Syntheses And Properties Of Organic-Inorganic Coordination Compounds Based On Bent Ligands Bridged By Five-membered Heterocycle And Schiff-base Ligands

The supramolecular chemistry driven by coordination interactions has recently become area of increasing interest. Self-assembly of organic ligands and inorganic metal ions is one of the most efficient and widely used approaches for the construction of organic-inorganic composite materials. Very recently, remarkable progress has been made in the area of supramolecular polymers. Many coordination compounds from zero- to three-dimesional structures have been synthesized and characterized by chemists in the world. In this thesis, a series of bent ligands bridged by the 1, 3, 4-oxadiazole, 4-amino-1, 2, 4-triazole and schiff-base unit, respectively, were synthesized. The coordination chemistry based on these new ligands and metal ions was investigated. In addition, a series of heterometal-containing coordination compounds based on schiff-base ligands have been synthesized. Totally 29 new coordination compounds were prepared and fully characterized by IR, elemental analysis, and X-ray single-crystal diffraction. The luminescent properties of the coordination compounds were investigated.I. Seventy coordination compounds generated from the 1, 3, 4-oxadiazole bridged ligands and d-block metals have been synthesized. The different coordination fashions between the rigid and semi-rigid ligands were investigated. The results demonstrated that the versatile coordination fashions of the semi-rigid ligands were quite different from which of the rigid ligands, and these differences influenced the structures of resulted compounds significantly.II. Four coordination compounds generated from the 4-amino-1, 2, 4-triazole bridged semi-rigid asymmetric ligand and Ag(I) ions have been synthesized. The counter anionic effect in the synthesis of the coordination compouds was investigated. Amino group is a well-known hydrogen bonds donor. The structures of supramolecular polymers generated from this asymmetric ligand are influenced by both coordination interactions and hydrogen bonds interactions besides counter anions. More over, the hydrogen bonds play structure-directing role on the construction of wall-like frameworks.III. New type of the symmetric schiff-base ligands were designed and synthesized. Coordination chemistry of the new ligands was investigated, and eight coordination compounds were obtained. Using"two-step"method, we synthesized mixed-metal supramolecular compounds. The neutral single-metal ligands generated from the schiff-base ligands and Cu(II) or Ni(II) salts were designed and then acted with other metal salts to obtain six novel mixed-metal coordination compounds.This study demonstrated that the use of bent 1, 3, 4-oxadiazole, 4-amino-1, 2, 4-triazole and schiff-base bridging ligands as precursors to bind transition metal and lanthanide metals, is in fact a new and efficient approach for synthesis of novel supramolecular systems with interesting chemical and physical properties. It provides a promising and convenient approach to access to the multifunctional materials for selected sorption, recognition, catalysis, and luminescence and magnets.