| In recent years, the coordination compounds with asymmetric ligand have received more and more attention because of their various structures and extensive applications in the filed of functional materials such as catalysis, luminescence and etc. This paper summarizes the research advances of 3,4-pyridinedicarboxylate coordination polymers. A series of coordination polymers constructed by 3,4-pyridinedicarboxylate and metal ions have been synthesized, and their crystal structures and properties were determined. In this paper, the main results as follows:First, four coordination polymers constructed by 3,4-pyridinedicarboxylate ligand and transition metal ions: [Zn(PDB)(phen)] (1), [Co(PDB)(2,2′-bipy)]n (2), [Ag2(PDB)] (3) and {[Mn2(PDB)2(2,2′-bpy)2(H2O)2]·2H2O} (4), have been hydrothermal synthesized and characterized by X-ray diffraction analysis, elemental analysis, IR, thermal analysis, and their fluorescent and magnetic properties were also studied. Additionally, fluorescent properties study indicates that complex 1, 3 and 4 show fluorescence, but the mechanisms of fluorescence are different. Magnetic properties study indicates that complex 4 shows weak anti-ferromagnetic interactions.In complexes 1-4, 3,4-pyridinedicarboxylate ligand adopts different coordination modes, which results in the former of various high dimensional supramolecular topological structures. The structures of complex 1 and 2 are similar, they both display two-dimensional layer structure. What different is that the two-dimensional layers are further connected byπ-πpacking interactions between 2,2′-bipy to form three-dimensional supramolecular network in complex 2. Complex 3 is a three-dimensional coordinated framework, which contains a mono- and dinuclear mixed one-dimensional polymeric chain. Complex 4 exhibits two-dimensional layer structure, which is further connected by hydrogen interactions to form three-dimensional supramolecular network.Second, six coordination polymers constructed by 3,4-pyridinedicarboxylate ligand and rare metal ions: [Ln2(PDB)2(OH)2(H2O)2]·H2O [Ln = Eu (5), Tb(6), Gd(7)], Ln(PDB)(OH) (H2O)2 [Ln = Eu (8), Tb(9)], [Sm2(PDB)3(phen)(H2O)·H2O]n (10) have been hydrothermal synthesized and characterized by X-ray diffraction analysis, elemental analysis, IR, thermal analysis, and their fluorescent and magnetic properties were also studied.Complexes 5, 6 and 7 are isostructural and exhibit the same two-dimensional topological network constructed by PDC-connected Ln-O-Ln double chains, which is further connected by hydrogen bonding interactions to form three-dimensional supramolecular network. Complexes 8 and 9 are isostructural and show the same two-dimensional layer structure, which is further connected by hydrogen bonding andπ-πpacking interactions to form three-dimensional supramolecular network. Complex 10 exhibit interesting one-dimensional nano-chain strcture, which is further connected by hydrogen bonding andπ-πpacking interactions to form three-dimensional supramolecular network. Additionally, fluorescent properties study indicates that complex 5, 8 and 6, 9 show characteristic transitions of Eu3+ and Tb3+, respectively. Magnetic properties study indicates that complex 5, 6 show different magnetic properties. Complex 5 show strong paramagnetic coupling interactions, while complex 6 show weak ferromagnetic coupling interactions. |
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