Synthesis, Characterization And Properties Of Coordination-directed Polymers Generated From Unsymmetrical Oxadiazole Semi-rigid Ligands And Nano-sized Architects

The chemistry of organic-inorganic coordination polymers and supramolecular complexes has recently become an active area of increasing interest internationally. 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. Recently, remarkable progress has been made in the area of molecular inorganic-organic hybrid compounds. The synthesis and characterization of infinite one-, two-, and three-dimensional networks have been an area of rapid growth. In this thesis, a series of bent ligands bridged by the 1, 3, 4-oxadiazole, 4-amino-1, 2, 4-triazole, respectively, were synthesized. The coordination chemistry based on these new ligands and metal ions was investigated. Totally 44 new coordination compounds were prepared and fully characterized by IR, elemental analysis, X-ray single-crystal diffraction and powdered X-ray diffraction. The luminescent properties, reversible ion-exchange, and thermal stability were investigated.1. The coordination chemistry based on two-armed unsymmetrical 1, 3, 4-oxadiazole bridging organic semi-rigid ligands and inorganic Cu(II),Cu(I),Co(II),Ni(II),Ag(I),Zn(II),Cd(II) and Hg(II) transition metal salts has been investigated. 44 new supramolecular compounds were synthesized based on them. The results indicate that the bend angle between the two terminal N-donors of the ligands, reactive solvent system,reactants ratio,reactive temperature, the counter-anions and the coordination group have great influence on the final structure and the properties of the product. Their luminescent properties which were influenced by the reversible ion-exchange were investigated in the solid state.2. Four new coordination polymers based on unsymmetrical 1, 3, 4-oxadiazole bridging organic semi-rigid ligands with different terminal groups were designed and synthesized. Their single crystal structures were characterized and investigated,also the influence of coordinative ability in determining the structure of the compounds was discussed. Their luminescent properties were investigated in the solid state.3. Six new two-armed symmetrical 4-amino-1, 2, 4-triazole bridging organic nano-scale rigid ligands were designed,synthesized and characterized. Their solvent thermal reactive conditions and luminescent properties were investigated primarily.We designed and synthesized a series of rigid and semi-rigid bent ligands bridged by 1, 3, 4-oxadiazole, 4-amino-1, 2, 4-triazole, and this study demonstrated that the use of bent ligands bridged by 1, 3, 4-oxadiazole, 4-amino-1, 2, 4-triazole unsymmetrical or symmetrical ligands as precursors to bind transition metals, is in fact an efficient approach for syntheses of novel supramolecular systems with interesting chemical and physical properties.