The Syntheses And Characterization Of The Decorated And Extended Structural Inorganic-organic Hybrids Based On Polyoxometalates Building Units

The aim of this thesis is the synthesis of new polyoxometalate compounds on the basis of molybdate and vanadate polyoxoanion clusters, which are decorated or bridged by various transition metal ions and organic N-containing ligands. The study on synthetic conditions and rules for these new compounds and the exploration of relationships between structures and properties for these new compounds are also carried out.Eleven new polyoxometalate compounds have been synthesized on the basis of hydrothermal technique synthesis methods and structurally characterized by elemental analyses, IR, XPS, TG and single crystal X-ray diffractions. The thermal stabilities and fluorescent activity of these compounds have been studied.1. A new polyoxometalate compounds on the basis of isopolymolybdate have been hydrothermally synthesized and structurally characterized: [Co(2,2'-bipy)3]4[Mo8O26]2?5H2O (1)Compounds 1 is an interesting 3D supramolecular network with 1D channels, in whichα- andβ-octamolybdate anions"guests"reside. It is the first example of a structure containing bothα- andβ-octamolybdates.2. A new polyoxometalate compounds on the basis of isopolymolybdate have been hydrothermally synthesized and structurally characterized: [Hbenzimi]4[(benzimi)2Mo8O26]·2H2O (2)Compounds 2 contains octamolybdates and the organic benzimidazole molecules, which directly modified the surface of octamolybdates, via extensive hydrogen-bonding interactions, forming a three-dimensional framework. It is interesting that the benzimidazole ligands have been synthesized by original place reaction.3. Eight new polyoxometalate compounds on the basis of molybdenum arsenate have been hydrothermally synthesized and structurally characterized: (4,4'-bipy)[Zn(4,4'-bipy)2(H2O)2]2[(ZnO6)(AsIII3O3)2Mo6O18]·7H2O (3) [Zn(phen)2(H2O)]2[(ZnO6)(AsIII3O3)2Mo6O18]·4H2O (4) [Zn(2,2'-bipy)2(H2O)]2[(ZnO6)(AsIII3O3)2Mo6O18]·4H2O (5) [Zn(H4,4'-bipy)2(H2O)4][(ZnO6)(AsIII3O3)2Mo6O18]·8H2O (6) (H24,4'-bipy)[CuI(4,4'-bipy)]2[H2AsV2Mo6O26]·H2O (7) (H24,4'-bipy)3[AsV2Mo6O26]·4H2O (8) (H24,4'-bipy)3[AsV2Mo6O26(H2O)]·4H2O(9) (H24,4'-bipy)2.5(H3O)[AsV2Mo6O26(H2O)]·1.25H2O (10)Compound 3 is constructed from two-dimensional square grid-like sheets linked by the polyanions [(ZnO6)(AsIII3O3)2Mo6O18]4- to form a three-dimensional supramolecular framework. Compound 4 and 5 possess the similar bisupported polyoxometalate cluster structure. Compound 6 is a three-dimensional supramolecular framework, constructed from zinc compounds and molybdenum arsenate. Compounds 3-6 represent the first characterized modify or extended structure compounds based on the polyanions [(ZnO6)(AsIII3O3)2Mo6O18]4-. Compound 7 exhibits the first 1D infinite ladder-like ribbon structure based on the polyanions [H2AsV2Mo6O26]4-. Compounds 6-8 represent three isomeric forms of [HxAs2Mo6O26](6-x)-. Compound 8 exhibits a new isomer. In addition, the fluorescent properties of compounds 3-5 are reported.4. A new polyoxometalate compounds on the basis of vanadate have been synthesized and structurally characterized: [Ni(phen)H2O][V2O6] (11)Compound 11 exhibits a two-dimensional layered structure based on vanadate. It is interesting that the compound 11 consists of left-handed and right-handed helical chains.