Variable-temperature magic-angle-spinning technique for studies of mobile species in solid-state NMR

Journal Article · Thu Jul 13 00:00:00 EDT 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100351a051· OSTI ID:7157904

Tokuhiro, Tadashi ^[1]; Mattingly, M ^[2]; Iton, L E ^[3]; Ahn, M K ^[4]

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1. Massachusetts Institute of Technology, Cambridge (USA)
2. Bruker Instruments, Inc., Billerica, MA (USA)
3. Argonne National Lab., IL (USA)
4. Indiana State Univ., Terre Haute (USA)

The utility of variable-temperature (VT) magic-angle-spinning (MAS) Fourier transform nuclear magnetic resonance (FT-NMR) spectroscopy is demonstrated for the study of mobile species in solids, especially when quadrupolar nuclei are being observed. A new VT-MAS probe is described for use in the temperature range 150-400 K, using spectrometers with high-field superconducting magnets. It has been utilized in studies of the bonding and dynamics of alkali-metal cations in hydrated zeolites at an applied field of 7.05 T. Results are presented for the cases of Cs/Na-A and Cs/Li-A zeolites, in which the Cs{sup +} ions exchange rapidly, at 293 K, between six-ring and eight-ring sites in the large cage, so that on the time scale of the NMR measurements the ions are indistinguishable and a single {sup 133}Cs resonance is observed. Below 250 K, two well-resolved signals are observed in the Cs/Na-A zeolite, 107 ppm apart. These are easily assigned to the Cs{sup +} ions in the two sites, the large difference in chemical shifts being attributed to the stronger bonding of Cs{sup +} ions at the six-ring sites. Three sites are distinguished in the Cs/Li-A zeolite, the third site being assigned to a position near a four-ring in the large cage.

• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 7157904
• Journal Information: Journal of Physical Chemistry; (USA), Vol. 93:14; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ZEOLITES
NUCLEAR MAGNETIC RESONANCE
ALUMINATES
CESIUM COMPOUNDS
DATA ANALYSIS
EXPERIMENTAL DATA
MEASURING INSTRUMENTS
MEASURING METHODS
MEDIUM TEMPERATURE
ALKALI METAL COMPOUNDS
ALUMINIUM COMPOUNDS
DATA
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MAGNETIC RESONANCE
MATERIALS
MINERALS
NUMERICAL DATA
OXYGEN COMPOUNDS
RESONANCE
360603* - Materials- Properties
400102 - Chemical & Spectral Procedures
400000 - Chemistry