The Reduction of Ytterbium (III) to Ytterbium (II)

If Yb(III) could be reduced to the highly unstable Yb(II), and temporarily stabilized, the separation of Yb from the other lanthanide elements could be facilitated. This facilitation would be based upon the considerably different chemistry of Yb(II) from the trivalent forms of all other lanthanides.

The reduction of Yb(III) to Yb(II) using Mg was attempted in various media. The effects of the media, precipitating agent, and environment were examined. The best experimental conditions for the reduction of Yb(III) to Yb(II) and the subsequent precipitation of YbSO4 were found to be the addition of ~0.35 g YbCl38H2O in 1.5 mL 3:1 ethanol:dioxane and 0.05 mL 17.4 M acetic acid to 0.15 g tetramethylammonium sulfate and ~0.20 g of 50 mesh Mg powder under nitrogen and over ice. Under these conditions, a maximum of 85% of the Yb(II) could be removed from the system.