Phosphomolybdic acid

Phosphomolybdic acid

Names
Other names Molybdophosphoric acid; dodecamolybdophosphoric acid
Identifiers
CAS Number	12026-57-2 (anhydrous)^Y 51429-74-4 (hydrate)^Y
3D model (JSmol)	Interactive image Interactive image
ChemSpider	9426978
ECHA InfoCard	100.031.544
EC Number	234-713-5
MeSH	Phosphomolybdic+acid
PubChem CID	11251951
UNII	RN225F04V1
InChI InChI=1S/12Mo.H3O4P.36O/c;;;;;;;;;;;;1-5(2,3)4;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;/h;;;;;;;;;;;;(H3,1,2,3,4);;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; Key: DHRLEVQXOMLTIM-UHFFFAOYSA-N
SMILES OP(=O)(O)O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O [Mo]18%21%24(O[Mo]%16%18%23(O[Mo]56(O1)(O[Mo]247(O[Mo]9%22(O[Mo]%12%13(O2)(O[Mo]3%11%14(O[Mo]%17%19(O[Mo](O3)(O4)(O5)([O++]67[P+]%15%20[O++]89[Mo]%10(O[Mo](O[Mo](O%10)(O%11)(O%12)([O++]%13%14%15)[O-])(O%16)(O%17)([O++]%18%19%20)[O-])(O%21)(O%22)[O-])[O-])(O%23)[O-])[O-])O)(O%24)[O-])[O-])O)[O-])O
Properties
Chemical formula	H3[PMo12O40]
Molar mass	1825.25 g/mol
Density	1.62 g/ml[1] (hydrate)
Melting point	79-90 °C[1]
Solubility in water	soluble
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Oxidiser[1] (hydrate)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is ^YN ?) Infobox references

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]

Bismuth phosphomolybdate catalyzes ammoxidation in the Sohio process.^[7]

See also

• Phosphotungstic acid
• Folin-Ciocalteu reagent

References

1. "Phosphomolybdic acid hydrate - Safety data sheet" (PDF). www.sigmaaldrich.com. 2016-07-18. Retrieved 2018-10-06.
2. 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.
7. "Sohio Acrylonitrile process". ACS Chemical Landmarks. Washington, DC: American Chemical Society. 2007. Retrieved 1 Aug 2024.