Electron-Impact Studies of Aromatic Hydrocarbons. III. Azulene and Naphthalene

Abstract
The observed ionization energies of naphthalene (8.26 eV) and azulene (7.72 eV) and the heats of formation of these compounds provides an energetic scheme consistent with the measured appearance potentials of secondary ions and the assumption of ionic intermediates common to both compounds. The occurrence of these common intermediate ions which lead to the observed fragmentation in these compounds is also demonstrated by the similarity of the mass spectra of these two compounds. Additional evidence is provided by observations made on the metastable ion transitions found in their mass spectra.