The Synthesis, Structure And Properties Of POM Compounds Based On Rigid Tetrazole,2,2’-biimidazole And Flexible Bis(Triazole) Ligands

In this thesis, the rigid ligands of5-phenyl-1H-tetrazole,2,2’-biimidazole and theflexible ligands of1,4-bis(1,2,4-triazol-1-y1)butane,1,6-bis(1,2,4-triazol-1-y1) hexanehave been used. Eleven novel multiple functional compounds based on transition metal anddifferent types of polyoxoanions have been synthesized under hydrothermal conditions andstructurally characterized by elemental analyses, IR, TG, XPRD, XPS and single crystalX-ray diffractions. The electrochemical and photocatalytic properties of some of thesecompounds have been investigated.1. Two compounds1and2modified by AgIcircles or AgIribbons have beenhydrothermally synthesized using the Keggin-type [PW12O40]3-and [PMo12O40]3-anionsand transition metal Ag+ions as inorganic building units and the rigid5-phenyl-1H-tetrazole ligand as organic ligand.[Ag8(ptz)4(HPWV2WVI10O40)]·2H2O (1)[Ag9(ptz)5][PMoVI11MoVO40]·H2O (2)(ptz=5-phenyl-1H-tetrazole)The synthetic conditions of compounds1and2are similar. But the differenttemperatures lead to the distinct structures of1and2. In compound1, AgI-ptz unitexhibits a molecular crown. These crown-like cycles are further supported by Kegginanions as tetra-dentate inorganic ligands to build a2D layer. Compound2exhibits a3DAg-ptz framework containing AgIribbons and hexa-nuclear AgIcircles. The[PMoVI11MoVO40]3-anions as inorganic ligand embed the channels of this3D Ag-ptzframework.2. Four new compounds based on CuI/IIions, Keggin anions and flexible bistriazoleligands with different lengths have been designed and synthesized.[CuI5(btx)4(PWVI10WV2O40)](3)[CuII2(btx)4(SiW12O40)](4)(btx=1,6-bis(1,2,4-triazol-1-y1)hexane)[CuI4(btb)2(μ-OH)(PW12O40)](5) [CuII2(btb)4(μ-Cl)(PW12O40)]·3H2O (6)(btb=1,4-bis(1,2,4-triazol-1-y1)butane)Compounds3and4are in the same Keggin-Cu-btx system with different oxidationstates of copper ions, leading to different3D frameworks. In3, there exist a three-foldinterpenetrating metal-organic framework, which are connected by anions to construct a3D structure. In4, the CuII-btx moiety shows a3D hexagonal channel-style framework.The Keggin polyanion offering four terminal oxygen atoms incorporates with the channelsof this CuII-btx MOF. Compound5exists a wave-like metal-organic2D layer. Furthermore,these layers are bridged by hydroxyl groups through Cu-(OH)-Cu bonds, reducing a3Dporous metal-organic framework (MOF). The Keggin anions are embedded in the channelsof this structure. In6, two adjacent2D CuII-btb layers covalently capture the Kegginanions to construct a hamburger-like subunit. Furthermore, these subunits are linked bychloro-bridges (Cu-Cl-Cu) and a3D framework with channels is built.3. Five different compounds (7-11) using different anions and transition metal ionshave been synthesized with the introduction of the rigid H2biim ligand as organic ligand.[Ag(H2biim)2]2·[Ag5(H2biim)10Na2(H2O)2(H3/2P2W18O62)2]·12H2O (7)[Cd(H2biim)2K(P2W18O62)1/2](8)[Zn2(H2biim)5(SiW12O40)]·4H2O (9)[Zn2(H2biim)5(SiMo12O40)]·4H2O (10)[Zn2(H2biim)4(Hbiim)2][H2(γ-Mo8O26)]·8H2O (11)(H2biim=2,2’-biimidazole)In7, two-supporting Wells-Dawson anions are modified by Ag-N subunits and linkedby Na+to build a1D chain. In8, adjacent anions are modified by Cd-N subunits to form a1D chain. Furthermore, the anion in the chain is fused by six K+ions and a3D frameworkis obtained. In9and10, these two isostructural compounds consist of Keggin anions andmetal-organic chains constructed by [Zn2(H2biim)5]4+subunits and a3D supramolecularframework is formed. Compound11is constructed by Zn(H2biim)2(Hbiim) subunits andMo8to form a1D supramolecular chain.