Platinum Complexes Suitable as Precursors for Synthesis in Nonaqueous Solvents

PLATINUM COMPLEXES SUITABLE AS PRECURSORS FOR SYNTHESIS IN NONAQUEOUS SOLVENTS 

SUBMITTED BY LARS I. ELDING, ARE OSKARSSON, and VADIM YU. KUKUSHKIN  

A prerequisite for preparative coordination chemistry in nonaqueous solvents is the availability of soluble complex compounds. The solubility in organic solvents of compounds of the type M [X] (M+ = the cation of an alkali metal) can be increased significantly if M+ is substituted by a bulky organic cation, Q+.1 

The -nitrido-bis(triphenylphosphorus)(l+) ion,2-4 [ (C6H5)3P 2N]+,is one of the most convenient counterions for such purposes. Compounds of the [ (C6H5)3P 2N][X] type are soluble in most commonly used organic solvents. They also often form good-quality single crystals, suitable for X-ray diffraction analysis. 

A 150-mL beaker or Erlenmeyer flask is filled with a solution of 0.566 g (1.36 mmol) of potassium tetrachloroplatinate(II), K.2[PtCl4] (purchased from Aldrich), in 60 mL of water and placed on a magnetic stirrer. A solution of 1.878 g (3.27 mmol) of [ (CeHs P NJCl (purchased from Aldrich) dissolved in 10 mL of ethanol is added dropwise from a 25-mL dropping funnel over a period of 10 min. A pink precipitate appears immediately after addition of the first few drops. After complete mixing, the reaction mixture is stirred at 20-25°C for 15 min. The fine-grained pink precipitate is collected on a Millipore filter (type HV, 0.45 pm other small-pore glass or paper filters can be used as well) or separated by centrifugation, washed three times with 3-mL portions of water, and dried in air at 80-90°C. 

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