| While the development of the synthesis and research in functional complexes, the researches in molecular materials with magnetic properties have developed rapidly. The special structures and magnetics of the polynuclear coplexes offer a new way to design and synthesize molecular magnets. In this kind of complexes, one or more diamagnetic atoms are between two paramagnetic metal ion. So, it is depend on good bridging ligands to improve TC. Oxalate is a excellent bridging ligands to transmit electronic effects between magnetic centers. In this paper, it is mainly directed toward the preparation of complex acting as ligands and heteropolynuclear complexes with oxalate as bridging ligand and 2,2'-bipy, 1,10-phen, 8-hydroxyquinoline etc. as terminal ligands. And 14 new complexes were synthesized.At chapter 1, the molecular—magnetic complexes and the properties of oxalate as bridging ligand has been summarized.At chapter 2, C2, C3, C4 were synthesized by K2[Cu(ox)2]·2H2O and 2-aminopyridine, imidazole, benzimidazle. They were characterized by elemental analysis, IR spectrum and thermal analysis. They are proved be linear structure.At chapter 3, Seven Cr—M heterobinuclear complexes (C6C11, C13) and two mononuclear complexes (C5, C12) were synthesized and characterized by elemental analysis, IR spectrum. The single—crystal structure for C5 was determined, which are organized in layers by hydrogen bonds and π—π interactions.At chapter 4, [Ni(phen)2(ox)]·5H2O (C14) was synthesized at first, and then [(phen)2Ni(ox)Mn(phen)]·H2O·(ClO4)2 (C15) was synthesized by C14 and Mn(ClO4)2·6H2O. They were characterized by elemental analysis, IR spectrum and Uv— Vis spectrum. The single—crystal structure for C5 was determined, which are organized in layers by hydrogen. bonds and π—π interactions and includes five—members ring (H2O)5. The population analysis with DFT for C14 and [Cu(phen)2(ox)]·5H2O were studied by means of Gaussian 03 package.At chapter 5, The susceptibility for C5 and C14 were determined and fitted by treorytically methods. C2 is ferromagnetic with C=0.402 cm3·mol-1·K, θ=3.8 K, J= 2.1 cm-1. C15 is antiferromagnetic with C=5.89 cm3·mor-1·K, θ= -17.85 K, J= -0.01cm-1. |
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