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.