title: Electronic absorption spectra of protonated pyrene and coronene in neon matrixes.
abstract: Protonated pyrene and coronene have been isolated in 6 K neon matrixes. The cations were produced in the reaction of the parent aromatics with protonated ethanol in a hot-cathode discharge source, mass selected, and co-deposited with neon. Three electronic transitions of the most stable isomer of protonated pyrene and four of protonated coronene were recorded. The strongest, S(1) ← S(0) transitions, are in the visible region, with onset at 487.5 nm for protonated pyrene and 695.6 nm for protonated coronene. The corresponding neutrals were also observed. The absorptions were assigned on the basis of ab initio coupled-cluster and time-dependent density functional theory calculations. The astrophysical relevance of protonated polycyclic aromatic hydrocarbons is discussed.
authors.affiliation: Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland.
authors.forename: Iryna
authors.initials: I
authors.lastname: Garkusha
authors.forename: Jan
authors.initials: J
authors.lastname: Fulara
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Sarre
authors.forename: John P
authors.initials: JP
authors.lastname: Maier
mesh_terms: D004583:Electrons; D009356:Neon / Q000737:chemistry*; D011083:Polycyclic Compounds / Q000737:chemistry*; D011522:Protons; D011721:Pyrenes / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D011083:Polycyclic Compounds; D011522:Protons; D011721:Pyrenes; D009356:Neon; C012256:coronene; C030984:pyrene