Uranium nitride compounds have been implicated in dinitrogen fixation, N-atom transfer catalysis, and are proposed as advanced fuels in generation IV nuclear reactors. The chemistry of uranium nitride complexes is less developed than that of transition metals, but the highly polarizing nature of uranium, its large ionic radius, and f electrons that can interact with the ligands could allow new types of transformations. Recently, a bimetallic U4+ nitride complex supported by the tris(tertbutoxy)siloxide ligand, [Cs{((ButO)3SiO)3U}2(µ-N)], was reported to activate CO2, CO, and H2 to yield complexes of dicarbamate (N(CO2)2)3−, cyanide CN−, and an imide hydride complex, respectively; the H2 reactivity is reversible. Further, reduction of [Cs{((ButO)3SiO)3U}2(µ-N)] with excess KC8 generated for the first time an isolable U3+ nitride complex, K3[{((tBuO)3SiO)3U}2(μ-N)], which reduces N2 to its tetraanion (N2)4− and facilitates its subsequent functionalization. The results to be presented describe the preparation of new uranium nitride complexes including those of U3+ since K3[{((tBuO)3SiO)3U}2(μ-N)] is the only example known to date. Specifically, syntheses of complexes with amide ligands will be presented and comparisons of small molecule and reduction reactivity between complexes of amide and siloxide ligands will be made.

Tuning reactivity of nitride bridged uranium complexes with amide and siloxide ligands

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.