Metal Recognition Behavior Study of Coumarin Containing Benzimidazole Moiety

• Main Authors: Chen, Jhih-Jung, 陳志榮
• Other Authors: Lin, Mei-Ching
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/9yfg6u

碩士 === 朝陽科技大學 === 應用化學系生化科技碩博士班 === 106 === In this research, a series of chemical sensor of the coumarin framework containing of benzimidazole unit was synthesized. We introduced electron donating group and electron withdrawing group on benzimidazole moiety to gain compounds B, T, NB. Compound N containing perimidine moiety was synthesized, too. The structures of compounds were confirmed by NMR, mass spectrometry. All the photophysical properties were characterized by UV-vis spectroscopy and fluorescence spectrophotometer. In the study of solvent effect, compound T presented excited state intramolecular proton transfer (ESIPT) property in polar protic solvent, which inhibit emission from keto form and cause a smaller Stokes shift. Metal recognition behaviors were performing in isopropanol or tetrahydrofuran media containing of water. Compounds B and T showed the recognition ability toward Cu2+ and Hg2+ ions. When the metal ion was added, the absorption intensity about 310 nm was decreased and the intensity at 400 nm was increased gradually. Also the fluorescence emission around 440 nm was inhibited; it results fluorescence-OFF when metal ions were existed. Compound NB was capable to recognize Cu2+ and Zn2+ through UV-vis absorption spectra. Job’s plot and titration experiment confirm the metal-ligand relationship of binding and the association constant Ks. B-Cu2+ presented with 2:1 binding ratio, Ks was found to be 3.41×109 M-2, B-Hg2+ showed a 1:1 stoichiometry, Ks was found to be 2.26×104 M-1.