Synthesis And Properties Of Metal-organic Frameworks Based On Organic Aromatic Polyearboxylate Ligand

It is not only the coordination polymer frameworks’ potential applications in porous materials, microelectronics, nonlinear optics, and catalysis which has triggered the current interest, but also their intriguing variety of topologies and entanglement motifs,during the past decade. So far, the most recognized method of designing structural architecture is mixing metal ions with useful organic ligands directly. Among kinds of organic ligands used as linkers in the design of supramolecular networks, aromatic polycarboxylates(O-donor) and N-containing heterocyclic rings are the most widely used due to their structural rigidity and flexible coordination modes. In recent years, as an eminent type of multi-dentate O-donor ligands, organic aromatic poly-carboxylate ligands have been extensively studied because of their diverse coordination modes and sensitivity to p H values of the carboxylate groups. Meanwhile, the flexible N-containing ligand possessed the merits of N-containing heterocyclic rings and its-CH2- spacer which can coordinate with the metal ions in various and allowed them with flexible conformation and better adaptability to construct polymeric networks. By varying the metal nodes they can yield the formation of the structures of higher dimensions even the special structure of interpenetration and spiral. In addition, the weaker noncovalent interactions, including hydrogen bonds or π···π interactions are also play an important role in the self-assembly process. However, more subtle conditions, such as p H values, molar ratio of reactants, counteranions and solvent etc., can effect the final structures. Hence, there is still a long way to predict the discrete coordination polymers through the self-assembly in crystal engineering before it will be possible to say that these ambitious projects have been fully realized.With a growing interest in the area of coordination polymers and host/guest chemistry, a certain number of transition metal ion coordination architectures have been reported in the literature. The main contents of the thesis are as following:1.we use Homophthalic acid and pbix [1,4-bis(imidazol-1-ylmethyl)benzene] as the organic ligand and transition metal as central ions, which were placed in the Teflon-lined stainless steel autoclave, and the autoclave was sealed, heated for several days. The results show that reacted condition and temperature have influence on the final structure.2.we use Homophthalic acid as the organic ligand and rare earth metal as central ions under the solvothermal method to explore the effect of different central metal ions on the final structure.3.In contrast with the Homophthalic acid ligands, the reactions of transition metal ions, 4,4’-sulfonyldibenzoic acid ligand and pbtx [1,4-bis(1,2,4-Triazole-1-ylmethyl)benzene], were used to show that different organic aromatic polycarboxylate ligand have influence on the final structure.