Spectroscopic studies of a fluorescent fluoresceinophane formed via a practical synthetic route

Abstract

A practical macrocycle synthesis incorporating a highly fluorescent fluorescein was developed. Photophysical, crystallographic and dynamic-NMR studies showed the alkyl tether forces a constrained conformation of the fluoresceinophane, which enhances the fluorescence quantum yields by reducing the excited-state deactivation pathways. Enhanced temperature-dependent fluorescence relative to its linear analogue was also found as a result of the constrained macrocycle conformation, while a manifold shift from the singlet to the triplet state still occurred in different polar solvents.