Biscrown-Annulated TTFAQ−Dianthracene Hybrid: Synthesis, Structure, and Metal Ion Sensing

A new fluorescence chemosensor (3) made up of a biscrown-annulated TTFAQ receptor and two anthracene fluorophores was designed and synthesized. Its solid-state structure was disclosed by X-ray crystallographic analysis, while fluorescence titrations indicated a high sensitivity for large hard metal cations such as Ba²⁺.