@article {610,
	title = {Influence of F content on the composition of Al-rich synthetic phlogopite: Part II. Probing the structural arrangement of aluminum in tetrahedral and octahedral layers by Al-27 MQMAS and H-1/F-19-Al-27 HETCOR and REDOR experiments},
	journal = {American Mineralogist},
	volume = {88},
	number = {7},
	year = {2003},
	note = {ISI Document Delivery No.: 699FDTimes Cited: 10Cited Reference Count: 28},
	month = {Jul},
	pages = {1046-1054},
	type = {Article},
	abstract = {The influence of F substitution on the local structure of Al in the tetrahedral and octahedral sheets of synthetic Al-rich phlogopite samples with nominal gel compositions of K(Mg3-xAlx)[Al1+xSi3-xO10] (OH)(y)(F)(2-y) between 0.0 less than or equal to x less than or equal to 0.8 and 0.5 less than or equal to y less than or equal to 1.8, was studied by Al-27 MAS, MQMAS, {H-1/F-19} {\textendash}> Al-27 2D CPMAS (HETCOR) and {H-1/F-19} Al-27 REDOR solid-state NMR and by IR spectroscopy. Changes in intensity of the absorption bands in the OH-stretching region of the IR spectra clearly indicate the incorporation of octahedral Al. Signals from the different phases can be separated in the Al-27 MQMAS NMR spectra by generation of an isotropic dimension in F1. The Al-27 quadrupolar parameters of the four phases were estimated from Al-27 MAS NMR spectra obtained at 104.26 and 208.42 MHz. The quadrupolar coupling constant and isotropic chemical shift increases with increasing Al content for the Al-IV site in phlogopite. The Al-VI site shows a clear increase of the asymmetry parameter and C-Q with increasing F content. The estimated Al-27 signal areas show the lowest amount of impurity phases at high OH contents and a stabilization of Al-VI sites by hydroxyl groups. The {H-1} {\textendash}> Al-27 2D CPMAS (HETCOR) NMR experiment at short contact times provides information about site neighborhoods of tetrahedral Al sites and Mg3OH as well as Mg2AlOH sites, whereas magnetization is only transferred to the octahedral At sites from hydroxyl groups in Mg2AlOH sites. The {F-19} {\textendash}> Al-27 2D CPMAS (HETCOR) NMR spectrum is dominated by Al-IV sites coupled to the Mg3F complex in phlogopite. Resonances from Mg2AlF complexes are not observed. Finally, the {H-1/F-19} Al-27 REDOR experiments support the results of the 2D CPMAS (HETCOR) experiments.},
	keywords = {ANGLE-SPINNING NMR, DOUBLE-RESONANCE, F-19 MAS-NMR, FLUORINE, HIGH-FIELD, NMR, QUADRUPOLAR NUCLEI, SI-29, SOLID-STATE NMR, SPECTRA, SUBSTITUTION},
	isbn = {0003-004X},
	url = {<Go to ISI>://000184045300013},
	author = {Fechtelkord, M. and Behrens, H. and Holtz, F. and Bretherton, J. L. and Fyfe, C. A. and Groat, L. A. and Raudsepp, M.}
}
@inbook {3404,
	title = {Powder x-ray diffraction and solid state NMR techniques for zeolite structure determination},
	booktitle = {Catalysis by Microporous Materials},
	series = {Studies in Surface Science and Catalysis},
	volume = {94},
	year = {1995},
	note = {ISI Document Delivery No.: BE31JTimes Cited: 4Cited Reference Count: 33Proceedings PaperInternational Symposium on Catalysis by Microporous Materials (ZEOCAT 95)JUL 09-13, 1995SZOMBATHELY, HUNGARYSARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	pages = {78-100},
	publisher = {Elsevier Science Publ B V},
	organization = {Elsevier Science Publ B V},
	address = {Amsterdam},
	abstract = {The synthesis of zeolites, porous aluminosilicates, had a large impact on the development of catalyst materials. The framework structures of these systems consist of Si and Al atoms, referred to as T-atoms, tetrahedrally coordinated to oxygen atoms to form topologies with well defined and regular channel systems. Cations are necessary to satisfy the charge on the Al atoms and are exchangeable. The T-atoms may also consist of any atom capable of isomorphorus substitutions for Si. Since good quality large zeolite crystals are not available, powder X-ray diffraction is used to derive structural information, and with improvements in powder diffraction instrumentation and the availability of synchrotron and rotating anode high intensity Xray sources, much higher quality structure data is obtained. The combined application of solid state NMR which probes short-range order, X-ray diffraction which is a long-range order technique and Rietveld refinement has greatly increased both the quantity and quality of structural information available.},
	keywords = {aluminum, COMBINATION, SI-29, ZSM-11},
	isbn = {0-444-82049-3},
	url = {<Go to ISI>://A1995BE31J00009},
	author = {Kokotailo, G. T. and Fyfe, C. A. and Feng, Y. and Grondey, H. and Gies, H. and Marler, B. and Cox, D. E.},
	editor = {Beyer, H. K. and Karge, H. G. and Kiricsi, I. and Nagy, J. B.}
}
