The Study Of Novel Polyoxometalates Decorated And Linked By Transition Metal-Organonitrogen Compounds

The aim of this thesis is the synthesis of new polyoxometalate compounds on the basis of saturated Keggin and Dawson-type polyoxoanion clusters, which are decorated or bridged by various transition-metal-organonitrogen compounds. The study on synthetic conditions and rules for these new compounds are also carried out.Nine new polyoxometalate compounds have been synthesized on the basis of hydrothermal technique and structurally characterized by elemental analyses, IR, TG, CV,photoluminescence and single crystal X-ray diffractions.1. Five new polyoxometalate compounds on the basis of Keggin,Dawson polyoxoanion cluster have been hydrothermally synthesized and structurally characterized:[Cu₅^I(4,4'-bpy)3(2,2'-bpy)4][BW12O40] (1)[Ni_0.5(2,2'-bpy)1.25][Ni(2,2'-bpy)3][Ni(2,2'-bpy)2(H20)(BW12O40)]·0.5H2O (2)[CuII(2,2'-bpy)2]2[SiW12O40] (3)[H2bpy]2[Zn(2,2'-bpy)3]2[Si2W18O62]·1.5H2O (4)[Ni(2,2'-bipy)3]3{[Ni(2,2'-bipy)2(H2O)](SiW12O40)}2(OH)2 (5)(2,2'-bpy = 2,2'-bipyridine, 4,4'-bpy = 4,4'-bipyridine),Compound 1 is that a novel [BW12O40]5- polyoxoanion bisupported by copper(I) coordination cations with mixed 2,2'-bpy and 4,4'-bpy ligands. Compound 2 is [Ni (2,2'-bpy)2 ]2+ supporting [BW12O40]5- polyoxoanion. Compound 3 shows a 2-D layer framework constructed from bisupporting Keggin polyoxoanion clusters and [Cu(2,2'-bpy)2]2+ coordination polymer fragments via weak covalent interactions, resulting in a 3-D network via supramolecular interactions. Compound 4 is a novel [Si₂W₁₈O₆₂]₈- and metal complex cations held together into three-dimensional supermolecular network through hydrogen-bonding andÏ€-Ï€interactions. compound 5 consists of two discrete {[Ni(2,2'-bipy)2(H2O)](SiW12O40)} heteropolyoxoanion, three [Ni(2,2'-bipy)3]2+ fragments and two counteranion OH-. Different basic building subunits formed a dimeric via hydrogen bonds and the dimerics gived rise to the 1D chainlike supramolecular architectures.2. two new polyoxometalate compounds on the basis of saturated Keggin-type polyoxoanion cluster have been hydrothermally synthesized and structurally characterized:[Zn(phen)2]2[PMoVI8VV4VIV2O42][Zn(phen)2(H2O)]2[PMoVI8 VV2VIV4O42]·7H2O (6)[Zn(2,2'-bipy)2]2[PMoVI11 MoVO40] (7)The most remarkable structural feature of Compound 6 is that there exist two distinct [PMo8V6O42] clusters. One is covalently linked by [Zn(phen)2] complexes to form 2D covalent layer, the other supports two [Zn(phen)2(H2O)] complexes forming a discrete bisupporting structure. It is interesting that discrete bisupporting clusters locate in the space of two adjecent covalently layers to form a novel 3D supramolecular framework。Compound 7 consists of one [PMo VI11 Mo VO40]4- heteropolyoxoanion and two[Zn(2,2'-bipy)2]2+ fragments . Different basic building subunits formed the 1D chainlike supramolecular architectures via hydrogen bonds. Then the 1D chain extended to 2-D layers with the same weak interactions.3. Two new interesting coordination polymers have been synthesized under hydrothermal condition:[Ni(C₆H₁₀O₄)(C₁₀H₈N₂)]_n (8)[Zn₃(C₆H₁₀O₄)₃(C₁₂N₂H₈)₂]_n (9)Complex 8 exhibits an interesting three-dimensional interpenetrating network. with mixed Adipate and 4,4'-bpy ligands. complex 9 is a two-dimensional network,with mixed Adipate and 1,10'- phen ligands. Furthermore, complex 9 exhibits photoluminescence property.