Applications of Coumarin Derivatives in the Heavy Metal Ions Sensing

• Main Authors: CHANG, WEI HSIN, 張維新
• Other Authors: Chen, Chao-Tsen
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/63510846199707419471

碩士 === 國立臺灣大學 === 化學研究所 === 91 === The objective of this thesis is to design and synthesize fluosensors 4-9, which consist of coumarin-based signal-transducing units and various recognition units. Structure features v.s. heavy metal selectivity will be discussed in details. Fluorosensor 4, which has no defined recognition site, displayed small fluorescence changes in the presence of 15 metal ions examined, whereas fluorosensor 5 having 15-monoazacrown-5 ether incorporated at the meta-position of benzoyl moiety showed tight binding with Ca2+, Ba2+, Cd2+, Pb2+ and displayed fluorescence enhancement. When the dipicolylamine recognition unit was introduced at the meta and para positions respectively, the corresponding fluorosensors 6, 7 bound Cd2+ and Zn2+ with high selectivity. Moreover, 12- and 26-fold fluorescence enhancement were observed for fluorosensors 6, 7 in acetonitrile upon addition of Cd2+ respectively. Selectivity towards metal ions remained the same in the case of fluorosensor 8, in which the ethylene unit intervened the benzoyl group and dipicolylamine, displaying 30-fold fluorescence enhancement for Cd2+, Zn2+ and Pb2+. Fluorosensor 9 containing the cyclen as recognition unit also bound Cd2+ with 30-fold fluorescence enhancement. Infrared and fluorescence spectroscopies in combination of nuclear magnetic resonance spectra indicated the carbonyl groups also involved in metal ions complexation. Single crystal structures of 6.Cd2+ and 9.Cd2+ further confirmed the role of the carbonyl groups and polyamine moiety in the complex structures.