| In the past decades, N-containing heterocyclic organic ligands have been widely used in the design and synthesis of transition-metal-based coordination polymers(or metal-organic frameworks) in crystal engineering not only because these organic ligands possess strong coordination ability and diverse backbones, but also because these solid crystalline materials have potential applications such as gas adsorption, catalysis, ion-exchange, luminescence, and so on. In this thesis, three flexible N-containing heterocyclic ligands containing perfluorinated backbones including 2,3,5,6-tetrafluoro-1,4-bis(imidazol-1-ylmethyl) benzene(tfbib), 2,3,5,6-tetrafluoro-1,4-bis(1,2,4-triazol-1-ylmethyl) benzene(tfbtb) and 2,3,5,6-tetrafluoro-1,4-bis(benzimidazole-1-ylmethyl) benzene(tfbbib) have been synthesized, and a series of new coordination polymers have been obtained by the reactions of these organic ligands with transition metal salts via common solvent evaporation and hydrothermal methods. Furthermore, the influence of counteranions, secondary organic ligands and reaction temperature on the structures and properties of the resulting complexes have also been investigated. Details are as follows:(1) Reaction of tfbib and Zn(OAc)2·2H2O in methanol at room temperature afforded a new complex [Zn(tfbib)(OAc)2]n(1).When the Zn(OAc)2·2H2O was replaced by Cd(NO3)2·4H2O, complex [Cd2(tfbib)(1,4-NDC)2]n(2) was hydrothermally synthesized using 1,4-naphthalenedicarboxylic acid(1,4-H2NDC) as auxiliary organic ligand. Single-crystal X-ray diffraction reveals that complex 1 is a one-dimensional(1D) coordination chain, while complex 2 features a three-dimensional(3D) coordination framework. In addition, the solid properties such as thermal stability and photoluminescence have also been studied briefly.(2) A series of new CuII, ZnII and CdII coordination polymers with ligand tfbtb were constructed via different synthetic strategies. Firstly, four CuII complexes [Cu(tfbtb)2(A)]n(A =(NO3)2 for 3,(BF4)2 for 4, SO4 for 5 and Br2 for 6) were prepared from the hydrothermal reaction of tfbtb with different copper(II) salts including Cu(NO3)2·3H2O, Cu(BF4)2, Cu SO4·5H2O and Cu Br2, respectively. Secondly, three ZnII complexes [Zn(Hfip)2(tfbtb)]n(7), [Zn(tfbtb)0.5(1,3-BDC)]n(8) and [Zn5(tfbtb)2(1,4-NDC)4(μ3-OH)2]n(9) were obtained from the hydrothermal reaction of Cd(NO3)2·4H2O and tfbtb in the presence of three aromatic acids as auxiliary ligands such as 5-fluoro-isophthalic acid(H2fip), isophthalic acid(1,3-H2BDC) and 1,4-naphthalenedicarboxylic acid(1,4-H2NDC), respectively. Moreove, assembly of Cd(NO3)2·4H2O with the mixed ligands of tfbtb and H2 fip at 130°C and 180°C yielded two new complexes [Cd(tfbtb)(fip)(H2O)2]n(10) and [Cd(tfbtb)1.5(fip)]n(11). X-Ray structural analysis indicates that complexes 3–6 are isostructural and display two-dimensional(2D) layered network. Complexes 7–9 display differenct coordination networks with 1D chain for 7, 2D sheet for 8, and 3D open framework for 9, respectively, illustrating the tunning effect of the auxiliary aromatic acid ligands on the connectivity and dimensionality of coordination networks. Upon differenct reaction temperature, complex 10 shows a 1D double-chain structure while complex 11 presents a 3D framework with a rare four-fold interpenetrated net, revealing the temperature-regulated effect.(3) A new N-containing heterocylic compound tfbbib has been synthezied and characterized. Hydrothermal reaction of Zn(NO3)2·6H2O, tfbbib and 1,4-H2 NDC yielded [Zn(tfbbib)(1,4-NDC)]n(12). Single-crystal X-ray diffraction reveals that 12 features a novel three-fold interpenetrated network, where both tfbbib and 1,4-NDC adopt bis-mondentate bridging coordination mode. |
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