Dichlorobis(ethylenediamine)nickel(II) is the inorganic compound with the formula NiCl<sub>2</sub>(en)<sub>2</sub>, where en = ethylenediamine. The formula is deceptive: the compound is the chloride salt of the coordination complex [Ni<sub>2</sub>Cl<sub>2</sub>(en)<sub>4</sub>]<sup>2+</sup>. This blue solid is soluble in water and some polar organic solvents. It is prepared by ligand redistribution from [Ni(en)<sub>3</sub>]Cl<sub>2</sub> and hydrated nickel chloride:
The rapid ligand redistribution is characteristic of the kinetic lability of octahedral nickel(II) complexes. In contrast with the lability of [Ni(en)<sub>3</sub>]Cl<sup>2+</sup> is the inertness of the isostructural tris(ethylenediamine)cobalt(III) cation.