Evaluation of Tellurium as a Fuel Additive in Neodymium-Containing U-Zr Metallic Fuel.

Phase-stability in a U-Zr-Te-Nd multi-component metallic fuel for advanced nuclear reactors is systematically investigated by taking into account binary, ternary and quaternary interactions between elements involved. Historically, the onset of fuel-cladding chemical interactions (FCCI) greatly limits the burnup potential of U-Zr fuels primarily due to interactions between lanthanide fission products and cladding constituents. Tellurium (Te) is evaluated as a potential additive for U-Zr fuels to bind with lanthanide fission products, e.

Production of Gas-Phase Uranium Fluoroanions Via Solubilization of Uranium Oxides in the [1-Ethyl-3-Methylimidazolium][F(HF)] Ionic Liquid.

A new methodology for gas-phase uranium ion formation is described in which UO is dissolved in neat N-ethyl,N'-methylimidazolium fluorohydrogenate ionic liquid [EMIm][F(HF)], yielding a blue-green solution. The solution was diluted with acetonitrile and then analyzed by electrospray ionization mass spectrometry. UF (a U(V) species) was observed at m/z = 352, and other than cluster ions derived from the ionic liquid, nothing else was observed.

Iron Fluoroanions and Their Clusters by Electrospray Ionization of a Fluorinating Ionic Liquid.

Metal fluoroanions are of significant interest for fundamental structure and reactivity studies and for making isotope ratio measurements that are free from isobaric overlap. Iron fluoroanions [FeF(4)](-) and [FeF(3)](-) were generated by electrospray ionization of solutions of Fe(III) and Fe(II) with the fluorinating ionic liquid 1-ethyl-3-methylimidazolium fluorohydrogenate [EMIm](+)[F(HF)(2.3)](-).

Generation of gas-phase zirconium fluoroanions by electrospray of an ionic liquid.

Rationale: New approaches for forming anions are sought that have strong abundance and no isobaric overlap, attributes that are compatible with the measurement of isotope ratios. Fluoroanions are particularly attractive because fluorine is monoisotopic, and thus will not have overlapping isobars with the isotope of interest. Since many elements do not have positive electron affinity values, they do not form stable negative atomic ions, and hence are not compatible with isotope ratio measurement using high sensitivity isotope ratio mass spectrometers such as accelerator mass spectrometers.

Fluorohydrogenate cluster ions in the gas phase: electrospray ionization mass spectrometry of the [1-ethyl-3-methylimidazolium(+)][F(HF)2.3(-)] ionic liquid.

Electrospray ionization of the fluorohydrogenate ionic liquid [1-ethyl-3-methylimidazolium][F(HF)2.3] ionic liquid was conducted to understand the nature of the anionic species as they exist in the gas phase. Abundant fluorohydrogenate clusters were produced; however, the dominant anion in the clusters was [FHF(-)], and not the fluoride-bound HF dimers or trimers that are seen in solution.

Investigation of uranyl nitrate ion pairs complexed with amide ligands using electrospray ionization ion trap mass spectrometry and density functional theory.

Ion populations formed from electrospray of uranyl nitrate solutions containing different amides vary depending on ligand nucleophilicity and steric crowding at the metal center. The most abundant species were ion pair complexes having the general formula [UO(2)(NO(3))(amide)(n=2,3)](+); however, singly charged complexes containing the amide conjugate base and reduced uranyl UO(2)(+) were also formed as were several doubly charged species. The formamide experiment produced the greatest diversity of species resulting from weaker amide binding, leading to dissociation and subsequent solvent coordination or metal reduction.

Electronic structure studies on deprotonation of dithiophosphinic acids in water clusters.

We report herein a computational study of proton transfer reactions between dithiophosphinic acids (HAs) and water clusters using B3LYP and MP2 methods. The ground-state and transition-state structures of HA-(H(2)O)(n) (n = 1, 2, 3) cluster complexes have been calculated. The influence of water molecules on energy barrier heights of proton transfer reactions has been examined in the gas phase and solution for bis[o-(trifluoromethyl)phenyl]- and bis(2,4,4-trimethylpentyl)dithiophosphinic acids (HA1 and HA2, respectively).

Investigations of acidity and nucleophilicity of diphenyldithiophosphinate ligands using theory and gas-phase dissociation reactions.

Diphenyldithiophosphinate (DTP) ligands modified with electron-withdrawing trifluoromethyl (TFM) substitutents are of high interest because they have demonstrated potential for exceptional separation of Am (3+) from lanthanide (3+) cations. Specifically, the bis( ortho-TFM) (L 1 (-)) and ( ortho-TFM)( meta-TFM) (L 2 (-)) derivatives have shown excellent separation selectivity, while the bis( meta-TFM) (L 3 (-)) and unmodified DTP (L u (-)) did not. Factors responsible for selective coordination have been investigated using density functional theory (DFT) calculations in concert with competitive dissociation reactions in the gas phase.