Düsseldorf 2007 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 14: Molecular Clusters
MO 14.3: Vortrag
Montag, 19. März 2007, 17:00–17:15, 6D
IR Spectra of Protonated Furan, Pyrrole, and Naphthalene — •Ulrich Lorenz1, Joel Lemaire2, Philippe Maitre2, Maria-Elisa Crestoni3, Simonetta Fornarini3, and Otto Dopfer1 — 1Institut für Optik und Atomare Physik, Technische Universität Berlin, Berlin, Germany — 2Laboratoire de Chimie Physique, UMR8000 CNRS-Université Paris-Sud 11, Faculté des Sciences d’ Orsay, Orsay Cedex, France — 3Dipartimento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università di Roma La Sapienza, Roma, Italy
Infrared Multiple Photon Dissociation (IRMPD) Spectra of protonated furan, pyrrole, and naphthalene are recorded in the 700 to 1800 cm−1 range in order to probe the preferred site of protonation. The species are generated by chemical ionization of the corresponding neutral compounds in a ICR mass spectrometer and dissociated employing the free electron laser at the Centre Laser Infrarouge Orsay. The comparison with the linear IR spectra calculated at the B3LYP/6-311G(2df,2pd) level of theory allows for the assignment of the most stable isomers as the carriers of the observed spectral features. The spectrum of protonated naphthalene is discussed in the context of the hypothesis that protonated polycyclic aromatic molecules (PAHs) might contribute to the astronomically observed Unidentified Infrared Emission (UIR) Bands.