First uranium(IV) triflates

Controlled Chemical Reduction of Uranyl Salts into UX4(MeCN)4 (X = Cl, Br, I) with Me3SiX Reagents

“…[24] UO 2 (OTf) 2 is a more accessible precursor than the iodide counterpart and access to the UX 4 (MeCN) 4 compounds directly from UO 2 (OTf) 2 would be a much more convenient route. [14] In agreement with previous observations on the distinct reactivities of analogous halide and triflate metal www.eurjic.org compounds, [14][15][16]18,19] reactions of UO 2 (OTf) 2 with Me 3 SiX in acetonitrile at 20°C were slower than those of UO 2 I 2 and required heating to go to completion. Whereas UO 2 (OTf) 2 was inert towards an excess of Me 3 SiCl in acetonitrile at 100°C, its treatment under the same conditions with Me 3 SiX led to the formation of UX 4 (MeCN) 4 (X = Br, I) and the successful preparation of tetrabromide 2, which was isolated in 72 % yield.…”

“…Here we report the reduction of UO 2 I 2 (thf) 3 [14] or UO 2 (OTf) 2 [15] with Me 3 SiX (X = Cl, Br, I) in acetonitrile, which provides a novel and convenient synthetic route to tetrahalides UX 4 -(MeCN) 4 . These reactions, which involve deoxygenation, halide exchange and reduction processes, are much influenced by the nature of the solvent, the Me 3 SiX reagent and the uranyl salt.…”

Combining theoretical chemistry and XANES multi-edge experiments to probe actinide valence states

“…(ii) UO 2 I 2 (py) 3 has been synthesized and characterized by X-ray diffraction by Berthet et al [11]. The uranium atom is found in the classical pentagonal bipyramidal configuration with the linear UO 2 fragment perpendicular to the equatorial plan defined by the three nitrogen atoms of the pyridine ligands and two non-adjacent iodide groups.…”

Isolation of a Uranyl [UO2]+ Species: Crystallographic Comparison of the Dioxouranium(V) and (VI) Compounds [UO2(OPPh3)4](OTf)n (n=1, 2)

“…In this context, the isolation of a pentavalent uranyl derivative, and the comparison of its crystal structure with that of its [UO 2 ] 2+ parent compound are highly desirable.In the course of our studies on the synthesis and structure of anhydrous uranyl triflate compounds, [10] Figure 1. The geometrical parameters are classical of hexavalent uranyl complexes; the linear {UO 2 } fragment is perpendicular to the equatorial plane defined by the uranium center and the four oxygen atoms of the OPPh 3 ligands.…”