Hexaamminenickel chloride is the chemical compound with the formula [Ni(NH<sub>3</sub>)<sub>6</sub>]Cl<sub>2</sub>. It is the chloride salt of the metal ammine complex [Ni(NH<sub>3</sub>)<sub>6</sub>]<sup>2+</sup>. The cation features six ammonia (called ammines in coordination chemistry) ligands attached to the nickel(II) ion.
[Ni(NH<sub>3</sub>)<sub>6</sub>]<sup>2+</sup>, like all octahedral nickel(II) complexes, is paramagnetic with two unpaired electrons localized on each Ni center. [Ni(NH<sub>3</sub>)<sub>6</sub>]Cl<sub>2</sub> is prepared by treating aqueous nickel(II) chloride with ammonia. It is useful as a molecular source of anhydrous nickel(II).
One commercial method for extraction of nickel from its sulfide ores involves the sulfate salt of [Ni(NH<sub>3</sub>)<sub>6</sub>]<sup>2+</sup>. In this process, the partially purified ore is treated with air and ammonia as described with this simplified equation: