title: Selective Liquid Membrane Transport of Lead(II) by an Acyclic Polyether Dicarboxylic Acid Ionophore.
abstract: The effects of the chain structure and substitutents in six acyclic polyether dicarboxylic acids and one acyclic polyether carboxylic acid upon the efficiency and selectivity of pH-driven Pb(2+) transport in a bulk chloroform membrane system have been assessed. Among the carriers, 1,2-bis[2-(o-carboxyphenoxy)ethoxy]-4-tert-butylbenzene (1) is found to exhibit high selectivity for transport of Pb(2+) compared with alkali metal cations and a variety of other divalent metal ion species. Ionophore 1 also extracts Pb(2+) from aqueous solution into chloroform with the loss of two protons. A 1:1 complex of Pb(2+) with di-ionized 1 was isolated.
authors.affiliation: National Institute of Materials and Chemical Research, 1-1 Higashi, Tsukuba, Ibaraki 305, Japan, Department of Chemistry, Faculty of Science and Engineering, Saga University, 1 Honjo, Saga 840, Japan, and Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409.
authors.forename: K
authors.initials: K
authors.lastname: Hiratani
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: H
authors.initials: H
authors.lastname: Sugihara
authors.forename: K
authors.initials: K
authors.lastname: Kasuga
authors.forename: K
authors.initials: K
authors.lastname: Fujiwara
authors.forename: T
authors.initials: T
authors.lastname: Hayashita
authors.forename: R A
authors.initials: RA
authors.lastname: Bartsch