title: Infrared Spectroscopy and Structure of (NO)(n) Clusters.
abstract: Nitrogen oxide clusters (NO)n have been studied in He droplets via infrared depletion spectroscopy and by quantum chemical calculations. The ν1 and ν5 bands of cis-ON-NO dimer have been observed at 1868.2 and 1786.5 cm(-1), respectively. Furthermore, spectral bands of the trimer and tetramer have been located in the vicinity of the corresponding dimer bands in accord with computed frequencies that place NO-stretch bands of dimer, trimer, and tetramer within a few wavenumbers of each other. In addition, a new line at 1878.1 cm(-1) close to the band origin of single molecules was assigned to van der Waals bound dimers of (NO)2, which are stabilized due to the rapid cooling in He droplets. Spectra of larger clusters (n > 5), have broad unresolved features in the vicinity of the dimer bands. Experiments and calculations indicate that trimers consist of a dimer and a loosely bound third molecule, whereas the tetramer consists of two weakly bound dimers.
authors.affiliation: Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Hoshina
authors.affiliation: Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Slipchenko
authors.affiliation: Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
authors.forename: Kirill
authors.initials: K
authors.lastname: Prozument
authors.affiliation: Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
authors.forename: Deepak
authors.initials: D
authors.lastname: Verma
authors.affiliation: Department of Chemistry and Ames Laboratory (US-DOE), Iowa State University , Ames, Iowa 50011, United States.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Schmidt
authors.affiliation: Advanced Biomedical Computing Center, DSITP, Frederick National Laboratory for Cancer Research , Frederick, Maryland 21702, United States.
authors.forename: Joseph
authors.initials: J
authors.lastname: Ivanic
authors.affiliation: Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
authors.forename: Andrey F
authors.initials: AF
authors.lastname: Vilesov
mesh_terms: D006371:Helium / Q000737:chemistry; D015394:Molecular Structure; D009589:Nitrogen Oxides / Q000737:chemistry*; D010316:Particle Size; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared
chemical_list: D009589:Nitrogen Oxides; D006371:Helium