HexaChloroplatinate , ammonium

The PGM concentrate is attacked with aqua regia to dissolve gold, platinum, and palladium. The more insoluble metals, iridium, rhodium, mthenium, and osmium remain as a residue. Gold is recovered from the aqua regia solution either by reduction to the metallic form with ferrous salts or by solvent-extraction methods. The solution is then treated with ammonium chloride to produce a precipitate of ammonium hexachloroplatinate(IV),... 

Platinum Compounds. Several Pt compds, including trimethylplatinum derivatives are explosively unstable (Ref 9). Ammipentahydroxo-platinum, H8NOsPt, explds fairly violently above 250°, as does the pyridine analogue (Ref 3). Ammonium Hexachloroplatinate(2-),... 

Boiling ammonium hexachloroplatinate with alkali gives a product (possibly potassium hexahydroxyplatinate) which after drying will explode violently on heating alone or with combustible materials. 

Ammonium hexachloroplatinate See Ammonium hexachloroplatinate Potassium hydroxide... 

Amminedecahydroxy diplatinum Amminepentahydroxyplatinum, 4571 Ammonium hexachloroplatinate, 4186 Ammonium tetranitroplatinate(II), 4578 Diacetatoplatinum(II) nitrate, 1510 Diamminedichloroaminotrichloroplatimun(IV), 4179... 

Compounds Ammonium chloroplatinate sodium chloroplatinate platinic chloride platinum chloride sodium tetrachloroplatinate potassium tetrachloroplatinate ammonium tetrachloroplatinate sodium hexachloroplati-nate potassium hexachloroplatinate ammonium hexachloroplatinate... 

Reactions with ammonium chloride or other ammonium salts form a lemon yellow precipitate of ammonium hexachloroplatinate, (NH4)2PtCl6 ... 

When sulfur and Pt sponge are ignited, some pladnum(IIi sulfide is formed. The naturally occurring mineral is called coopente. When heated in air 01 IP. the products are metallic Pt and S. Platinum(IV) sulfide can be made by heating ammonium hexachloroplatinate(IV) or Ptand S at 650°C. When precipitated by H>S from chloroplatinic acid, the compound may exist as PtS2- H2S. 

Ammonium dinitramide, 4523a Ammonium 3,5-dinitro-l,2,4-triazolide, 0819 Ammonium l,2-ethylenebis(nitramide), 0968 Ammonium fluoride, 4293 Ammonium fluorochromate, 4218 Ammonium hexachloroplatinate, 4180 Ammonium hexacyanoferrate(II), 2572 Ammonium hexanitrocobaltate(3—), 4200 Ammonium hydrogen sulfite, 4540 Ammonium hydroxide, 4539... 

Several platinum compounds, including trimethylplatinum derivatives, are explosively unstable. Some compounds of the other platinum group metals are also of limited stability. Individually indexed compounds are Amminedecahydroxydiplatinum, 4588 Amminepentahydroxyplatinum, 4566 Ammonium hexachloroplatinate, 4180 Ammonium tetranitroplatinate(II), 4573 Diacetatoplatinum(II) nitrate, 1507 Diamminedichloroamidotrichloroplatinum(IV), 4173... 

Ammonium Hexachloroplatinate. Heating with potassium hydroxide yields product, which when dry, explodes on contact with combustible materials.3... 

Hexachloroplatinic(JV) acid (H2[PtCl6 ) yellow precipitate of ammonium hexachloroplatinate(IV)... 

Pfeiffer s application of Werner s theory to crystals and the advent of new experimental techniques led a number of scientists in various countries to use X-ray diffraction to determine crystal structures of coordination compounds. American chemist Ralph W. G. Wyckoff(l 897-1994) chose ammonium hexachloroplatinate(IV) as a crystal that should... 

SYNS AMMONIUM HEXACHLOROPLATIN-ATE(IV) AMMONIUM PLATINIC CHLORIDE DIAMMONTUM HEXACHLOROPLATINATE (2-) PLATINIC AMMONIUM CHLORIDE... 

Inasmuch as ammonium hexachloroplatinate(IV) is employed in the gravimetric determination of platinum and ammonium ion, its pyrolysis has been extensively studied decomposition begins at 185°, producing as intermediates cis- and irans-[Pt(NH3)2Cl2]. Ignition at higher temperatures yields spongy platinum ... 

In aqueous suspension, the ammonium ion in ammonium hexachloroplatinate(IV) is oxidized by chlorine ... 

The work of Alfred Werner led to a considerable understanding of the stereochemistries of arrangements of ligands. This understanding was reinforced by X-ray diffraction studies of metal complexes, for example, in the determination of the structures of ammonium hexachloroplatinate and chloropalladite, shown in Figure 15.4. In these there are six groups around the metal ion, at an equal distance, rather like a small portion of the sodium chloride structure. 

FIGURE 15.4. Metal coordination in ammonium hexachloroplatinate (Ref. 28). (a) Chemical formula, and (b) stereoview. 

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