Bis[μ(3)-N′-oxidopyridine-2-carbox­imidamidato(2−)]bis­[μ(2)-N′-oxido­pyridine-2-carboximidamidato(1−)]tetra­pyridine­tetra­nickel(II) dinitrate

The title compound, [Ni(4)(C(6)H(5)N(3)O)(2)(C(6)H(6)N(3)O)(2)(C(5)H(5)N)(4)](NO(3))(2), is a tetra­nuclear nickel complex containing a single-decker cation, located on an inversion center. The two unique Ni(II) cations are N,N′,N′′,O-chelated by carbox­imid­amid­ate(2−) and carboximidamidate(1−) anions, forming a distorted four-coordinate planar structure, while the other two Ni(II) atoms are N,N′,O,O′-chelated by the same bridging ligands and two pyridine mol­ecules, affording six-coordinated metals in an octa­hedral geometry. The cation is isostructural with the complex crystallized with perchlorate counter-ions in place of nitrate.