Chiral metal complexes. 45*. the structure of chloro-{6s,15s-(4r,13r-dimethyl)-1,5,10,14 tetraazatricyclo-[13,3,1,1^6,10]eicosane}copper(ii)

The crystal and molecular structure of chloro-{6S,15S-(4R, 13R-dimethyl)-1,5,10,14-tetraazatricyclo[13,3,1,1^6.10]eicosane}copper(II)pcrchlorate, [Cu(S-mac6)Cl]ClO₄, has been determined by X-ray analysis. Crystal data: C₁₈H₃₆N₄O₄Cl₂ cu is orthorhombic, space group P2₁2,2₁, a = 11.915(2), b = 12.290(2), c = 15.705(6) A Z = 4. The structure was refined by full-matrix least squares procedures to R = 0.040 for 2477 unique non-zero (I> 1.5σ(I)) reflections and with η = 1.02(7) confirming the absolute configurations of the chiral centres. The N₄ macrocycle coordinates to the copper atom in a square-planar arrangement with Cu-N_sec of 2.005(5) and Cu-N_ter of 2.060(4) Å, and a square-based pyramidal geometry is completed by a chloride ion, Cu-Cl 2.711 (2)Å. Folding of the non-chelate six-membered rings produces a conformation such that only one face of the complex ion is available for axial coordination of unidentate ligands.