Design, Syntheses And Properties Of Metal-organic Frameworks With 1,1’:4’,1’’-terphenyl-2’,4,4’’,5’-tetracarboxylate

Over the past two decades, a lot of coordination polymers（nonporous CPs and porous CPs also called metal-organic frameworks, MOFs） have been synthesized based on a variety of organic ligands and they exhibit the fascinating functional properties and potential applications in the fields such as luminescence, magnetism, gas storage, sensor, catalysis, ion exchange and so on. In this thesis, 1,1’:4’,1’’-terphenyl-2’,4,4’’,5’-tetracarboxylate（H4L） and 1,10-phenanthroline are used as organic ligand, and different metal ions are used as metal centers. Under solvothermal conditions, eighteen new coordination polymers were synthesized. These complexes（1-18） were characterized by single crystal X-ray diffraction, powder X-ray diffraction, fluorescent spectrum, IR spectrum, elemental analysis and thermogravimetric analysis. In general, the main contents of this thesis are summarized as follows:1. Based on 1,1’:4’,1’’-terphenyl-2’,4,4’’,5’-tetracarboxylate and some metal ions(Mg²⁺、Ni²⁺、Co²⁺、 Ag+), seven 3D coordination polymers were synthesized. Single crystal X-ray crystallographic analysis reveals that complexes 1-3 are isostructural. All complexes except 4 possess a series of parallel aligned M-O-C chains linked along two directions by para-terphenyl moieties of L4- ligands to lead to the three-dimensional frameworks. In 4, each dinuclear Ni2 unit is linked with other four dinuclear Ni2 units by para-terphenyl moieties of L4- ligands to lead to the three-dimensional 4,4-connected binodal（42.84）（42.84） topological network. The emission of complex 1 should be originated from the coordinated L4- ligands. However, for the d10 metal compound, the emission of complex 7 may be the result of synergistic effects of the intraligand charge transfer（ILCT）, charge transfer between the Ag+ ions and the L4- ligands（LMCT or MLCT） and the Ag-Ag interactions.2. Based on 1,1’:4’,1’’-terphenyl-2’,4,4’’,5’-tetracarboxylate,1,10-phenanthroline and transition metal ions(Mn²⁺、Ni²⁺、Co²⁺), five new coordination polymers were prepared by solvothermal reactions. The 8, 10, 11 and 12 possess the 2D（4,4） network. The 9 features the 3D framework, which can also be rationalized as a binodal 4,4-connected（42.84）（42.84） topological network. The H4 L in 8-12 display various coordination modes and coordination configurations. The variety of coordination modes may be the origin of the diversity of networks of 8-12.3. Based on 1,1’:4’,1’’-terphenyl-2’,4,4’’,5’-tetracarboxylate, and lanthanoid metal ions(Gd³⁺、Eu³⁺、Tb³⁺、Dy³⁺、Ho³⁺、Er³⁺), six new coordination polymers were prepared by solvothermal reactions. Single crystal X-ray crystallographic analysis reveals that they are isostructural. The L4-ligands act as μ7-bridge and μ8-bridge, respectively. The ligand unit serves as a 4-connected linker to connect four SBUs（[Ln4（COO）12]） to form a 3D framework. Photoluminescence properties of the complexes were investigated, complexes 13-18 exhibit blue-violet luminescence at about 400 nm, which may be originated from the coordinated L4- ligands. In addition, 14 and 15 have the characteristic emission peaks of Eu³⁺ and Tb³⁺, respectively. The phenomena indicate the uncompleted energy transfer between L4- ligands and lanthanoid ions.