Heteropolymetalate

In chemistry, the heteropolymetalates are a subset of the polyoxometalates, which consist of three or more transition metal oxyanions linked together by shared oxygen atoms to form a closed 3-dimensional molecular framework.

In contrast to isopolymetalates, which contain only one kind of metal atom, the heteropolymetalates contain differing main group oxyanions.

Many exceptions to these general statements exist, and the class of compounds includes hundreds of examples.

The Keggin ion for example is common to both molybdates and tungstates with diverse central heteroatoms.

This trend reflects the stabilizing influence of the tetrahedral oxyanion that "glues" together the transition metal oxo framework.

Heteropolymetalates:
K 5 [IMo 6 O 24 ]· n H 2 O
Ag 7 [PV 12 O 36 ]· n H 2 O
(NH 4 ) 4 [NiMo 6 O 24 H 6 ]·5H 2 O
K 3 [CrMo 6 O 24 H 6 ]· n H 2 O
(NH 4 ) 8 [CeMo 12 O 42 ]·8H 2 O
A polyoxovanadate (POV) of the species V 14 Sb 8 O 42 in the alpha form. The isomers differ by the position of the half-rings toward each other. This POVs can be linked e.g. by octahedrally coordinated nickel(II).
Dawson ion Dawson structure, [X 2 M 18 O 62 ] n −