Assembly And Properties Of Polyoxometalates-based Functional Compounds Constructed From Bis-triazole /Flexible Bis-amines Derivatives Ligands

In this thesis, eight new polyoxometalates(POMs)-based functional transition metal complexes and supramolecular compounds constructed from bis-triazols and flexible bis-amines derivatives have been synthesized under hydrothermal conditions and structurally characterized bysingle crystal X-ray diffractions, PXRD, IR, TG, XPS and EDS. The electrochemical properties and photocatalytic properties of these compounds have been studied.1. Different Keggin-type [VW12O40]3-(VW12) and [PMo12O40]3-(PMo12) anions have been used as inorganic building units and structure-directed agents to assemble with rigid pyridino-bistriazol ligands and AgI ions under hydrothermal conditions, three new POMs-based complexes have been synthesized. The influence of different POMs anions and ligands coordination modes on the assembly and structures of the compounds has been discussed.In compound 1, [VW12O40]3- was in-situ transformed from [Si W12O40]4- anion. Eight AgI ions were connected by six HL1/H2L1 ligands with three coordination modes forming an unprecedented [Ag8(HL1)4(H2L1)2] cluster, which connected with six [VW12O40]3- anions to construct a 2D double-layer(3,6)-connected network with {43}2{46.66.83} topology. In compound 2, L1 ligands and AgI ions are linked in alternate sequence to form a 1D [Ag2(HL1)( H2L1)]n band. The adjacent bands are connected by pairs of [H2PMo12O40]- anions to generate a 1D ‘‘railway-like’’ double-chain structure. In compound 3, four AgI ions were connected by four HL2/H2L2 ligands forming a tetranuclear cluster,which were connected together by AgI and L2 to construct an infinite chain. The [PMo12O40]3- anions as inorganic ligands linked the adjacent 1D chains to form a 2D layer structure. The ligand’s coordination modes and different POMs anions have important influence on the final structures of compound 1–3. In addition, the electrochemical behavior and potocatalytic degradation performance methylene blue and rhodamine B of these compounds have been investigated, which show good potocatalytic and electrochemical activities.2. The flexible bis-amines derivatives with different length were used to assemble with Keggin-type [Si Mo12O40]4- anions and Cu(NO3)2 under hydrothermal conditions, three new POM-based supramolecular compounds were synthesized:Compounds 4-6 are supramolecular compounds composed of discrete bis-amide derivatives and [Si Mo12O40]4- polyanions, which exhibit three different supramolecular frameworks directed by the different hydrogen bonding interactions. Compounds 4 and 5 are 1D supramolecular chain, compound 6 is a 2D supramolecular layer. Although the Cu(NO3)2 does not participate the reaction, it is important for the construction of the supramolecular compounds. The bis-amide derivatives with different length also show some influnce on the final structures. In addition, the electrochemical behaviors of these compounds have been investigated, the results indicate that compounds 4-6 show good electrochemical property.3. Using bis-triazol derivatives with different flexibility to assemble with different POMs and metal ions under hydrothermal conditions, two new POMs-based metal-organic complexes were obtained:In compound 7, rigid bis-triazols ligands and metal AgI ions are connected together to form a 2D metal-organic layer, Wells-Dawson type [P2WVI17WVO62]7- as inorganic ligands link the 2D metal-organic layer to form a 3D metal-organic framework. In compound 8, flexible bis-triazols ligands coordinate with CoII ions to form a 1D metal-organic chain, and basket-shaped {K?P6Mo18O73} anions also coordinate with metal CoII ions and connect adjacent 1D chains to form a 2D layer. In addition, the electrochemical behavior of compound 7 has been investigated, the results indicate that compound 7 shows good electrochemical property.