Actinide cation-cation complexes

Thesis/Dissertation · Thu Dec 01 04:00:00 EST 1994

DOI:https://doi.org/10.2172/34204· OSTI ID:34204

Stoyer, Nancy Jane ^[1]

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1. Univ. of California, Berkeley, CA (United States)

The +5 oxidation state of U, Np, Pu, and Am is a linear dioxo cation (AnO₂⁺) with a formal charge of +1. These cations form complexes with a variety of other cations, including actinide cations. Other oxidation states of actinides do not form these cation-cation complexes with any cation other than AnO₂⁺; therefore, cation-cation complexes indicate something unique about AnO₂⁺ cations compared to actinide cations in general. The first cation-cation complex, NpO₂⁺•UO₂²⁺, was reported by Sullivan, Hindman, and Zielen in 1961. Of the four actinides that form AnO₂⁺ species, the cation-cation complexes of NpO₂⁺ have been studied most extensively while the other actinides have not. The only PuO₂⁺ cation-cation complexes that have been studied are with Fe³⁺ and Cr³⁺ and neither one has had its equilibrium constant measured. Actinides have small molar absorptivities and cation-cation complexes have small equilibrium constants; therefore, to overcome these obstacles a sensitive technique is required. Spectroscopic techniques are used most often to study cation-cation complexes. Laser-Induced Photacoustic Spectroscopy equilibrium constants for the complexes NpO₂⁺•UO₂²⁺, NpO₂⁺•Th⁴⁺, PuO₂⁺•UO₂²⁺, and PuO₂⁺•Th⁴⁺ at an ionic strength of 6 M using LIPAS are 2.4 ± 0.2, 1.8 ± 0.9, 2.2 ± 1.5, and ~0.8 M^-1.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE; Department of Education
• DOE Contract Number: AC03-76SF00098; W-7405-ENG-48
• OSTI ID: 34204
• Report Number(s): LBL--36455; ON: DE95008491; CNN: Department of Education Fellowship Grant P200A10143
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CHEMICAL PROPERTIES
NEPTUNIUM COMPLEXES
PLUTONIUM COMPLEXES
STABILITY
URANYL COMPLEXES