| Popis: |
Publisher Summary RUB-13 was first synthesized in 1987 and characterized as a zeolite containing trace amounts of boron. This chapter presents an improved synthesis and the crystal structure of RUB-13, which represents a new porous structure type. RUB-13 was synthesized in the system SiO 2 :H 3 BO 3 :1,2,2,6,6-pentamethylpiperidine: Ethylenediamine:H 2 O under hydrothermal conditions at 160°C in silica tubes. The twinned crystals were investigated using Weissenberg- and precession methods to determine the twinning law. The structure determination was performed with single crystal intensity data collected from one twin individuum on a SYNTEX R3 diffractometer (2Θ max =55°, λ=0.7107A). 29 Si CP/MAS NMR experiments were run on a BRUKER MSL 400 spectrometer. The boron content after calcination was determined with an ICP spectrometer (Phillips PU 7000). The density of the as-synthesized material was measured using the swim and sink method. |
