A Study of theThermal C-C and C-H Bond Cleavage in the Aromatic Molecules: Acenaphthene and Acenaphthylene

The thermal decomposition of the two aromatic hydrocarbons Acenaphthene and Acenaphthylene is studied applying the open shell semiempirical (Hartree-Fock) PM3 method. In this study all internal coordinates were varied, except the coordinate chosen to describe thereaction. All possible intermediates were considered on describing the reaction scheme. Thepreferred reaction path was assigned on the basis of comparing the activation energies of thedifferent paths. The treatment shows that the preferred reaction paths lead to the formation ofacetylene as a final product. This result is similar, but in the reverse direction, to formertheoretical and experimental results reported in the literature, which showed that acetylene is a basic building unit within the natural formation reactions of Polycyclic Aromatic Hydrocarbonmolecules.