title: Vibrationally resolved high-resolution NEXAFS and XPS spectra of phenanthrene and coronene.
abstract: We performed a combined experimental and theoretical study of the C1s Near-Edge X-ray Absorption Fine-Structure (NEXAFS) spectroscopy and X-ray Photoelectron Spectroscopy in the gas phase of two polycyclic aromatic hydrocarbons (phenanthrene and coronene), typically formed in combustion reactions. In the NEXAFS of both molecules, a double-peak structure appears in the C1s → LUMO region, which differ by less than 1 eV in transition energies. The vibronic coupling is found to play an important role in such systems. It leads to weakening of the lower-energy peak and strengthening of the higher-energy one because the 0 - n (n > 0) vibrational progressions of the lower-energy peak appear in nearly the same region of the higher-energy peak. Vibrationally resolved theoretical spectra computed within the Frank-Condon (FC) approximation and linear coupling model agree well with the high-resolution experimental results. We find that FC-active normal modes all correspond to in-plane vibrations.
authors.affiliation: Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Fronzoni
authors.affiliation: Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy.
authors.forename: Oscar
authors.initials: O
authors.lastname: Baseggio
authors.affiliation: Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Stener
authors.affiliation: Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm, Sweden.
authors.forename: Weijie
authors.initials: W
authors.lastname: Hua
authors.affiliation: Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm, Sweden.
authors.forename: Guangjun
authors.initials: G
authors.lastname: Tian
authors.affiliation: Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm, Sweden.
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Istituto di Ricerche sulla Combustione, IRC-CNR, P.le Tecchio, 80, 80125 Napoli, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Apicella
authors.affiliation: Istituto di Ricerche sulla Combustione, IRC-CNR, P.le Tecchio, 80, 80125 Napoli, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Alfé
authors.affiliation: CNR-IOM, Laboratorio TASC, 34149 Trieste, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: de Simone
authors.affiliation: CNR-IOM, Laboratorio TASC, 34149 Trieste, Italy.
authors.forename: Antti
authors.initials: A
authors.lastname: Kivimäki
authors.affiliation: CNR-IMIP, 00016 Montelibretti, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Coreno
mesh_terms: D003198:Computer Simulation; D005740:Gases / Q000737:chemistry; D008956:Models, Chemical; D015394:Molecular Structure; D010616:Phenanthrenes / Q000737:chemistry*; D056951:Photoelectron Spectroscopy / Q000379:methods*; D011083:Polycyclic Compounds / Q000737:chemistry*; D014732:Vibration; D056928:X-Ray Absorption Spectroscopy / Q000379:methods*
chemical_list: D005740:Gases; D010616:Phenanthrenes; D011083:Polycyclic Compounds; C031181:phenanthrene; C012256:coronene