Synthesis, Characterizations And Properties Of Rare-earth Metal Microporous Materials

Following the discovery of microporous crystalline aluminophosphates, new open-framework metal phosphates have attracted considerable attention because of their potential applications in catalysis, adsorption, ionic conduction, ion exchange, and optoelectronics.In the past decades, the pseudo-tetrahedral phosphite group, HPO32-, has been employed as a building unit to replace the tetrahedral phosphate group, which gives rise to a new class of phosphite compounds. In contrast to the large numbers of transition-metal phosphites, the reports on rare-earth phosphites are rare.Metal-organic frameworks, a new kind of microporous materials, have attracted much attention because of their various topologies and potential application in magnetism and enantioselective separation. Materials with rare earth element are of great interests due to their amazing optical and magnetic properties arising from 4f electrons. In recent years, many research groups have choosen rare earth elements as metal centers to assemble metal organic frameworks and a number of novel frameworks have been synthesized.This research focused on the synthesis and characterizations of phosphites, sulfate and coordination polymers of rare earth and summarized the rules of synthesis.In this work, a new neodymium phosphite monohydrate Nd(H2O)(HPO3) (H2PO3)·H2O (1) which has a layered structure was synthesized under mild hydrothermal conditions.and characterized by single crystal X-ray diffraction. It is also characterized by powder X-ray diffraction, inductively coupled plasma analysis, elemental analysis, IR spectra and thermogravimetric analysis.Compound 1 is built up from NdO8 dodecahedron and [HPO3]- pseudo-tetrahedral units, forming 4-membered ring channels.A new neodymium sulfate Nd2(SO4)3(H2O)4(2) which has a new three dimensional open-framework was synthesized under mild hydrothermal and solvothermal conditions. It is characterized by single crystal X-ray diffraction powder, X-ray diffraction, inductively coupled plasma analysis, elemental analysis, IR spectra and thermogravimetric analysis. Compound 2 is constructed from two distinct motifs, a one-dimentional [Nd2O16(SO4)3]∞chain and a single 4-ring (S4R) unit, which are connected by sharing vertexes to form the 3D inorganic framework with 4, 8-member ring channels along [010] direction.A three dimentional rare earth coordination framework [Y2(NIPH)3 (DMF)4]·DMF (3) has been synthesized through the reaction of yttrium nitrate salt and H2NIPH in the presence of triethylamine molecules. It is characterized by single crystal X-ray diffraction.powder, X-ray diffraction, inductively coupled plasma analysis, elemental analysis, IR spectra and thermogravimetric analysis. The thermogravimetric analysis shows that compound 3 has a nice thermal stability. The 3D framework of compound 3 is comstructed from YO8 dodecahedron and NIPH. The NO2 unit of NIPH makes the YO8 dodecahedron is not linked with each other. Compound 3 has potential applications in catalysis and hydrogen storage because of the channels in different directions.