Ammonium hexachloroplatinate
Overview
Ammonium hexachloroplatinate, also known as ammonium chloroplatinate, is an inorganic compound with the formula (NH4)2PtCl6. It is a rare example of a soluble platinum(IV) salt that is not hygroscopic. It forms intensely yellow solutions in water. In the presence of 1M NH4Cl, its solubility is only 0.0028g/100 mL.
Preparation and structure
The compound consists of separate ammonium cations and octahedral [PtCl6]2- anions. It is usually generated by treating a solution of chloroplatinic acid with a solution of an ammonium salt.[1] The fine yellow salt precipitates. The complex is so poorly soluble that this step is employed in the isolation of platinum from ores and recycled residues.[2]
Uses and reactions
This yellow powder is used in platinum plating.
Heating (NH4)2PtCl6 under a stream of hydrogen at 200 °C produces platinum sponge. Treatment with chlorine gives H2PtCl6.[1]