Ammonium hexachloroosmate(IV)

Ammonium hexachloroosmate(IV)

Names
IUPAC name Ammonium hexachloroosmate(IV)
Identifiers
CAS Number	12125-08-5
3D model (JSmol)	Interactive image
ChemSpider	145801
ECHA InfoCard	100.031.977
EC Number	235-188-5
PubChem CID	11729867
CompTox Dashboard (EPA)	DTXSID70923737
InChI InChI=1S/6ClH.2H3N.Os/h6*1H;2*1H3;/q;;;;;;;;+4/p-4 Key: SRBXXQDKBKTWOC-UHFFFAOYSA-J
SMILES [NH4+].[NH4+].Cl[Os-2](Cl)(Cl)(Cl)(Cl)Cl
Properties
Chemical formula	Cl6H8N2Os
Molar mass	439.01 g·mol^−1
Appearance	red crystals
Density	2.93 g/cm^3
Melting point	170
Solubility in water	poorly soluble
Hazards
GHS labelling:
Pictograms	[1]
Signal word	Warning
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Ammonium hexachloroosmate(IV) is an inorganic chemical compound with the chemical formula (NH₄)₂OsCl₆.^[2][3]

Synthesis

Ammonium hexachloroosmate(IV) can be produced by the reduction of osmium(VIII) oxide with iron dichloride in an acidic medium in the presence of ammonium ions:^[4][5]

OsO₄ + 4FeCl₂ + 8HCl + 2NH₄Cl → (NH₄)₂[OsCl₆] + 3FeCl₃ + 4H₂O

Physical properties

Ammonium hexachloroosmate(IV) forms dark red crystals of the cubic system,^[6] space group Fm3m, cell parameters a = 0.9729 nm, Z = 4.

It is poorly soluble in cold water.^[7]

Chemical properties

The compound is reduced by hydrogen to metallic osmium:^[8][9]

3(NH₄)₂[OsCl₆] → 3Os + 2N₂ + 16HCl + 2NH₄Cl

(NH₄)₂[OsCl₆] + 2H₂ → Os + NH₄Cl + 4HCl

Uses

The compound is used as a pharmaceutical, organic, and chemical intermediate.^[10]

References

1. "Ammonium hexachloroosmate(IV)". Sigma Aldrich. Retrieved 17 October 2024.
2. "Ammonium Hexachloroosmate". American Elements. Retrieved 17 October 2024.
3. Brauer, Georg (2 December 2012). Handbook of Preparative Inorganic Chemistry V2. Elsevier. p. 1603. ISBN 978-0-323-16129-9. Retrieved 17 October 2024.
4. Dwyer, F. P.; Hogarth, J. W.; Rhoda, Richard N. (January 1957). "Ammonium Hexachloroosmate(IV)". Inorganic Syntheses. Inorganic Syntheses. Vol. 5. pp. 206–207. doi:10.1002/9780470132364.ch60. ISBN 978-0-470-13164-0. Retrieved 17 October 2024.
5. Inorganic Syntheses, Volume 5. John Wiley & Sons. 22 September 2009. p. 206. ISBN 978-0-470-13268-5. Retrieved 17 October 2024.
6. Armarego, W. L. F. (27 August 2022). Purification of Laboratory Chemicals: Part 2 Inorganic Chemicals, Catalysts, Biochemicals, Physiologically Active Chemicals, Nanomaterials. Butterworth-Heinemann. p. 7. ISBN 978-0-323-95828-8. Retrieved 17 October 2024.
7. Haynes, William M. (19 April 2016). CRC Handbook of Chemistry and Physics, 94th Edition. CRC Press. p. 4-46. ISBN 978-1-4665-7115-0. Retrieved 17 October 2024.
8. Lay, Peter A.; Magnuson, Roy H.; Taube, Henry; Vassilian, Asbed (January 1986). "Pentaammineosmium(III) and Hexaammineosmium(III) Complexes". Inorganic Syntheses. Vol. 24. pp. 269–277. doi:10.1002/9780470132555.ch73. ISBN 978-0-471-83441-0. Retrieved 17 October 2024.
9. Meyer, Gerd; Möller, Angela (30 June 1991). "Thermolysis of ternary ammonium chlorides of rhenium and the noble metals". Journal of the Less Common Metals. 170 (2): 327–331. doi:10.1016/0022-5088(91)90336-3. ISSN 0022-5088. Retrieved 17 October 2024.
10. "Ammonium hexachloroosmate(IV), 99.9% (metals basis), Os 42.5% min, Thermo Scientific Chemicals". Fisher Scientific. Retrieved 17 October 2024.