Potassium tetrachloroplatinate(II)

Chemical Properties

Red/Brown, Tetragonal Crystals

Uses

Potassium tetrachloroplatinate solution is used in the preparation of platinum (Pt) nanoparticles. Ligands like ammonia or triphenyl phosphine can able to replace the chloride ligands to afford various derivatives. The replacement by ammonia results in the preparation of cisplatin, which is used in the cancer treatment. Further, it is used as catalyst in the hydroarylation reaction.

Uses

In photography, in acid toning baths.

General Description

Potassium tetrachloroplatinate(II) is a ruby red crystalline solid and can be prepared by reacting potassium hexachloroplatinate (IV) with cuprous chloride.

Flammability and Explosibility

Non flammable

Safety Profile

Human poison by ingestion. Poison experimentally by intraperitoneal route. Corrosive to human skin by intradermal route. Mutation data reported. Human systemic effects: eosinophha, gastritis, renal function tests depressed. When heated to decomposition it emits toxic fumes of Cland K2O. Used as a catalyst for hydroformulations, photocatalysts, and dissociation of water. See also PLATINUM COMPOUNDS.

Synthesis

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.

Purification Methods

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