Syntheses And Self-Asembly Reaction Of 1, 3, 4-Oxadiazole Bridging Ligands And Pyridyl-4, 5-Imidazole Dicarboxylic Acid Ligands

The chemistry of organic-inorganic coordination polymers and supramolecular complexes 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. Recently, remarkable progress has been made in the area of molecular inorganic-organic hybrid compounds. The synthesis and charaterization of infinite one-, two-, and three-dimensional networks have been an area of rapid growth. In the thesis, a series of novel single and multi-armed oxadiazole bridging ligands and pyridyl-4, 5-imidazole dicarboxylic acid ligands have been synthesized. The coordination chemistry of these novel ligands with transition metal ions was investigated. In addition, two 1, 3, 4-oxadiazole bridging ligands end-capped by chelating Schiff-base coordination sites have been designed and synthesized. The coordination chemistry based on one of the two ligands with metal ions was primarily investigated. Totally 27 new coordination compounds were prepared by solution reactions or by hydrothermal methods, and fully characterized by IR, elemental analysis and single-crystal X-ray diffraction. The solid state luminescent properties and electrical conductive properties of selected coordination compounds were investigated primarily.1. The coordination chemistry based on single and multi-armed oxadiazole bridging ligands with inorganic Ag(I) and Cu(II) salts has been investigated. Nineteen new coordination compounds, namely [Ag(L1)]PF₆·CH₃OH (1), [Ag(L1)]ClO₄·CH₃OH (2), Cu(L2)(NO₃)₂·2(CH₂Cl₂) (3), Cu(L2)₂(ClO₄)₂·2(CH₂Cl₂) (4), Cu(L2)Cl₂ (5), [Cu₄(L3)4(C₄H₈O)₂(H₂O)₂](ClO₄)4 (6), {[Ag(L4)(EtOH)]BF₄}_n (7), {[Ag(L4)(EtOH)]ClO₄}_n (8), {[Ag(L4)(CH₃OH)]SO₃CF₃}_n (9), {Ag(L6)SbF₆}_n (10), {[Ag(L7)]SbF₆·(C6H₆)} n(11), {[Ag(L9)](THF)SbF₆·0.5(C6H₆)}_n (12), {[Ag(L9)](THF)ClO₄·0.5(C6H₆)} n(13), {[Ag(L9)](THF)SO₃CF₃·0.5(C6H₆)}_n (14), {{[Ag(L9)]BF₄}·2(CH₂Cl₂)·0.5(C6H₆)}_n (15), {Ag(L10)SbF₆}_n (16), {[Ag (L10)](ClO₄)·0.5(C6H₆)}_n (17), {[Ag(L10)](BF₄)·0.5(C6H₆)}_n (18) and [Cu2(L11)(EtOH)]Cl (19) were synthesized based on them, respectively. Their single crystal structures and luminescent properties were investigated in the solid state.2. The coordination chemistry of pyridyl-4, 5-imidazoledicarboxylic acid ligands with inorganic Mn(II), Zn(II) and Cd(II) salts has been investigated. Five new coordination polymers, namely {Mn(C₁₀H₅N₃O₄)(H₂O)}_n (20), {Zn(C₁₀H₅N₃O₄)(H₂O)}_n (21), {Cd(C₁₀H₅N₃O₄)(H₂O)₂}_n (22), {[Mn(C₁₀H₅N₃O₄)(H₂O)]·1.5(H₂O)}_n (23) and {Cd(C₁₀H₅N₃O₄)(H₂O)}_n (24) were synthesized based on them, respectively. Their single crystal structures and luminescent properties were investigated in the solid state.3. Synthesis of Cu(II)-macrocyclic ring-containing ploymer complex , namely {[Cu₂(L15)₂](unknown solvate)}_n (25), based on 1, 3, 4-oxadiazole bridging ligand end-capped by chelating Schiff-base coordination sites and Cu(AcO)₂ was investigated primarily. Furthermore, based on {[Cu₂(L15)₂](unknown solvate)}_n (25) and silver ion, AgI-CuII mixed-metal polymer, namely {[Ag₂Cu₂(L15)₂](ClO₄)₂(unknown solvate)}_n (26) was synthesized. Their single crystal structures were determined by X-ray single-crystal diffraction.4. The luminescent properties of selected organic ligands and coordination compounds were investigated in the solid state. The results show that the emission wavelength and intensity of free organic molecules were significantly affected by their incorporation into the metal-containing coordination compounds.5. The electrical conductive properties of selected compounds were investigated. The primary result indicates that these compounds behave as typical semi- conductors.The results reported herein demonstrate that the use of bent 1, 3, 4-oxadiazole bridging ligands and pyridyl-4, 5-imidazole dicarboxylic acid ligands as precursors to bind transition metal ions, is in fact a new and efficient approach for synthesis of novel supramolecular networks with interesting chemical and physical properties.