Potassium tetrachloroplatinate
Names
IUPAC name
Potassium tetrachloridoplatinate(2–)
Other names
Potassium chloroplatinite
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.030.034 Edit this at Wikidata
EC Number
  • 233-050-9
UNII
  • InChI=1S/4ClH.2K.Pt/h4*1H;;;/q;;;;2*+1;+2/p-4 checkY
    Key: RVRDLMCWUILSAH-UHFFFAOYSA-J checkY
  • InChI=1/4ClH.2K.Pt/h4*1H;;;/q;;;;2*+1;+2/p-4/rCl4Pt.2K/c1-5(2,3)4;;/q-2;2*+1
    Key: RVRDLMCWUILSAH-SSOJXQLRAM
  • [K+].[K+].Cl[Pt-2](Cl)(Cl)Cl
Properties
K2PtCl4
Molar mass 415.09 g/mol
Appearance reddish solid
Density 3.38 g/cm3
Melting point 265 °C (509 °F; 538 K)
0.93 g/100 mL (16 °C)
5.3 g/100 mL (100 °C)
Hazards
GHS labelling:
GHS05: CorrosiveGHS06: ToxicGHS07: Exclamation markGHS08: Health hazard
Danger
H301, H315, H317, H318, H334
P261, P264, P270, P272, P280, P285, P301+P310, P302+P352, P304+P341, P305+P351+P338, P310, P321, P330, P332+P313, P333+P313, P342+P311, P362, P363, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
3
0
0
Flash point Nonflammable
Related compounds
Other anions
 Potassium hexachloroplatinate
Other cations
 Sodium chloroplatinate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Potassium tetrachloroplatinate(II) is the chemical compound with the formula K2PtCl4. This reddish orange salt is an important reagent for the preparation of other coordination complexes of platinum. It consists of potassium cations and the square planar dianion PtCl42−. Related salts are also known including Na2PtCl4, which is brown-colored and soluble in alcohols, and quaternary ammonium salts, which are soluble in a broader range of organic solvents.

Preparation

Potassium tetrachloroplatinate is prepared by reduction of the corresponding hexachloroplatinate salt with sulfur dioxide.[1] K2PtCl4 is one of the salts that is most easily obtained from platinum ores. The complex is appreciably soluble only in water. Treatment with alcohols, especially in the presence of base, causes reduction to platinum metal. Organic tetrachloroplatinate salts, such as [PPN]2PtCl4 are soluble in chlorocarbons.[2]

Reactions

The chloride ligands on [PtCl4]2− are displaced by many other ligands. Upon reaction with triphenylphosphine, [PtCl4]2− converts to cis-bis(triphenylphosphine)platinum chloride:

PtCl42− + 2 PPh3 → cis-PtCl2(PPh3)2 + 2 Cl−

The anti-cancer drug Cisplatin can similarly be prepared:[1]

PtCl42− + 2 NH3 → cis-PtCl2(NH3)2 + 2 Cl−

Enedithiolates displace all four chloride ligands to give bis(dithiolene) complexes.[3] Reduction gives colloidal platinum of potential interest for catalysis.[4]

Historically, an important reaction involves ammonia and [PtCl4]2−. This reaction affords a deep green precipitate with empirical formula PtCl2(NH3)2. This material, known as Magnus' green salt, is a semiconducting coordination polymer consisting of chains of alternating [PtCl4]2− and [Pt(NH3)4]2+ centres.[5]

References

  1. ^ a b Keller, R. N.; Moeller, T. (2007). "Potassium Tetrachloroplatinate(II): (Potassium Chloroplatinite)". Inorg. Synth. 7: 247–250. doi:10.1002/9780470132333.ch79. ISBN 9780470132333.
  2. ^ Elding, L. I.; Oskarsson, A.; Kukushkin, V. Yu (2007). "Platinum Complexes Suitable as Precursors for Synthesis in Nonaqueous Solvents". Inorg. Synth. 31: 276–279. doi:10.1002/9780470132623.ch47. ISBN 9780470132623.
  3. ^ Scott D. Cummings; Richard Eisenberg (1995). "Acid-Base Behavior of the Ground and Excited States of Platinum(II) Complexes of Quinoxaline-2,3-dithiolate". Inorg. Chem. 34 (13): 3396–3403. doi:10.1021/ic00117a005.
  4. ^ Ahmadi, T. S.; Wang, Z. L.; Green, T. C.; Henglein, A.; El-Sayed, M. A. (1996). "Shape-Controlled Synthesis of Colloidal Platinum Nanoparticles". Science. 272 (5270): 1924–6. Bibcode:1996Sci...272.1924A. doi:10.1126/science.272.5270.1924. PMID 8662492. S2CID 34481183.
  5. ^ Caseri, W. (2004). "Derivatives of Magnus' green salt; from intractable materials to solution-processed transistors". Platinum Metals Review. 48 (3): 91–100. doi:10.1595/147106704X1504.
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