Potassium tetrachloroplatinate

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Potassium tetrachloroplatinate
Identifiers
CAS number 10025-99-7 YesY
PubChem 61440
ChemSpider 55364 YesY
EC number 233-050-9
Jmol-3D images Image 1
Properties
Molecular formula K2PtCl4
Molar mass 415.09 g/mol
Appearance reddish solid
Density 3.38 g/cm3
Melting point

265 °C

Solubility in water 0.93 g/100 mL (16 °C)
5.3/100 mL (100 °C)
Hazards
EU Index 078-004-00-7
EU classification Toxic (T)
Irritant (Xi)
R-phrases R25, R41, R42, R43
S-phrases S23, S24, S26, S37
NFPA 704
NFPA 704.svg
0
3
0
Flash point Non-flammable
Related compounds
Other anions Potassium hexachloroplatinate
Other cations Sodium chloroplatinate
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

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 [edit]

Potassium tetrachloroplatinate is prepared by reduction of the corresponding hexachloroplatinate salt with hydrazine.[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. Conversion to organic salts, such as [PPN]2PtCl4 are soluble in chlorocarbons. [2]

Reactions [edit]

The chloride ligands on [PtCl4]2- are displaced by many other ligands to afford derivatives:

PtCl42− + 2 PPh3cis-PtCl2(PPh3)2 + 2 Cl

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

PtCl42− + 2 NH3cis-PtCl2(NH3)2 + 2 Cl

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

Historically, an important reaction involves ammonia and [PtCl4]2-. This reaction affords a deep green precipitate with the 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 [edit]

  1. ^ a b Keller, R. N.; Moeller, T. (1963). "Potassium Tetrachloroplatinate(II)". Inorg. Synth. 7: 247–250. doi:10.1002/9780470132333.ch79. 
  2. ^ Elding, L. I.; Oskarsson, A.; Kukushkin, V. Yu (1997). "Platinum Complexes Suitable as Precursors for Synthesis in Nonaqueous Solvents". Inorg. Synth. 31: 276–279. doi:10.1002/9780470132623.ch47. 
  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): 1924ff. doi:10.1126/science.272.5270.1924. 
  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.