Calix[4]arene derivatives containing azine functionality: A Zn(II)-responsive fluorescent sensor

The complexation reactions between metal(II) salts and a calix[4]arene derivative (1) with pendant arm Schiff bases which contain azine functionalities are described. The calix[4]arene derivative 1 is weakly fluorescent, but this fluorescence is quenched when it is deprotonated by base. The fluorescence only returns, and is in fact greatly enhanced, in the presence of zinc(II) ions.

Graphical abstractThe calix[4]arene derivative 1 is weakly fluorescent. The fluorescence is greatly enhanced in the presence of zinc(II) ions only.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch Highlights► Much effort has gone into measuring both the concentration and distribution of Zn(II) in cells. ► This has resulted in a small number of zinc-selective fluorescent sensors. ► Despite this development, almost all sensors developed suffer from competitive bindings. ► Recently, we have devised a series of rigid calix[4]arene derivatives. ► This paper focuses on the complexation reactions of one derivative and its fluorescent properties.