Crystal structures of the hydro-sodalite Na6[AlSiO4]6 8H2O and of the anhydrous sodalite Na6[AlSiO4]6

Single-crystal X-ray diffraction and variable-temperature MAS NMR study on the heterogeneous network clathrate Na[N(CH3)4]7[Si8O20].54H2O

“…A planar hexagonal coordination by O atoms would cause a large electric field gradient at the 23Na nuclei (spin ~), resulting in a very strong quadrupolar interaction and, therefore, excessive line broadening with a typical quadrupolar lineshape. This is exactly the case for the anhydrous sodalite phase Na6[A16Si6024], where the alkali cations are almost planar coordinated by six O atoms of the aluminosilicate framework (Felsche, Luger & Baerlocher, 1986;Engelhardt, 1991). Moreover, it was recently shown that lineshapes affected by quadrupolar interaction may also occur if dynamic reorientation of the Na environment generates an electric field gradient on time average (Kempa, Engelhardt, Buhl, Felsche, Harvey & Baerlocher, 1991).…”

Caracterização e análise estrutural da hidroxisodalita sintetizada a partir de amostras de solo amazônico

“…Estes minerais, geralmente estão presentes nos solos da região amazônica, conforme mostrado na análise química. A análise do difratograma da amostra A14-b, resultante do tratamento térmico, revelou a ocorrência de material amorfo característico da metacaulinita [32], conforme observado também pelas técnicas termogravimétrica e infravermelho. Foi mencionado que a metacaulinita é um material muito mais reativo do que a caulinita para a síntese de zeólitas [30].…”

Silver Hydro Sodalite [Ag3(H2O)4]2[Al3Si3O12]2: Synthesis and Structure Determination by Combination of X-ray Rietveld Refinement, Thermogravimetry, FT-IR, and1H-MAS NMR Spectroscopy

“…Our studies demonstrate that the arrangement of the non-framework species in aluminosilicate silver hydro sodalite SHS is considerably different to the corresponding structures in its sodium analogue [Na 3 (H 2 O) 4 ] 2 [Al 3-Si 3 O 12 ] 2 [17] and in the sodalite cages of hydrated silver zeolite A. [15] In all cases, one sodalite cage contains three metal cations and four water molecules.…”

“…[17] This indicates that the Na ϩ ions interact with similar strengths with the framework and with the water molecules. The corresponding values for SHS show that the Ag ϩ cations prefer coordination to the framework oxygen atoms.…”