title: The electronic characterization of biphenylene--experimental and theoretical insights from core and valence level spectroscopy.
abstract: In this paper, we provide detailed insights into the electronic structure of the gas phase biphenylene molecule through core and valence spectroscopy. By comparing results of X-ray Photoelectron Spectroscopy (XPS) measurements with ΔSCF core-hole calculations in the framework of Density Functional Theory (DFT), we could decompose the characteristic contributions to the total spectra and assign them to non-equivalent carbon atoms. As a difference with similar molecules like biphenyl and naphthalene, an influence of the localized orbitals on the relative XPS shifts was found. The valence spectrum probed by photoelectron spectroscopy at a photon energy of 50 eV in conjunction with hybrid DFT calculations revealed the effects of the localization on the electronic states. Using the transition potential approach to simulate the X-ray absorption spectroscopy measurements, similar contributions from the non-equivalent carbon atoms were determined from the total spectrum, for which the slightly shifted individual components can explain the observed asymmetric features.
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
authors.forename: Johann
authors.initials: J
authors.lastname: Lüder
authors.affiliation: CNR-IOM, Laboratorio TASC, Sincrotrone Trieste, S.S. 14 Km 163.5, Basovizza, I-34149 Trieste, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: de Simone
authors.affiliation: Department of Physical and Chemical Sciences, University of l'Aquila, Via Vetoio, 67100 l'Aquila, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Totani
authors.affiliation: CNR-ISM, S.S. 14 Km 163.5, Basovizza, I-34149 Trieste, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Coreno
authors.affiliation: CNR-IOM, Laboratorio TASC, Sincrotrone Trieste, S.S. 14 Km 163.5, Basovizza, I-34149 Trieste, Italy.
authors.forename: Cesare
authors.initials: C
authors.lastname: Grazioli
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
authors.forename: Biplab
authors.initials: B
authors.lastname: Sanyal
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
authors.forename: Olle
authors.initials: O
authors.lastname: Eriksson
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
authors.forename: Barbara
authors.initials: B
authors.lastname: Brena
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
authors.forename: Carla
authors.initials: C
authors.lastname: Puglia
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D003198:Computer Simulation; D005740:Gases / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D056928:X-Ray Absorption Spectroscopy
chemical_list: D001713:Biphenyl Compounds; D005740:Gases; D009281:Naphthalenes; C031721:naphthalene; D002244:Carbon