Highly efficient production of neutral carbon atoms in the ultraviolet multiphoton fragmentation of aromatic molecules

We report the observation of highly efficient production of neutral carbon atoms under moderate ultraviolet laser fluxes in the multiphoton fragmentation of several aromatic molecules. These processes are detected under collision-free conditions by resonance-enhanced three-photon MPI line resonances of carbon in its ground or first excited term. For the cases of C₆F₆ and benzaldehyde, at least, it can be demonstrated that atomization precedes ionization of the parent molecule to a significant extent, indicating rapid dissociation of the neutral parent as an important atom formation channel entrance.