Synthesis, Crystal Structures And Properties Of Lanthanide Cluster Compounds

In recent years, polynuclear lanthanide metal compounds have attracted extensive attention because of their interesting topology and potential applications such as gas adsorption, molecule selection, cation exchange, optics and magnetism. In this thesis, on the one hand, we combined lanthanide metal center with sulphuric acid ligand to synthesize two lanthanide-sulfates. On the other hand, under hydrothermal conditions, we use4,4’-oxydibenzoic acid (H2oba, H2L) as main ligand to synthesize thirteen novel polynuclear lanthanide metal coordination polymers.1、Two lanthanide-sulfates Er4(SO4)4(OH)4(H2O)3(1) and Y4(SO4)4(OH)4(H2O)3(2) were hydrothemally synthesized from lanthanide metal Er and Y and H2SO4ligand. Both compounds1and2contain helical tubes and channels constructed from double left-and right-handed helical chains. Further structural analysis reveals that compound1and2exhibit unusual high (3,12)-connected binodal network.2、Five lanthanide-organic compounds, namely Sm5(oba)7(OH)(H2O)3(3), Eu5(oba)7(OH)(H2O)3(4), Dy5(oba)7(OH)(H2O)3(5) and Er5(oba)7(OH)(H2O)3(6) have been obtained by using lanthanide metal ions, H2oba and imidazole as starting materials. Compounds3-6are isomorphous and exhibit3D network with{Ln3} clusters and L2-ligands.3、Four new lanthanide-organic compounds, namely Tb2(oba)(2-pc)2(OH)2(7) Dy2(oba)(2-pc)2(OH)2(8), Ho2(oba)(2-pc)2(OH)2(9) and Er2(oba)(2-pc)2(OH)2(10)(2-pc=2-pyrazinecarboxylic acid), have been obtained under hydrothermal conditions, which constructed by main ligand (H2oba) and auxiliary ligand (2,3-pyrazinedicarboxylic acid). Compounds7-10are isomorphous and exhibit2D layered structures by incorporating{Lrn} clusters as building blocks.4、Five novel lanthanide-organic compounds, namely Ho3(oba)4(na)(11), Er3(oba)4(na)(12), Tm3(oba)4(na)(13), Yb3(oba)4(na)(14) and Y3(oba)4(na)(15)(na=nicotinic acid), have been obtained by using lanthanide metal ions, main ligand (H2L) and auxiliary ligand (2,3-pyridinedicarboxylic acid). Compounds11-15are isomorphous and have high connected binodal3D net by assigning the L’" ligand as a three-connected node and the{Er3} cluster as a11-connected node.Furthermore, the single crystal X-ray diffraction analyses, the infrared, elemental analysis, powder X-ray diffraction and thermogravimetric analysis were also studied. The topology and the fluorescence properties of some compounds have also been studied and discussed in the thesis.