Low temperature fluorescence spectra of atropisomeric perylene dyes

The site selection spectra of highly photostable perylene fluorescent dyes at 4.2 K in a glassy matrix of three different organic solvents (ethanol, methyl tetrahydrofuran, n-butyl acetate) are presented. The spectra ofthe two isomers are identical for a given solvent and only very minute differences are detectable between different solvents. We conclude that the influence of the matrix on the fluorescence spectra is of only minor importance. The influence of the orientation in the matrix is negligible