Cyclooctenyl bis triethylphosphine platinum II tetraphenylborate

To Solution A, prepared as described in Section A, is added a quantity of cycloocta-1,5-diene (0.21 mL, 1.7 mmol). A solution of sodium tetraphenylborate(l —) (274 mg, 0.8 mmol) in methanol (5 mL) is prepared in a separate Schlenk flask (50 mL). Under a flow of N2, the sodium tetraphenylborate(l —) solution is added to the stirred mixture of Solution A containing the cycloocta-1,5-diene. A white solid precipitates within a few minutes and is collected by filtration. 

The dried product is dissolved in 1 to 2 drops of dichloromethane and then 1 to 2mL of methanol are added. The product separates out as white crystals. Yield 0.52 g (79%). 

The product is air stable in the solid state. In solution gradual decomposition sets in after 2 to 3 days. 

The H NMR spectrum, recorded in a chloroform-d, solution, shows three 

The 31P H NMR spectrum, also recorded in a chloroform- solution, shows one signal at 5 8.7 ppm flanked by its platinum satellites (1JPltP = 3664 Hz), indicating that the two triethylphosphines are magnetically equivalent. 

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