title: High-energy collision-induced dissociation of small polycyclic aromatic hydrocarbons.
abstract: High-energy collision-induced dissociation (CID) experiments on polycyclic aromatic hydrocarbons (PAHs) having 2-6 rings, naphthalene, anthracene, phenanthrene, fluoranthene, pyrene and coronene, were performed, and the relative abundances of their fragment ions were investigated as a function of collision energy. The results revealed that the PAHs except naphthalene showed a bimodal-type distribution of positive fragmentation ions, which is closely similar to the fragment-ion distribution reported for the CID of three-dimensional fullerene, C(60)(+) and C(70)(+). The three-ring isomers of anthracene and phenanthrene and the four-ring isomers of fluoranthene and pyrene can be distinguishable in their spectra under an electron ionization energy of 70 eV, but the high-energy CID spectra of the three- and four-ring isomers were almost identical. The fragmentation corresponding to fragment ions in the low-mass region of the bimodal CID spectra could be interpreted by the simple statistical model that fragment ions are formed by random evaporation from the molecular ions after a considerable structural rearrangement, 'phase transition', occurring at some high-energy state.
authors.affiliation: Department of Applied Chemistry, Kansai University, Suita, Osaka 564-8680, Japan. arak@ipcku.kansai-u.ac.jp
authors.forename: R
authors.initials: R
authors.lastname: Arakawa
authors.forename: M
authors.initials: M
authors.lastname: Kobayashi
authors.forename: T
authors.initials: T
authors.lastname: Nishimura
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons