Hexaamminenickel chlorideHexaamminenickel chloride is the chemical compound with the formula Cl2. It is the chloride salt of the metal ammine complex 2+. The cation features six ammonia ligands attached to the nickel ion.Properties and structure2+, like all octahedral nickel complexes, is paramagnetic with two unpaired electrons localized on each Ni center. Cl2 is prepared by treating aqueous nickel(II) chloride with ammonia. It is useful as a molecular source of anhydrous nickel.Related compoundsOne commercial method for extraction of nickel from its sulfide ores involves the sulfate salt of 2+. In this process, the partially purified ore is treated with air and ammonia as described with this simplified equation: