533. Ammonium Molybdate(VI)

Nomenclature

CAS number: 12027-67-7
Ammonium molybdate (Mo7O246) (6:1); hexaammonium molybdate (Mo7O246); ammonium heptamolybdate; ammonium paramolybdate.
H24Mo7N6O24; mol wt 1163.80.
H 2.08%, Mo 57.71%, N 7.22%, O 32.99%.
(NH4)6Mo7O24.

Description and references

Prepn and structure: Guiter, Compt. Rend. 220, 146 (1945); Lindqvist, Acta Chem. Scand. 2, 88 (1948). Toxicity studies: L. T. Fairhall et al., “The Toxicity of Molybdenum,” U.S. Public Health Service Bulletin No. 293, Washington D.C. (1945) 39 pp. Synthetic use as a catalyst in oxidation reactions: B. Sur et al., Synthesis 1985, 652; B. M. Choudary et al., Synlett 1994, 450; N. Ismail, R. N. Rao, Chem. Lett. 7, 844 (2000). Use in colorimetric determns: S. D. Carson, Anal. Biochem. 75, 472 (1976); M. M. Abdel-Khalek, M. S. Mahrous, Talanta 31, 635 (1984); T. Aman et al., Anal. Lett. 35, 1007 (2002); L. H. Marcolino-Junior et al., ibid. 38, 2315 (2005).

Properties

Colorless or slightly greenish or yellowish crystals. Sol in water. Practically insol in alcohol.

Derivative

Tetrahydrate.

Nomenclature

CAS number: 12054-85-2
H24Mo7N6O24.4H2O; mol wt 1235.86.
H 2.61%, Mo 54.34%, N 6.80%, O 36.25%.

Properties

Colorless or slightly greenish or yellowish crystals. Loses one water at 90°; dec 190°. Sol in 2.3 parts water. Practically insol in alcohol. pH of 5% aq soln 5.0 to 5.5.

Use

In photography and for decorating ceramics; chromogenic reagent in detection and determn of phosphates, arsenates, lead; also as a colorimetic reagent for alkaloids and many other substances. Oxidant in organic synthesis.