The synthesis and characterization of novel germanium vanadate compounds and inorganic-organic hybrid open framework compounds | | Posted on:2004-11-24 | Degree:Ph.D | Type:Thesis | | University:University of Houston | Candidate:Whitfield, Tabatha Renee | Full Text:PDF | | GTID:2461390011961530 | Subject: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 | PDF Full Text Request | Related items |
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