β Scribed by Halimaton Hamdan; Jacek Klinowski
No coin nor oath required. For personal study only.
Al quadrupole nutation NMR provides valuable information on the structure of amorphous aluminosilicates derived from zeolite Y by chemical treatment. The local Al environment, ofwhich several kinds can be resolved in the two spectral dimensions, depends vitally on the mode of preparation of the sample. Treatment of the samples with aqueous KOH converts six-coordinated Al to four-coordination.
The results arc of great assistance for the interpretation of *'Al spectra of crystalline aluminosilicates.
π SIMILAR VOLUMES
AI NhlR nulnlion experiment for qundrupolar nuclei d ~rwlopcd by Snmoson and Lippmnn has been applied 10 "Al spins in rhe zeoliw co~~lysr H-ZSM-5. The "Al numGon sprc~a change with WBE~ con~cnl in the portzs or this zcolik. rrom which ir can bc concluded thal in the hydrated SWIG many "Al nuclei arc
Quadrupole nutation 17Al NMR monitors the changes in the chemical environment of aluminium during dealumination and subsequent realumination of zeolite Y. Two-dimensional nutation spectra unambiguously demonstrate that extra-framework aluminium enters four-coordinated (tetrahedral) framework sites d
H-27Al cross-polarization magic-angle spinning (PC/MA.?) NMR has been used to monitor selectively the non-framework aluminium (AINF) species in dealuminated zeolite Y (Si/AI=4.0-14). \*'AI quadrupole nutation with fast ( 12.5 kHz) MASand radiofrequency excitation fields up to 220 kHz reveals resonan
## Abstract The spatial ordering of aluminum atoms in CsAl(SiO~3~)~2~ and 3Al~2~O~3~Β·2SiO~2~ was probed by ^27^Al dipolar solidβstate NMR spectroscopy. The ^27^Al response to a Hahn spinβecho pulse sequence in a series of aluminumβcontaining model crystalline compounds demonstrates that quantitativ
## Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a βFull Textβ option. The original article is trackable v