Studies On The Synthesis And Properties Of Some Inorganic Functional Materials

Recently there has been great interesting in studying functional materials.In this dissertation we studied on the rare earth complexes as the luminescence materials,the lithium ion cathode materials,and some other functional nanomaterials.The main content of this dissertation is listed below:First,we reviewed recent research and progress of rare earth luminescence materials,lithium ion cathode materials and some functional nanomaterials.Second,two kinds of new ligands N,N'-di(pyridine N-oxide-2-yl)pyridine-2,6-dicarboxamide (H₂L¹) and N,N'-Bis(2-pyridinecarboxamide-1-N-oxide)-1,2-Ethane (L²) and their corresponding rare earth complexes were synthesized and characterized. It is found that the composition and the structure of the complexes formed by H₂L¹ with rare earth ion change with alternating synthesis condition as well as with different rare earth ion.Direct reaction of H₂L¹ with rare earth ion forms Ln(H₂L¹)(NO₃)₃·nH₂O(Ln = Y,Eu,Gd,Tb,n = 1;Ln = La,n = 2).The rigid structure of free ligand changes little after coordination because of intramolecular hydrogen bonded interaction.Nevertheless,dehydrogenated complex,ScL¹NO₃·2H₂O, is formed by direct reaction of H₂L¹ with Sc³⁺.We also confirmed its structure by employing X-ray analysis to determine the crystal structure.It's interesting that each molecule of the complex self-assemble to form right hand helical 1D supermolecular chain by intermolecular hydrogen bonded interaction.Also we succeeded in synthesizing dehydrogenated complexes LnL¹NO₃·nH₂O(Ln = Y,Eu,Gd,Tb,n = 1; Ln = La,n = 2) by adjusting the pH when H₂L¹ reacted with rare earth ion.It is found that the rigid structure of free ligand changed a lot in the as formed complexes.Such a structure change plays an important role on the luminescence properties of the Eu³⁺, Tb³⁺ complexes.The fluorescent intensity of the luminescent non-dehydrogenated complexes is much higher than the corresponding dehydrogenated complexes.While ligand L² forms LnL²(NO₃)₃·H₂O(Ln = Eu,Gd,Tb) with rare earth ion.It is found that as formed Eu and Tb complexes show good luminescence properties.The fluorescent intensity is higher than the corresponding complexes formed by non N-oxide matrix.We also explained the luminescence properties by employing triplet energy level of the ligand.Third,considering simplification of synthesis method and modification of electrochemical properties,we first time synthesized the precursor of LiMn₂O₄, LiHMn₂cit₂·2H₂O and LiMncit·H₂O as the precursor of o-LiMnO₂ in an organic solvent by employing citric acid as a chelating ligand.The structure and composition of each precursor were also characterized by using element analyses,titration,ICP, XRD.Pure phase cathode materials spinel LiMn₂O₄ and layered o-LiMnO₂ were formed by optimizing calcined conditions of precursors.It is found that the decomposed matter of citric acid can restrain effectively the reuniting of as formed cathode material.Fourth,in order to study on the size and shape control of inorganic nanomaterials, semi-conductor Ag2Te nanowires with varied in diameter from several to tens of nanometers and with several micrometers in length were synthesized and characterized.Also we synthesized Ag₂Te nanoparticles as well as CdS nanotetrahedrons and nanorods using high temperature organic phase method.