10025-99-7

Red/Brown, Tetragonal Crystals

In photography, in acid toning baths.

Nonflammable

To a suspension of 9.72g (0.02mol) of potassium hexachloroplatinate(IV) in 100cm3 of water, in a 250cm3 beaker, is added in small portions 1.0g (0.01mol) of hydrazine dihydrochloride. Excess hydrazine dihydrochloride must be avoided to prevent the formation of hydrazine complexes and the reduction of potassium hexachloroplatinate(IV) to platinum when the solution is made basic with ammonia during cisplatin synthesis. The mixture is stirred mechanically while the temperature is raised to 50-65°C over 5-10 minutes. This temperature is maintained for about 2 hours until only a small amount of yellow potassium hexachloroplatinate(IV) remains in the deep red solution. The temperature is then raised to 80-90°C to ensure completion of the reaction, and the mixture is cooled in an ice bath and filtered. The latter is washed with several 10cm3 portions of ice water until the washings are colourless. The washings and deep red filtrate contain pure potassium tetrachloroplatinate(II) and HCl(aq). Half of this solution is used to make the cisplatin.

It forms crystals from aqueous 0.75M HCl (20mL/g) between 100o and 0o. Wash them with ice-cold water and dry.