The Synthesis and Crystal Structure of Thiocyanate-Bridged Bi-Copper(II) Macrocyclic Complex of 1,4,7,12,15,18-Hexaazacyclodocosane [Cu-2(SCN)(3)(C36H38N6)](2)(ClO4)(2)

In the study on the model of the active site of superoxide dismutase, some copper(II) macrocyclic complexes have been synthesized. This paper discribes the synthesis and crystal structure of a new mu-thiocyanato-complex.. The crystal belongs to monoclinic space group P-2/n with a = 16.274(8), b = 8.110 (3), c = 23.109 (10) angstrom. = 98.46. (4) beta = 98.46(4)degrees, V = 3030 angstrom(3), Z= 4, D-c = 1.5/g.cm(-3). The crystal structure was solved by direct method and difference Fourier synthesis The refinement with anisotropic temperature factors for non-hydrogen atoms gave the final diecrepanoy factor R = 6.088 for 1945 reflections. The macrocycles are at the symmetric center of the cell. Both coppers are in a distorted square-pyramidal environment The two copper ions in the lame macrocycle are noninteracting (Cu-Cu = 5.478 angstrom). The copper ions in the different macrocycles are bridged by thiocyanate to form a infinite chain in the crystal. The Basal positions of the pyramid consist of three nitrogen atoms of the diethylenetriamine fragment of the macrocycle and one nitrogen atom from a non-bridged thiocyanate ligand and the vertex of the distorted square-pyramid is nitrogen or sulfur atom of the bridged thiocyanate. The distance of two copper ions bridged by thiocyanate is 6.695 angstrom. The interaction of copper with the vertical nitrogen atom (Cu-N=2.315 angstrom) is stronger thou with vertical sulfur atom (Cu.S=2.824 angstrom)