High-energy collision-induced dissociation of small polycyclic aromatic hydrocarbons

✍ Scribed by Arakawa, Ryuichi; Kobayashi, Mako; Nishimura, Toshihide

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 92 KB
• Volume: 35
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(200002)35:2<178::aid-jms927>3.0.co;2-s

✦ Synopsis

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 Y and C 70 Y . The three-ring isomers of anthracene and phenanthrene and the four-ring isomers of fluoranthene and pyrene can be distingushable 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', occuring at some high-energy state.