Phosphorescence of matrix-isolated naphthalene and phenanthrene

Abstract

Naphthalene and phenanthrene emission is reported in argon, krypton, xenon, methane and sulfur hexafluoride between 20°K and 0.4 of the solvent melting point. Methane solutions emit only fluorescence, argon solutions fluoresce and phosphoresce, but krypton solutions phosphoresce only. With increasing heavy atom effect, total emission increases, while the phosphorescence lifetimes decrease. After annealing, all samples show pronounced and reversible temperature dependence of phosphorescence intensity, while the T 1 → S 0 lifetimes remain essentially constant.