Synthesis,Structure And Properties Of New Coordination Polymers Based On POMs

Coordination polymers(CPs),are assembled by the central metal ions and organic ligands,to form crystalline materials with periodic and highly regular network.CPs as a class of inorgani-organic hybrid material,have series of abundant topologies and size-controllable channel systems potential applying in gas storage,optics,electrics,magnetism,catalysis and biological activity,so they become one of the most attractive fields in chemistry and material science.POMs as a classic polyoxometalate,with a wealth of structural diversity,most of them have larger volume filling in the pores as a template,occupying the space,avoiding the formation of interpenetrating.POMs has high negative charge filled in the pores of the metal organic framework can play a role in balancing the charge to stable metal-organic framework.Moreover,POMs also has a significant chemical and structural diversity.Therefore work together to build coordination polymers containing POMs and organic components may be capable of binding to the structural characteristics of the different components in order to obtain an unusual structure and properties.In this thesis,6 complexes based on flexible zwitterionic carboxylic acid ligands have been synthesized under the hydrothermal/solvothermal method and structurally characterized by single crystal X-ray diffraction,IR,ICP and XRD.Some complexes characterized by fluorescence and electrochemistry.Specific research results are as follows:1:Two novel 2D layered compounds containing helical chains,[Dy L1(H2O)4][PMo12O40]·2.75H2O(HNU-7)and[Gd L1(H2O)4][PMo12O40]·5.75H2O(HNU-8),have synthesized using[PMo12O40]3" as a template.Structural analysis show HNU-7 and HNU-8 are isomorphic coordination polymers,where only HNU-7 will be described.In the compound,Dy2 clusters and L1 ligands are alternately connected to form a chain Dy2-L1-Dy2,and the electrostatic attraction effect between the guest molecules[PMo12O40]3" and N+ of L1 ligands lead to left-hand and right-hand helix.[PMo12O40]3" as charge balancing agent and structure inducing agent play a key role in supra-molecular structure HNU-7,their success in the future design of synthetic synthesis of coordination polymers containing helix has important reference value.2:Two lanthanide POMs coordination polymers,[ErL2(H2O)5][PMo12O40]·0.5H2O(HNU-9)and[ErL22(H20)2][PWi2O40]·3H2O(HNU-10),have synthesized using 1,1’-(1,4-phenylenebis(methylene))bis(3-carboxypyridin-1-ium)chloride(H2L2·Cl2)as ligand,H3PMo12O40 and H3PW12O40 as template under hydrothermal conditions.The central metal ion Er3+ of HNU-9 and HNU-10 is nine of coordination mode,connected with the L2 ligand and H2O.Wherein,HNU-9 only uses bi-dentate chelating coordination modes connected with L2 ligands,and HNU-10 using bi-dentate chelating and bi-dentate federation coordination mode.It is why different spatial structure of HNU-9 and HNU-10 that difference connected mode in them.In addition,HNU-9 just has one template agent but HNU-10 has POMs and L2 ligands as template agents.Therefore,whether the guide template synthesis,or coordination mode can lead to different spatial configuration,which provides a theoretical basis for the future.3:Two polyoxometalate[(CH3)2NH]3[H3PMo12O40](HNU-11)and L12[H3PMo12O40](HNU-12)have synthesized under solvothermal method.In HNU-11,Keggin-POMs units were linked by hydrogen bonding to form a two-dimensional layer,the layers accumulated in ABCD mode following c-axis.And the guest molecules distributed of the interlayer,stabilizing the 2D structure and expanding it into a 3D supramolecular structure.In HNU-12,L1 molecules through hydrogen bonds connect with each other to form a 1D chain structure.Adjacent chains are staggered,but their twist directions are the opposite.[PMo12O40]3-anions insert L1 chains by electrostatic attraction to the N+ of L1 ligands to balance the positive of skeleton,supporting and stabilizing the structure.