The Energy of the Excimer Luminescence of Naphthalene under a Variety of Geometrical Configurations

A four-electron ASMO treatment of the interaction of two naphthalene molecules to yield excimers of D2h, C2, or S4 is developed, and the energies of these excimers are calculated as a function of the angle, α, between corresponding bonds of the two molecules. It is shown that excimers are stable at two configurations, α=0° and α=75°; that the excimer with α=0° does not emit because of the forbidden character of the transition, and that the excimer with α=75° emits and is considered to play a predominant role in the observed excimer fluorescence.