| The aim of this dissertation is to construct new POM-based hybrid compounds with various structures by using classical Keggin anions as building blocks and explore the assembling methods and rules. With the middle temperature hydrothermal reactions, thirteen new Keggin-type polyoxometalates were obtained based on molecular design and assembly. The compounds were characterized and the results summarized as follows:1. Three ID POM-based hybrids constructed by monosubstitutive Keggin anions were synthesized and characterized: [H2PCuWnO39]2[Cu(4,4'-Hbpy)(4,4'-bpy)0.5(OH)]2(4,4'-bpy)2(4,4'-H2bpy)-7 H2O (1), [CuPWnO39]2[Cu5(dmp),0]-4H2O (2) and [HPCoW,,O39](4,4'-Hbpy)2(4,4'-H2bpy)-2H2O (3) (4,4'-bpy = 4,4'-bipyridine; dmp = 1,2-propylene diamine), of which, 1 possesses an unprecedented ladder-like structure with two subchains of Keggin anions joined by [Cu2(4,4'-Hbpy)2(4,4'-bpy)(OH)2] units through the bridging oxygen atoms from the Keggin anions, 2 has ID straight Keggin chains, and 3 is the first example of POM with a helical structure formed by Keggin anions.2. Four new extended POM-based hybrids were prepared and characterized: [PW, ,039Ni(4,4'-Hbpy)]-(4,4'-H2bPy)2-H20 (4), [PW, ,O39Ni(4,4'-bPy)] [Ni(4,4'-Hbpy)2(H2O)2]-Hbpy-8H20 (5), [PW,,O39Ni(4,4'-bpy)][Ni(4,4'-Hbpy)2(H2O)2]-Hbpy-6H20 (6) and [SiWnO39Ni(4,4'-bpy)][Ni(4,4'-Hbpy)2 (H2O)2]-H2bpy6H2O (7). 4-7 are the first Keggin-based hybrids constructed from functionalized Keggin anion [PWuO39Ni(4,4'-bpy)]5~ or [SiWnO^Ni (4,4'-bpy)]6". The crystal structure analyses of 5-7 reveal that the position of the substitutive second metal in the Keggin anion plays an important role in the structures of the compounds. The successful preparation of 4-7 indicates that the substituted Keggin anion [PWnO39Ni(4,4'-bpy)]5' or [SiW11O39Ni(4,4'-bpy)]6~ can function as a structurally versatile building block. From the fact that Keggin anion can be substituted by different kinds and numbers of transition metal ions, it can be concluded that a great number of new Keggin-based metal-coordination polymers may be expected by the assembly of the functionalized Keggin anion.3. Four Keggin anion-based hybrids were synthesized and characterized: [Cu2(4,4'-bpy)4(H20)4KSiW1204oH4,4'-bPy)2-4H20 (8), [Cu2(4,4'-bpy)4(H20)3]-(PW1204o)-9.5H20(9),[Cu2(4,4'-bPy)4(H20)4]-(PMol204o)-8 H2O (10) and [Cu2(4,4'-bpy)2](HPW12O4o)-5H20 (11), of which, 8-10 are the novel examples of microporous 3D coordination polymers assembled by the POM and the 2D metal-organic network through the electrostatic attraction between them, and 11 exhibits ID sandwich structure. The successful syntheses of 8-10 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 Keggin-based 3D coordination polymers are expected by selecting proper POMs unit and 2D metal-organic network.4. Two Keggin-based hybrids were prepared and characterized: [Ni2(4,4'-HbPy)4(4,4'-bpy)(H20)6](SiW,204o)2-13H20 (12) and [Ni(4,4'-Hbpy)2(4,4'-bpy)(H2O)2](SiW|2O4o)-6H2O (13). 12 and 13 both show 3D supramolecular networks assembled by the Keggin anion and transition metal complex through the hydrogen bonding interactions between them. The 2D substructure of 13 is constructed for the first time by the hydrogen bonding interactions between transition metal coordination polymer and POM. Since Keggin anion looks like ellipsoid and has rich oxygen atoms, the 2D substructure of 13 can be extended into another new 3D structure through the hydrogen bonding interactions between the POM and the linker. The successful syntheses of 12 and 13 demonstrate the possibility of bridging transition metal complexes with heteropolyanion via hydrogen bonding interactions to construct supramolecular arrays and may provide interesting experimental data for supramolecular chemistry and crystal engineering. Besides the POM hybrids discussed above, other eleven...
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