Conformational difference between singlet and triplet excimers of naphthalene as revealed by luminescence of 1,2-di-α-naphthylethane

Abstract

Fluorescence and phosphorescence of 1,2-di-α-naphthylethane in isooctane at room temperature have been investigated to deduce the possible conformational difference between singlet and triplet excimers of naphthalene. The fluorescence of the compound is essentially that of the naphthalene monomer, while the phosphorescence is nearly identical to the triplet excimer emission from naphthalene. This result strongly suggests that the geometry of the triplet excimer is distinctly different from the sandwich-pair geometry favored by the singlet excimer.