The Hydrothermal Synthesis, Crystal Structures And Properties Study Of Novel Germanates

The unique structures of microporous compounds show abundant content on catalysis, ion exchange, adsorption and radioactive waste remediation research. The synthesis, crystal structures and properties of new germanates not only have meanings on subjects of theoretic research, but also possess applied prospect. In this thesis, nine novel germanate compounds which were templeted with organic amine and chiral metal complex as structure-directing agents (SDAs) have been synthesized under hydrothermal conditions. All of the structures were determined by single crystal X-ray diffraction and characterized by Elemental Analysis, IR, at the same time, their properties were studied by TG .1. Three new germanates Ge₇O₁₂(OH)₄(C₄N₃H₁₃)0.5(H₂O)5 1, Ge₇O₁₂(OH)₄(H₂O)6 2 and Ge₇O₁₂(OH)₄(C₄NH₁₁)1.5(H₂O)1.5 3 have been synthesized under hydrothermal conditions and characterized by IR spectroscopy, powder XRD, TG and single crystal X-ray diffraction. Compound 1 crystallizes in the cubic space group P-43m with a= 7.7119(5) A, V= 458.65(5) A3, Z=1. Compound 2: Cubic, P-43m, a = 7.7653(17) A, V= 457.48(17) A3, Z=1. Compound 3: Cubic, P-43m, a = 7.705(2) A, V= 457.4(2) A3, Z=1. These germanates keep the same inorganic topological framework, which is assembled from Ge4(OH)₄ cubane and chiral intertwined Ge-O double helices.2. Two new germanates Ge₇O₁₂(OH)₄(C₆N₄H₁₈)1.2 4 and Ge₁₀O₂₀(H₂O)(C₆N₄H₁₈)0.4 5 have been synthesized under hydrothermal conditions and characterized by IR spectroscopy, TG and single crystal X-ray diffraction. Compound 4 crystallizes in the cubic space group P-43m, a= 7.7080 A, V= 457.96 A3, Z=1, R1 =0.0259 for the reflections with I>2σ(I) and wR2 =0.0760. Compound 5: tetragonal, P4/mcc with a = 8.8315 A, c= 14.4466 A, V =1126.77 A3, Z=2, R1 =0.0282 for the reflections with I>2σ(I) and wR2 =0.0797. Both germanates are prepared by using tris-(2-aminoethyl)-amine as SDA, but possess the different topological inorganic framework. The three-dimensional structure of 4 has a topological framework with 8-membered ring channels, which is assembled from Ge4(OH)₄ cubane and GeO4 tetrahedra, while compound 5 has the same topological framework as the reported germanate ASU-7, which constructed by double 4-membered rings (D4R, Ge8) and GeO4 tetrahedra.3. Two new germanates Ge₂₅O₄₆(OH)10(C₆N₄H₂₂)0.5(H₂O)6 6 and Ge₂₅O₄₆(OH)10 (C₈N₅H₂₇)0.5 (H₂O)6 7 have been synthesized under hydrothermal conditions and characterized by IR spectroscopy, powder XRD, TG and single crystal X-ray diffraction. Compound 6 crystallizes in the tetragonal space group I4/m with a = 10.5002(8) A, c = 36.839(6) A, V= 4061.7(8) A3, Z=2. Compound 7: Tetragonal, I4/m, a = 10.4968(2) A , c = 36.9635(13) A, V = 4072.74(18) A3, Z=2. Both germanates keep the same novel inorganic framework with 10-Ring channels.4. In the system of GeO₂- H3BO3-Pb(OAC)2.3H₂O-Pyride-H₂O-HF, a germanate PbGeO3 8 was synthesized by using organic amine as the structure-directing agent. we determine the crystal structure for the first time. Compound 8 crystallizes in the rhombohedral space group R-3 with a = 9.3282A,α=β=γ=113.4560°, V = 537.36(9) A3, Z=18. The three-dimensional open framework possesses 6-ring channels viewed along [111] direction.5. A new germanate (C10H18N)2[GeF6] 9 has been synthesized under hydrothermal conditions, it was a simple salt of adamantamine and germanium fluoride. Compound 9 crystallizes in the monoclinic space group C2/m with a = 11.099(2) A,b = 6.7458(13) A,c = 4.179(3) A,β= 97.844(3)°, V = 1051.7(4) A3, Z=2. The structure consists of discrete adamantylammonium cations lying on crystallographic mirror planes and hexa- fluoridogermanate anions disordered about sites of 2/m point symmetry. In the latter, the Ge atom lies on the site of 2/m symmetry, one F atom lies on the mirror plane and two further F atoms are included in general positions with 50% site occupancy. The cations and anions lie in layers with N—H…F hydrogen bonds formed between them.