A pyrene-based fluorescent sensor for Zn~(2+) ions: a molecular 'butterfly'

摘要

A simple pyrene-based triazole receptor has been synthesised and shown to self-assemble in the presence of ZnCl_2 in an exclusively 2:1 ratio, whereas a mixture of 2:1 and 1:1 ratios are observed for other Zn~(2+) salts. The pyrene units are syn in orientation; this is supported by a strong excimer signal observed at 410 nm in the presence of ZnCl_2 in acetonitrile. DFT calculations and 2D NMR support the proposed structure. The design and synthesis of molecular receptors to target metal analytes via changes in fluorescence are topics of current interest as fluorescence signals are easily perturbed with any change to the fluorophore's local environment.