On the statisticodynamical approach of final state distributions in simple bond fissions

Abstract

When the energy available to the products of a barrierless unimolecular reaction is of the order of 100 cm⁻¹, phase space theory leads usually to a good description of product state distributions. This is no longer the case for energies of the order of 1000 cm⁻¹. It seems, for example, that the excitation of the recoil energy distribution is underestimated by the theory as suggested by experimental results on the photodissociations of C₂O and NCO. As an alternative, we propose a statisticodynamical approach of the previous processes based in part on transition state theory and in part on assumptions relative to the dynamics in the exit-channel. The recoil energy distributions obtained are now in good agreement with the measured ones, in spite of the simplicity of their mathematical expressions.