This Is AuburnElectronic Theses and Dissertations

Crossroads and Terminations in Transuranium Chemistry




Bray, Travis

Type of Degree



Chemistry and Biochemistry


The focus of this dissertation is published results from my doctoral research at Auburn University, the scope of which is multifaceted. The first topic covers recent research devoted to developing a better understanding of the structural diversity and related physical properties of early actinide compounds containing either selenite or iodate. These studies are primarily driven by the presence of 79Se (t1/2 = 1.1 x 106) and 129I (t1/2 = 1.7 x 107), both of which are long-lived ? - emitting isotopes produced through the fission of 235U, in spent nuclear fuels. From the redox chemistry of selenium one would predict that it will exist as either the selenate (SeO42-) or the selenite (SeO32-) vi anion, while iodine is expected to be present as either the iodide anion, I-, or the iodate oxoanion (IO3-). The subject of my second research focus, phosphonates have been of special interest with regards to f – element chemistry as a result of their use in separations. Structural studies of these systems with transuranium elements have been limited due to the difficulties faced when working with these radioactive metals and their insolubility and tendency to form powders or microcrystalline precipitates. Topics include the structure-property relationships for the following published compounds or, in the case chapter 6, compound submitted for publication: Na2[UO2(IO3)4(H2O)] (Ch. 2: Bray, T. H.; et al., Inorg. Chem., 2006, 45, 8251-8257.), An(IO3)4 (An = Np, Pu) and Np(IO3)4·nH2O (Ch. 3: Bray, T. H.; et al., Inorg. Chem., 2007, 46, 3663-3668.), Pu(SeO3)2 (Ch. 4: Bray, T. H.; et al., J. Solid State Chem., 2008, 181, 493-498.), NpFPO4 and Cs2Np2F7PO4 (Ch. 5: Bray, T. H.; et al., J. Solid State Chem., 2007, 180, 70-74.), [C6H14N2][(UO2)4(HPO4)2PO4)2(H2O)]·H2O (Ch. 6: Bray, T. H.; et al., ?Synthesis and Structure of [C6H14N2][(UO2)4(HPO4)2(PO4)2(H2O)]·H2O: An Expanded Open-Framework Amine-Bearing Uranyl Phosphate,? In press: Journal of Solid State Chemistry April 24, 2008.), and Np(CH3PO3)(CH3PO3H)(NO3)(H2O)·H2O (Ch. 7: Bray, T. H.; et al., Inorg. Chem., 2007, 46, 10959-10961.)