Electron-Impact Studies of Aromatic Hydrocarbons. II. Naphthacene, Naphthaphene, Chrysene, Triphenylene, and Pyrene

The systematic survey of ionization-dissociation processes of fused-ring aromatic compounds initiated previously is continued. Mass spectra and appearance potentials of the singly and doubly charged molecule ions are reported. The observed ionization energies of naphthacene (6.95 eV), naphthaphene (7.53 eV), chrysene (8.01 eV), triphenylene (8.19 eV), and pyrene (7.72 eV) are compared with available spectroscopic data, with values obtained from molecular orbital calculations, with the available empirical and semiempirical methods, and with other electron-impact data.