Tetra­kis(pyridazine-κN)bis­(seleno­cyanato-κN)nickel(II) pyridazine disolvate

The reaction of nickel(II) nitrate with potassium seleno-cyanate and pyridazine leads to crystals of the title compound, [Ni(NCSe)(2)(C(4)H(4)N(2))(4)]·2C(4)H(4)N(2). The Ni(II) atom is coordinated by two terminal N-bonded seleno-cyanate anions and four pyridazine ligands within a slightly distorted octa-hedral geometry. The crystal structure contains two crystallographically independent pyridazine molecules in cavities of the structure, which are not coordinated to the metal centres. The structure is pseudo-C-centered due to the positioning of the discrete coordination complexes; the non-coordinating pyridazine molecules, however, break the C-centering. In the subcell, these ligands are disordered around centres of inversion, which do not coincide with the mid-point of the mol-ecules.