Spectroscopic and electrochemical studies of selected lanthanides and actinides in concentrated aqueous carbonate and carbonate-hydroxide solutions and in molten dimethyl sulfone
Electrochemical and spectroscopic studies of neptunium, plutonium, americium, californium, and terbium in concentrated aqueous carbonate and carbonate-hydroxide solutions have been carried out. Changes in the absorption spectra of Np(VII), Np(V), Pu(VI), Pu(V), Am(VI), and Am(V) in concentrated Na/sub 2/CO/sub 3/ solution and in the formal potentials of the Np(VI)/Np(V) and Pu(VI)/Pu(V) couples as a function of pH were observed. Heptavalent neptunium in concentrated Na/sub 2/CO/sub 3/ solution could only be producted at pH values close to or greater than 14. Plutonium(VII) in 2 M Na/sub 2/CO/sub 3/ solution could only be produced at hydroxide ion concentrations in excess of about 2.5 M. The complexation of Np(VII) and Pu(VII) in Na/sub 2/CO/sub 3/-NaOH solution seems to be mainly by hydroxide ions. Neptunium(IV) and plutonium(IV) are insoluble in Na/sub 2/CO/sub 3/ solution above ca. pH 11-12. Neptunium(III) in carbonate solution is rapidly oxidized by water to Np(IV). Plutonium(III) is insoluble in Na/sub 2/CO/sub 3/ solution. In K/sub 2/CO/sub 3/ solution Pu(III) is stable to oxidation by water but is very sensitive to air oxidation. The redox properties of Cf(III) in Na/sub 2/CO/sub 3/ and K/sub 2/CO/sub 3/ solutions at pH values from 8 to 14 were investigated. The oxidation of terbium(III) in K/sub 2/CO/sub 3/-KOH solution was studied. Spectroscopic and electrochemical studies of cerium, samarium, europium, ytterbium, uranium, neptunium, plutonium, and americium in molten dimethyl sulfone (DMSO/sub 2/) at 400 K were performed. Differences in the DMSO/sub 2/ solution absorption spectra of trivalent Sm, Eu, and Yb and divalent Eu compared with those in aqueous solution were observed. Complexation effects on the spectra of Ce(III), Ce(IV), U(VI), Np(VI), Pu(VI), and Am(VI) are more noticeable in poorly coordinating DMSO/sub 2/ than they are in water. 123 references, 54 figures, 11 tables.
- Research Organization:
- Univ. of Tennessee, Knoxville, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AS05-76ER04447
- OSTI ID:
- 5993632
- Report Number(s):
- DOE/ER/04447-187; ON: DE85006381
- Resource Relation:
- Other Information: Portions are illegible in microfiche products. Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AMERICIUM COMPOUNDS
ABSORPTION SPECTRA
ELECTROCHEMISTRY
CALIFORNIUM COMPOUNDS
REDOX REACTIONS
CERIUM COMPOUNDS
EUROPIUM COMPOUNDS
NEPTUNIUM COMPOUNDS
COMPLEXOMETRY
RAMAN SPECTRA
SOLUBILITY
PLUTONIUM COMPOUNDS
SAMARIUM COMPOUNDS
TERBIUM COMPOUNDS
OXIDATION
URANIUM COMPOUNDS
YTTERBIUM COMPOUNDS
AQUEOUS SOLUTIONS
COMPARATIVE EVALUATIONS
EXPERIMENTAL DATA
HIGH TEMPERATURE
PH VALUE
POTASSIUM CARBONATES
SODIUM CARBONATES
SODIUM HYDROXIDES
SULFONES
ACTINIDE COMPOUNDS
ALKALI METAL COMPOUNDS
CARBON COMPOUNDS
CARBONATES
CHEMICAL REACTIONS
CHEMISTRY
DATA
DISPERSIONS
HYDROGEN COMPOUNDS
HYDROXIDES
INFORMATION
MIXTURES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
RARE EARTH COMPOUNDS
SODIUM COMPOUNDS
SOLUTIONS
SPECTRA
TRANSPLUTONIUM COMPOUNDS
TRANSURANIUM COMPOUNDS
400702* - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials
400201 - Chemical & Physicochemical Properties
400400 - Electrochemistry