title: Absorption spectra of ground-state and low-lying electronic States of copper nitrosyl: a rare gas matrix isolation study.
abstract: The reaction of ground-state Cu atoms with NO during condensation in solid argon, neon, and binary argon/neon mixtures has been reinvestigated. In addition to the ground-state already characterized in rare gas matrixes by its nu1 mode in reactions of laser-ablated Cu with nitric oxide, another very low lying electronic state is observed for CuNO in solid argon. Photoconversion and equilibrium processes are observed between the two lowest lying electronic states following photoexcitations to second and third excited states in the visible and near-infrared. The electronic spectrum of the CuNO complex was also recorded to understand the photoconversion processes. In solid neon, only the ground state (probably 1A') and the second and third excited states are observed. This suggests that interaction with the argon cage stabilizes the triplet state to make 1A' and 3A' ' states almost isoenergetic in solid argon. On the basis of previous predictions founded on DFT calculations on the very low lying 1A' and 3A' ', a mechanism is proposed, involving the singlet-triplet state manifolds. For these two lower and one higher electronic states, 14N/15N, 16O/18O, and 63Cu/65Cu isotopic data on nu1, nu2, and nu3 have been measured. On the basis of harmonic force-field calculations and relative intensities in the vibronic progressions, some structural parameters are estimated. The molecule is bent in all electronic states, with Cu-N-O bond angles varying slightly around 130 +/- 10 degrees , but the Cu-N bond force constants are substantially different, denoting larger differences in bond lengths.
authors.affiliation: Université Pierre et Marie Curie-Paris 6, CNRS UMR 7075, LADIR, case 49, 4 place Jussieu 75252 Paris, France.
authors.forename: Lahouari
authors.initials: L
authors.lastname: Krim
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Wang
authors.forename: Laurent
authors.initials: L
authors.lastname: Manceron
authors.forename: Lester
authors.initials: L
authors.lastname: Andrews
mesh_terms: D001128:Argon / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D004583:Electrons; D009356:Neon / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D011789:Quantum Theory; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D014732:Vibration
chemical_list: D009569:Nitric Oxide; D009356:Neon; D001128:Argon; D003300:Copper