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

摘要

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 ₄Ge_7.34V_1.66O₂₀, 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 Fe_0.28 V_0.72(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, Fe_0.28V_0.72(OH) _0.8(NH₄)_0.2(C₈H₄O₄ )]·0.53(C₈H₆O₄), Fe(OH)(C ₈H₄O₄)