Multiple-quantum magic-angle-spinning

In order to remove the anisotropic effects of quadrupolar interactions which can obscure MAS spectra other techniques such as Double Rotation (DOR) [18, 19], Dynamic Angle Spinning (DAS) [18] or Multiple Quantum Magic Angle Spinning (MQMAS) have to be employed. Of these the most simple to apply practically is MQMAS, which can be conducted on a standard MAS-equipped NMR spectrometer. A number of texts and review papers discuss MQMAS in significant technical detail [20, 21]. 

MQMAS was first proposed in 1995 by Harwood and Frydman [22, 23]. The aim of the technique is to refocus the second-order quadrupole effects, which otherwise 

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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). 

Medek, A., Harwood, ).S., and Frydman, L (1995) Multiple-quantum magic- angle spinning NMR a new method for the study of quadrupolar nuclei in solids. /. Am. Chem. Soc., 117, 12779-12787. 

Goldbourt, A. and Madhu, P.K. (2005) Multiple-quantum magic-angle spinning high-resolution NMR spectroscopy of half-integer spin quadrupolar nuclei. Annu. Rep. NMR Spectrosc., 54, 81-153. 

MQMAS NMR multiple quantum magic-angle spinning NMR... 

R. Lefort, J. W. Wiench, M. Pruski and J.-P. Amoureux, Optimization of data acquisition and processing in Carr-Purcell-Meiboom-Gill multiple quantum magic angle spinning nuclear magnetic resonance. /. Chem. Phys., 2002,116, 2493-2501. 

Progress in Multiple-Quantum Magic-Angle Spinning NMR Spectroscopy... 

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