Low-dimensional compounds containing cyano groups. II. catena-Poly[[(2,2'-bipyridine-kappa(2)N:N')(dicyanamido-kappa N)copper(II)]-mu-dicyanamido-kappa(2)N:N'

Abstract

The crystal structure of the title compound, [Cu(C(2)N(3))(2)(C(10)H(8)N(2))](n), is formed by neutral zigzag chains of the [-NC-N-CN-Cu[(bpy)N(CN)(2)]-NC-N-CN-] type running along the c axis (bpy is 2,2'-bipyridine). The Cu atoms in the chains are pentacoordinated in the form of a distorted tetragonal pyramid, with a CuN(5) chromophore. The coordination sites are occupied by two N atoms of one bpy molecule in the basal plane [Cu-N 2.018 (4) and 2.025 (2) A] and by three terminal N atoms of two dicyanamide ligands. One of the dicyanamide ligands is coordinated in a monodentate fashion through a nitrile N atom in the basal plane [Cu-N 1.963 (4) A]. The second acts as an end-to-end bridging ligand to a neighbouring Cu atom and is coordinated by one nitrile N atom in the basal plane [Cu-N 2.001 (2) A], while the second nitrile N atom occupies the apical position [Cu-N 2.159 (2) A] and originates from the bridge connecting another Cu atom. The shortest intrachain Cu.Cu distance is 8.212 (1) A, as a consequence of the large bridging ligand, whereas the minimum interchain distance between Cu atoms is only 5.77 (7) A, because of the interdigitation of the chains.