Abstract A novel Zn(Π) xanthone–crown ether complex ( 2 ) was synthesized and demonstrated to selectively detect HSO 4 - over other anions by fluorescence and UV–vis absorption spectroscopy. In contrast, xanthone–crown ether ( 1 ) did not show detectable affinity for all the anions examined.
Xanthone-crown ether (1) reacts with NaClO4, Mg(ClO4)2 and Al(ClO4)3 forming the one-dimensional chain dinuclear polymer [Na2·1·(ClO4)2] (2), the mononuclear complex [Mg·1·(H2O)2](ClO4)2 (3) and an interesting sandwich complex [Al·(1)2·(H2O)6](ClO4)3 (4) with different ratios of metal-to-ligand, respectively. The anion recognition experiment results show that the magnesium complex (3) is a good colorimetric and fluorescent detector for HSO4â with high sensitivity and selectivity.