The calculation of the potential energy surface (PES) for the reaction of cyclopenta[b]naphthalene radical C13H9 with molecular oxygen O2 is presented. It employs modern quantum-chemistry methods, which allows us to find out the most energetically favorable reaction pathways leading to the destruction of five- A nd six-membered rings in the PAH structure. Computed energy and frequencies values for reactants, intermediates, transition states, and products on the considered PES will be then utilized to calculate the rate constants and product branching ratios for the above-mentioned reaction using up-to-date methods of statistical physics. As a result of the calculations, we predicted the most energetically favorable reaction pathway to lead to the cyclopenta[b]naphthalene-1-one + OH products.
