Multichromophoric supramolecular systems. Recovery of the distributions of decay times from the fluorescence decays.

The fluorescence decays of a tetrachromophoric calix[4]arene and a heptachromophoric cyclodextrin with appended pyridin-2'-yl-1,2,3-triazole groups, and their complexes with the cadmium ion, are analyzed with a sum of compressed hyperbola. Such functions are shown to be well suited for the recovery of the underlying distributions of decay times. The heterogeneity of the micro-environments experienced by the chromophores, and/or their mutual interactions in the excited state can in this way be displayed graphically. A fit with a sum of four exponentials is also found to be satisfactory, but the respective parameters lack direct physical meaning.