Studies on the fluorescence decay times of anthracene and perylene excimers in rigid matrices at low temperatures in relation to the structures of excimers

Abstract

The fluorescence decay times of excimers of anthracene, perylene, pyrene and 1-methylnaphthalene have been studied in a rigid cyclohexane matrix of low temperatures. From the observed long decay times of the excimer fluorescence, it has been concluded that the excimer fluorescence is due to the electronically (symmetry) forbidden transition and that the excimers of these molecules have the summetrical overlapping sandwich structure. In addition to this, a ground state dimer of pyrene which is responsible to the excimer fluorescence in the cyclohexane matrix has been found out by measuring the excitation spectrum of the excimer fluorescence.