S. C. Lee, R. Izatt, Xian Zhang
May 28, 2001
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0
Influential Citations
19
Citations
Journal
Inorganica Chimica Acta
Abstract
Abstract Four 8-hydroxyquinoline-containing tetraazacrown ethers were studied for their potential application as highly selective Cu 2+ receptors. Equilibrium constants for complexation of these tetraazacrown ethers with H + , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ , Cd 2+ , and Pb 2+ were determined in aqueous solution at 25°C by potentiometry. The most stable complexes were formed with Cu 2+ . The UV–Vis spectra of two of the ligands were studied in the presence and absence of the metal ions. The Cu 2+ complexes exhibited unique absorption peaks at 655 nm in aqueous acetic acid buffer solution (pH 4.76). Thus, these systems demonstrated copper(II) ion selectivity. Three of the ligands showed both 1:1 and 1:2 complexation with Cu 2+ (L:Cu 2+ ). In competitive transport experiments using bulk liquid membranes, Cu 2+ was transported selectively from a mixture containing all of the above metal ions.