title: Assignment of photoelectron spectra of halide-water clusters: contrasting patterns of delocalization in Dyson orbitals.
abstract: Ab initio electron propagator calculations in various self-energy approximations provide accurate assignments of peaks observed in the photoelectron spectra of complexes that comprise a fluoride or chloride anion and two or three water molecules. More than one minimum structure is found in all four cases. When the halide anion is Cl(-), the first three final states may be described as quasi-degenerate (2)P chlorine atoms coordinated to water molecules. Higher final states consist of a chloride anion juxtaposed to a positive charge that is delocalized over the water molecules. For the clusters with fluoride anions, most of the final states correspond to Dyson orbitals that are delocalized over the F and O nuclei. A variety of F-O σ and π bonding and antibonding patterns are evident in the Dyson orbitals. The assignment of low-lying spectral peaks to halide p orbital vacancies or to delocalized solvent orbitals is more valid for the chloride clusters than for the fluoride clusters, where a delocalized picture arises from strong bonding interactions between F 2p and H2O 1b1 orbitals.
authors: Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312, USA.
authors: O
authors: O
authors: Dolgounitcheva
authors: V G
authors: VG
authors: Zakrzewski
authors: J V
authors: JV
authors: Ortiz
mesh_terms: D006219:Halogens / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D011789:Quantum Theory; D014867:Water / Q000737:chemistry*
chemical_list: D006219:Halogens; D014867:Water