Stuttgart 2012 – scientific programme

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MO: Fachverband Molekülphysik

MO 1: Vibrational Spectroscopy

MO 1.6: Talk

Monday, March 12, 2012, 12:00–12:15, V38.03

FTIR- and Ramanspectroscopy of Substituted Paracyclophane Molecules — •Jörg Herterich, Susanne Zeißner, Ingo Fischer, and Thiemo Gerbich — Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg

The vibrational structures of three paracyclophanes were investigated, ortho-dihydroxy-[2.2]paracyclophane (o-DHPC), mono-hydroxy[2.2]paracyclophane (MHPC) and 2,11-dithia[3.3]paracyclo- phane.

Gas-phase infrared spectroscopy helps to identify the most stable isomer in the gas phase, while FT-Raman spectroscpy permits to study the low-frequency vibrations that give insight into the pi-pi-interactions of the molecules. For o-DHPC the IR spectrum confirms that the EZ rotamer dominates, while for MHPC the spectra indicate a larger contribution of the Z rotamer than expected. The Raman spectrum of 2,11-dithia[3.3]paracyclophane showed a dominance of the trans isomer. The Raman spectra also show that the wavenumber of the lowest frequency twist mode is overestimated by density functional theory in all three molecules.