| Summary: | 碩士 === 國立中央大學 === 化學研究所 === 93 === Two N,N’-diphenylpyridine-2,6-dicarboxamide-based fluorescent chemosensors M1 and M2 were designed and synthesized for sensing anions. The binding affinity of M1 and M2 toward various anions was investigated by UV-Vis and fluorescence spectroscopy. Several anions were surveyed in this research, including hydrogen phosphate, pyrophosphate, halides, cyanide, nitrate, hydrogen sulfate and acetate. Notably, both M1 and M2 are particularly sensitive to anions with tetrahedron geometry, i.e. pyrophosphate and hydrogen phosphate. In general, binding constants of these two anions are higher than other anions with different geometries. The 1:1 binding ratio of the chemosensor-anion complex was determined by Job-plot. A blueshift in fluorescence spectra of M1 and M2 were observed upon titration of with fluoride, pyrophosphate and hydrogen phosphate. It is believed that blueshift was induced by raising the LUMO with the formation of hydrogen bonds between the anions and amide hydrogens.
In addition, M2 formed gel-like structure in certain solvents. Some tubular structures were constructed after solvent evaporation, which could be observed by microscopes. The study of the nature and properties of the gel is under progress.
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