Studies On Synthesis, Structures And Properties Of Coordination Polymers With Thiazole-, Imdazole-and Pyrazole-based Ligands

The rational design of metal-organic coordination architectures with desired functions are one of the most attractive fields in current coordination chemistry, due to their fascinating structures and potential applications. The ligands containing imidazole (pyrazole and thiazole) groups have been demonstrated to be good bridging ligands due to their diverse coordination modes. However, the studies of coordination chemistry of imidazole- and thiazole-based flexible acetate acid as well as some rigid ligands containing bis(imidazole) were rarely reported. In this thesis, five ligands and their twenty-nine complexes with various structures and topologies have been synthesized and characterized. Several factors influencing the final structures, such as the coordination modes of metal ions, the properties of ligands, pH value of reaction conditions and other factors were discussed. Furthermore, luminescent, magnetic and gas adsorption properties of some complexes have also been studied. The main contents are summarized as below:1. Eight metal complexes have been synsthesized from the first used ligands (H2L1, HL2). In this chapter, a new flexible ligand, 2-(1H-benzimidazol-2-ylthio) acetic acid (H2L1) which contains both carboxylate and imidazole groups, as bridging ligand was synthesized to construct ZMOFs, and disscuss some factors on coordination polymers. Another new ligand 2-carboxymethylmercapto-1,3,4-thiadiazole acid (HL2) which contains both carboxylate and thiadiazole groups, have been utilized to construct two 3D MOF which exhibit both porosity and metamagnetic behaviors.2. The (1-pyrazolyl)pyridazine (L3 and L4) and (1-imdazolyl)pyridazine (L5) ligands and its nine transitional metal complexes (such as AgⅠ, CuⅡ, CoⅡ, NiⅡand CdⅡ) have been synthesized and structurally characterized. The influences of the metal ions on the formation of coordination frameworks and the diverse coordination modes of the ligands are discussed. In addition, luminescent properties of some AgⅠcomplexes have also been studied. 3. Ligand L5 containing two imidazolyl group is a neutral bridging ligand, and anion from the metal salts usually has an anion effect to the final structure when L5 is coordinated to metal ions. Here, by the introduction of some carboxylate ligand into the system, 12 metal complexes containing ZnⅡ, CdⅡand CoⅡwith interesting frameworks have been constructed and the influences of the auxiliary ligands have also been investigateed.