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The synthesis and characterization of novel germanium vanadate compounds and inorganic-organic hybrid open framework compounds

Posted on:2004-11-24Degree:Ph.DType:Thesis
University:University of HoustonCandidate:Whitfield, Tabatha ReneeFull Text:PDF
GTID:2461390011961530Subject:Chemistry
Abstract/Summary:PDF Full Text Request
The investigation into the synthesis of open framework germanium vanadates has led to the discovery of several new vanadium germanate compounds. The compounds were characterized by single crystal/powder X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, electron microscopy, magnetic susceptibility measurements, and elemental analysis. Three germanium atom capped vanadate clusters Cs6[Ge4V16O42(OH) 4]·4.7 H2O, (pipH2)4(pipH) 4[Ge8V12O50·(H2O)], and K5H8Ge8V12SO52·10H 2O, have been formed via hydrothermal synthesis. The structures contain cluster ions based on the {lcub}V18O42{rcub} Keggin anion. The structures are built from edged-shared VO5 square pyramids and corner-shared GeO4 or GeO3(OH) tetrahedra.; Two novel vanadium oxide-germanium oxide layered compounds, (C6 H10N2)2(Ge2V4O 14)(H2O)2 and Cs2Ge2V 4O16, have also been formed via hydrothermal synthesis. Both structures are layers built from V2O5 chains, which are formed by edge-shared V(IV)O5 square pyramids. The chains are interconnected by GeO3(OH) tetrahedra. The interlamellar space is occupied by 1,4-diaminocyclohexane cations and water for (C 6H10N2)2(Ge2V4O 14)(H2O)2 and Cs+ and water for Cs2Ge2V4O16.; Single crystals of a new three-dimensional vanadium germanate, Na 4Ge7.34V1.66O20, were prepared by hydrothermal synthesis. The dense three-dimensional framework is constructed from chains of Ge/V-O cluster anions that are linked to one another through infinite helical chains of Ge/VO4 tetrahedra. Small voids in the framework are occupied by sodium ions.; In the second phase of research, microporous structures composed of metal-oxo groups interconnected by multifunctional rigid organic ligands were explored. The structures were also characterized by the same methods as the previous work. Two novel inorganic-organic hybrid polymers, Ni(pydc)(H2O) (pydc = pyridine dicarboxylate) and Ni4 (2-pzc)4(V 6O17)·xH2O (pzc = pyrazine carboxylate) were hydrothermally synthesized. Ni(pydc)(H2O) adopt three-dimensional framework structures. Ni4 (2-pzc)4(V6O 17)·xH2O is a new chiral structure that was produced by incorporating an asymmetric organic ligand into a framework structure.; Single crystals of the novel organic-inorganic frameworks Fe0.28 V0.72(OH)0.8(NH4)0.2(C 8H4O4)]·0.53(C8H6O 4), Fe(OH)(C8H4O4)·C5H 7N, Fe(C3H7NO)(C8H4O 4), and Fe3(C8H4O4) 3 (C5H5N)2, have been prepared by hydrothermal and solvothermal synthesis in the presence of oxidizing agents. The first three compounds are three-dimensional frameworks with large diamond shaped channels in one dimension. The new phases, Fe0.28V0.72(OH) 0.8(NH4)0.2(C8H4O4 )]·0.53(C8H6O4), Fe(OH)(C 8H4O4)...
Keywords/Search Tags:Framework, Synthesis, Compounds, Germanium, New, Novel, Three-dimensional
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