Study On The Solvthermal Synthesis And Structure Of Inorganic-Organic Hybrid Compound Based On Polyoxometalates

Polyoxometalate compounds on the basis of Keggin type polyoxoanionclusters exhibit a variety of structures, and is so expected to be applied incatalysis, medicine, materials and so on. Exellent functional materials withnovel crystal structure and unique property are prospected to be obtained byselecting organic ligands and POMs (polyoxometalates) as building blocks.In this thesis, we choose Keggin type polyoxometalat as inorganicbuilding block, 2, 2' -bipyridine-3, 3'-dicarboxylic acid as organic ligand, rareearth Sm as templating to synthesize coordination compound containingPOMs under hydrothermal conditions.According to the principles of molecular design, we selectedSmCl₃-6H₂O,H₂bpdc,(NH₄)₃PO₄·MoO₃·xH₂O as reactants, studied the factorsaffecting the compound synthesis, and got the coordination compound(C₁₀H₉N₂)₃-(PMo₁₂O₄₀) under certain conditions. The produt is characterizedby IR,EDS,elemental anylasis and single crystal X-ray diffractions. Theresult shows that the product is a novel compound not reported yet with bothorganic ligand and polyoxoanion coordinated.The crystal (C₁₀H₉N₂)₃·(PMo₁₂O₄₀) is triclinic, space group P-1with a=11.851(2) A, b=12.771(3) A, c= 19.034(4)A,α=90.23(3)°,β=90.50(3)°,γ=112.57(3)°, V=2660.0(9)A³, Z=2, Dc=2.864 mg/m³,μ(Mo Kα)=2.871mm^-1, F(000)=2176, R₁=0.0416,ωR₂=0.1327.The organic ligand andpolyoxoanion are coordinated by electrostatic power and hydrogen bondeffection, forming 3D net structure containing cavity. The study on the optical property of the powder sample throughUV-VIS-NIR diffuse reflection spectra suggests that the title compound issemiconductor with band gap of 0.8 eV.Thermogravimetric analysis (TGA)of the crystalline complex shows that (C₁₀H₉N₂)₃(PMo₁₂O₄₀) is thermallystable up to 250℃.The synthesis of the coordination compound promoted thedevelopment of material science. And it does good things to the study ofprinciples about synthesis of the crystal and the property study, the propertystudy and the crystal structure through a variety of experiments.