Bis(ethyl­enediamine)nickel(II) dinitrate

In the title complex, [Ni(C2H8N2)2](NO3)2, the two ethyl­enediamine groups, (en), and the nitrate anions are related by an inversion center at the Ni atom. The coordination about the Ni atom can be described as a tetragonally distorted octahedron with four equatorial sites occupied by the N atoms of the (en) groups and the two axial sites by the nitrate anions through a `semi-coordinating' Ni⋯O interaction of 2.5539 (15) A. The remaining O atoms of the nitrate groups participate in N—H⋯O hydrogen-bonding interactions with the (en) ligand.