Uranium(IV) Halide (F−, Cl−, Br−, and I−) Monoarene Complexes

The syntheses of four nearly isostructural uranium­(IV) monoarene complexes, supported by the arene anchored tris­(aryloxide) chelate, [(Ad,MeArO)3mes]3–, are reported. Oxidation of the uranium­(III) precursor [((Ad,MeArO)3mes)­U], 1, in the presence of tetrahydrofuran (THF) results in THF coordination and distortion of the equatorial coordination sphere to afford the uranium­(IV) η6-arene complexes, [((Ad,MeArO)3mes)­U­(X)­(THF)], 2–X–THF, (where X = F, Cl, Br, or I) as their THF adducts. The solvate-free trigonally ligated [((Ad,MeArO)3mes)­U­(F)], 2–F, was prepared and isolated in the absence of coordinating solvents for comparison.