title: Highly silver ion selective fluorescence ionophore: fluorescent properties of polythiazaalkane derivatives bearing 8-(7-hydroxy-4-methyl)coumarinyl moiety in aqueous solution and in liquid-liquid extraction systems.
abstract: Two novel fluoroionophores, N-(7-hydroxy-4-methylcoumarin-8-ylmethyl)-3,9-dithia-6-azaundecane (1) and N-(7-hydroxy-4-methylcoumarin-8-ylmethyl)-3,9-dithia-6-azaundecane (2), were synthesized as fluorescence extractants for selective silver determination. The absorption and fluorescence spectra were measured in aqueous 1,4-dioxane solution (28 v/v%) in the absence and presence of silver ion, and their acid dissociation constants were determined from the pH-dependent spectral changes. In the liquid-liquid extraction of some metal ions from neutral aqueous solution into dichloromethane phase, compounds 1 and 2 exhibited excellent silver ion selectivity, and dramatic fluorescence spectral changes were observed in the dichloromethane solutions containing these compounds. The determination limit of 2 for silver ion was 2.0 x 10(-8) mol dm(-3) in the liquid-liquid extraction.
authors.affiliation: Department of Applied Chemistry, Faculty of Systems Engineering, Wakayama University, Sakaedani 930, Wakayama, Wakayama, 640-8510, Japan. skmt@sys.wakayama-u.ac.jp
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Sakamoto
authors.forename: Junichi
authors.initials: J
authors.lastname: Ishikawa
authors.forename: Hideji
authors.initials: H
authors.lastname: Osuga
authors.forename: Kunio
authors.initials: K
authors.lastname: Doi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Wada