Design, Synthesis, Crystal Structure And Properties Of 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.In view of reasons above, we have designed and synthesized three kinds of copper(II) precursors with dissymmetric and symmetric oxamido-bridge structure.1 The synthesis of new compounds with dissymmetric oxamido-bridge mononuclear complexes1.1 Through condensing 2-Aminotherephthalic acid, ethyl oxalyl chloride and ethylenediamine, a new ligand N'-(2-Aminoterephthalic acid)-N''-(Ethylenediamine)oxamidate(H4aeoe) has been synthesized. Its mononuclear complex Na2[Cu(aeoe)]·3H2O has also been obtained. Through the self-assembly of mononuclear complex Na2[Cu(aeoe)]·3H2O with transitional metal ions respectively, we have gottten five complexes: {[Cu(aeoe)M(H2O)3·2H2O]2}n (M = Mn(II)(1), Co(II)(2), Zn(II)(3), Ni(II)(4)) are 1-D ladder-like chain structure and [Cu(aeoe)Ni(H2O)3·0.5H2O]2(5) is 2D layer structure. Their crystal structure have been determined by X-ray analysis. Magnetic susceptibility measurements of complexes (1), (2), (4) and (5) indicate that the interaction between metal ions are antiferromagnetic.1.2 Through condensing 2-Aminotherephthalic acid, ethyl oxalyl chloride and 1,3-Propanediamine, a new ligand N'-(2-Aminoterephthalic acid)-N''-(1,3-Propanediamine)oxamidate(H4aeop) has been synthesized. Its mononuclear complex Na2[Cu(aeop)]·3H2O has also been obtained. Through the self-assembly of mononuclear complex Na2[Cu(aeop)]·3H2O with transitional metal ions respectively, we have gotten two complexes: {[Cu(aeop)Mn(H2O)3·2H2O]2}n(1) and [Cu(aeop)Co(H2O)4·4H2O](2). They are all 3D supramolecular structure. Their crystal structures have been determined by X-ray analysis. Magnetic susceptibility measurements of complexes (1) and (2) indicate that the interaction between metal ions are antiferromagnetic.2 The synthesis of new compounds with symmetric oxamido-bridge mononuclear complex2.1 Through condensing 2-Aminotherephthalic acid and oxalyl chloride, we obtained a new ligand N, N'-bis(2-Aminotherephthalic acid)oxamido, Its mononuclear complex Na4[Cu(atox)]·2H2O has also been obtained. Through the self-assembly of mononuclear complex Na4[Cu(atox)]·2H2O with Ni(CH3COO)2·4H2O and CoCl2·6H2O respectively , we obtained two slide fastener complexes [Cu(atox)Ni(H2O)4·Ni(H2O)6·3H2O](1) and [Cu(atox)Co(H2O)4·Co(H2O)6·4H2O](2), Their crystal structure have been determined by X-ray analysis. Magnetic susceptibility measurements of complex (1) indicate that the interaction between Cu(II)-Ni(II) metal ions is antiferromagnetic.