Stuttgart 2012 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
MO: Fachverband Molekülphysik
MO 21: Poster 3: Cluster, Collisions, Energy Transfer, Photochemistry, Spectroscopy in He-Droplets
MO 21.23: Poster
Thursday, March 15, 2012, 16:30–19:00, Poster.IV
High Resolution IR Spectroscopy of Benzene Monomer and Dimer at Ultracold Temperature — •Sarah Grün, Torsten Poerschke, and Daniel Habig — Ruhr-University Bochum, Bochum, Germany
π⋯π and CH⋯π interactions are of special interest concerning stabilization mechanisms in DNA or proteins. Therefore, benzene, as the smallest aromatic molecule, and its dimer was used as a model and starting point for theoretical and experimental studies in the last decades. Our measurements were carried out using a high power cw-IR-OPO in combination with a helium nanodroplet spectrometer. We obtained IR spectra of benzene and benzene dimer in the C-H-stretching region of 3000-3110 cm−1. From the pressure dependence of IR-spectra, we assigned benzene monomer as well as dimer bands. The latter, we assigned to the tilted T-shaped (TTS) structure based on comparative treatment of the experimental results with theoretical predictions as well as gas phase studies from other groups. Parallel-displaced (PD) and perfect T-shaped (PTS) structure were not observed in this frequency region. In addition, we found a splitting of the ν8+ν19 combination band for benzene monomer, which was not splitting in gas phase matrices. This can be explained with an additional Fermi resonance coming from the helium matrix.