| Recently, an increasing number of material scientists pay more and more attentions on the research field of coordination polymers, not only because of its versatilities on structure but also due to its widely potential applications such as catalysis, drug delivery, chemical sensing, magnetic properties. In this context, we are interested in small molecule and inorganic ion recognition based on flurorescence and magnetic complexes. This thesis mainly includes following three parts:1. Two new isomorphous microporous metal-organic frameworks (MOFs) Eu-MOF and Gd-MOF have been systhesized under the solvothermal conditions by using a rigid tetracarboxylic acid ligand containing a lewis basic nitrogen atom. The two compounds are shown as 2D microporous structure and there are pridiyl nitrogen atoms direct into the pores. The Eu(Ⅲ)-MOF(1) has a characteristic red fluorescence of Eu(Ⅲ) and the Gd(Ⅲ)-MOF(2) possess a blue fluorescence emission attributing to the organic ligand. Considering these properties mentioned above, these two materials are both used in the fluorescence recognition experiments. As a result, these two compounds both show sensitive and selective recognition towards o-, m-and p-nitrophenol in water systems, Additionally, the Gd(Ⅲ)-MOF also has a recognition ability towards Fe(Ⅲ) ion in aqueous solution. This discovery has important guiding significance for the detection of pollutants in water and the detection of Fe (Ⅲ) ions which play an important role in the organism.2. Four coordination polymers have been obtained based on several zwitterionic carboxylate ligands and sodium azide:[Mn3(L2)(N3)6(H2O)4](3),[Co3(L3)(N3)6(H2O)6](4)(L2=1,1’-di(4-carboxyl phenyl)-4,4’-dipyridine,L3=1,2,4,5-tetra(4-carboxylpyridyl-l-methylene)benzene),[Mn3(L4)4(N3)(C H3CH2OH)(H2O)]C1O4·4H2O(5)and[Co3(L2)4(N3)2(H2O)2]-4N03(6)(L4=chloride[4-(1-carboxylphe nyl)pyridine-3)benzonic-acid],L2=dichloride[1,1’-di(4-carboxylphenyl)-4,4’-dipyridine]. The metal ions in compound 3 and 4 are both connected by mixed bridge consisting by carboxylate and azide. The connecting mode can be simplified as AABAA alternating 1D chains, then the chains are interlinked into a 2D layer by the zwitterionic carboxylate ligands. The alternating mixed bridges are (EO-N3)(OCO) and (EO-N3)2 which transmit antiferromagnetic interaction between Mn(II) ions in complex 3, while in complex 4, the alternating bridges are (EO-N3)(OCO)2 and (EO-N3)2 which transmit ferromagnetic coupling between the Co(Ⅱ) ions. In the structures of complexes 5 and 6, there are (μ-COO)2(μ2-O) bridges which linked Mn(Ⅱ) or Co(Ⅱ) ions into Mn3 or Co3 trinuclear units. For the Mn3 units, the μ2-O atoms are from the carboxylate groups of organic ligands in compound 5 and from water molecules in 6. The trinuclear units are connected into 1D chains and 3D pcu network in compounds 5 and 6 respectively. The mixed bridges transmit antiferromagnetic interactions in both compounds. The magnetic data are fitted by using appropriate models for compound 3,5 and 6 and the obtained values are reasonable compared with other reported ones.3. Five complexes are synthesized by using two isomers of zwitterionic carboxylate ligands and the crystal structures are analyzed. |
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