Design, Synthesis, Crystal Structure And Properties Of Oxamido-bridged Multidimensional 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. The Oxamidates containing Aromatic Carboxylic acid groups and diamine groups are the good multi-functional bridging organic ligands , which can chelate as well as bridge metal ions to construct discrete and extended structures, further forming 1D, 2D or 3D configuration polymers or supermolecular complexes.Taking account of the above reasons, we have designed and synthesised assymetrical oxamidate ligand including Aromatic Carboxylic acid groups and diamine groups, mononuclear complexes and 1D, 2D and 3D supramolecular compounds. The complexes were characterized by X-ray crystallography, spectroscopic, thermal and magnetic property.1. through the aminolysis reaction of ethyl oxalyl chloride and ester, we have prepared the complex N-(2,5-dicarboxyl phenyl)-N -(2-amido propyl) oxamidate, and the dissymmetrical oxamidate ligand(H₄L) containing carboxyl and amine group, via which further obtained mononuclear Na2(CuL) and four kinds of heterobinuclear coordination compounds through the reaction of the Na₂(CuL) with the M²⁺(M= Co²⁺, Ni²⁺, Zn²⁺). Compound (1), (2), (4) showed 1 D chain-liked structure and (3) was 3 D supramolecular structure via the link of H-bonds. Their crystal structures were characterized the X-ray crystallogram datum and magnetic susceptibility measurement for complex (1), (2), and (3) indicated that the interaction between ions was antiferromagnetic.2. The 2 D heterobinuclear complex {[Cu₂(aeoe)₂Gd₂(OX)(H₂O)₆]·6.5H₂O}_n had been obtained by the reaction of the mononuclear precursor Na₂[Cu(aeoe)]·3H₂O withGd(NO₃)₃·6H₂O. magnetic susceptibility measurement for the complex showed that the interaction between ions was weak ferromagnetic. And the complex was characterized by IR-spectroscopic and X -ray crystallography. 3. the reaction of the mononuclear complex Na₂[Cu(aeop)]·3H₂O with M²⁺(M= Ni²⁺, Zn²⁺) had resulted in three kinds of heterobinuclear complexes, and complex (1) was 1 D chain-liked structure and the other two showed 3 D structures. These compounds were characterized by X-ray crystallography, IR-spectroscopic, elemental analysis and magnetic properties.