Construction Of Coordination Polymers Based On A Novel Tripyridyl Substituted Triazole Ligand

Metal-organic frameworks (MOFs) material is one of current hot research topic of coordination polymer, which focuses on not only the interesting structural architectures, but also the potential applications as new functional materials in electroluminescence, adsorption and separation, catalysis and magnetism.In this thesis, a novel tripyridyl substituted triazole building block3,4-bis(2-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (L) is initially employed, to assemble with different transition metal ions, which affords eighteen novel coordination complexes:[Zn(L)2(H20)2](C104)2(1),{Zn(L)(dca)Cl}n (2),{Zn(L)(dca)I}2(3),{[Cd(L)2](C104)2(H20)}n (4),{Cd(L)(dca)Cl}n (5),{Cd(L)(dca)Br}n (6),{[Cd(L)(dca)(C104)](H20)0.25}n (7),{[Cd(L)(dca)2(H2O)](H2O)}2(8),{Cu(L)08-(dca)2(H20)0.6}n (9),{Cu(L)(dca)Cl}n (10),{Cu(L)(N3)2}n (11),{Cu(L)(SCN)2}n(12), Cu(L)2(tcm)2(13),{[Co(L)(dca)2(H20)](CH3OH)0.5(H20)0.5}n (14),{[Co(L)(dca)2]-(H20)0.5}n (15),{[Co(L)(N3)2](H20)o.5}n (16),[Co(L)(SCN)2](H2O)2(17) and [Co(L)2(H2O)2](tcm)2(H2O)2(18), dca=N(CN)2-, tcm=C(CN)3-). All complexes have been characterized by single-crystal X-ray diffraction, IR, elemental analysis, powder X-ray diffraction.Single-crystal X-ray diffraction analyses indicate that the structures of these ZnⅡ/CdⅡ complexes mainly depend on the radii of counterions. Complexes2,5and6display3-D networks, the radii of halogen anions(Cl-and Br) are small, in which ligand L adopt transiod conformation. In complexes1,3,4,7and8, the radii of anions (ClO4-、I-and SO42-) are large, ligand L take cisoid conformation, which lead to complexes display variety of structures, ranging from0-D to2-D. Furthermore, the thermal stability of ZnⅡ/CdⅡ complexes were studied, and the luminescent properties of L and complexes2,3,5-8were tested at room temperature.The structures of CuⅡ/CoⅡ complexes are relevant to the pseudohalogen auxiliary ligands, metal ions and the reactant ratio. Complexes can exhibit versatile structures in different pseudohalogen anions conditions.11,13and15display1-D,0-D and2-D structures, which mainly attribute to different pseudohalogen anions (N3-, tcm, dca). Ligand L adopts transiod conformation in CuⅡ complexes (10-13), while takes cisoid conformation in CoⅡ complexes(14-16,18), the results show that under the same conditions, the metal ion can influence the structures of coordination polymer. Complex9shows1-D chain structure and10displays3-D networks structure,which depends on the ratio of L/M/dca. Complexes14and15also have different stoichiometric ratios and exhibit1-D and2-D structures respectively. In addition, higher-dimensional extended networks are further formed with the aid of additional secondary interactions such as H-bonding and stacking interactions in complexes1115,17and18...