Hydrothermal Synthesis And Structure Studying Of Organic-inorganic Materials Based On Tungstophosphate

Through selecting the transition metal cations as templating and multidentate organic ligands and polyoxometalates(POMs) as building blocks, inorganic-organic hybrid material was synthesized based on the principles of molecular design and crystal engineering. Polyoxometalat compounds on the basis of Keggin type polyoxoanion clusters exhibit a variety of structures, and is so expected to be applied in catalysis, medicine, materials and so on.In this thesis, we choose Keggin type Polyoxometalat as inorganie building bloek, 4,4'-bipyridine as organic ligand, and transition metal Co to synthesize coordination compound containing POMs under hydrothemal conditions. The structure and properties of produt is characterized by IR,EDS,UV,TG,ingle crystal X-ray diffractions. The influencing factors on framewok of hybrid compound were also studied prelimiarily.It was found that both the pH value and starting material quotas of the reaetion system affect the final production greatly. The species of the second metal and the species of the the orgaic template are key factors for the production.The results showed that (PCoW₁₁O₃₉)(H₂bpy)₂(Hbpy)·H₂O is triclinic, space group P2(1)/c with a = 13.581(2)(?), b = 26.865(3)(?), c= 18.471(3) (?), Z=2,α=γ= 90°,β= 126.000(2)°, V = 5452.1(13)(?)³.The compound (PCoW₁₁O₃₉)(H₂bpy)₂(Hbpy)·H₂O was polyoxometal ate-organic hybrid material based on Keggin type heteropolyanions. In the inorganic-organic hybrid material, the heteropoly anions and pr otonatede bpyH were built into a double Parallel chains by hydroge n bonds. The adjacentchains formed a 2-D planar tructure by N-H…O hydrogen bonds.Thermogravimetric analysis (TG) of the crystalline complex shows that (PCoW₁₁O₃₉)(H₂bpy)₂(Hbpy)·H₂O is thermally stable uo to 435. 5℃.From UV-Vis-NIR reflectance spectra, it's found that compound have optical energy gap of 2.2 eV and belong to semiconductor.