Bis(benzonitrile)dichloroplatinum(II)

Bis(benzonitrile)dichloroplatinum(II) can be prepared as a mixture of cis and trans complexes. The reaction of Palladium(II) Chloride in benzonitrile at room temperature for 7 h yields a mixture that can be separated chromatographically to yield 26% trans- and 58% cis-PtCl2(PhCN)2. An alternate route requires stoichiometric amounts of potassium tetrachloroplatinate(II) and benzonitrile stirred at room temperature for one week. Trituration of the product with hot benzene yields pure cis-PtCl2(PhCN)2 in 60% yield; the cooled benzene solution yields pure trans-PtCl2(PhCN)2 in 20% yield.