Platinic acid, tetrachloro

To 45 ml. of 5 M aqueous hydrochloric acid in a 125-ml. Erlenmeyer flask is added 4.5 g. of potassium tetrachloro-platinate(II) (0.00108 mole). The flask is sealed with a rubber, serum cap and deoxygenated immediately by flushing for 30 minutes with nitrogen or ethylene through a polyethylene tube extending into the solution and attached to a needle inlet, with another needle as gas outlet. (Some undissolved potassium tetrachloroplatinate(II) may remain at this stage.) Forty milli-... 

The methods previously reported for the preparation of tetrachloroplatinic(II) acid1 and platinum(II) chloride are laborious and difficult to control. Platinum(II) chloride has been prepared by the thermal decomposition of ammonium hexachloroplatinate(IV)2 or of anhydrous platinum-(IV) chloride.3 According to a recent report,4 hydrazine sulfate is an effective reducing agent for the preparation of tetrachloroplatinate(II) salts from the corresponding hexachloroplatinate(IV) salts. This procedure has been extended to the preparation of aqueous tetrachloro-platinic(II) acid and solid platinum (II) chloride. 

It is probable that tetrachloro(diethyIene)diplatinum(II) was first prepared by Zeise by decomposition of trichloro-(ethylene)platinic(II) acid.1 Boiling hexachloroplatinic-(IV) acid with chloroform also gave the compound.2 However, it was first obtained in sufficient quantity for investigation by Anderson,3 who boiled an ethanolic solution of sodium hexachloroplatinate(IV) 6-hydrate until reduction to platinum(II) was complete. This procedure is tedious, and the yields are affected markedly by impurities in the platinum salt and by the presence of other platinum metals.4 Optimum yields of 75% are obtained only after much experience. The general method of Kharasch and Ashford,5 involving adding an olefin to a suspension of platinum(IV) chloride in warm benzene or glacial acetic... 

Tetrammineplatinum(II) chloride may be prepared by heating any one of the following with excess aqueous ammonia until a colorless solution results platinum(II) chloride tetrammineplatinum(II) tetrachloroplatinate(II) (Magnus s green salt), [Pt(NH3)4][PtCl4] diamminedi-chloroplatinum, [Pt(NH3)2Cl2] or a solution of tetra-chloroplatinic(II) acid. The present method involves the preparation of pure tetrammineplatinum(II) tetrachloro-platinate(II) and its subsequent reaction with aqueous ammonia. 

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