Nitrosyl Hexachloroplatinate IV

Submitted by RICHARD T. MORAVEK and GEORGE B. KAUFFMANt Checked by TARIQ MAHMOODt 

Nitrosyl hexachloroplatinate(IV) was first prepared by the action of excess aqua regia on platinum and has been reported since by several investigators using essentially the same method. It can also be prepared by the action of fuming nitric acid on platinum(IV) chloride solution or on hexachloroplatinic(IV) acid. The yields obtained by the above methods are quite low, and extreme care is necessary in order to isolate the compound. 

In addition to these preparations in aqueous solution, the compound has also been prepared in low yield by the action of nitrosyl chloride at 100° on platinum. This low yield is due to incomplete reaction and the difficulty of separating the deliquescent powder from the unreacted metal. It is possible to prepare the compound in higher yield by the action of nitrosyl chloride on platinum(II) or platinum(IV) chloride. Neither platinum(II) nor platinum(IV) chloride is readily obtained commercially. Furthermore, platinum(IV) chloride is quite hygroscopic and is difficult both to prepare and to handle. 

The following modification of the literature method utilizes pure platinum metal. The manipulations involved are fairly simple, and the equipment used is kept to a minimum. 

Four grams (0.021 mole) of pure platinum wire (for example, 0.02S-in. diameter platinum wire, 99.9 + %) (Alfa Products] is cut into short lengths ( I mm) with scissors. It is placed in a large ampule made from a 16-in. length 

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O2CIF, Chloryl fluoride, 24 3 02Cl2N2Pt, Nitrosyl hexachloroplatinate-(IV) (2 1), 24 217... 

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