Jm. Berg et al., PLUTONIUM(IV) MONONITRATE AND DINITRATE COMPLEX-FORMATION IN ACID-SOLUTIONS AS A FUNCTION OF IONIC-STRENGTH, Journal of radioanalytical and nuclear chemistry, 235(1-2), 1998, pp. 25-29
Titrations of Pu(IV) with HNO3 in a series of aqueous HClO4 solutions
ranging in ionic strength from 2 to 19 moral were followed using visib
le and near-infrared absorption spectrophotometry. The Pu 5f-5f spectr
a in the visible and near IR range change with complex formation. At e
ach ionic strength, a series of spectra were obtained by varying nitra
te concentration. Each series was deconvoluted into spectra of Pu4+(aq
), Pu(NO3)(3+) and Pu(NO3)(2)(2+) complexes, and simultaneously their
formation constants were determined. When corrected for the incomplete
dissociation of nitric acid, the ionic strength dependence of each fo
rmation constant can be described by two parameters, beta(0) and Delta
epsilon using the formulae of specific ion interaction theory.