The chemistry of plutonium(VI) in aqueous carbonate solutions

Conference · Mon Jan 01 04:00:00 EST 1990

OSTI ID:6613846

Stout, B E; Choppin, G R ^[1]; Sullivan, J C ^[2]

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1. Florida State Univ., Tallahassee, FL (USA). Dept. of Chemistry
2. Argonne National Lab., IL (USA)

The dynamic behavior of carbonate ion as a ligand that interacts with the hexavalent actinyl ions of U, Np, and Pu has been examined by {sup 13}C NMR. The first order rate parameter that describes the exchange between bulk solution and bound carbonate decreases with increasing pH. At a pH of 10.0, 25{degree}C, the respective values of k for the U(VI), Np(VI) and Pu(VI) complexes are 27.1 {plus minus} 0.3, 64.7 {plus minus} 3.3 and 706 {plus minus} 29. The variation of k with temperature was used to calculate the values of {Delta}H{sup +} = 53 and 42 kJ/M; and {Delta}S{sup +} = {minus}40 and {minus}71 J/M-K for the uranyl and neptunyl systems, respectively. A plausible reaction scheme for the exchange reaction is considered. The influence of these slow carbonate exchange reactions on selected electron transfer reactions is noted. 19 refs., 4 figs., 2 tabs.

• Research Organization: Argonne National Lab., IL (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6613846
• Report Number(s): CONF-900802-10; ON: DE90017839
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ACTINIDE COMPLEXES
ACTINIDES
ACTIVATION ENERGY
AQUEOUS SOLUTIONS
CARBON COMPOUNDS
CARBONATES
CHEMICAL REACTIONS
COMPLEXES
DISPERSIONS
ELECTRON TRANSFER
ELEMENTS
ENERGY
LIGANDS
METALS
MIXTURES
NEPTUNIUM COMPLEXES
NMR SPECTRA
OXYGEN COMPOUNDS
PLUTONIUM
PLUTONIUM COMPLEXES
REAGENTS
SOLUTIONS
SPECTRA
TRANSURANIUM COMPLEXES
TRANSURANIUM ELEMENTS
URANIUM COMPLEXES