title: Voltage-Controlled Fluorometry of the Transfer of Nonfluorescent Ions across the 1,2-Dichloroethane/Water Interface Using Fluorescent Ionophores.
abstract: The voltage-driven transfer of alkali and alkaline-earth metal ions across the polarized 1,2-dichloroethane (DCE)/water interface has been measured fluorometrically by using two fluorescent ionophores, coumarin 153-linked monoaza-15-crown-5 (C153-crown(O(4))) and two-coumarin 153-linked diaza-18-crown-6 ((C153)(2)-K(22)). The 1:1 complex formation prevails for both monovalent and divalent ion transfer, when the concentration of C153-crown(O(4)) in DCE is at the micromolar level. In the Mg(2+) ion transfer, the formation of the 1:2 (metal-ligand) complex becomes significant at the millimolar level of C153-crown(O(4)). C153-crown(O(4)) seems to adsorb at the interface. The complexation of Ba(2+) with (C153)(2)-K(22) is significantly slower than the complexation with C153-crown(O(4)).
authors.affiliation: Department of Physical Chemistry, Yokohama National University, Yokohama 240, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kakiuchi
authors.forename: K
authors.initials: K
authors.lastname: Ono
authors.forename: Y
authors.initials: Y
authors.lastname: Takasu
authors.forename: J
authors.initials: J
authors.lastname: Bourson
authors.forename: B
authors.initials: B
authors.lastname: Valeur