The Synthesis Of Zn²⁺ And ClO^- Chemosonsers And Its Applications

As a new analysis technique to detect trace pollution in water encironment, optical chemical sensor has been paid more attention to in recent years. Compared with the traditional methods, optical chemical sensor are more sensitive and selective, simple operation, low cost, can be used for online detection, etc. In this thesis two chemosensors were designed and synthesized to detect Zn²⁺ and hypochlorite (ClO^-). The photophysical and sensing properties of these complex for Zn²⁺ and hypochlorite have been investigated by the UV-Vis and emission spectra, and 1H NMR spectroscopy. Otherwise we also made test paper for there rapid detection.(1) A new fluorescent Zn²⁺ chemosensor (3) based on functionalized 8-hydroxylquinoline has been synthesized and characterized. Compound 3 shows weak fluorescence in CH3CN–HEPES buffer solution (50 mM, pH 7.2,v/v = 1:9), but the fluorescence is significantly enhanced upon binding to Zn²⁺ through a zinc(II)-catalyzed ester hydrolysis reaction to form a highly emissive zinc(II) complex. This suggests that 3 can be served as a typical―switch–on‖chemosensor with high selectivity for Zn²⁺ over other metal ions. Furthermore we prepared the test papers to detecting Zn²⁺ in practical application.(2) Designed and synthesised a sensitive phosphorescent chemosensor for selective detection of hypochlorite. Complex 1 is weakly emissive in solution at ambient temperature. When 1 reacts with ClO^-, however, the emission is remarkably enhanced, in which the oxime in L1 is oxidized to a carboxylic acid in L2. The produced complex exhibits bright orange-yellow luminescence. The selective and competitive experiments revealed that complex 1 shows high sensing selectivity and sensitivity for ClO^- over other reactive oxygenspecies (ROS) and metal ions. Also we prepared the test papers to detecting ClO^- in practical application.