Studies On Rare Earth Supramolecular Complexes With Podand Ligands And Their Montmorillonite Composite Luminescent Materials

Podand-type ligands have drawn much attention in recent years,mainly due to their particular selective coordinating capacity,spheroidal cavities,and novel coordinational structure when they coordinate with metal ions.Rare earth elements are a group of special inorganic ions with good luminescent,electronic and magnetic properties.Among these podands having potential applications in functional supramolecular chemistry,amide-type podands have drawn much attention in preparing rare earth complexes with strongly luminescent properties. Amide-type podand ligands have the advantages in simple synthesis,adjustable structure and changeable sensitive conjugate groups,which make their complexes indicating good luminescent properties.In order to investigate the coordination properties of the amide-type podand ligands with rare earth ions,and the influence of different skeleton and the functional terminal groups of the ligands and different anions to luminescent properties of the rare earth complexes,this dissertation reported the synthesis and characterization of amide-type podand ligands L~Ⅰ～L~Ⅸ. The luminescent properties of the complexes have also been comprehensively investigated.The application of the rare earth complexes are limited by the poor optical,thermal and chemical stabilities.Stable inorganic solid matrices which can change the structure and chemical microenvironment of guest molecules or ions, could affect the luminescent properties of guest molecules or ions distinctly.So the hybrid of the rare earth organic complexes with suitable inorganic solid matrices is a desirable way to improve the luminescent properties and the stabilities of the complexes,develop novel rare earth luminescent materials and widen their application field.We intercalate rare earth luminescent complexes with amide-type podands into the interlayer space of montmorillonite(MT)and obtain novel rare earth complex-MT supramolecular composite luminescent materials which have better luminescence properties,better chemical and optical stabilities compared with their pure complexes.The dissertation includes following six chapters:1.A brief review of investigation progress of podand ligands supramolecular complexes,rare earth luminescent complexes and composite montmorillonite materials were summarized.2.Two same flexible framework of tripodal ligands L~Ⅰand L~Ⅱusing [N-(phenylmethyl)]acetamide and(N-phenyl)acetamide as terminal groups and 65 rare earth complexes include rare earth salts of five different anions have been synthesized and characterized.The research results show that all the complexes have bicapped structures of lanthanide-organic coordination cations.The structures of complexes can be affected remarkably by the counter anions.Based on crystal diffraction analysis,the influence of the counter anions to the complex structures, hydrogen bonds andπ-πstacking interactions in building novel supramolecular, and space topological structures in supermolecules have been studied.3.Four podand ligands L~Ⅲ-L~Ⅵcontaining different rigid framework and using [N-(phenylmethyl)]aeetamide as terminal groups and their 28 rare earth picrate complexes have been synthesized and characterized.The single-crystal X-ray analysis of the picrates complexes of L~Ⅲand L~Ⅳreveals that there are 1:1(M:L) type complexes with the rare earth ions coordinated with three bidentate picrate groups and four oxygen donor atoms from the tetradentate ligand.Based on crystal diffraction analysis,hydrogen bonds andπ-πstacking interactions in building novel supramolecular,and space topological structures in supermolecules have been studied.4.Three different podand ligands L~Ⅲ-L~Ⅵwith rigid framework using N-benzylsalicylamide and N-(3-pyridylmethyl)salicylamide as terminal groups and 31 rare earth nitrate and perchlorate complexes have been synthesized and characterized.The crystal structures of the complexes show that all the rare earth nitrate complexes of L~Ⅶand L~Ⅷare(6,3)honeycomb and(10,3)-a type coordination polymers,which are very uncommon in the rare earth complexes with podand ligands.5.Photoluminescence studies of europium and terbium complexes show that all the terminal groups have good sensitive function to europium and terbium ions. The framework and terminal groups of ligands,the counter anions have effects on the luminescent properties of rare earth complexes.6.The Eu/Tb complexes prepared in chapter two were intercalated into the interlayer space of MT by solid-liquid ion exchanging,and formed Eu/Tb-organic montmorillonite composite luminescent materials.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 composite materials have better chemical and optical stabilities compared with their pure complexes.The ligands involved in the dissertation are listed as follows:L~Ⅰ:2,2',2"-nitrilotris-(N-phenylmethyl)acetamideL~Ⅱ:2,2',2"-nitrilotris-(N-phenyl)acetamideL~Ⅲ:2,2'-[(1,2-ethanediyl)bis(oxy)]bis[N-(phenylmethyl)]acetamideL~Ⅳ:2,2'-[(1,2-phenylene)bis(oxy)]bis[N-(phenylmethyl)]acetamideL~Ⅴ:2,2'-[(1,2-naphthalene)bis(oxy)]bis[N-(phenylmethyl)]acetamideL~Ⅵ:2,2',2"-[(1,2,3-phenylene)tri(oxy)]bis[N-(phenylmethyl)]acetamideL~Ⅶ:2,5-bimethyl-1,4-bis {[(2'-benzylaminoformyl)phenoxyl]methyl} benzeneL~Ⅷ:1,3,5-tris{[(2'-benzylaminoformyl)phenoxyl]methyl} benzeneL~Ⅸ: 2,5-dimethyl-1,4-di{[2'-(3-pyridylmethylaminoformyl)phenoxyl]methyl}benzene...