Syntheses, Structure And Property Studies Of N-heterocyclic And Aromatic Carboxylate Ligands And Coordination Polymers

In recent years, coordination polymers become one of the hotspots for coordination chemistry, due to their unique spatial structure and great potential for practical applications in materials and catalysis. So it is meaningful for us to design and synthesis novel ligands and coordination polymer. Nine N-hetero -cyclic and aromatic carboxylate ligands were designed and synthesized, five of them are new compounds and reported for the first time. Three coordination polymers were synthesized with two of them as ligands by solvolthermal process. All of them are reported for the first time. The crystal structures of them were chractered by single-crystal X-ray diffraction and the fluorescence measurements, hydrothermal stability, electrochemical properties and calculate -ions of quantum chemistry have been investigated. The main works are as following:1.Using 2-cyanopyridine as the starting material, 5-(2-pyridinyl)-1,2,4- triazole (ligand L1) and 4,4'-bis[5-(2-pyridinyl)-1,2,4-triazol-1- ylmethyl]biphe nyl (ligand L2) have been synthesized throughmulti-stepreactions. Using 4 -(bromo methyl)benzonitrileasthestartingmaterial, 2,4,6-tris{[4-(1,2,4-triazol-1 -ylmethyl)]phenyl}-1,3,5-triazine (ligand L3), 2,4,6-tris{[4-(benzimidazol-1-yl methyl)]phenyl}-1,3,5-triazine (ligand L4), 2,4,6-tris{[4-(benzotriazol-1-ylme thyl)]phenyl}-1,3,5-triazine (ligand L5) and 2,4,6-tris{[5-(2-pyridinyl)-1,2,4 -triazol-1-ylmethyl]phenyl}-1,3,5-triazine (ligand L6) have been synthesized. Using 3-hydroxy -2-naph thoic acid as the starting material, 3-(carboxymethoxy) -2-naphthoic acid has been synthesized through multi-step reactions. (ligand L7). Using p-Methylbenzaldehyde as the starting material, 4,4'-dimethylbenzilic acid (ligand L8) and 4,4'-di carboxybenzilic acid (ligand L9) have been synthesized through multi-step reactions. All the stuctrures of intermediates and products have been charactered by IR,1H-NMR, 13C-NMR.2. Complex 1 has been synthesized with ligand L7 and the transition metal Co(II) salt by solvolthermal reaction. On the other hand, two Cu(II) complexes have been synthesized with ligand L1 and Cu(II) salts, which show different structures in different coordination modes. All these complexes were reported for the first time. Pressed of time,the complexes of other ligands haven't been synthesized,they must be sythesized by the future work of the research. 3. The structures of complex 1, 2, 3 and ligand L2 have been determined by single-crystal X-ray diffraction. The thermogravimetry of complex 1 has been also determined. The fluorescence properties of all the complexes have been measured and anylyzed. The electrochemical properties of all the complexes have been anylyzed in details. Furthermore, quantum chemistry calculations were performed on all the complexes and ligand L2 according to their crystal data, and their stability, energy of molecular orbital and composing were also discussed.