Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Hydrothermal Synthesis and Characterization of Transition Metal Oxides(Izmir Institute of Technology, 2004) Şahin, Aytaç; Eanes, MehtapHydrothermal method has proven to be an excellent method for the synthesis of novel metal oxides and vanadates. This research pertains to the synthesis of novel lead chlorovanadate compound and of a known alkali metal trivanadate compound, KV3O8 by hydrothermal method This method has been used to synthesize many inorganic oxide compounds Hydrothermal synthesis is the use of aqueous solvents under high temperature and high pressure to dissolve and recrystallize materials. Compounds with interesting structure and physical properties are often obtained from this technique that is known as one of the low-temperature synthesis techniques for solid state compounds. There are many studies that have been done on oxides in the Pb-V-O systems There are also many vanadium oxides containing Pb, V, O elements in Pb-V-O system such as Pb1.32V8.35O16.7, PbV6O11, PbV2O6, Pb2V3O8.5, and .-PbxV2O5 bronzes (x . 0.3). In an attempt to synthesize vanadium oxides at low temperature, we were able to obtain needle shaped yellow crystals of PbVO3Cl. In the nature, there is a kombatite mineral, Pb14(VO4)2O9Cl4, with the same composition of elements. A new lead chlorovanadate, PbVO3Cl, was obtained from the reaction of NaVO3 and PbCl2 in aqueous solution of B(OH)3. The compound was prepared in an autoclave that was filled with aqueous solution of B(OH)3 and heated at 170oC for 3 days. The compound crystallizes in the space group Pnma of the orthorhombic system with formula units in a cell of dimensions a . 10.022(2)Master Thesis Hydrothermal Synthesis of Solid State Materials and Crystallography(İzmir Institute of Technology, 2004) Özmen, Bahar; Eanes, MehtapThe structure solution of the new polyoxovanadate compound([V16O31(OH)7]Cl· 15H2O), has been done by the SHELX crystal solution software. The compound was synthesized solvothermally at 170 0C in the Northwestern University. The compound crystallizes in the space group C2/c of the monoclinic system with eight formula units in a cell of dimensions a = 18.070 (2) Å, b = 17.414 (2) Å, c = 15.1154 (18) Å, â= 97.696 (2)°, V= 4713.8 (10) Å3 (T = 153 K). The structure is composed of vanadium-oxygen clusters encapsulating Cl¯ anion. Each of the V centers has square pyramidal geometry coordinated by five O atoms. The 16 (VO5) units are fused together through common edges to form (V16O38) cage with Cl¯ anion in the middle. The single crystals of the [Ni(en)3(VO3)2] compound was synthesized by hydrothermal method. [Ni(en)3(VO3)2] compound is in the crystal system of hexagonal and in the space group P61. The unit cell parameters are a = 8.9940 (13) Å, b = 8.9940 (13) Å, c = 34.001 (7) Å and á = 90 0, â = 90 0, ã = 120 0. The structure is composed of VO4 tetrahedras which are joined with others by sharing corners into infinite chains running along the c axis. The complex cation [Ni(en)3]2+ are located between the chains The chain in the compound has a repetitive sequence of 12-nuclear corner-sharing tetrahedras. The compound was synthesized at 160 0C for 3 days in the steel reaction autoclaves which have PTFE (Polytetrafluoroethylene) cups in them.