Crystal structure of dicyanatobis(pyridinato)-copper(II)

The crystal structure of dicyanatobis(pyridinato)copper(II), C₁₂H₅CuN₄O₂, was determined from 658 X-ray diffraction data obtained by the -2 scanning technique with MoK radiation on a SYNTEX P2₁ four-circle diffractometer. The blue crystals are tetragonal:I4₁/a,a = 15.649(3),c = 9.917(3) Å, andZ = 8. The structure was determined by the heavy-atom method and refined by full-matrix least squares toR = 7.1%. Nonhydrogen atoms were refined anisotropically, and the positional parameters of hydrogen atoms were calculated from geometrical considerations. The copper atom is planarlytrans coordinated by two nitrogen atoms from the NCO groups and two nitrogen atoms from the pyridine molecules. The oxygen atoms from two of the approximately linear NCO groups complete the Cu(II) coordination as a distorted octahedron. Through their oxygen and nitrogen atoms, the NCO groups link the metal atoms to the skeleton structure. The bond lengths are 1.15 and 1.18 Å for N-C and C-O, respectively, the N-C-O bond angle being 176.8 °. The bond lengths Cu-N in square-planar coordination are 1.95 and 2.05 Å, while the Cu-O bonds are out of plane and 2.61 Å in length.Part XVIII in the seriesCyanatocopper(II) complexes with organic ligands; Part XVII: J. Kohout, A. Malejova and J. Gazo, Chem. Zvesti, in press.