and IR Spectroelectrochemical Methods as Tools to Analyze Conjugated Organic Compounds
Published on: October 12, 2018
On the interpretation of IETS spectra of a small organic molecule
1Institut für Festkörperphysik, Abteilung ATMOS, Leibniz Universität Hannover, Hannover, Germany.
Abstract:
We have investigated vibrational spectra of nitrobenzene molecules adsorbed on Cu(111) by low temperature inelastic electron tunneling spectroscopy. This molecule, which should support 39 internal modes, only gives rise to seven peaks in the spectra. We outline a comparison with ensemble IR data and interpret the small number of vibrational peaks by the superposition of a multitude of almost isoenergetic vibrational modes. The non-detectability of further modes cannot be understood in terms of symmetry considerations. Additional modes in the spectra are attributed to external molecular-metal vibrations.
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