Assembly Chemistry Of Polyoxometalates Decorated By D¹⁰Metal-Organonitrogen Polymeric Chain

The aim of this thesis is to synthesize new organic-inorganic hybrid compounds based on polyoxometalates, various organic bridging N-donor ligands and d10ions, to study the synthetic conditions and rules for these compounds, to analysis influence of the length of ligand, the size of polyoxometalates and the pH values of reaction system on the structural formation, respectively, and to explore the relationships between structures and nature of the materials. In this paper, twenty-two new organic-inorganic hybrid compounds based on polyoxometalates and d10ions have been synthesized by utilizing phnz, bipy and bpe ligands. All these compounds have been structurally characterized by elemental analyses, IR, TG, XPRD, XPS, and X-ray single crystal diffractions. The roles of these compounds under hydrothermal conditions and the factors influencing the structures of these compounds have also been studied.1. Six new organic-inorganic hybrid compounds have been prepared by using polyoxometalates with the different size and type as building blocks and introducing Cu-bipy coordination polymeric chains:Compounds 1-3 were obtained based on the different size Keggin POMs modified by Cu-bipy coordination polymeric chains, which were the first examples of full oxidized Keggin POMs bonding to Cu-bipy coordination polymeric chains via linear Od-Ob-Od atoms of single M3O13 triad. Compound 1 represents 1D chain based on tri-track Cu-bipy coordination polymeric chains modifying Keggin POMs, and compounds 2 and 3 are isomorphic and represent 2D layer based on tetra-track Cu-bipy coordination polymeric chains modifying Keggin POMs. Their difference of structures indicates that the linking mode between POMs and Cu-bipy coordination polymeric chains can be changed by fine-tuning the size of POMs. Compounds 4-6 were obtained based on Cu-bipy coordination polymeric chains modifying the different type POMs. 4 represents 2D layer based on tetra-track Cu-bipy polymeric chain modifying Lindqvist POMs; 5 is the first example of 3D Wells-Dawson POMs modified by tetra-track Cu-bipy coordination polymeric chains, and 6 exhibits also 3D framework based on infinite track Cu-bipy coordination polymeric chains modifying POMs. Furthermore, by inspection of the structures of 1-6, it is believed that the size of POMs is important for the formation of the structures.2. Five new organic-inorganic hybrid compounds have been prepared by using Keggin polyoxometalates as building blocks and introducing the Cu-N polymeric chains with different unit length:Compounds 7-9 were obtained based on the Keggin POMs modified by the different length's Cu-N coordination polymeric chains. Compound 7 represents 1D chain structure, in which the POMs become pendants of the tri-track Cu(bipy) chains projecting towards two sides in the"up and down"mode; Compound 8 represents also 1D chain structure, in which the POMs become beam of the bi-track Cu-bpe chains in the"side by side"mode; And compound 9 represents a supramolecular structure. By inspection of the structures of 7-9, it is believed that the unit length of Cu-N coordination polymeric chains is important for the formation of the structures. Compounds 10 and 11 represent the modifying chemistry of {AsMo12O40} POMs. 10 exhibits the highest connected number and the highest dimension of modifying bivanadyl capped Keggin POMs. By changing the length of ligand, 1D"ladder"structure of 11 is obtained. Their successful isolation further riches the target syntheses of the hydrothermal synthesis chemistry.3. Four new compounds based on Wells-Dawson POMs have been prepared by introducing the Ag salts and bipy ligands in different pH value:Compounds 12-15 were obtained based on the Wells-Dawson POMs under the same reaction condition but in different pH range, which show that the pH value of the reaction plays a key role in the structural control of self-assemble process. Because of the pH selectivity of the Ag source, compounds 12 and 13 were isolated in the lower pH value, and represented 3D framework constructed by the multi-track Ag-N polymeric chains modifying Wells-Dawson POMs. Compound 12 exhibits (4,4) connected NbO topology represented by the Schl?fli symbol of (64·82)(64·82), and compound 13 exhibits the highest connection of the modifying Wells-Dawson POMs and a complicated topology represented by the Schl?fli symbol of (92·12)(8·104·12)(32·102·112)(3·6·102·122). When the pH value went on increasing , the supramolecular structural 14 and 15 were isolated due to the disappearance of the Ag source and the decreasing coordination ability of ligands. 4. Five new organic-inorganic hybrid compounds based on the high-dimensional and high-connecting POMs have been targeted syntheses by introducing the M-N polymer complexes:Compounds 16-20 all represent the highest dimensional and the highest connecting POMs ramification. Compounds 16-19 are isomorphic and exhibit (4·6) connected 3D topology represented by the Schl?fli symbol of (41·64·81)(42·63·810), in which Keggin POMs as hexad-dentate inorganic ligands coordinate with metal ions, representing the highest connecting number of modifying Keggin POMs. Compound 20 is (3·4·6) connected 3D topology represented by the Schl?fli symbol of (3·7·8)(63·8)(64·82)(64·82) (32·4·75·82·9·10), in which Wells-Dawson POMs as ennead-dentate inorganic ligands coordinate with metal ions, representing the highest connecting number of modifying Wells-Dawson POMs.5. Two new organic-inorganic hybrid compounds have been prepared by using Lindqvist polyoxometalates as templates and introducing Cu-N coordination polymers:Compounds 21 and 22 are novel examples of porous 3D coordination polymers assembled by the Lindqvist anions as templates,Lindqvist anions connect 2D metal-organic network through the hydrogen bonding, and the anions lie in the pores. The successful syntheses of 21 and 22 indicate a novel approach to assemble porous Keggin-based 3D coordination polymers. Because of the diversity of the 2D metal-organic networks and rich structures of POMs, a great number of porous POM-based 3D coordination polymers are expected by selecting proper POMs unit and 2D metal-organic network.