Yttrium is generally not very interesting, but it's violurate is brightly yellow.
I dissolved about 0.5-0.7 g of violuric acid monohydrate (mine was freshly made and still wet so I don't know exactly, it's an excess of over 3:1 to
the yttrium used however) in 50 mL of boiling 95% ethanol - had some insoluble grey-brown stuff so I filtered that off. To that solution was added
about 0.25 g of YCl3 (it should be noted that YCl3 is very hygroscopic and mine was slightly wet so this amount is also lower
than I measured out here) in about 1 mL of water to the boiling ethanol solution while stirring. It turned yellow and after about a minute of strong
stirring and boiling the solution became turbid, it was boiled for five minutes longer and left to cool until luke warm. The yellow precipitate was
vacuum filtered off and washed with some 95% ethanol. The solution that passes through is slightly yellow and deposits only small amounts of
additional precipitate with more yttrium chloride solution. The solid was then air dried. Yield was about 0.166 g. (Because this was all done a bit
sloppy I didn't bother to calculate a % yield.)
The product is of the composition [Y(Vio)2(H2O)2]Vio · 6 H2O where HVio is violuric acid.
The preparation comes from Gad, A. A. M., Farag, I. S. A., & Awadallah, R. M. (1992). Synthesis and Characterisation of Scandium (III)-, Yttrium
(III)-, and Lanthanum (III) Violurate Complexes. Crystal Research and Technology, 27(2), 201–210. doi:10.1002/crat.2170270210
[Edited on 2-4-2021 by Diachrynic] |