Chemistry:Chloroosmic acid
 Solution of chloroosmic acid
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| Names | |
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| IUPAC name
Dihydrogen hexachloroosmate(2-)
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Other names
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| EC Number |
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PubChem CID
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| Properties | |
| Cl6H2Os | |
| Molar mass | 404.95 g·mol−1 |
| Appearance | Reddish-purple or black crystalline solid.[1][2] Yields greenish yellow to reddish brown solutions[2][3] |
| Density | 5.3-5.65 g/cm3 (hexahydrate)[4] |
| Melting point | decomposes[1] |
| very soluble | |
| Solubility | Insoluble in organic solvents[2] |
| Hazards | |
| GHS pictograms |  
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| GHS Signal word | Danger |
| H301, H311, H314, H331 | |
| P260, P261, P262, P264, P264+265Script error: No such module "Preview warning".Category:GHS errors, P270, P271, P280, P301+316Script error: No such module "Preview warning".Category:GHS errors, P301+330+331, P302+352, P302+361+354Script error: No such module "Preview warning".Category:GHS errors, P304+340, P305+354+338Script error: No such module "Preview warning".Category:GHS errors, P316Script error: No such module "Preview warning".Category:GHS errors, P317Script error: No such module "Preview warning".Category:GHS errors, P321, P330, P361+364Script error: No such module "Preview warning".Category:GHS errors, P363, P403+233, P405, P501 | |
| Related compounds | |
Other anions
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Hexachloroplatinic acid |
Other cations
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Sodium hexachloroosmate, Potassium hexachloroosmate, Ammonium hexachloroosmate(IV) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Chloroosmic acid (also known as hexachloroosmic acid, and dihydrogen hexachloroosmate) is an inorganic chemical compound with the chemical formula H
2OsCl
6. It exists as a dark hygroscopic solid. It forms a hexahydrate.[5]
Synthesis
Hexachloroosmic acid can be prepared by reducing osmium tetroxide in hydrochloric acid with alcohol and heating.[3][6] Ferrous chloride is sometimes used in place of alcohol.[7]
- OsO
4 + 4FeCl
2 + 10HCl → H
2OsCl
6 + 4FeCl
3 + 4H
2O
Another way of preparing it is by dissolving osmium dioxide in hydrochloric acid.[8]
- OsO
2 + 6HCl → H
2OsCl
6 + 2H
2O[9]
It can also be prepared by reducing potassium osmate with hydrochloric acid under heating.[2]
Properties
Solid crystals of hexachloroosmic acid have been described as reddish-purple in color,[2] while commercial vendors describe it as black.[1][5] In solution, it exhibits colors ranging from yellowish green to reddish brown.[6][3][2] Owing to its highly hygroscopic nature, solutions of hexachloroosmic acid can be evaporated down to a syrup without crystallization.[3] As an acid, it is corrosive.
Reactions
When strong alkali is added to hexachloroosmic acid, it decomposes and precipitates osmium dioxide.[8][6]
It also reacts with alkali chlorides to yield hexachloroosmate salts, such as ammonium hexachloroosmate(IV).[3]
The coordination complex [H(DMSO)
2]
2(OsCl
6) can be made by reacting chloroosmic acid in ethanol with dimethyl sulfoxide.[10]
References
- ↑ 1.0 1.1 1.2 "Dihydrogen Hexachloroosmate(IV) Hydrate". American Elements. https://www.americanelements.com/dihydrogen-hexachloroosmate-iv-hydrate-27057-71-2.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Chiririwa, Haleden; Muzenda, Edison (November 2014). "The Preparation and Characterisation of Osmium (IV), Osmium (II), and Osmium (0) Complexes from Refinery Materials". International Conference on Chemical Engineering & Advanced Computational Technologies: 32–33. https://iieng.org/images/proceedings_pdf/9367E1114015.pdf. Retrieved 19 June 2025.
- ↑ 3.0 3.1 3.2 3.3 3.4 Gilchrist, Raleigh (June 8, 1932). "A new determination of the atomic weight of Osmium". Bureau of Standards Journal of Research 9 (3): 279–290. doi:10.6028/jres.009.021. https://nvlpubs.nist.gov/nistpubs/jres/9/jresv9n3p279_A2b.pdf. Retrieved 19 June 2025.
- ↑ "Dihydrogen hexachloroosmate (IV) hexahydrate". Cymit Quimica. https://cymitquimica.com/products/08-93-7610/27057-71-2/dihydrogen-hexachloroosmateiv-hexahydrate/?srsltid=AfmBOorgEDza0nmsmnqnHbqe-e6NAD5r-GS314M-uBas3GLlrtyp1zIq.
- ↑ 5.0 5.1 "Dihydrogen hexachloroosmate (IV) hexahydrate". Strem Catalog. https://www.strem.com/product/93-7610?srsltid=AfmBOoq_F-Mrg6was1qBb05_9W3q7TEgNAllUtfXYFCYLhqQO74Io8IC.
- ↑ 6.0 6.1 6.2 Gilchrist, Raleigh (1931). "A method for the separation and gravimetric determination of osmium". J Res Bur Stand 6 (3): 421–448. doi:10.6028/jres.006.028. https://nvlpubs.nist.gov/nistpubs/jres/6/jresv6n3p421_a2b.pdf. Retrieved 19 June 2025.
- ↑ Buckingham, D.A. (1961). Preparation and Oxidation-Reduction Potentials of Some Osmium Compounds (PhD thesis). Australian National University. p. 4.
- ↑ 8.0 8.1 Stopinski, Orin (September 1977). "Platinum-Group Metals". Environmental Health Effects Research Series (Washington, DC: Environmental Protection Agency): 85–86. https://nepis.epa.gov/Exe/ZyPDF.cgi/91013EPF.PDF?Dockey=91013EPF.PDF. Retrieved 19 June 2025.
- ↑ Sidgwick, N.V. (1950). The Elements and Their Compounds. 2. London: Oxford University Press. p. 1494. http://www.sciencemadness.org/library/books/the_chemical_elements_and_their_compounds_v2.pdf. Retrieved 20 November 2025.
- ↑ Rudnitskaya, O.V.; Kultyshkina, E.K.; Dobrokhotova, E.V.; Anan'ev I.V. (2014). "Synthesis and Structure of [H(DMSO)22[OsX6] (X=Cl, Br)"]. Russian Journal of Coordination Chemistry 20: 911-912. https://link.springer.com/article/10.1134/S1070328414120124. Retrieved 21 November 2025.
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