Recent Advances in Lanthanide-Containing Polyoxotungstates

The area of lanthanide-containing polyoxometalates has been a field of large interest for several years due to the interesting structural and physicochemical properties of such compounds. This chemistry is dominated by tungsten based POMs, as a large number of vacant (lacunary) polytungstate precursors is known (as opposed to vanadium or molybdenum based POMs). The main subclasses in this field are lanthanide-containing iso- and hetero-polytungstates. The number of examples in the latter class is significantly larger than the former, probably because more lacunary hetero- than iso-polytungstates are known. Here we report on recent examples of lanthanide-containing iso- and hetero-polytungstates with a focus on synthetic and in particular structural aspects. The compounds discussed include discrete molecular species as well as 1-, 2- and 3-D solid-state assemblies.