Chemistry:Sodium hexachloroplatinate

From HandWiki
Sodium hexachloroplatinate
Structure of sodium hexachloroplatinate(IV)
Sample of sodium hexachloroplatinate(IV)
Names
Other names
Sodium chloroplatinate
Disodium platinum hexachloride
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 240-983-5
UNII
Properties
Na2PtCl6
Molar mass 453.7742 g/mol (anhydrous)
561.86588 g/mol (hexahydrate)
Appearance Orange crystalline solid
Density 2.5 g/cm3
Melting point 110 °C (230 °F; 383 K)
Soluble
Hazards
GHS pictograms GHS05: CorrosiveGHS06: ToxicGHS09: Environmental hazard
GHS Signal word Warning
H300, H301, H317, H318, H334
P261, P264, P270, P272, P280, P285, P301+310, P302+352, P304+341, P305+351+338, P310, P321, P330, P333+313, P342+311, P363, P405, P501
Related compounds
Other anions
Sodium hexafluorophosphate
Sodium hexafluoroaluminate
Other cations
Potassium hexachloroplatinate
Ammonium hexachloroplatinate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is ☑Y☒N ?)
Infobox references

Sodium hexachloroplatinate(IV), the sodium salt of chloroplatinic acid, is an inorganic compound with the formula Na2[PtCl6], consisting of the sodium cation and the hexachloroplatinate anion. As explained by Cox and Peters, anhydrous sodium hexachloroplatinate, which is yellow, tends to form the orange hexahydrate upon storage in humid air. The latter can be dehydrated upon heating at 110 °C.[1]

The compound is utilised as the most common chemical shift reference in platinum-195 NMR spectroscopy, relative to which the shifts of other platinum species in solution are reported.[2]

Preparation and reactions

Sodium hexachloroplatinate is obtained as an intermediate in the preparation of Pt complexes, often starting with the dissolution of platinum in aqua regia, giving hexachloroplatinic acid, which is then reacted with sodium chloride and evaporated, leaving the salt behind.[3]

Pt + 4 HNO3 + 6 HCl → H2[PtCl6] + 4 NO2 + 4 H2O
H2[PtCl6] + 2 NaCl → Na2[PtCl6] + 2 HCl

The compound can be converted back to platinum metal via conversion to the ammonium salt followed by thermal decomposition, allowing platinum metal to be recovered from laboratory residues.

Na2[PtCl6] + 2 NH4Cl → (NH4)2[PtCl6] + 2 NaCl
3 (NH4)2[PtCl6] → 3 Pt + 2 N2 + 2 NH4Cl + 16 HCl

This compound also reacts with a base, such as sodium hydroxide, producing [Pt(OH)6]−2 ion.[4]

Applications

A 1.2 M solution of sodium hexachloroplatinate in D2O is the most commonly chosen reference compound for chemical shifts in 195Pt NMR. The salt is chosen as it is commercially available at a lower price relative to other platinum compounds, and it possesses high solubility enabling quick acquisition of spectra.[2]

References

  1. Cox, Lawrence E.; Peters, Dennis G. (1972). "Disodium Hexachloroplatinate(IV)". Inorganic Syntheses. 13. pp. 173–176. doi:10.1002/9780470132449.ch34. ISBN 9780470132449. 
  2. 2.0 2.1 Priqueler, Julien R. L.; Butler, Ian S.; Rochon, Fernande D. (2006). "An Overview of 195 Pt Nuclear Magnetic Resonance Spectroscopy" (in en). Applied Spectroscopy Reviews 41 (3): 185–226. doi:10.1080/05704920600620311. ISSN 0570-4928. Bibcode2006ApSRv..41..185P. http://www.tandfonline.com/doi/abs/10.1080/05704920600620311. 
  3. Kauffman, George B.; Teter, Larry A. (1963). "Recovery of Platinum from Laboratory Residues". Inorganic Syntheses. 7. pp. 232–236. doi:10.1002/9780470132388.ch61. ISBN 9780470132388. 
  4. Vasilchenko, Danila; Berdyugin, Semen; Komarov, Vladislav; Sheven, Dmitriy; Kolesov, Boris; Filatov, Evgeny; Tkachev, Sergey (2022). "Hydrolysis of [PtCl6]2− in Concentrated NaOH Solutions". Inorg. Chem. 61 (15): 5926–5942. doi:10.1021/acs.inorgchem.2c00414. PMID 35380806.