The Synthesis and Structure of SSZ-73: an All-Silica Zeolite with an Unusual Framework Topology
This paper reports the synthesis, characterization, and crystallographic studies of the new all-silica zeolite SSZ-73. The framework topology of SSZ-73 is isostructural with the aluminophosphate STA-6 (SAS). SSZ-73 is prepared from fluoride-containing gels using 3-ethyl-1,3,8,8-tetramethyl-3-azoniabicyclo[3.2.1]octane cation as a structure-directing agent. SSZ-73 is an all-silica zeolite with a one-dimensional system of eight-ring pores. However, SSZ-73 possesses a remarkably high micropore volume (0.25 cm{sup 3}/g) due to the rather large cages in the structure. A single-crystal X-ray diffraction study of the as-made material shows that fluoride resides within the double six-ring cages of the SAS framework. Molecular docking studies were performed for the two geometric isomers of the structure-directing agent in the all-silica frameworks of SAS, RTH, ITE, and STF. The studies suggest that the isomer with the ethyl group cis to the bridgehead carbon is the likely structure-directing agent for SSZ-73 and that the other isomer may be responsible for the small amounts of RTH impurity observed in some preparations of SSZ-73.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 929943
- Report Number(s):
- BNL-80538-2008-JA; CMATEX; TRN: US200822%%941
- Journal Information:
- Chemistry of Materials, Vol. 19; ISSN 0897-4756
- Country of Publication:
- United States
- Language:
- English
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