tetraoxoosmateVI

Tetraoxoosmate(VI) refers to the chemical species containing osmium in its +6 oxidation state bonded to four oxygen atoms. The most common and well-characterized form is the osmate(VI) anion, [OsO4]2-. This anion typically exists in aqueous solutions and is a derivative of osmium tetroxide, OsO4. Osmium tetroxide itself is a volatile, crystalline solid with a high melting point and is known for its toxicity. When osmium tetroxide reacts with bases, such as hydroxide ions, it forms the tetraoxoosmate(VI) anion.

The tetraoxoosmate(VI) anion is a strong oxidizing agent, similar to other osmium species. Its color in solution can vary depending on the counterion and concentration, but it is often described as yellow or orange. It plays a role in certain chemical reactions, particularly in osmium-catalyzed oxidation processes, where it can act as an intermediate or a reagent. The stability of the tetraoxoosmate(VI) ion is dependent on the pH of the solution. In acidic conditions, it can be further oxidized or disproportionate. Its synthesis and handling require care due to the potential toxicity of osmium compounds.