Ammonium hexachloroplatinate

Ammonium hexachloroplatinate
Names
	IUPAC name Ammonium hexachloroplatinate(IV)
	Other names ammonium chloroplatinate
Identifiers
CAS Number	16919-58-7 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:59604 ;
ChemSpider	10628022 ;
ECHA InfoCard	100.037.233
CompTox Dashboard (EPA)	DTXSID10893445 ;
	InChI InChI=1S/6ClH.2H3N.Pt/h61H;21H3;/q;;;;;;;;+4/p-4 Key: PCCGQTHFYHJATL-UHFFFAOYSA-J ; InChI=1/6ClH.2H3N.Pt/h61H;21H3;/q;;;;;;;;+4/p-4/rCl6Pt.2H3N/c1-7(2,3,4,5)6;;/h;2*1H3/q-2;;/p+2 Key: PCCGQTHFYHJATL-WPAIPAOFAY;
	SMILES [NH4+].[NH4+].Cl[Pt-2](Cl)(Cl)(Cl)(Cl)Cl;
Properties
Chemical formula	(NH4)2PtCl6
Molar mass	443.87 g/mol
Appearance	yellow crystals
Odor	odorless
Density	3.065 g/cm3
Melting point	380 °C (716 °F; 653 K) decomposes
Solubility in water	0.289 g/100ml (0 °C); 0.7 g/100ml (15 °C); 0.499 g/100ml (20 °C); 3.36 g/100ml (100 °C)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Ammonium hexachloroplatinate, also known as ammonium chloroplatinate, is the inorganic compound with the formula (NH₄)₂[PtCl₆]. It is a rare example of a soluble platinum(IV) salt that is not hygroscopic. It forms intensely yellow solutions in water. In the presence of 1M NH₄Cl, its solubility is only 0.0028 g/100 mL.

Preparation and structure

The compound consists of separate tetrahedral ammonium cations and octahedral [PtCl₆]²⁻ anions. It is usually generated as a fine yellow precipitate by treating a solution of hexachloroplatinic acid with a solution of an ammonium salt.^[2] The complex is so poorly soluble that this step is employed in the isolation of platinum from ores and recycled residues.^[3]

As analyzed by X-ray crystallography, the salt crystallizes in a cubic motif reminiscent of the fluorite structure. The [PtCl₆]^2- centers are octahedral. The NH₄⁺ centers are hydrogen bonded to the chloride ligands.^[4]

Uses and reactions

Ammonium hexachloroplatinate is used in platinum plating. Heating (NH₄)₂[PtCl₆] under a stream of hydrogen at 200 °C produces platinum sponge. Treating this with chlorine gives H₂PtCl₆.^[2]

References

^ "ammonium hexachloroplatinate(IV)". Chemister.ru. 2007-03-19. Retrieved 2014-06-03.
^ ^a ^b George B. Kauffman (1967). "Ammonium Hexachloroplatinate(IV)". Inorganic Syntheses. Inorganic Syntheses. 9: 182–185. doi:10.1002/9780470132401.ch51. ISBN 978-0-470-13240-1.
^ Cotton, S. A. Chemistry of Precious Metals, Chapman and Hall (London): 1997. ISBN 0-7514-0413-6.
^ Verde-Gómez, Y.; Alonso-Nuñez, G.; Cervantes, F.; Keer, A. "Aqueous solution reaction to synthesize ammonium hexachloroplatinate and its crystallogrpahic and thermogravimetric characterization" Materials Letters, 2003, volume 57, p 4667-4672. doi:10.1016/S0167-577X(03)00381-1

[1] "ammonium hexachloroplatinate(IV)". Chemister.ru. 2007-03-19. Retrieved 2014-06-03.

[Kauuf-2] George B. Kauffman (1967). "Ammonium Hexachloroplatinate(IV)". Inorganic Syntheses. Inorganic Syntheses. 9: 182–185. doi:10.1002/9780470132401.ch51. ISBN 978-0-470-13240-1.

[3] Cotton, S. A. Chemistry of Precious Metals, Chapman and Hall (London): 1997. ISBN 0-7514-0413-6.

[4] Verde-Gómez, Y.; Alonso-Nuñez, G.; Cervantes, F.; Keer, A. "Aqueous solution reaction to synthesize ammonium hexachloroplatinate and its crystallogrpahic and thermogravimetric characterization" Materials Letters, 2003, volume 57, p 4667-4672. doi:10.1016/S0167-577X(03)00381-1

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