標題: A specific and ratiometric chemosensor for Hg(2+) based on triazole coupled ortho-methoxyphenylazocalix[4]arene
作者: Wang, Nae-Jen
Sun, Chung-Ming
Chung, Wen-Sheng
應用化學系
Department of Applied Chemistry
公開日期: 21-Oct-2011
摘要: Calix[4]arene 3, which contains two distal triazole groups on the lower rim and two distal o-methoxyphenylazo groups on the upper rim, was synthesized and found to be a specific and ratiometric sensor for Hg(2+) in a polar protic solvent. A series of o-methoxyphenylazo derivatives (3, 4, 5, 7, and 9) were synthesized, which proved that the lower-rim triazoles and the hydroxyl azophenol(s) were the major ligands for metal ion binding. Though analogues 4 and 10 showed some sensitivity for Hg(2+), compound 3 was the only ratiometric chemosensor for Hg(2+) among the series of azocalix[4]arenes synthesized in this work. The formation of 3. Hg(2+) complex was supported by UV/vis and NMR titration studies and Mass spectrometry. Based on the symmetrical features of NMR spectra of 3 center dot Hg(2+), the complex is believed to be symmetrical with respect to the calix[4]arene cavity. Furthermore, the complex was determined to be 1:1 binding stoichiometry by Job's plot, and the association constant was determined to be 4.02 x 10(3) M(-1) using Benesi-Hildebrand plot. (C) 2011 Elsevier Ltd. All rights reserved.
URI: http://dx.doi.org/10.1016/j.tet.2011.08.052
http://hdl.handle.net/11536/18629
ISSN: 0040-4020
DOI: 10.1016/j.tet.2011.08.052
期刊: TETRAHEDRON
Volume: 67
Issue: 42
起始頁: 8131
結束頁: 8139
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