title: Infrared spectroscopy of niobium oxide cluster cations in a molecular beam: identifying the cluster structures.
abstract: Infrared spectra of niobium oxide cluster cations are measured via IR multiple photon dissociation spectroscopy in the 400-1650 cm(-1) region. The cluster cations are obtained directly from a laser vaporization source and irradiated with the infrared light emitted by a free electron laser. For those oxide clusters that fragment after excitation, the IR spectra are recorded by measuring the cluster intensity changes as a function of the IR wavelength. The spectra of all examined oxide clusters exhibit two main absorption features that can be assigned to vibrations of terminal (Nb=O) or bridging (Nb-O-Nb) oxide groups. For selected clusters DFT calculations at the B3LYP/LACVP* level have been performed and the calculated vibrational spectra are compared to the experimental data to identify the gas phase structures of the clusters.
authors.affiliation: FOM Institute for Plasma Physics Rijnhuizen, Edisonbaan 14, NL-3439 MN Nieuwegein, The Netherlands. fielicke@rijnh.nl
authors.forename: André
authors.initials: A
authors.lastname: Fielicke
authors.forename: Gerard
authors.initials: G
authors.lastname: Meijer
authors.forename: Gert
authors.initials: G
authors.lastname: von Helden