title: Vibrational spectra of small silicon monoxide cluster cations measured by infrared multiple photon dissociation spectroscopy.
abstract: The first gas-phase infrared spectra of silicon monoxide cations (SiO)(n)(+), n = 3-5, using multiple photon dissociation in the 550-1250 cm(-1) frequency range, are reported. All clusters studied here fragment via loss of a neutral SiO unit. The experimental spectra are compared to simulated linear absorption spectra from calculated low energy isomers for each cluster. This analysis indicates that a "ring" isomer is the primary contributor to the (SiO)(3)(+) spectrum, that the (SiO)(4)(+) spectrum results from two close-lying bicyclic ring isomers, and that the (SiO)(5)(+) spectrum is from a bicyclic ring with a central, fourfold-coordinated Si atom. Experiment and theory indicate that the energies and energetic orderings of (SiO)(n)(+) isomers differ from those for neutral (SiO)(n) clusters.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA. dneumark@berkeley.edu
authors.forename: Etienne
authors.initials: E
authors.lastname: Garand
authors.forename: Daniel
authors.initials: D
authors.lastname: Goebbert
authors.forename: Gabriele
authors.initials: G
authors.lastname: Santambrogio
authors.forename: Ewald
authors.initials: E
authors.lastname: Janssens
authors.forename: Peter
authors.initials: P
authors.lastname: Lievens
authors.forename: Gerard
authors.initials: G
authors.lastname: Meijer
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Neumark
authors.forename: Knut R
authors.initials: KR
authors.lastname: Asmis
mesh_terms: D000327:Adsorption; D000465:Algorithms; D002412:Cations / Q000737:chemistry; D007536:Isomerism; D053758:Nanoparticles / Q000032:analysis / Q000737:chemistry*; D010087:Oxides / Q000032:analysis / Q000737:chemistry*; D017785:Photons; D012825:Silicon / Q000737:chemistry*; D017655:Silicon Compounds / Q000032:analysis / Q000737:chemistry*; D013055:Spectrophotometry, Infrared / Q000379:methods
chemical_list: D002412:Cations; D010087:Oxides; D017655:Silicon Compounds; C116473:silicon monoxide; D012825:Silicon