INOR 540 |
| Understanding the molecular-level behavior of f-element compounds in near-neutral and alkaline solutions is essential for developing theoretical tools to predict solution behavior and separation efficiency in multi-metal, multi-ligand systems. This knowledge enables the development of innovative alkaline-based processes for spent nuclear fuel reprocessing. Adding H2O2 to alkaline solutions significantly alters the chemical and thermodynamic behavior of f-element compounds, including their oxidation state, coordination chemistry, and solubility. For example, small amounts of H2O2 rapidly reduces Pu(VI) to Pu(IV), forming a mixed-ligand complex in carbonate solutions. The first peroxo-carbonato Pu(IV) compound, Na8Pu2(O2)2(CO3)6•12H2O, with an architecture unprecedented among the 5f-elements, has been synthesized and structurally characterized. Peroxide can also undergo ligand-exchange reactions with Ln(III), and the resulting peroxo-carbonato complex has significantly lower solubility. We will report on the chemistry (structures and solution speciation) of +III and +IV f-element compounds in peroxide-carbonate solutions, and discuss experiments which revealed synergistic effects between Ln(III) and U(VI). |
|
Chemistry of Lanthanides and Actinides
2:00 PM-5:20 PM, Tuesday, August 21, 2007 BCEC -- 212, Oral
Division of Inorganic Chemistry |