Hexafluorostannates

Hexafluorostannates are a class of inorganic compounds with the general formula M2SnF6, where M is a monovalent cation, typically an alkali metal or ammonium. These compounds are salts derived from hexafluorostannic acid, H2SnF6. They are characterized by the presence of the hexacoordinate hexafluorostannate anion, [SnF6]2-. The tin atom in this anion is in the +4 oxidation state. Hexafluorostannates are often crystalline solids and can exhibit a range of colors depending on the specific cation and any potential impurities. Many are soluble in water, though solubility can vary significantly. They are generally synthesized by reacting tin(IV) compounds, such as tin(IV) oxide or tin(IV) chloride, with hydrofluoric acid and a source of the desired cation. For example, potassium hexafluorostannate (K2SnF6) can be prepared by reacting tin(IV) oxide with hydrofluoric acid in the presence of potassium hydroxide or potassium fluoride. Hexafluorostannates have found some limited applications in areas such as electroplating, as catalysts, and in the preparation of other fluorine-containing compounds. Some of these compounds may possess toxicological properties and should be handled with appropriate safety precautions.