Synthesis and general characterisation of RUB-22: A new microporous silicate possessing an interrupted framework structure
RUB-22, a new tetramethylammonium (TMA, (N(CH3)4) silicate, was synthesised in the system TMAOH/SiO2/H2O/(CH3OH). Typically a reaction mixture consisting of 2.8 tetramethylammonium hydroxide / 1 - 3.8 tetramethylorthosilicate / 55.5 H2O was heated at 160癈 for 8 days. The resulting colorless crystals are isometric, monoclinic prisms (0.33 祄 in size) and have a density of 1.86(3) g/cm3. The X-ray powder pattern can be indexed based on a Ccentered monoclinic unit cell with a = 13.665(3) ? b = 13.248(2) ? c = 12.316(1) ? = 112.71(1)? The unit cell formula was determined as TMA4Si32O60(OH)12. Infrared and NMR spectroscopy indicated the presence of a large amount of Si-OH and/or Si-O- groups. Some properties of RUB-22 are very similar to those of RUB-10, TMA4Si32B4O72 (zeolite framework type RUT). Comparison of experimental and simulated X-ray powder patterns indicated that RUB-10 and RUB-22 possess an identical framework topology with the exception that one ninth of all TO4 tetrahedra of the RUB-10 framework (probably the BO4 tetrahedra) are replaced by H3O4 hydroxyl nests in the case of RUB-22.
S. Latzel B. Marler Oberhagemann C. Osterhoff H. Gies
Dept. of Geology, Mineralogy and Geophysics, Ruhr University, D-44780 Bochum, Germany
国际会议
北京
英文
2007-08-12（万方平台首次上网日期，不代表论文的发表时间）