IR-photodissociation spectroscopy of mass-selected gas phase cluster ions

Recent results on the IR-photodissociation spectroscopy of mass-selected gas phase cluster ions in the spectral region from 600 to 1600 cm-1 are presented. The experiments were performed employing a novel experiment setup, consisting of the tandem mass spectrometer, a temperature-controllable He-filled radio frequency ion trap and the free electron laser FELIX (FROM Institute for Plasmaphysics, Nieuwegein, The Netherlands). The application of this technique to the study of the IR-spectroscopy of transition metal oxide cluster cations and halogen atom - halogenhybrid cluster anions of the type Br- (HBr)n with n = 1 - 3 is described. In combination with electronic structure calculations these results allow for a unique structural characterization of the studied cluster ions. For both type of cluster ions these experiments represent, to the best of our knowledge, the first experimentally determined gas phase IR spectra of these compound classes. (author)