Synthesis Of Amides Probes And Their Application In The Detection Of Hg(Ⅱ)

As a typical heavy metal, Mercury has been known as a toxic metal since antiquity. To monitor and prevent mercury pollution, efforts are being made worldwide to develop new mercury detecting strategies for monitoring mercuric ion from the environment and biological samples, now several techniques are available. Fluorescent molecular sensing has attracted much attention over the years for its many inherent merits including high specificity and high sensitivity. As a link of material science and analysis chemistry, the study in fluorescent sensor and novel sensor material has received a growing attention with the rapid development of cross subject. This technology has been widely used for the real-time in situ detection of the molecular events both in the environmental chemical, analytic chemistry, and bio-medicinal science. The fluorescence intensities of common probes (both fluorescence quenching and fluorescence enhancement) are influenced by experimental factors such as photobleaching, excitation intensity, the micro-environment around the dye, and the concentration of the dye. The new probes based on the mechanism of charge transfer (CT) can normalize the variation of these effects and provide more robust and precise measurement results. In this work, the design, synthesis, and photophysical properties of six amide receptor fluorescent molecular sensors are presented. Moreover, sensing properties are also investigated. The results are shown as follows:1. A series of novel fluorescent probes for metal ions with amide receptor are designed and synthesized. A supramolecular complex has been synthesized under hydrothermal condition. This complex shows photoluminescence property indicating that it may be applied in the development of luminescent materials.2. The influence of concentration and pH value is investigated. On this basis, we find a new probe (compound 2) based on the mechanism of photoinduced electron transfer (PET) can be used to indicate Hg (â…¡) for its "ON-OFF" property. We also get another two new probes for their red-shift in fluorescence-emission after adding the Hg (â…¡).3. The amide receptor derived from 1,4-benzenedicarbonyl chloride and N-phenyl-o-phenylenediamine (compound 5) and another amide receptor derived from benzene-1,3,5-tricarbonyl chloride and N-phenyl-o-phenylenediamine (compound 6) could be used to specifically bind Hg2+ ion in acetonitrile solution by an amide deprotonation mechanism. We find these new fluorescent probes sense Hg (II) by means of a spctrofluorometer with a large red-shift in emission (blue to green). Investigated results revealed that only Hg (II) can significantly be discerned.