title: The unidentified interstellar infrared bands:  PAHs as carriers?
abstract: Infrared emission spectra of gas-phase naphthalene and pyrene have been measured in the range of 3 to 7.5 micrometers with ultraviolet laser desorption-excitation and a spectroscopic technique featuring single-photon counting in the infrared. The spectra were compared with the unidentified infrared emission bands that are observed in many astronomical objects. Marked discrepancies between those observations and the laboratory emission spectra in the wavelengths and relative intensities of principal spectral features led to the conclusion that small neutral unsubstituted polycyclic aromatic hydrocarbons cannot be the carriers of the unidentified infrared emission bands.
authors.affiliation: Department of Chemistry, University of California, Berkeley 94720-1460, USA.
authors.forename: S
authors.initials: S
authors.lastname: Schlemmer
authors.forename: D J
authors.initials: DJ
authors.lastname: Cook
authors.forename: J A
authors.initials: JA
authors.lastname: Harrison
authors.forename: B
authors.initials: B
authors.lastname: Wurfel
authors.forename: W
authors.initials: W
authors.lastname: Chapman
authors.forename: R J
authors.initials: RJ
authors.lastname: Saykally
mesh_terms: D001256:Astronomy / Q000379:methods*; D009281:Naphthalenes / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000737:chemistry; D011721:Pyrenes / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D009281:Naphthalenes; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; C031721:naphthalene; C030984:pyrene