Magic angle spinning oxygen-17 NMR of aluminum oxides and hydroxides

Journal Article · Thu Sep 07 04:00:00 EDT 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100355a034· OSTI ID:6986072

Walter, T H; Oldfield, E ^[1]

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1. Univ. of Illinois, Urbana-Champaign (USA)

The authors have obtained magic angle spinning {sup 17}O nuclear magnetic resonance spectra of {sup 17}O-labeled {alpha}-Al{sub 2}O{sub 3}, boehmite (AlO(OH)), bayerite (Al(OH){sub 3}), and several transitional aluminas, including {gamma}-, {eta}-, {delta}-, and {theta}-Al{sub 2}O{sub 3}. Cross polarization from {sup 1}H to {sup 17}O has been used to enhance the hydroxyl oxygen resonances of boehmite and bayerite and to allow the observation of hydroxyl groups on the surface of {gamma}-Al{sub 2}O{sub 3}. The spectra yield nuclear quadrupole coupling constants, electric field gradient tensor asymmetry parameters, and isotropic chemical shifts for each chemically distinct oxygen site. The quadrupole coupling constants for tetrahedrally coordinated oxide sites (OAl{sub 4}) range from 1.2 to 2.2 MHz, while those of trigonally coordinated hydroxide sites (Al{sub 2}OH) are in the 5-6-MHz range. Trigonally coordinated oxide sites (OAl{sub 3}), arising as a result of cation vacancies in the transitional aluminas, are estimated to have quadrupole coupling constants of approximately 4 MHz. It is shown that the observed quadrupole coupling constants and asymmetry parameters are in generally good agreement with the results of electric field gradient calculations based on a point charge model.

• OSTI ID: 6986072
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 93:18; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400000 -- Chemistry
400201 -- Chemical & Physicochemical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM HYDROXIDES
ALUMINIUM OXIDES
CATALYSTS
CHALCOGENIDES
DATA
DATA ANALYSIS
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
HYDROGEN COMPOUNDS
HYDROXIDES
INFORMATION
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MEASURING INSTRUMENTS
MEASURING METHODS
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUMERICAL DATA
OXIDES
OXYGEN 17
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
RESONANCE
STABLE ISOTOPES