Chiral metal complexes. 46*. the structure of {6s,14s-(4r,12r-dimethyl)-1,5,9,13-tetraazatricyclo- [12,2,l,l⁶’⁹]octadecane}perchloratocopper(ii) perchlorate

The crystaland molecular structure of {6S, 14S-(4R, 12R-dimethy 1)-1,5,9,13-tetraazatricyclo[12,2,1,1⁶-⁹]-octadecane} perchloratocopper(II) perchlorate, [Cu(S-mac5)C1O₄]C1O₄ has been determined by X-ray analysis. Crystal data: C,₆H₃2N₄O₈C1₈C1₂cuis monoclinic, space group P2₁, a = 11.340(3), b= 13.713(2), c = 15.002(1) A, β = 97.13(1)°, Z = 4. The structure was refined by full-matrix least-squares procedures to R = 0.056 for 3494 non-zero (I > 2σ(l)) reflections and with η = 1.03(11) confirming the configurations at the chiral centres. The two independent cations are structurally equivalent with the N₄ macrocycle coordinating to the copper atom in a square-planar arrangement with Cu-N_secof 1.988(6) and Cu-N_test of 2.019(5) A, and a square-based pyramidal geometry is completed by an oxygen atom of a perchlorate ion, Cu-O 2.63(1) A. Folding of the non-chelate five-membered rings produces a conformation such that one face of the complex ion is more available for axial coordination of unidentate ligands.