Syntheses,Structures And Properties Of Metal-organic Complexes Based On Heterocyclic Ligands With Nitrogen

In recent years, with the rapid development of high technology, materials science has become one of the hottest area of modern chemistry, multiple functional materials are showing rapid development momentum. Wherein, the metal-organic framework compounds due to its diverse structure, exhibited very broad applications in photoluminescence materials, ion exchange, optoelectronic materials, gas adsorption and catalysis. In this paper, we use pyridyl-imidazole derivatives and associated three-pyridine carboxylic acid as ligand, or flexible dicarboxylic acid as an auxiliary ligand, with metal salts by hydrothermal and natural evaporation method got fourteen new complexes. The structures were characterized by single crystal X-ray analysis, elemental analysis, IR, UV-Vis spectra and fluorescence spectra of thermogravimetric analysis to study the thermal stability of complexes of the pore structure compound specific surface area and pore size distribution analysis, to develop their potential use in catalysis.These results will be introduced from the following aspects:1. Introduces the concept of a metal-organic framework compounds, its research and developing prospects. Synthesis prospects of the metal-organic compounds.2. Three different single molecule complexes based on 2-(2’-pyridyl)-imidazole or 2-(2’-pyridyl)-benzimidazole ligand were self-assembied by hydrothermal and natural evaporation method. The crystal structure of complex [Cu(PyIm)Cl]·(H20) 1 (PyIm=2-(2’-pyridyl)-imidazole) belongs to orthorhombic, Pnna space group, three dimensional supramolecular structure is assembled by hydrogen bonds between molecules. The crystal structure of complex [Ni(PBIm)Cl]·(H2O) 2 (PBIm= 2-(2’-pyridyl) benzimidazole) belongs to monoclinic, C2/c space group, it self-assembles into a two dimensional layered structure by hydrogen bond interactions. Binuclear nickel complexes [Ni2(PBIm)2Cl2(CH3CH2O)2] 3 belongs to monoclinic, P21/c space group, a 1D chain of 3 is assembled by intermolecular hydrogen bonds. Their fluorescence properties and thermal properties were investigated.3. Three different single-molecular complexes were obtained based on the reactions of 2-(1H-benzimidazol-2-yl)-4-bromophenolate with transition metal salt: [Co(Ci3H8BrN2O)2] 4, [Ni(C13HgBrN2O)2] 5, [Co(C13H8BrN2O)2]·2(CH3OH) 6 and [Zn(Ci3H8BrN2O)2]·DMF·3H2O 7. The crystal structure of 4 belongs to monoclinic, P21/c space group, and a three dimensional supramolecular structure is assembled by hydrogen bonding interactions among molecules.5 belongs to monoclinic, P21/c space group, it self-assembles into a two dimensional layered structure by hydrogen bonds. Complexes 6 and 7 belong to triclinic system, space group Pi, one-dimensional chain of 6 is assembled by intermolecular hydrogen bonds, whereas 7 self-assembles into a two-dimensional layered structure by hydrogen bonding interactions. Thermal stability and fluorescent properties of these complexes were also investigated.4. Four new coordination compounds, [Ni(L)2]·H2O 8、[Cu(L)(C104)]n 9、 [Cu(L)(p-bdc)] 10、{[Cu2(L)2(p-bdc)]·2(H2O)}n 11 (L= 4’-carboxy-2,2’:6’,2"-terpy-ridine, H2tp = terephthalic acid), were synthesized by employing the 4’-carboxy-2,2’:6’,2"-terpyridine and terephthalic acid acted as an auxiliary ligand under hydrothermal conditions. The single molecule complex 8 belongs to orthorhombic, I-42d space group, it self-assembles into two dimensional layered structure by hydrogen bonding interactions. Complex 9 displays 1D chain structure composed of ligands and metal ions. Complex 9 belongs to monoclinic system, space group P21/c, a 2D layered structure is assembled by hydrogen bonds between the chains. The single molecule complex 10 belongs to triclinic system, space group Pi, a 3D network is assembled by hydrogen bonds. Complex 11 displays 1D chain structure, belongs to triclinic system, space group Pi, and it self-assembles into a 3D netlike structure by the inter-chain hydrogen bond interactions5. Three complexes were self-assembied based on 4’-carboxy-2,2’:6’,2"-terpyridine with pathalic acid, (o-bdc), adipic acid (adip) and trimesic acid (trim) as auxiliary ligands,{[Mn(L)(o-bdc)]·H2O}n 12、{[Mn(L)(adip)]·H2O}n 13、 [Mn(L)(trim)(H2O)]n 14. The structures were characterized by single crystal X-ray analysis. Complex 12 displays 2D layered structure. The 2D layered structure is further extended to a 3D supramolecular network. Both the complex 13 and 14 display 1D chain structure composed of ligands and metal ions, and 2D layered structure are assembled by hydrogen bonds between the chains. The thermal stability, pore structural compound specific surface area and pore size distribution of complexes of were analysized.