Synthesis,Crystal Structure And Properties Studies Of Nitrogen Heterocyclic And Of Carboxylic Complexes

Nitrogen-containing heterocyclic and carboxylic ligands are one of the most commonly used organic ligands constructing metal coordination polymers and supramolecular self-Assembly.1,3,5-triazine bridges with rigid nitrogen heterocyclic or carboxylic ligands, which has aroused people’s attention and interest because of their large rigid planes and diversity coordination patterns. Triazine derivatives complexes are not only with the rich and varied structure, but also very wide application, which are sensors, molecular carriers, air storage materials, ion exchangers and catalyst materials, and so on. Therefore, intensive study of s-triazine ligands and their complexes is of great realistic significance.This paper chose1,3,5-triazine rings as the mother, introducing small organic molecules like nitrogen azoles (imidazole and pyrazole) and carboxylic acids (rigid and flexible carboxylic acids), respectively, in which three chlorine atoms in triazine rings were substituted, so as to obtain a series of organic ligands L1to L6. Through the diffusion and hydrothermal method, we synthesized a series of coordination polymers successfully with s-triazine derivative ligands and transition metals or rare earth metals,and took characterization with their structures, including Element Analyzers, Infrared Spectrometer, X-ray Single Crystal Diffraction, Fluorescence Spectroscopy and UV-vis Absorption Spectroscopy. What’s more,we studied their optical properties. This paper is divided into four chapters, the main contents are as follows:In chapter2, we synthesized two kinds of s-triazine nitrogen azole ligands and their complexes, and discussed their crystal structures and optical properties.we synthesized complexes [Zn2(C9H6N7O)4]·5(H2O)(1) and [CuL (H2O) Cl]n (2), using organic ligands2,4,6-tris(imidazol-l-yl)-1,3,5-s-triazine (TITZ) and2,4,6-tris (pyrazol-1-y1)-1,3,5-s-triazine(TPZT). we took structure characterization on ligands and their complexes, X-single crystal diffraction on crystal structure determinations of1and2was carried out.(1) The complex [Zn2(C9H6N7O)4]-5(H2O)(1) was synthesized by the reaction of ligand L1and ZnCl2in an H-shaped tube.The crystal structure of [Zn2(C9H6N7O)4]-5(H2O)(1) has been determined by single-crystal X-ray analysis. The crystal of complex1is monoclinic, space group C2/c, Zn2+is coordinated with three imidazolyl nitrogen atoms and one carboxylic oxygen atom. A study of the fluorescence property of the compound1was carried out, It revealed that the complex1occurred a fluorescence quenching phenomenon,which can provide a new detecting Zn2+method using in environmental engineering and biotechnology. (2) The complex [CuL (H2O)Cl]n(2) was synthesized by the reaction of ligand L2and CuCl2by solvent evaporation.The crystal structure of [CuL (H2O)C1]n(2) has been determined by single-crystal X-ray analysis. The crystal of complex2is monoclinic, space group P2(1)/n.The complex defines a zigzag1D covalent chain, along the b cell axis, through apical copper-oxygen bonds. The geometric configuration of Cu(II) is tetrahedron. The packing is then correctly described as a hydrogen and weakly covalent bonded3D network.In chapter3, we synthesized four kinds of s-triazine carboxylic ligands, however, we only focused on the study of related properties of4,4’,4"-s-triazine-1,3,5-triyltri-p-aminobenzoate (H3TATAB) and its complexes.(1) The solubility of H3TATAB is very poor in water.However its sodium salt Na3TATAB is soluble in water, so as to determine the calcium chelate(75.85mg/g). The chelating stability constants of the three kinds of rare earth metal ions Eu3+,Tb3+,Nd3+were determinated. Their value were is large with1gK1=12.42;1gK2=10.72;1gK33=13.63respectively.It indicates that the coordination capacity of H3TATAB with the rare earth metal ions are very strong.(2) We adopted hydrothermal method to synthesized three new type of complexes with ligand H3TATAB and rare earth metal ions Eu3+, Tb3+, Nd3+. Compared with H3TATAB, the three complexes appeared significant displacement by the infrared and uv-vis spectra analysis, which indicated that ligand H3TATAB and rare earth metal ions occured coordination reaction. A study of the fluorescence property of the compound3and4was carried out, it showed that Eu3+and Tb3+complexes had strong absorption peak at614,619nm and545nm, respectively, with the performance of red and green lightting. And may be good candidates for light-emitting diodes(LEDs) and light applications.In short, this topics had designed and synthesized two kinds of crystals using s-triazine nitrogen azoles ligands (TITZ, TPZT), meanwhile, three kinds of rare earth compounds were built by s-triazine carboxylic acid ligand (H3TATAB). Their optical performance research had been carried out.All of above, the research of this paper has made contributions to provide many synthesis footage about the design and synthesis of s-triazine derivatives.