12molybdophosphates

12-Molybdophosphoric acid, commonly referred to as 12-molybdophosphoric acid or simply 12-molybdophosphate, is a polyoxometalate compound with the chemical formula H₃PMo₁₂O₄₀·nH₂O. It belongs to the family of heteropoly acids, which are composed of a central heteroatom (in this case, phosphorus) surrounded by a framework of molybdenum-oxygen clusters. This compound is notable for its well-defined structure and diverse applications in chemistry and materials science.

The structure of 12-molybdophosphoric acid consists of a central phosphorus atom bonded to 12 molybdenum atoms, forming a nearly spherical Keggin-type polyoxometalate. The acid form is highly soluble in water and polar solvents, allowing it to dissociate into its constituent ions. Its protonated form, often denoted as [PMo₁₂O₄₀]³⁻, is a strong Brønsted acid and exhibits catalytic properties in various organic reactions.

12-Molybdophosphoric acid is widely used as a catalyst in organic synthesis, particularly in oxidation reactions, such as the selective oxidation of alcohols to aldehydes or ketones. It can also function as a homogeneous or heterogeneous catalyst when immobilized on solid supports. Additionally, it plays a role in analytical chemistry as a reagent for the detection and quantification of certain metal ions, such as cerium, due to its ability to form colored complexes.

In materials science, 12-molybdophosphoric acid is explored for its potential in the synthesis of metal-organic frameworks (MOFs), hybrid materials, and porous structures. Its acidic properties and ability to coordinate with metal ions make it useful in the construction of functionalized materials for applications like catalysis, gas storage, and separation processes.

The compound is typically prepared by reacting phosphoric acid with molybdenum trioxide in aqueous solution, followed by acidification to yield the desired polyoxometalate. Its stability and tunable properties continue to make it a subject of interest in both fundamental research and industrial applications.