Study on the anion recognition properties of synthesized receptors (III): Convenient synthesis and anion recognition property of bisthiosernicarbazone derivative

A new series of bisthiosemicarbazone derivative receptors (1, 2 and 3) have been synthesized by simple steps in good yields. Their anion recognition properties were studied by UV-Vis and H-1 NNM spectroscopy. The result showed that the receptors 1, 2 and 3 all had a better selectivity to F-, CH3COO- and H2PO4-, but no evident binding with Cl-, Br-, I-, NO3- and HSO4-. Upon addition of the three anions to the receptors in DMSO, the solution acquired a color change from colorless to dark yellow that can be observed by the naked-eyes, thus the receptors can act as fluoride ion sensors even in the presence of other halide ions. The data showed that it was regular that the three receptors had different binding ability with the three anions. For the same anion, the association constants followed the trend: receptor 1 > 3 > 2. The UV-Vis data indicates that a 1 : 1 stoichiometry complex is formed through hydrogen bonding interactions between compound 1, 2 or 3 and anions.