Abstract: In the study on the model of the active site of superoxide dismutase, some hicopper (Ⅱ) maerocyclic complexes have been synthesized. This paper discribes the synthesis and crystal structure of a new μ-thiocyanato-complex. The crystal belongs to monoclinic space group P2/n with a=1.6274(8), b=0.8110(3), c=2.3199(10) nm, β=98.46(4)°, V=3.030 nm, Z=4, D_c=1.57 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 discrepancy factor R=0.088 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 same macrocycle are noninteracting (Cu-Cu=0.5478 nm). The copper ions in the different macrocycles are bridged by thiocyanate to form a infinite chain in the crystal. The bassal positions of the pyramid consist of three nitrogen atoms of the diethylenetriamine fragment of 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 0.6695 nm. The interaction of copper with the vertical nitrogen atom (Cu-N=0.2315 nm) is stronger than with vertical sulfur atom (Cu-S=0.2824 nm).

Key words: Crystal structure, [Cu₂(SCN)₃(C₁₆H₃₈N₆)]₂(ClO₄)₂