Synthesis, characterization, and structures of two new tetranuclear copper complexes with azido/dicyanamide bridges containing chiral Schiff base ligand

Two new copper complexes [Cu-4(mu-L)2(mu(1,1)-N-3)(2)(N-3)(2)] (I) and [Cu-4(mu-L)(2)(mu(1,5)-Dca)(2)(Dca)(2)] (II) (H2L = (1R,3S)-N',NaEuro(3)-bis[5-methoxysalicylidene]-1,3-diamino-1,2,2-trimethylcyclopentane, Dca = dicyanamide ions) were synthesized and structurally characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction (CIF files CCDC nos. 1013673 (I), 1013672 (II)). The two complexes crystallize in monoclinic P2(1)/c and triclinic space group, respectively. Both the complexes consist of two crystallographically independent copper ions connected by a double phenoxo bridges, which are further linked to the other symmetry-related half of the molecule by two end-on azido bridges or mu(1,5)-dca groups.