Uranium(III) Complexes with Bulky Aryloxide Ligands Featuring Metal–Arene Interactions and Their Reactivity Toward Nitrous Oxide

We report the synthesis and use of
an easy-to-prepare, bulky, and robust aryloxide ligand starting from
inexpensive precursor materials. Based on this aryloxide ligand, two
reactive, coordinatively unsaturated U­(III) complexes were prepared
that are masked by a metal–arene interaction via δ-backbonding. Depending on solvent and uranium starting material,
both a tetrahydrofuran (THF)-bound and Lewis-base-free U­(III) precursor
can easily be prepared on the multigram scale. The reaction of these
trivalent uranium species with nitrous oxide, N2O, was
studied and an X-ray diffraction (XRD) study on single crystals of
the product revealed the formation of a five-coordinate U­(V) oxo complex
with two different molecular geometries, namely, square pyramidal
and trigonal bipyramidal.