Photophysics of meso-substituted anthracenes. Part 1.—Solutions and isolated vapours

Abstract

The excess-energy dependence of the photophysics of a number of meso-substituted anthracene derivatives has been studied in the isolated vapour phase. By use of a model involving singlet/triplet energy-level inversion, and by comparison with results in the relaxed vapour phase, an explanation of these widely varying properties is proposed in terms of differing rates of vibrational redistribution and non-radiative decay processes in the triplet manifold. Fluorescence quantum yields and lifetimes have been measured in both phases and non-exponential decays for anthracene, 9-cyanoanthracene and 9,10-diphenylanthracene in the relaxed vapour phase are reported.