Expanding the Library of Uranyl Amide Derivatives: New Complexes Featuring the <i>tert</i>-Butyldimethylsilylamide Ligand

New uranyl derivatives featuring the amide ligand, −N­(SiHMe₂)^<i>t</i>Bu, were synthesized and characterized by X-ray crystallography, multinuclear NMR spectroscopy, and absorption spectroscopies. Steric properties of these complexes were also quantified using the computational program Solid-G. The increased basicity of the free ligand −N­(SiHMe₂)^<i>t</i>Bu was demonstrated by direct comparison to −N­(SiMe₃)₂, a popular supporting ligand for uranyl. Substitutional lability on a uranyl center was also demonstrated by exchange with the −N­(SiMe₃)₂ ligand. The increased basicity of this ligand and diverse characterization handles discussed here will make these compounds useful synthons for future reactivity

Spectroscopic and Structural Elucidation of Uranium Dioxophenoxazine Complexes

Uranium derivatives of a redox-active, dioxophenoxazine ligand, (DOPO^q)₂UO₂, (DOPO^sq)­UI₂(THF)₂, (DOPO^cat)­UI­(THF)₂, and Cp*U­(DOPO^cat)­(THF)₂ (DOPO = 2,4,6,8-tetra-<i>tert</i>-butyl-1-oxo-1<i>H</i>-phenoxazin-9-olate), have been synthesized from U­(VI) and U­(III) starting materials. Full characterization of these species show uranium complexes bearing ligands in three different oxidation states. The electronic structures of these complexes have been explored using ¹H NMR and electronic absorption spectroscopies, and where possible, X-ray crystallography and SQUID magnetometry