Design, Synthesis, Crystal Structure And Properties Of Asymmetrical Oxamido-bridged Complexes

The design of metal-containing building blocks to spontaneously assembly into interesting molecular architectures is of considerable interest in view of the nature of magnetic exchange interactions between metal ions through bridging ligands. A successful strategy leading to one-, two-, and three-dimensional (1D, 2D, 3D) systems is the using of metal cations of link reactively stable coordination compounds containing potential bridging blocks, i.e. the"complex as ligand"approach. These anionic precursors are particularly suitable for designing heterobinuclear complexes or heterobimetallic chain compounds and have played an important role in the development of molecular magnetism.(Ⅰ) Using mononuclear complexes Na[Cu(oxbe)]·1.5H2O,Ni(ClO4)2·6H2O and dpt (dpt=3,3′-diaminodipropypamine), we have synthesized a heterobinuclear complexe. Using mononuclear complexes Na[Cu(oxbe)]·1.5H2O,Cu(ClO4)2·6H2O and tmen (tmen=N,N,N′,N′-tetramethylenediamine), we obtained two kinds of cyclic tetranuclear copper(Ⅱ) complexes, their crystal structures have been determined by X-ray analysis. Magnetic susceptibility measurements indicate that the interaction between copper ions is antiferromagnetic.(Ⅱ) Using new ligand H3obea, we have synthesized two 2D coordination polymers. They have been characterized by means of elemental analysis, IR, thermogravity analysis. Magnetic susceptibility measurements indicate that the interaction between ions is antiferromagnetic. The exchange integrals are equal to -56.2 cm-1 and -45.8 cm-1(Ⅲ) Using mononuclear complexes Na[Cu(oxbe)]·1.5H2O and Cu(ClO4)2·6H2O, we firstly obtained a dissymmetrical oxamido-bridged 1D coordination polymer, the cis and trans conformations of the ligand are coexist in the complex. It has been characterized by means of elemental analysis, IR, thermogravity analysis. Magnetic susceptibility...