University of Texas at El Paso
Trevor W. Hayton
Faculty Sponsor's Department(s):
Chemistry and Biochemistry
Uranium-Carbon Multiple Bonds
Separation of the minor actinides from the lanthanides possess a major problem within high-level nuclear waste separation. Traditionally separation of these elements is inefficient and relies on the use of toxic chemicals. The synthesis of new actinide-element bonds that feature a higher degree of covalency may provide the experimental data needed for designing chelators with greater selectivity for the actinides over their 4f congener. Unfortunately, a complete fundamental understanding of uranium-multiple linkages with other main-group elements has been obscured by limited examples of known molecules. The syntheses of actinides motifs featuring higher bond orders would provide varying electronic structures, allowing us to probe covalency by observing changes in 5f and 6d orbital participation. In particular, the synthesis of uranium-carbon multiple bonded molecules is of interest as the π character involved in these bonds is expected to yield a stronger covalent interaction. One of the synthetic routes we propose is the reaction of strained cyclopropenes (3,3-diphenylcyclopropene and bis(diisopropylamino)cyclopropenylidene) with tris((hexamethyldisilyl)amido)uranium(III), where the metal center is expected undergo two-electron oxidation by cleaving the highly strained cyclopropene ring, yielding a U=C bond. Such a case would represent the first “Schrock”-type carbene of the actinides, an interesting motif not yet elucidated, providing insight into covalency of high valent uranium-organic frameworks. The syntheses of these complexes will lay the foundation for using DFT computational studies to understand the degree of f and d orbital participation in U=C bonds.