Metal-ion recognition. Competitive bulk membrane transport of transition and post transition metal ions using oxygen-nitrogen donor macrocycles as ionophores
J. Kim et al., Metal-ion recognition. Competitive bulk membrane transport of transition and post transition metal ions using oxygen-nitrogen donor macrocycles as ionophores, J CHEM S DA, (19), 2000, pp. 3453-3459
Citations number
67
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS
A series of competitive metal ion transport experiments have been performed
. Each involved transport from an aqueous source phase across a chloroform
membrane phase into an aqueous receiving phase. The source phase contained
equimolar concentrations of cobalt(II), nickel(II), copper(II), zinc(II), c
admium(II), silver(I) and lead(II) while the membrane phase incorporated an
ionophore chosen from a series of single-ring and double-ring macrocyclic
ligands (incorporating mixed oxygen-nitrogen donor sets) together with hexa
decanoic acid. The transport process was 'driven' by a back flux of protons
, maintained by buffering the source and receiving phases at pH 4.9 and 3.0
, respectively. Transport selectivity for copper(II) was observed in all ca
ses. The results confirm that consideration of the mass balance of the meta
l ions present across all three transport phases is important for a fuller
understanding of the nature of the discrimination process for the present s
ystems.