In chemistry, the term stannate or tinnate refers to compounds of tin (Sn). Stannic acid (Sn(OH)4), the formal precursor to stannates, does not exist and is actually a hydrate of SnO2. The term is also used in naming conventions as a suffix; for example the hexachlorostannate ion is SnCl6(−2. In materials science, two kinds of tin oxyanions are distinguished:
orthostannates contain discrete SnO44− units (e.g. K4SnO4) or have a spinel structure (e.g. Mg2SnO4) metastannates with a stoichiometry MIISnO3, MI2SnO3 which may contain polymeric anions or may be sometimes better described as mixed oxides These materials are semiconductors.
Examples Barium stannate, BaSnO3 (a metastannate) Cobalt stannate, Co2SnO4, primary constituent of the pigment cerulean blue Dysprosium stannate, Dy2Sn2O7 Lead stannate, Pb2SnO4, "Type I" lead-tin yellow Potassium stannate, formally potassium hexahydroxostannate(IV), formula K2Sn(OH)6 Zinc Stannate, formula ZnSnO3, used as a flame retardant additive for polymers. Sodium stannate, formally sodium hexahydroxostannate(IV), formula Na2Sn(OH)6
See also Stannite Silicate
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