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

Studies of trivalent uranium (U3+) and neptunium (Np3+) are restricted by the tendency of these ions to oxidize
in the presence of air and water, requiring manipulations to be carried
out in inert conditions to produce trivalent products. While the organometallic
and high-temperature reduction chemistry of U3+ and, to
a much smaller extent, Np3+ has been explored, the study
of the oxoanion chemistry of these species has been limited despite
their interesting optical and magnetic properties. We report the synthesis
of U3+ and Np3+ sulfates by utilizing zinc amalgam
as an in situ reductant with absolutely no regard
to the exclusion of O2 or water. By employing this method
we have developed a family of alkali metal U3+ and Np3+ sulfates that are air and water stable. The structures,
electronic spectra, and magnetic behavior are reported.