Platinum tetrachloride

The colloidal catalysts have been prepared in different particle sizes by the reduction of platinum tetrachloride with formic acid in the presence of different amounts of alkaloid. Optical yields of 75-80% ee were obtained in the hydrogenation of ethyl pyruvate with chirally modified Pt sols (Equation 3.7). The catalysts were demonstrated to be structure-insensitive since turnover frequencies (ca. 1 sec-1) and enantiomeric excess are independent of the particle size. 

When NH4C1 is added to a solution of platinum tetrachloride, sparingly soluble ammonium chloroplatinate is obtained, which on ignition gives spongy platinum. 

Hexachloroplatinic acid is obtained in an intermediate step during extraction of platinum from minerals. The compound is formed when platinum is dissolved in aqua regia containing a higher proportion of HCl and subsequently is evaporated repeatedly with hydrochloric acid, preferably in a chlorine atmosphere. Alternatively, hexachloroplatinic acid may be obtained by dissolving platinum tetrachloride, PtCh, in water. 

Hexachloroplatinic acid decomposes completely when ignited, leaving a residue of spongy platinum. Hexachloroplatinic acid on heating at 300°C in chlorine forms platinum tetrachloride ... 

It also may be obtained by thermal decomposition of platinum tetrachloride, PtCh, or hexachloroplatinic acid ... 

Platinum dioxide is obtained as its monohydrate, Pt02 H20, a brown-red precipitate, upon boiling a solution of platinum tetrachloride, PtCh, with sodium carbonate. 

Platinum tetrachloride is used to prepare chloroplatinic acid and many platinum complexes, particularly with ammonia. Such complexes were pre-... 

Platinum tetrachloride is prepared by decomposition of hexachloropla-tinic(lV) acid, H2PtCl6, in a stream of chlorine gas at 300°C. 

Elemental composition Pt 52.56%, Cl 47.44%. Platinum tetrachloride may be dissolved in water and analyzed for platinum (see Platinum). Also, it may be identified by its physical properties and certain precipitation reactions after dissolving in HCl (see Platinic Acid, Hexachloro). 

Platinum Dichloride Platinum Dioxide Platinum Hexafluoride Platinum Monoxide Platinum Tetrachloride Plutonium Polonium Potassium Potassium Acetate Potassium Bicarbonate Potassium Bisulfide Potassium Borohydride Potassium Bromate Potassium Bromide Potassium Carbonate... 

Complexes between metal salts and alkenes have been known since 1827 but they were not understood until the latter half of this century. For example, Zeise isolated stable yellow crystals after refiuxing an alcoholic solution of platinum tetrachloride,74 Zeise s salt is now made from KjPtCI4 and C2H4 ... 

Talanova, G. G., Yatsimirskii, K. B., and Kravchenko, O. V. (2000) Peculiarities of Dipotassium Palladium Tetrachloride (K PdCli) and Dipotassium Platinum Tetrachloride ( PtCLt) Complexation with Polymer-supported Dibenzo-18-crown-6, Ind. Eng. Chem. Res. 39, 3611-3615. 

Platinum Trichloride, PtCl3, results3 when platinum tetrachloride is heated to 390 C. in a current of pure, dry chlorine for several hours. 

Platinum Tetrachloride, Platinic Chloride, PtCl4.—This salt was first prepared in a hydrated form by Norton,5 who, however, failed to isolate the anhydrous salt. This latter may be obtained by heating partially dehydrated chlor-platinic acid in a current of chlorine at 360° C.6 The possibility of preparing it in this way has been disputed,7 but Gutbier, who carried out a number of experiments with chlor-platinic acid under a variety of conditions, was able to prepare the salt quite easily. In the neighbourhood of 60° C. the crystals melt in their... 

Platinum tetrachloride is also obtained by heating chlor-platinic acid to 165° C. in a current of hydrogen chloride for fifteen hours. ... 

Platinum tetrachloride is not formed by merely heating chlor-platinic acid in air, because it decomposes before the whole of the hydrogen chloride is eliminated, yielding the dichloride.4 When heated to 370° C. in an atmosphere of chlorine it begins to dissociate ... 

Platinum tetrachloride is reddish brown in colour, somewhat hygroscopic, and moderately soluble in warm water with evolution of heat (see below). It is but slightly soluble in alcohol, but easily soluble in acetone.6... 

Platinum tetrachloride is reduced in solution by iodine at the ordinary temperature to the dichloride ... 

When dry, platinum tetrachloride is reduced to the metal by a current of hydrogen even below 80° C.2 Its solution is reduced by powdered cobalt, with precipitation of metallic platinum. Thus 1 ... 

Hydrates of Platinum Tetrachloride.—Platinic chloride combines with water to yield a series of hydrates. The odahydrate, PtCl4. 8H20, crystallises from aqueous solutions of the salt in the form of red needles.3... 

The dihydrate, PtCl4.2H20 or H2PtCl4(OH)2, has not been isolated in the pure state. It exists in solution when platinum tetrachloride is dissolved in water, and is described under the name of tetrachlor-dihydroxy-platinic acid (see p. 296). 

HexachloX-pIatinic Acid, HjPtClg, is obtained in solution when platinum tetrachloride is dissolved in aqueous hydrochloric acid. 

Potassium Chlor-platinate, K2PtCla, is most readily obtained by adding potassium chloride to an acidulated solution of platinum tetrachloride. It crystallises in cubic octahedra which are yellow in colour and but slightly soluble in water, and still less soluble in alcohol. The formation of this salt is therefore utilised in the quantitative estimation of potassium and platinum. 

Silver Chlor-platinate, AgsPtCle, is obtained as a yellow precipitate by adding silver nitrate in excess to a cold solution of chlor-platinic acid. It is not quite pure, since it is slowly decomposed even by cold water, yielding silver chloride and a solution of platinum tetrachloride,6 which is dihydroxy-tetrachlor-platinic acid, PtCl4.2H20 or H2PtCI4(OH)2. 

Hexahydroxy-platinic Acid, H2Pt(OH)6, or Pt0,.4H20, is obtained as a white precipitate on neutralising with acetic acid in the cold a well-diluted solution of platinum tetrachloride which has been boiled with excess of caustic soda. 

Platimc Sulphide, Platinum Disulphide, PtS2, is obtained as a dark precipitate on passing hydrogen sulphide into an aqueous solution of platinum tetrachloride. It is necessary to effect the precipitation at about 90° C., otherwise coloured precipitates are obtained consisting most probably of thioplatinic acids.7... 

PLATINUM SPONGE see PJD500 PLATINUM TETRACHLORIDE see PJE250 PLATINUM (2 ), NITROTRICHLORO-, DIPOTASSIUM see PLN050... 

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