Magic-angle spinning usefulness

T. Vosegaard, P. Florian, D. Massiot and P. J. Grandinetti, Multiple quantum magic-angle spinning using rotary resonance excitation. J. Chem. Phys., 2001, 4618-4624. 

Solid-state Alnmr spectroscopy has been much used in recent years to study the composition and structure of aluminisilcates (pp. 351 -9) and other crystalline or amorphous Al compounds. The technique of magic angle spinning (MAS) must be used in such cases. ... 

The intercalates of sheet aluminosilicates (clays) and of graphite are demonstrated to be efficient catalysts for a variety of reactions, and results obtained using several analytical techniques, including magic angle spinning KMR, are presented. For the clay family,... 

We used modifications of the standard solid-state CP-MAS (cross-polarisation, magic-angle spinning) experiment to allow the proton relaxation characteristics to be measured for each peak in the C spectrum. It is known that highly mobile, hydrated polymers can not be seen using either usual CP-MAS C spectrum or solution NMR (6). We found, however, that by a combination of a long-contact experiment and a delayed-contact experiment we could reconstruct a C spectrum of the cell-wall components that are normally too mobile to be visible. With these techniques we were able to determine the mobility of pectins and their approximate spatial location in comparison to cellulose. 

The other vibrational spectroscopies, laser Raman and magic angle spinning NMR, have also been useful. Despite its low resolution, high resolution EELS has been usefiil in UHV work for assessment of surface cleanliness and for the identification of adsorbed species. 

A. R. Tate, P. J. D. Foxall, E. Holmes, D. Molca, M. Spraul, J. K. Nicholson, J. C. Lindon 2000, (Distinction between normal and renal cell carcinoma kidney cortical biopsy samples using pattern recognition of H-l magic angle spinning (MAS) NMR spectra), NMR Biomed. 13, 64-71. 

Although limited by sensitivity, chemical reaction monitoring via less sensitive nuclei (such as 13C) has also been reported. In 1987 Albert et al. monitored the electrochemical reaction of 2,4,6-tri-t-butylphenol by continuous flow 13C NMR [4]. More recently, Hunger and Horvath studied the conversion of vapor propan-2-ol (13C labeled) on zeolites using 1H and 13C in situ magic angle spinning (MAS) NMR spectroscopy under continuous-flow conditions [15]. 

In the vast majority of cases where NMR is used to localise cations in zeolites, one or both of the following techniques is used Magic Angle Spinning (MAS) or Multiple Quantum Magic Angle Spinning (MQMAS). 

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