Potassium Hexafluoroplatinate IV

To 1 g. of potassium hexachloroplatinate(IV) in the quartz or Kel-F bottle about 6 ml. of bromine is added to act as moderator. Excess bromine trifluoride (3-4 ml.) is then added dropwise, and the resulting red solution is boiled until the bromine is expelled (3-5 minutes), leaving a clear yellow solution. This is then frozen in liquid nitrogen and transferred to a vacuum line where excess bromine trifluoride is removed by pumping, initially at 20°C. and later for half an hour at 120°C. to remove the last traces of BrFs. The product remains as. a pale yellow powder (yield 0.8 g., 100 %). It may be recrystallized from water, but it is best to extract with warm water, filter, and precipitate the salt from solution by addition of acetone. Anal. Calcd. for K2PtF6 K, 20.1 Pt, 50.4 F, 29.5. Found K, 19.8 Pt, 50.0 F, 29.1. 

Potassium hexafluoroplatinate(IV) may be identified by its x-ray powder diffraction pattern6 and infrared spectrum7 which in a Nujol mull has bands as follows 583(vs), 282(s), 259(ms) cm.-1. The crude product before recrystallization is sufficiently pure for most purposes but preparations carried out in quartz usually contain some potassium hexafluorosilicate, which may be detected by its very intense infrared absorptions at 741 and 483 cm.-1.8 

Peacock, Progr. Inorg. Chem., 2, 193 (1960) A. G. Sharpe, Adeem. Fluorine Chem., 1, 29 (1960) N. Bartlett in Preparative Inorganic Reactions, W. L. Jolly (ed.), Vol. 2, p. 301, Interscience Publishers, a division of John Wiley Sons, Inc., New York, 1965 A. G. Sharpe, in Non-aqueous Solvent Systems, T. C. Waddington (ed.), Academic Press, Inc., New York, 1965. 

TETRAKIS (TRIPHEN YLPHOSPHINE)DICHLORO-RUTHENIUM (II) AND TRIS (TRIPHEN YLPHOSPHINE)-DICHLORORUTHENIUM (II) 

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Potassium trichlorotrifluoroplatinate(IV) may be identified by its x-ray powder photograph and infrared and ultraviolet spectra.3 Possible impurities are potassium hexafluorosilicatef and hexafluoroplatinate(IV) which may be detected by their infrared spectra (see subsection on properties of potassium hexafluoroplatinate(IV) below]. Any unreacted potassium hexachloroplatinate(IV) may be detected by its very intense (e = 24,500) ultraviolet absorption at 38,200 cm.-1 in aqueous solution.3 The product cannot be purified by recrystallization from water, since it disproportionates in aqueous solution. A... 

Potassium fluoride forms a deep yellow solid when the oxyfluoride is sublimed over it. A-Ray photography showed this to be potassium hexafluoroplatinate(v) with a little potassium hexafluoroplatinate(iv) and residual potassium fluoride. 

Write formulas for the following compounds, using brackets to enclose the complex ion portion (a) tri-amminebromoplatinum(II) nitrate (h) dichlorobis(ethylenediamine)cobalt(Il) monohydrate, (c) penta-amminesulfatocobalt(III) bromide, (d) potassium hexafluoroplatinate(IV), (e) tetraaquadibromochro-mium(lll) chloride, (/) ammonium heptafluorozirconate(lV). 

Also, a fluorination reaction has been noted for a polyhalide. Sharpe and Emeleus found that potassium hexafluoroplatinate(IV), K2Ptp6, is formed when potassium tetrafluorobromide, KBrp4, is heated with metallic platinum. Since both Brp3 and KP are inert towards platinum, the experimenters concluded that the polyhalide is responsible for the reaction. 

Recently, Chernyaev, Nibolaev, and Ippolitov reported a reaction between potassium hexachloroplatinate(IV) and chlorine trifluoride. The reaction takes place at 500°C and yields potassium hexafluoroplatinate(IV) in surprisingly high yield. 

Complex Fluorides of Platinum iv).— Although hexafluoroplatinic(iv) acid cannot be synthesized in water, its hydrolysis is so slow that the alkali, alkaline-earth, and rare-earth salts have aU been made from the acid in aqueous solution. The crystal structure of the potassium salt shows that the hexafluoroplatinate(iv) ion possesses the regular octahedral shape expected for a dizg electron configuration. 

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