Poly[diamminedi-μ(3)-dicyanamido-copper(II)]

The asymmetric unit of the title polymeric mononuclear Cu(II) complex, [Cu(C(2)N(3))(2)(NH(3))(2)](n), contains one half-mol­ecule, the complex being completed through inversion symmetry, with the Cu(II) atom situated on the centre of symmetry. The coordination polyhedron around Cu(II) is a Jahn–Teller-distorted [CuN(6)] octa­hedron. The terminal N atoms of two dicyanamide ligands and two ammine ligands form an approximate square plane, with N—Cu—N bite angles of 89.72 (5) and 90.28 (5)°. The coordination polyhedron is completed in the axial positions by the central amide-type N atoms of two additional dicyanamide ligands, with an elongated Cu—N distance of 2.548 (1) Å. In turn, each of the four dicyanamide ligands, acting as bidentate, link the Cu(II) ions into a two-dimensional polymeric structure parallel to (100). The ammine H atoms are involved in inter­molecular hydrogen bonding with the free terminal N atoms of neighbouring dicyanamide ligands, yielding a three-dimensional network.