Ammonium dimolybdate (ADM) is the inorganic compound with the formula (NH₄)₂Mo₂O₇. It is a white, water-soluble solid. ADM is an intermediate in the production of

molybdenum Molybdenum is a chemical element with the symbol Mo and atomic number 42 which is located in period 5 and group 6. The name is from Neo-Latin ''molybdaenum'', which is based on Ancient Greek ', meaning lead, since its ores were confused with le ...

compounds from its ores. Roasting typical ore produces crude molybdenum(VI) oxides, which can be extracted into aqueous

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogeno ...

, affording

ammonium molybdate Ammonium molybdate can refer to: *Ammonium orthomolybdate, (NH4)2MoO4 * Ammonium heptamolybdate, (NH4)6Mo7O24, usually encountered as the tetrahydrate *Ammonium phosphomolybdate Ammonium phosphomolybdate is the inorganic salt of phosphomolybdic ac ...

. Heating solutions of ammonium molybdate gives ADM. Upon heating, solid ammonium dimolybdate decomposes to

molybdenum trioxide Molybdenum trioxide describes a family of inorganic compounds with the formula MoO3(H2O)n where n = 0, 1, 2. These compounds are produced on the largest scale of any molybdenum compound. The anhydrous oxide is a precursor to molybdenum metal, a ...

: : (NH₄)₂Mo₂O₇ → 2 MoO₃ + 2 NH₃ + H₂O In terms of its chemical structure, the anion is a polymeric consisting of distorted octahedral Mo centers liked by tetrahedral molybdate centers. When prepared in the absence of water as its

tetrabutylammonium Tetrabutylammonium is a quaternary ammonium cation with the formula (C4H9)4sup>+. It is used in the research laboratory to prepare lipophilic salts of inorganic anions. Relative to tetraethylammonium derivatives, tetrabutylammonium salts are more ...

salt, dimolybdate adopts the centrosymmetric structure observed for dichromate.

References

{{Molybdates Molybdates