Studies On Rare Earth Complexes With Podands And The Montmorillonite Intercalation Composite Luminescent Materials

Lanthanide ions possess fascinating optical properties and their discovery, as well as responsive luminescent stains for biomedical analysis, medical diagnosis, and cell imaging rely heavily on lanthanide ions. Compared with conventional luminescent materials, lanthanide complexes have high photoluminescence efficiency along with a narrow emission spectrum, large Stokes shifts, and long fluorescent lifetime, which make them useful alternatives to radioactive probes and organic dyes. To explore the relationships between the structures of ligands and their complexes, we have synthesized and characterized lanthanide complexes with three series structurally related ligands, amide-type N-tripodal ligands (L1～4),Aromatic amide-type ligands (L5～8) and carboxylate ligands (H2L9～11). Based on the characterizations of the complexes, solid-state luminescent properties of the complexes were researched. Meanwhile, the luminescent complexes with carboxylate ligands have been intercalated into the interlayer space of montmorillonite (Na-MT) and obtain novel lanthanide complex-MT supramolecular composite luminescent materials. Intercalation of lanthanide(Ⅲ) complexes into a layered inorganic host has a beneficial effect on both the complex stability and the luminescence performance. The dissertation includes following four chapters:Chapter1:A brief review of investigation progress of lanthanide luminescent complexes and composite interlayer hybrid materials were summarized.Chapter2:Amide-type N-tripodal ligands L1～4have been designed and the lanthanide nitrate complexes have been synthesized and characterized. The composition and structure of the complexes can be characterized by means of elementary analysis, molar conductance, IR and single-crystal X-ray analysis. The luminescent properties of the complexes were studied. The study demonstrates that changing terminal groups of the ligands results in an ability to sensitize different lanthanide ions in amide-type N-tripodal ligands system. This is also supported by DFT calculations.Chapter3:Aromatic amide-type ligands L5～6have been designed and the lanthanide nitrate complexes have been synthesized and characterized. The composition and structure of the complexes can be characterized by means of elementary analysis, IR and single-crystal X-ray analysis. We also learned that replacement of the nitrogen atoms in the terminal groups significantly affects the conformational distortion of the nonplanar ligand, which considerably changes the overall frameworks from homodinuclear species to1-dimensional zig-zag coordination polymer.Chapter4:Aromatic amide-type ligands L7～8have been designed and the lanthanide nitrate and picrate complexes have been synthesized and characterized. The composition and structure of the complexes can be characterized by means of elementary analysis, IR and single-crystal X-ray analysis. A series of lanthanide metal-organic frameworks (MOFs) possessing the4f homometallic2D non-interpenetrating (6,3) honeycomb-like topological network structures with lanthanide atoms acting as "three-connected" centers have been assembled by the bridging L7～8ligands.Chapter5:Novel organic-inorganic luminescent interlayer hybrid materials were assembled through solid-liquid ion exchanging reaction between terbium chloride with carboxylate ligands H2L9～11intercalated into the interlayer space of montmorillonite (Na-MT). The results of characterization show that the guest complex ions arranged in the interlayer space of MT in the formation of a monolayer and the composite materials formed through the supramolecular interactions between the host layers and the guest complex ions had regular layered structure. The luminescent properties of the composite materials were preliminarily studied. The result shows that the carboxylate ligands H2L10～11while the groups bind with-OCH3or-CF3compared with carboxylate ligands H2L9, display more efficient insertion due to the supramolecular interactions between the host layers and the guest complex ions.The ligands involved in the dissertation are listed as follow:L1:2,2',2"-nitrilotris(N-(pyridin-3-ylmethyl)acetamide)L2:2,2',2"-nitrilotris(N-(pyridin-2-ylmethyl)acetamide)L3:2,2',2"-nitrilotris(N-benzylacetamide)L4:2,2',2"-nitrilotris(N-(naphthalen-1-ylmethyl)acetamide)L52,2'-(((2,4,6-trimethyl-1,3-phenylene)bis(methylene))bis(oxy))bis(N-(pyridin-3-ylmethyl)benzami de)L62,2'-(((2,4,6-trimethyl-1,3-phenylene)bis(methylene))bis(oxy))bis(N-(pyridin-2-ylmethyl)benzami de)L7:2,2'-[(1,2-naphthalene)bis(oxy)]bis[N-(phenylmethyl)]acetamideL8:2,2'-(((2,5-dimethyl-1,4-phenylene)bis(methylene))bis(oxy))bis(N-benzylbenzamide)H2L9:2,2'-(((2,4,6-trimethyl-1,3-phenylene)bis(methylene))bis(oxy))dibenzoic acidH2L10:2,2'-(((2,4,6-trimethyl-1,3-phenylene)bis(methylene))bis(oxy))bis(4-methoxybenzoic acid) H2L112,2'-(((2,4,6-trimethyl-1,3-phenylene)bis(methylene))bis(oxy))bis(4-(trifluoromethyl)benzoic acid)...