Appearance brown crystals | ||
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Ammonium hexachloroiridate is the inorganic compound with the formula (NH4)2[IrCl6]. This dark brown solid is the ammonium salt of the iridium(IV) complex [IrCl6]2−. It is a commercially important iridium compound. It is one of the most common complexes of iridium(IV).
Contents
Structure
The compound has been characterized by X-ray crystallography. The salt crystallizes in a cubic motif like that of ammonium hexachloroplatinate. The [IrCl6]2− centers adopt octahedral molecular geometry.
Uses
It is a key intermediate in the isolation of iridium from ores. Most other metals form insoluble sulfides when aqueous solutions of their chlorides are treated with hydrogen sulfide, but [IrCl6]2− resists ligand substitution. Upon heating under hydrogen, the solid salt converts to the metal:
(NH4)2[IrCl6] + 2 H2 → Ir + 6 HCl + 2 NH3