Phosphomolybdic acid is the heteropolymetalate with the formula H3[Mo12PO40]·12H2O. It is a yellow solid, although even slightly impure samples have a greenish coloration. It is also known as dodeca molybdophosphoric acid or PMA, is a yellow-green chemical compound that is freely soluble in water and polar organic solvents such as ethanol. It is used as a stain in histology and in organic synthesis.[2]

Histology

Phosphomolybdic acid is a component of Masson's trichrome stain.[3]

Organic synthesis

Phosphomolybdic is used as a stain for developing thin-layer chromatography plates,[4] staining phenolics, hydrocarbon waxes, alkaloids, and steroids. Conjugated unsaturated compounds reduce PMA to molybdenum blue. The color intensifies with increasing number of double bonds in the molecule being stained.[5]

Phosphomolybdic acid is also occasionally used in acid-catalyzed reactions in organic synthesis. It has been shown to be a good catalyst for the Skraup reaction for the synthesis of substituted quinolines.[6]

See also


References

  1. ^ a b c "Phosphomolybdic acid hydrate - Safety data sheet" (PDF). www.sigmaaldrich.com. 2016-07-18. Retrieved 2018-10-06.
  2. ^ a b Dias, J. A.; Dias, S. C. L.; Caliman, E. (2014). "Keggin Structure Polyoxometalates". Inorganic Syntheses: Volume 36. Inorganic Syntheses. Vol. 36. p. 210-217. doi:10.1002/9781118744994.ch39. ISBN 9781118744994.
  3. ^ "Masson's Trichrome for Muscle and Collagen". StainsFile. Archived from the original on 2013-07-02. Retrieved 2018-10-06.
  4. ^ "Stains for Developing TLC Plates" (PDF). McMaster University.
  5. ^ Burstein, Shlomo (1953). "Reduction of Phosphomolybdic Acid by Compounds Possessing Conjugated Double Bonds". Analytical Chemistry. 25 (3): 422–424. doi:10.1021/ac60075a012. ISSN 0003-2700 – via ACS Publications.
  6. ^ Chaskar, Atul; Padalkar, Vikas; Phatangare, Kiran; et al. (2010). "Miceller-Mediated Phosphomolybdic Acid: Highly Effective Reusable Catalyst for Synthesis of Quinoline and Its Derivatives". Synthetic Communications. 40 (15): 2336–2340. doi:10.1080/00397910903245141. ISSN 0039-7911. S2CID 94978408 – via Taylor & Francis Online.