DiamminedizincII

Diamminedizinc(II) is a coordination compound with the chemical formula [Zn(NH₃)₂]²⁺. This formula represents a complex ion, not a neutral compound, as it carries a net positive charge. In this complex, two ammonia molecules (NH₃) are coordinated to a central zinc ion (Zn²⁺). The "di" in diamminedizinc indicates the presence of two ammonia ligands. The "(II)" signifies that the zinc ion is in the +2 oxidation state.

The formation of diamminedizinc(II) occurs when ammonia is added to solutions containing zinc(II) ions. Ammonia is a Lewis base, and it donates electron pairs to the Lewis acidic zinc(II) ion, forming coordinate covalent bonds. This complex is typically found in aqueous solutions.

Diamminedizinc(II) is often encountered in qualitative analysis and in certain industrial processes. For instance, it can be formed during the precipitation and dissolution of zinc hydroxide. Zinc hydroxide, Zn(OH)₂, is insoluble in pure water but dissolves in the presence of excess ammonia to form the soluble diamminedizinc(II) complex. This property is utilized to differentiate zinc from other metal ions. The complex can exist in equilibrium with other ammine complexes of zinc, such as tetraamminedizinc(II), [Zn(NH₃)₄]²⁺, depending on the concentration of ammonia.