Two-dimensional MAS-NMR spectra which correlate fast and slow magic angle spinning sideband patterns

A new NMR experiment which allows a measurement of the chemical shift aniso tropy (CSA) tensor under magic angle spinning (MAS) is described. This corr elates a fast MAS spectrum in the omega (2) dimension with a sideband patte rn in omega (1) in which the intensities mimic those for a sample spinning at a fraction of the rate omega (r)/N. This method is particularly useful f or accurately measuring narrow shift anisotropies. Since the sidebands inte nsities in omega (1) are identical to those expected at omega (r)/N, standa rd methods can be used to extract the principal tensor components. The natu re of the experiment is such that a minimal number of t(1) increments is re quired. (C) 2001 Elsevier Science B.V. All rights reserved.