Pyrovanadates
Pyrovanadates are a class of inorganic compounds containing the pyrovanadate anion, V2O7^4-. This anion is characterized by two vanadium atoms linked by an oxygen atom, with a total charge of -4. Pyrovanadates are typically formed from the dehydration of metavanadates or orthovanadates at elevated temperatures. The structure of the pyrovanadate anion can vary, exhibiting different bridging modes between the vanadium centers. Common examples of pyrovanadates include alkali metal pyrovanadates, such as sodium pyrovanadate (Na4V2O7) and potassium pyrovanadate (K4V2O7). These compounds are often found as crystalline solids. Their synthesis usually involves heating vanadate precursors or reacting vanadium oxides with alkali metal carbonates or hydroxides at high temperatures. Pyrovanadates have found applications in various fields. They can act as catalysts in chemical reactions, particularly in oxidation processes. Some pyrovanadates exhibit interesting magnetic or optical properties, making them candidates for materials science research. Additionally, they have been explored as components in ceramic formulations and as pigments. The chemistry of pyrovanadates is closely related to that of other polyoxovanadates, which represent a diverse family of vanadium-oxygen cluster anions.