Document Server@UHasselt >
Research >
Research publications >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/2164

Title: Probing the shape and stereochemistry of molecular orbitals in locally flexible aromatic chains: A Penning ionization electron spectroscopy and Green's function study of the electronic structure of biphenyl
Authors: Kishimoto, N
Hagihara, Y
Ohno, K
FRANCOIS, Jean-Pierre
DELEUZE, Michael
Issue Date: 2005
Citation: JOURNAL OF PHYSICAL CHEMISTRY A, 109(46). p. 10535-10546
Abstract: We report on the results of an exhaustive study of the interplay between the valence electronic structure, the topology and reactivity of orbitals, and the molecular structure of biphenyl by means of Penning ionization electron spectroscopy in the gas phase upon collision with metastable He*(2(3)S) atoms. The measurements are compared with one-particle Green's function calculations of one-electron and shake-up valence ionization spectra employing the third-order algebraic diagrammatic construction scheme [ADC(3)]. Penning ionization intensities are also analyzed by means of the exterior electron-density model and comparison with photoelectron spectra: in contrast with the lines originating from sigma orbitals, ionization lines belonging to the pi-band system have large Penning ionization cross sections due to their greater extent outside the molecular van der Waals surface. The involved chemi-ionization processes are further experimentally investigated using collision-energy-resolved Penning ionization electron spectroscopy. The cross sections of pi-ionization bands exhibit a markedly negative collision-energy dependence and indicate that the interaction potential that prevails between the molecule and the He-*(2(3)S) atom is strongly attractive in the pi-orbital region. On the other hand, the partial ionization cross sections pertaining to sigma-ionization channels are characterized by more limited collision-energy dependencies, as a consequence of rather repulsive interactions within the sigma-orbital region. A comparison of ADC(3) simulations with the Penning ionization electron spectra and UV photoelectron spectra measured by Kubota et al. [Chem. Phys. Lett. 1980, 74, 409] on thin films of biphenyl deposited at 170 and 109 K on copper demonstrates that biphenyl molecules lying at the surface of polycrystalline layers adopt predominantly a planar configuration, whereas within an amorphous sample most molecules have twisted structures similar to those prevailing in the gas phase.
Notes: Tohoku Univ, Dept Chem, Grad Sch Sci, Aoba Ku, Sendai, Miyagi 9808578, Japan. Hasselt Univ, Theoret Chem Grp, Dept SBG, B-3590 Diepenbeek, Belgium.Ohno, K, Tohoku Univ, Dept Chem, Grad Sch Sci, Aoba Ku, Sendai, Miyagi 9808578, Japan.ohnok@qpcrkk.chem.tohoku.ac.jp michael.deleuze@uhasselt.be
URI: http://hdl.handle.net/1942/2164
DOI: 10.1021/jp053678f
ISI #: 000233436900009
ISSN: 1089-5639
Category: A1
Type: Journal Contribution
Validation: ecoom, 2006
Appears in Collections: Research publications

Files in This Item:

There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.