Study On Design, Syntheses And Properties Of Metal-organic Coordination Polymers Base On A New Tridentate Carboxylic Acid

Metal-organic frameworks (MOFs), also known as coordination polymers, are a type of self-assembly constructed by metal ions and organic ligands. They are new crystalline materials that have an extensive application prospect. Owing to their high surface areas, uniform pores and other characteristics, they have attracted intense attentions for their potential applications in gas storage, separation, catalysis, luminescence, magnetism and so on. In this study, we focus on a new tridentate aromatic carboxylic acid as the basic building block. Under solvothermal condition, we got a series of new metal-organic coordination polymers. And they are been characterized by means of single X-ray crystallography, IR spectroscopy, elemental analysis, therrnogravimetric analysis for further research of their useful properties.1. A novel3D metal-organic frameworks as [Zn(pdcd)-H2O]-(C2H5OH)]n (1) with double ThSi2interpenetrating topological structure was been synthesized under solvothermal conditions by using this new tridentate aromatic carboxylic acid1-(4-carboxyphenyl)-2,5-dimethyl,1H-pyrrole-3,4-dicarboxylic acid (H3pdcd) and zinc ions. Despite the double interpenetrating structure, the metal-organic frameworks have middle-sized channels with6.85×6.49A along a axis. The compound1display high thermal stability, it will not collapse until it was heated above300℃.2. Two coordination polymers,[Zn(Hpdcd)(bbi)](DMSO)(2H2O)]n (2) and [[Ni(Hpdcd)(bbi)·H2O]2H2O]n (3), have been solvothermally synthesized, by modulating metal ions and solvent system, by using H3pdcd and bbi (bbi=1,1’-(1,4-butanediyl)bis(imidazole)). It is noteworthy that the H3pdcd has similar coordination behavior in these two compounds, the H3pdcd ligand has a preference for head-to-end coordination mode and the uncoordinated carboxylic group acts as side arm, resulting in the interesting interdigitation phenomena in2and3.