@article {5080, title = {Location of the fluoride ion in tetrapropylammonium fluoride silicalite-1 determined by H-1/F-19/Si-29 triple resonance CP, REDOR, and TEDOR NMR experiments}, journal = {Journal of the American Chemical Society}, volume = {123}, number = {28}, year = {2001}, note = {ISI Document Delivery No.: 451LFTimes Cited: 48Cited Reference Count: 50}, month = {Jul}, pages = {6882-6891}, type = {Article}, abstract = {The location of the fluoride ion in tetrapropylammonium fluoride silicalite-1 ([TPA]-F-[Si-MFI]), an as-synthesized siliceous zeolite with the MEI topology, has been unambiguously determined using solid-state NMR experiments alone. With the H-1 {\textendash}> Si-29 CP-INADEQUATE experiment, the 12 peaks in the highly resolved Si-29 MAS NMR spectrum of [TPA]-F-[Si-MFI] were assigned. Using these peak assignments it was possible to perform H-1/F-19/Si-29 triple resonance CP, REDOR, and TEDOR experiments to measure F-Si distances and thus locate the fluoride ion. It is covalently bonded to Si-9 in the [4(1)5(2)6(2)] cage of the zeolite framework and exchanges between two "mirror-related" Si-9 sites, making them equivalent on the NMR time scale. The importance of this result and the general applicability of the approach are discussed.}, keywords = {3-DIMENSIONAL BONDING CONNECTIVITIES, 5-COORDINATE, CONTAINING OCTADECASIL, CROSS-POLARIZATION NMR, CRYSTAL-STRUCTURE, DETERMINATIONS, DISTANCE, MAS-NMR, NATURAL-ABUNDANCE, PROTON-ENHANCED NMR, SILICON, SOLID-STATE SI-29}, isbn = {0002-7863}, url = {://000169803000018}, author = {Fyfe, C. A. and Brouwer, D. H. and Lewis, A. R. and Chezeau, J. M.} }