Fast magic-angle spinning

Among fast MAS methods, homonuclear and heteronuclear DQ techniques have proven the most powerful and versatile. A detailed description of the principles of high-resolution DQ NMR spectroscopy of solids can be found in a previous review in this series.17 Recent developments are covered in extended papers on 

One way of studying molecular motions involves monitoring the reduction of dipole-dipole couplings probed by DQ spinning sidebands. The site selectivity is particularly high for heteronuclear DQ coherences. In Fig. 8, simulated sideband patterns are plotted for the C-H group, which is a sensitive probe of phenylene rotational motions, often met in practice. At low temperatures, one would expect 

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Rocha, )., Carr, S.W., and Klinowski,). (1991) A1 quadrupole nutabon and H - A1 cross-polarizabon solid-state NMR studies of ulbastahle zeolite Y with fast magic-angle spinning. Chem. Phys Lett., 187, 401-408. 

A.T. Kreinbrink, C.D. Sazavsky, J.W. Pyrz, D.G.A. Nelson, R.S. Honkonen, Fast magic angle spinning F NMR of inorganic fluorides and fluoridated apatitic surfaces, J. Magn. Reson. 88 (1990) 267-276. 

J. C.C. Chan, C-REDOR Rotational double resonance under very fast magic angle spinning, Chem. Phys. Lett. 335 (2001) 289-297. 

Fig. 4. Quadrupolar powder patterns (a) Spin NMR powder pattern showing that the central -)<- ) transition is broadened only by dipolar coupling, chemical shift anisotropy, and the second-order quadrupolar interactions, (b) Spin 1 NMR powder pattern for a nucleus in an axially symmetric electric field gradient (see text). The central doublet corresponds to 6 = 90° in Eq. (10). The other features of low intensity correspond to 6 = 0° and 6 = 180°. (c) Theoretical line shape of the ) - -) transition of a quadrupolar nuclear spin in a powder with fast magic-angle spinning for different values of the asymmetry parameter t (IS) ...

Currently, solid-state NMR spectroscopy is a rapidly developing technique in all branches of chemistry. Solid-state NMR spectra are capable of providing information that is difficult or impossible to obtain from measurements in solution. In isotropic solutions, or in the fast Magic Angle Spinning (MAS) spectra of solids, the observed isotropic chemical shift represents the result of motional averaging of the principal components (5n, 22, and 33) of the chemical-shift tensors. The spinning rate decreases. 

Fig. 7. A PISEMA pulse sequence for studies under a fast magic angle spinning condition. The modified SEMA pulse sequence in the tx period recovers I S dipolar couplings under MAS. Unlike other SLF pulse sequences, this pulse sequence does not require the synchronization of the tx period with the spinning speed of the rotor.

Fast magic-angle spinning (>20 kHz) has been appUed to the study of Li fCo02 (0.48 < X < 1.05), showing that there are nonequivalent CoOe octahedra present in this potential material for lithium-ion batteries. However, not much NMR data was extracted owing to the severe overlap of the spinning sideband manifolds. ... 

I. Kawamma, Y. Degawa, S. Yamaguchi, K. Nishimma, S. Tuzi, H. Saitd, Pressure induced isomerization of retinal on bacteriorhodopsin as disclosed by fast magic angle spinning NMR, Photochem. Photobiol. 83 (2007) 346—350. 

B.H. Meier, Cross polarization under fast magic angle spinning thermodynamical considerations, Chem. Phys. Lett. 188 (1992) 201-207. 

S. Laage, A. Marchetti, J. Sein, R. PieratteUi, H.J. Sass, S. Grzesiek, A. Lesage, G. Pintacuda, L. Emsley, Band-selective H— C cross-polarization in fast magic angle spinning sohd-state NMR spectroscopy, J. Am. Chem. Soc. 130 (2008) 17216-17217. 

A. Brinkmann, A.P.M. Kentgens, Proton-selective H distance measurements in fast magic-angle-spinning solid-state NMR spectroscopy for the determination of hydrogen bond lengths, J. Am. Chem. Soc. 128 (2006) 14758. 

S. Parthasarathy, Y. Nishiyama, Y. Ishii, Sensitivity and resolution enhanced solid-state NMR for paramagnetic systems and biomolecules under very fast magic angle spinning, Acc. Chem. Res. 46 (2013) 2127-2135. 

K. J. Pike, Fast magic-angle spinning implications. Encyclopedia of Magnetic Resonance, John Wiley Sons, Ltd., Chichester, England, 2010. 

Very fast magic angle spinning 2D solid-state NMR sub-micro-Hter sample... 

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