The Syntheses, Structures And Properties Of Metal-Organic Frameworks Based On Multi-Carboxylate Ligands

Metal-organic frameworks (MOFs) is formed through the organic ligands and metal ions or metal clusters. From the end of the90end of the year, the MOFs has experienced a rapid development stage. During this period, a large number of novel MOFs have been synthesized, and the applications are also constantly expand. Showing potential application in gas storage and separation, catalytic, optical and magnetic. Compare with the traditional porous materials, such as activated carbon, zeolite, MOFs not only have a diverse structure, large internal surface areas and ultralow density, but also can been synthesiszed by rational design.In this thesis, the amide functional group is employed as the basis of the modification sites, and the bridging ligand to assemble with transition metal ions and afforded a series of three dimentional architectures. The synthesis, crystal structure, IR, TGA of these complexes will be documented in detail. The gas adsorption properties of some complexes have also been studied. The main results can be summarized as follow parts:1. Design and synthesis of ligand5-(3,5-dicarboxybenzamido)isophthalic acid (H4DBPC): It was obtained from organic reaction using1,3,5-benzenetricarboxylic acid and5-aminobenzoic acid and was characterized by IR spectrum,1H-NMR spectrum.2. Three dimensional metal-organic frameworks with large pore:Solvothermal reactions of5-(3,5-dicarboxybenzamido)isophthalic acid (H4DBPC) and transitional metal ions Cd(II) and Co(II) afforded four coordination polymers Co2(DBPC)(DMA)4(1), Co2(Py)2(DBPC)(DMA)2(2), Cd2(DBPC)(DMA)3(3) and Co2(DBPC)(DMA)3(4). Compound1exhibit a three dimensional framework with Co2as SBUs and bridging ligands. Changing the coordinating solvent molecules in the assembly procedure affords its isostructural compound2. Compound3was built by binuclear Cd clusters as SBUs and the ligands with different coordination modes to form a novel three dimensional architecture. Solvothermal reactions of H4DBPC and Co(II) with DMF and H2O affords compound4features a three dimensional framework. Which compounds2wsa carried out the adsorption test and the catalytic test.3. Metal-organic frameworks with the regulation of pH:By regulating the PH value of the reaction system three compounds was obtained [Zn(DBPC)]·2H3O+·H2O(5),[Cd(DBPC)]·2H3O+·2H2O(6) and [Zn2(DBPC)2]·Cl·5H3O+(7). Compound5displays a two-fold interpenetrated three dimensional architecture consisting of nononuclear zinc and bridging ligands. Compound6and compound5are isomorphism. Compound7also exhibit a two-fold interpenetrated three dimensional framework, which the nononuclear zinc is five-coordination connected by ligands with different coordination modes. From these compounds we can see, by adding hydrochloric acid, the ligand will not easy deprotonation under the acidic conditions, leading to reduce the coordination sites and easy interpenetrating, reducing the porosity of the skeleton.4. Ancillary ligands in the synthesis of metal organic framework; By attempting to add the terephthalic acid, Benzene-1,3,5-tricarboxylic acid, etc in the reaction system, hoping to get more diverse topology of the framework, but just obtain two compounds without the coordination of H4DBPC:Cd3(BTC)2(H2O)5·H2O(8) and Gd2(BDC)3(DMF)2(H2O)2(9).5. Supertetrahedral cluster of metal organic framework:Synthesis of two simple Supertetrahedral cluster:[Ga10S16(C6H7O+·2C6H7N (10)[(Ga10S16)2(C6H7N)6(N2C12H10)]·4C6H8N (11).