| The rational design and synthesis of metal-organic coordination polymers based upon self-assembly principle of organic ligands and metal ions has become an attractive and promising research area, owing to their intriguing structural topologies and their potential application in catalysis, luminescence, magnetism, gas absorption and molecule recognition. In the construction of coordination polymers, the combinational use of carboxylate ligands and neutral nitrogen-containing bridging ligands is one attractive approach, the assembly of the mixed ligands with metal ions has been widely used. In comparison with rigid ligands with single conformation, flexible bridging ligands usually possess several conformations, they can freely bend or rotate to meet for the coordination geometries of metal ions, resulting in unexpected frameworks with beautiful aesthetics and useful properties, but the prediction and control of target products is concomitantly complicated.Base on the viewpoint, in this thesis, we chose1,2-bis(4-pyridyl)ethane (Bpe),1,2-bis(pyridyl)ethylene (Bpy),1,2-bis(imidazol-1’-yl)ethane (Bime),1,4-bis(imidazol-1’-yl)butane (Bimb) and1,4-bis(2-methylimidazol-l’-yl)butane (Bmib) as flexible nitrogen-containing bridging ligands,5-hydroxyl-isophthalate (H2ip-OH),5-nitro-isophthalate (H2ip-NO2),1,4-bis[(pyridinium-4-carboxylate)methyl]benzene dibromide (Bpmb-2HBr) as dicarboxylate ligands, the self-assembly of the mixed ligands with metal ions under hydrothermal/solvothermal/amibent conditions, generated ten novel metal-organic coordination polymers,[Co2(ip-OH)2(Bpe)]n (1),[Co2(ip-OH)2(Bpy)2]n (2),[Co(ip-OH)(Bpe)]n (3),{[Co2(ip-NO2)2(Bimb)1.5]-0.5H2O}n (4),{[Ni2(ip-NO2)2(Bimb)1.5]·0.5H2O}n (5),{[Ni4(ip-NO2)3(Bimb)2(μ2-OH)2(H2O)]-CH3CH2OH}n (6),[Zn(ip-NO2)(Bmib)]n (7),[Co(ip-NO2)(Bmib)]n (8),[Cd3(Bime)2(Bpmb)(μ-Br)2Br4·DMF]n (9) and [Cd2(Bimb)2(μ-Br)2Br2]n (10). All of the complexes were characterized by single crystal X-ray diffraction, X-ray powder diffraction, IR spectra and elemental analysis. The corresponding luminescence, magnetism and thermogravimetric analysis were also investigated. Complexes1,3,4,5,6,7and8are three-dimensional networks, while complexes2,9and10are two-dimensional layes. Thermogravimetric analyses show that the complexes possess good thermal stability, their decomposition temperatures are in the range from330℃to420℃except for complex9(246℃). |
