decavanadate

Decavanadate refers to the polyoxometalate anion [V10O28]6−, a high-nuclearity oxide cluster composed of ten vanadium centers linked by oxide bridges. In the parent species, all vanadium atoms are in the +5 oxidation state. The anion is a member of the vanadium oxide family of polyoxometalates and is typically isolated as salts with alkali or organic counterions. Its structure features multiple V–O–V linkages that create a compact, highly condensed inorganic framework.

In solution, decavanadate forms under conditions that promote condensation of smaller vanadate units and is sensitive to pH, concentration, and redox state. It can interconvert with other vanadate species as the solution conditions change, and it is often studied by techniques such as infrared, ultraviolet–visible spectroscopy, and NMR.

Redox chemistry is a notable aspect of decavanadate. The cluster can undergo stepwise reduction to various reduced forms, and these redox transitions are accessible electrochemically. The parent V(V) form is typically yellow or colorless, while reduced species can exhibit color changes, sometimes appearing blue, reflecting changes in the electronic structure of the cluster.

Applications and relevance in chemistry include its use as a catalyst and as a redox mediator in oxidation reactions and electrochemical contexts. Decavanadate serves as a model system for studying the behavior of large transition-metal oxometalate clusters, their interconversions, and their reactivity toward substrates or as components in materials chemistry. Preparation generally involves condensation of vanadate sources under controlled acidity to yield decavanadate salts with various counterions.