Synthesis, Characterization And Crystal Structure Of Metal-organic Complexes Based On N-O Containing Mixed Ligands

The rational design and synthesis of metal-organic coordination polymers (MOPs) is of significant interest currently, not only due to their potential applications such as catalysis, molecular magnets, photoluminescence, ion exchange, adsorption, and phase separation, but also because of their enormous variety of interesting molecular architectures and topologies. In this paper, by the self-assembly of mixed ligands and transition metal ions,9novel metal-organic coordination compounds have been solvothermally synthesized and characterized, and complexes have been determined by X-ray single crystal diffraction, thermal analysis, X-ray powder diffraction, elemental analysis or fluorescence spectroscopy. The text is divided into four chapters, each chapter is as follows:In the preamble of the first chapter, the basic principles and concepts of supramolecular chemistry, coordination chemistry and metal organic complexes have been introduced. Selected focus on the factors influencing the structure of the coordination complexes.In the second chapter, using nitrogen-containing heterocyclic ligands and oxyanion ligand as mixed-ligand to self-assemble with cadmium ions, two novel structures of complexes1and2:{[Cd6(dpb)6(HCOO-)(H2O)4]-4NO3-·4H2O}n (1){[Cd4(tib)4(H2O)4(NO3-)6]·2NO3}n(2)(dpb=1,4-bis-(4-pyridyl)-benzene, tib=1,3,5-tris(1-imidazolyl)benzene). In1, the coordinated formate ligand from in situ hydrolyzation of DMF binds metal centers to generate a rigid2D metal-formate honey-comb layer, further connected by dpb ligands to result in a3D pillar-layer complex; while complex2possesses2-fold interpenetrating2D framework with an extremely rare (3,4) connected topology.In the thrid chapter, by one-pot reaction of H2L (H2L=2,2’-(4,6-dimethyl-5-nitro-1,3-phenylene)bis(methylene)-bis-(sulfanediyl)) and copper ions under solvothermal condition, two metal-organic coordination complexes, Cu2(L)2(py)4·4dmso (3) and Cu2(L)2(py)6·3dmso·py (4) have been synthesized in one reaction vessel. Interestingly, pure rhombus-shaped phase of complex4was obtained when0.15mL of pyridine was added in the reaction. In this chapter, we will focus on the syntheses, structures and characteristions of these two complexes.In the fourth chapter, we selected a meta dicarboxylic acid ligand (H2dna= 4,6-dimethyl-5-nitroisophthalic acid), by changing the N-containing bidentate ligand to assemble with Cd or Zn ions five new metal-organic coordination complexes with diverse and interesting structural topologies were formed. Moreover, the coordination modes of the dna ligand as well as the comparisons and effects of N-donor ligands on the structures of the complexes also have been discussed in detail.