Preparation of Uranium(III) Triflate in Tetrahydrofuran by Reduction of U(OTf)₄with Zinc amalgam

Abstract

In order to develop an alternative preparation method of uranium(III) precursors soluble in aprotic organic solvent used for the preparation of uranium(III) compounds, U(IV) triflate, U(OTf) 4, in tetrahydrofuran (THF) was reduced to produce uranium(III) triflate. U(OTf)4 in THF was completely reduced by large excess of zinc within 25 minutes. Energies and molar coefficients of the absorption bands of U(III) triflate are close to those of U(III) in 1M HCl aqueous solution especially in the range of (9 ∼ 14)×10 3 cm −1 . U(III) triflate solution maintains its oxidation state in THF is when it is contacted with zinc amalgam for more than a week.

Straightforward Reductive Routes to Air-Stable Uranium(III) and Neptunium(III) Materials

“…It has been shown that under inert air conditions aqueous solutions of U 3+ and Np 3+ can be produced electrochemically or by zinc amalgam . This technique was used to produce the hydrated trihalides, formate, a variety of sulfate complexes, and most recently the aquo triflate series. − The U 3+ sulfate complexes have the general formula AU(SO 4 ) 2 ·XH 2 O (A = NH 4 + , Na + , K + , Rb + , Cs + ) or U 2 (SO 4 ) 3 ·8H 2 O. These were synthesized under low-temperature inert-atmosphere conditions producing marginally air-stable products, and while the reflectance spectra and magnetic susceptibilities were reported, the only crystal structure published from all of these sulfate compounds is that of NH 4 U(SO 4 ) 2 ·4H 2 O .…”