@inbook {833,
	title = {Measuring the silion fluoride bond distance in zeolites},
	booktitle = {Recent Advances in the Science and Technology of Zeolites and Related Materials, Pts a - C},
	series = {Studies in Surface Science and Catalysis},
	volume = {154},
	year = {2004},
	note = {ISI Document Delivery No.: BBR47Times Cited: 0Cited Reference Count: 19Proceedings Paper14th International Zeolite Conference on Recent Advances in the Science and Technology of Zeolites and Related MaterialsAPR 25-30, 2004Cape Town, SOUTH AFRICASARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	pages = {1319-1323},
	publisher = {Elsevier Science Bv},
	organization = {Elsevier Science Bv},
	address = {Amsterdam},
	abstract = {A common misconception is that X-ray diffraction is the best way to measure bond distances. However, in some cases where disorder is present it can yield incorrect answers. The silicon-fluoride bond distance in fluoride-containing zeolite SFF has been measured using two magic angle spinning NMR techniques. Both techniques, variable contact time cross polarization and spinning side hand intensity fitting give shorter Si-F bond distances than X-ray diffraction.},
	keywords = {5-COORDINATE SILICON, COMPLEX, IFR, IONS, LOCATION, MEDIA, MOLECULAR-SIEVES, SOLID-STATE NMR, STF, TEMPLATE},
	isbn = {0167-29910-444-51805-3},
	url = {<Go to ISI>://000227357201022},
	author = {Darton, R. J. and Brouwer, D. H. and Fyfe, C. A. and Villaescusa, L. A. and Morris, R. E.},
	editor = {VanSteen, E. and Claeys, M. and Callanan, L. H.}
}
@article {834,
	title = {Solid-state NMR studies of the fluoride-containing zeolite SSZ-44},
	journal = {Chemistry of Materials},
	volume = {16},
	number = {4},
	year = {2004},
	note = {ISI Document Delivery No.: 774YATimes Cited: 12Cited Reference Count: 21},
	month = {Feb},
	pages = {600-603},
	type = {Article},
	abstract = {Magic-angle spinning NMR has been used to probe the local structure of as-made zeolite SFF containing occluded fluoride and NN-diethyl-2,6-dimethylpiperidinium. The Si-F bond distance has been measured using two methods: variable contact time cross polarization studies (1.74 Angstrom) and spinning sideband intensity fitting at relatively slow spinning speeds (1.79 Angstrom). Both measurements yield results that are significantly shorter than the internuclear Si-F distance as measured by single-crystal X-ray diffraction (similar to1.9 Angstrom), which is based on the average positions of the atoms due to disorder and hence does not reflect the true bond distance.},
	keywords = {5-COORDINATE SILICON, COMPLEX, IFR, IONS, LOCATION, MEDIA, MOLECULAR-SIEVES, SPECTROSCOPY, STF, TEMPLATE},
	isbn = {0897-4756},
	url = {<Go to ISI>://000189012900008},
	author = {Darton, R. J. and Brouwer, D. H. and Fyfe, C. A. and Villaescusa, L. A. and Morris, R. E.}
}
@article {382,
	title = {Combined solid state NMR and X-ray diffraction investigation of the local structure of the five-coordinate silicon in fluoride-containing as-synthesized STF zeolite},
	journal = {Journal of the American Chemical Society},
	volume = {124},
	number = {26},
	year = {2002},
	note = {ISI Document Delivery No.: 567YYTimes Cited: 41Cited Reference Count: 48},
	month = {Jul},
	pages = {7770-7778},
	type = {Article},
	abstract = {The local structure of the [SiO4/2F](-) unit in fluoride-containing as-synthesized STF zeolite has been experimentally determined by a combination of solid-state NMR and microcrystal X-ray diffraction to be very close to trigonal bipyramidal. Because the fluoride ions are disordered over two sites, the resulting local structure of the [SiO4/2F](-) unit from a conventional XRD refinement is an average between tetrahedral SiO4/2 and five-coordinate [SiO4/2F](-), giving an apparent F-Si distance longer than expected. The correct F-Si distance was determined by slow spinning MAS and fast spinning F-19/Si-29 CP and REDOR solid-state NMR experiments and found to be between 1.72 and 1.79 Angstrom. In light of this, the X-ray structure was re-refined, including the disorder at Si3. The resulting local structure of the [SiO4/2F]- unit was very close to trigonal bipyramidal with a F-Si distance of 1.744 (6) Angstrom, in agreement with the NMR results and the prediction of Density Functional Theory calculations. In addition, further evidence for the existence of a covalent F-Si bond is provided by a F-19{\textendash}>Si-29 refocused INEPT experiment. The resonance for the five-coordinate species at -147.5 ppm in the Si-29 Spectrum is a doublet due to the F-19/Si-29 J-coupling of 165 Hz. The peaks in this doublet have remarkably different effective chemical shift anisotropies due to the interplay of the CSA, dipolar coupling, and J-coupling tensors. The distortions from tetrahedral geometry of the neighboring silicon atoms to the five-coordinate Si3 atom are manifested in increased delta(aniso) values. This information, along with F-Si distances measured by F-19{\textendash}>Si-29 CP experiments, makes it possible to assign half of the Si-29 resonances to unique tetrahedral sites. As well as determining the local geometry of the [SiO4/2F](-) unit, the work presented here demonstrates the complementarity of the solid-state NMR and X-ray diffraction techniques and the advantages of using them together.},
	keywords = {5-COORDINATE SILICON, C-13 NMR, CONTAINING OCTADECASIL, CROSS-POLARIZATION, DISTANCE DETERMINATIONS, LOCATION, MOLECULAR-SIEVES, P-31 NMR, POLARIZATION TRANSFER, PROTON-ENHANCED NMR},
	isbn = {0002-7863},
	url = {<Go to ISI>://000176516400032},
	author = {Fyfe, C. A. and Brouwer, D. H. and Lewis, A. R. and Villaescusa, L. A. and Morris, R. E.}
}
@article {4397,
	title = {Low temperature syntheses of highly-ordered framework materials: The aluminium phosphate ammonium taranakite},
	journal = {Zeitschrift Fur Anorganische Und Allgemeine Chemie},
	volume = {624},
	number = {10},
	year = {1998},
	note = {ISI Document Delivery No.: 125PHTimes Cited: 1Cited Reference Count: 34},
	month = {Oct},
	pages = {1712-1717},
	type = {Article},
	abstract = {The formation of a highly crystalline ammonium analogue of the aluminium phosphate mineral taranakite at ambient temperature and above is described. The high crystallinity and ordering of the products obtained when ammonium is used as a templating agent suggests that it is intimately involved in the structure. At long crystallization times and at higher temperatures, transformation to the framework structure of AlPO4-15 occurs. Results from powder x-ray diffraction, solid state NMR, electron microscopy, thermal and element analyses are presented and discussed. They demonstrate the high degree of crystallinity and ordering of the taranakite samples synthesized by this method. These results - in particular the very mild synthesis conditions - suggest the possibility that there may be sequestering of ammonium phosphate fertilizers in form of NH4-taranakite from their interaction with clay materials in soils.},
	keywords = {CHANNELS, MOLECULAR-SIEVES, SOLIDS},
	isbn = {0044-2313},
	url = {<Go to ISI>://000076245700026},
	author = {Schwieger, W. and Altenschildesche, H. M. Z. and Kokotailo, G. T. and Fyfe, C. A.}
}
