PHOTODISSOCIATION SPECTROSCOPY OF EXCIMERS IN NAPHTHALENE CLUSTERS

The naphthalene excimers, produced upon selective excitation of the van der Waals trimer and tetramer, are studied by photodissociation spectroscopy with fluorescence detection. These excimers absorb efficiently in the near-IR and visible regions, with a maximum at 700 nm, which results in a strong depletion of the excimer fluorescence. The absorption band is assigned to a transition between the excimer states, both originating from configuration interaction of the 1L(a) molecular excitaton states and the charge resonance states. Excitation into this band produces monomer fragments, providing strong evidence that the upper excimer state is dissociative or weakly bound.