Electrochemical Oxidation of Am(V) Ions in HNO₃Solutions

Electrochemical Oxidation of Am(III) and Am(V) Ions in HNO3 Solutions Containing Potassium Phosphotungstate K10P2W17O61

“…The procedures of electrochemical oxidation of Am(III) and Am(V) and spectrophotometric monitoring of various oxidation states of americium are presented elsewhere [7,8].…”

“…In [7,8] we studied electrochemical oxidation of Am(III) and Am(V). Additional studies and comprehensive analysis of experimental data suggested a new interpretation of the kinetics of electrochemical oxidation of Am(III), revealing common features and differences in the kinetics of Am(III) and Am(V) electrochemical oxidation.…”

Formal oxidation potentials of the Np(VI)-Np(V) couple and schemes of formal oxidation potentials of Np and am ions in HNO3 solutions containing potassium phosphotungstate K10P2W17O61

“…The formal oxidation potentials of the Am(IV)-Am(III) (E f 0 = 1.54 V) and Am(VI)-Am(V) (E f 0 = 1.55 V) couples were determined experimentally in our studies [12,13]. The Comparison of the schemes of the Np and Am potentials for the phosphotungstate solutions at pH 4.0, constructed previously [1], and for 1 M HNO 3 solutions containing KPW shows that, in both systems, the E f 0 values for respective couples vary in the same direction with close shifts of the potential shifts.…”

Synthesis and Structural Examination of Complexes of Am(IV) and Other Tetravalent Actinides with Lacunary Heteropolyanion α2-P2W17O6110−

“…The two main isomers of P 2 W 17 O 61 10− , α 1 and α 2 , differ by the site from which the [W(VI)O] 4+ group is removed. The complexation and redox properties of actinide complexes with P 2 W 17 O 61 10− heteropolyanions in solutions and in solids were studied in recent works. − Tetravalent actinides form extremely strong complexes both by electrostatic interaction of high-charge cations and anions and by 4-fold coordination of cations by oxygen atoms of lacuna. As a result, the redox potentials of An(IV)/An(III), An(V)/An(IV), and An(VI)/An(IV) pairs shift in such a way that tetravalent Np, Pu, Am, Cm, and Bk become much more stable than aqua ions relative to reduction, and U(IV) becomes much more stable relative to oxidation.…”