In chemistry an antimonate is a compound which contains a metallic element, oxygen, and antimony in an oxidation state of +5. These compounds adopt polymeric structures with M-O-Sb linkages. They can be considered to be derivatives of the hypothetical antimonic acid , or combinations of metal oxides and antimony pentoxide, .
Historically these compounds were assumed to be analogous to the phosphates and formulas such as and were used and the compounds described as hydrated meta-antimonates and pyro-antimonates. It is now known that is actually , containing the anion, and that is actually . Wells A.F. (1984) Structural Inorganic Chemistry 5th edition, Oxford Science Publications
Nomenclature IUPAC recommendations are that compounds with anions containing antimony(V) have the antimonate(V) suffix or antimonate followed by a charge number, for example the ion would be called hexahydridoxidoantimonate(V) or alternatively hexahydroxidoantimonate(1−).Nomenclature of Inorganic Chemistry—IUPAC Recommendations 2005 Red Book 2005.pdf
Examples Some examples of antimonates and their structures are shown below: has a superstructure with isolated units. Sodium antimonate, , has the ilmenite structure, with hexagonal close packed oxide ions with each ion, and occupying a third of the octahedral sites. has the trirutile structure, which is similar to the rutile structure except that there are two different cations in the lattice. has the rutile structure with random occupancy. Lead antimonate, , Naples yellow, has the pyrochlore structure. Calcium antimonate, , has the weberite structure. Ferric ortho-antimonate, or , has the rutile structure with random occupancy.
See also Antimonate mineral Antimonide Antimonite
References