Synthesis, Structures And Properties Of Lanthanide Complexes Constructed With Rigid And Flexible Polycarboxylate Ligands

The synthesis, structures and properties of lanthanide coordination polymers based on the assembly of rigid and flexible carboxylate-containing ligands are our mainly work. The aim is to study the structural variety of lanthanide-carboxylate coordination polymers, and discuss the design, synthesis and characterizations of new coordination polymers with novel structures. 16 lanthanide coordination polymers were synthesized by choosing different organic ligands. In the synthesis aspect, we study how to affect the structures on the source of metal, organic ligands, template and pH value. The structures of complexes 1-16 were determined by the X-ray crystal diffractometer. All complexes are mainly characterized by elemental analysis, IR spectrum and UV spectrum. The thermogravimetric analysis and photoluminescent properties were also discussed. This paper, we have synthesized 16 complexes as following: Note: H2ad = adipic acid; 2,5-H2pydc = 2,5-pyridine dicarboxylic acid; H2suc = succinic acid; p-H2BDC = 1,4-benzene dicarboxylic acid; bipy = 2,2'-bipyridine; H2glu = glutaric acidMixed organic ligands (i) adipic acid and 2,5-pyridine dicarboxylic acid, (ii) succinic acid and 1,4-benzene dicarboxylic acid, (iii) glutaric acid and 2,2'-bipyridine were chosen to construct lanthanide coordination polymers. In chapter three, Ln3+ are connected by adipic acid ligand to form a 1D chain structure, and the chains link to each other by 2,5-pyridine dicarboxylic acid to lead to a 2D layer structure, which are further connected by 2,5-pyridine dicarboxylic acid to form an intricate 3D framework. In chapter four, Ln3+ are connected by succinic acid ligand to form a 2D layer structure, which are further linked to each other by 1,4-benzene dicarboxylic acid to lead to a 3D net structure. It is noticeable that no solvent molecule is directly connected to the framework of these complexes, so it seems to be more potential for them to produce functional luminescent materials considering the quenching effect of -OH oscillators on luminescence. In chapter five, we discuss the roles of the rigid ligands in the conformation of lanthanide coordination frameworks, and a series of Ln-multicarboxylate coordination complexes with low dimensional framework were obtained. In addition, we also discuss the influence of the introduction of Zn for the luminescence of Ln3+ in two Ln-2,5-pydc-Zn complexes in chapter six. The paper layed a foundation for further design and synthesis of the system.