title: Stability order of the lanthanide chelates of two disubstituted 3-hydroxy-4H-pyran-4-ones in aqueous solution.
abstract: The stability constants of the 1:1 chelates formed by tervalent lanthanides with 2-bromo-3-hydroxy-6-(hydroxymethyl)-4H-pyran-4-one and 3-hydroxy-6-(hydroxymethyl)-2-iodo-4H-pyran-4-one were determined by spectrophotometric titration in aqueous potassium chloride solution at 25 degrees . The determinations were done at two different ionic strengths near 0.1 and the value at I = 0.1 was interpolated. The log beta(101) values of both complex series exhibit the same trend; the stability increases gradually with decrease in the ionic radius and shows a break at Gd and Lu.
authors.affiliation: Division of Analytical Chemistry, University of Helsinki, Vuorikatu 20, SF-00100 Helsinki, Finland.
authors.forename: R
authors.initials: R
authors.lastname: Petrola
authors.forename: P
authors.initials: P
authors.lastname: Lampen
authors.forename: S
authors.initials: S
authors.lastname: Lindroos