Insights into the Electronic Structure of a U(IV) Amido and U(V) Imido Complex

Reaction of the N-heterocylic carbene ligand (i)PrIm (L-1) and lithium bis(trimethylsilyl)amide (TMSA) as a base with UCl4 resulted in U(IV) and U(V) complexes. Uranium's +V oxidation state in (HL1)(2)[U(V)(TMSI)Cl-5] (TMSI=trimethylsilylimido) (2) was confirmed by HERFD-XANES measurements. Solid state characterization by SC-XRD and geometry optimisation of [U(IV)(L-1)(2)(TMSA)Cl-3] (1) indicated a silylamido ligand mediated inverse trans influence (ITI). The ITI was examined regarding different metal oxidation states and was compared to transition metal analogues by theoretical calculations.

Automated summary

This study investigates the structure and properties of the reaction products of N-heterocyclic carbene ligand and lithium bis(trimethylsilyl)amide with UCl4 through experiments and theoretical calculations. It was found that silylamido ligand mediates an inverse trans influence (ITI). This study is important for understanding the manifestation of ITI in different metal oxidation states and its similarity to transition metals.