A Study On The Synthesis, Structures And Properties Of Supramolecular Compounds Materials Based On The Keggin-type Polyoxometalate Clusters

Polyoxometalates (POMs) have been widely studied for their structural versatility andpotential application in many fields, such as catalysis, medicine, sorption and materialsscience. By using hydrothermal methods and convenient aqueous solution synthesismethods, a series of polyoxometalate supramolecular complexes based on organic ligands,metal compounds and polyoxometalates (POMs) had been synthesized via coordinationbonds and supramolecular interaction. The study on synthetic conditions and rules and theexploration of relationships between structures and properties for these new compoundswere also carried out. The8new polyoxometalate compounds were:H3PW12O40·3EtOH (1)H3PMo12O40·5MA·31H2O (2)H3PMo12O40·4DMF·4EtOH·6H2O (3)H3PMo12O40·(CH3)3N·5(CH3)2NH (4)2C5H12O3·C6H14O3·[(C10H10N2)3(PMo12O40)2](5)2H2O·2C8H16O4·2CH3OH·2C2H6O2·H3PMo12O40(6){Ln(H2O)9(PW12O40)}·5H2O (Ln=Pr, Yb, Ce)(7){Nd(H2O)9(PMo12O40)}·9H2O (8)；The synthesized compounds were characterized by single crystal X-ray diffraction, IR,elemental analysis and TG, and the fluorescence properties and electrochemical propertiesof some compounds were also studied. The structural analysis results showed that compound1presented a3D stacked structures which was formed by hydrogen bonds between basicPOMs units, the guest molecule ethanol was filled in the3D structure and linked withPOMs by C-H...O hydrogen bonds to stabilize the3D supramolecular structure;compound2presented a2D layer structure which was made by hydrogen bondingbetween POMs units, and also traps a2D-infinite water layers L30(6), the water layerslinked with POMs layers to form a3D supramolecular structure; compound3presented a3D supramolecular framework which was formed by hydrogen bonds between tetra-corewater ring and DMF, POMs unit were filled in and also stabilized the framework; Incompound4POMs units was filled in the ocean of guest molecules dimethylamine andtrimethylamine, POMs units was linked by hydrogen bonding to form a two-dimensional layers, the guest molecules stabilized the2D structure and also expanded it into a3Dsupramolecular structure; compound5presented a2D plane made by hydrogen bondsbetween the POMs chain and4,4-bpy; compound6presented an unusual bicappedKeggin compound with two O atoms as caps connecting with the POMs via four hydrogenbonds, the ether molecule was also linked with O atom by hydrogen bonds; compounds7and8presented a2D layer structure which was made up by hydrogen bonds between thePOMs and {Ln(H2O)9}3+.