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 anisotropy (CSA) tensor under magic angle spinning (MAS) is described. This correlates a fast MAS spectrum in the ω2 dimension with a sideband pattern in ω1 in which the intensities mimic those for a sample spinning at a fraction of the rate ωr/N. This method is particularly useful for accurately measuring narrow shift anisotropies. Since the sidebands intensities in ω1 are identical to those expected at ωr/N, standard methods can be used to extract the principal tensor components. The nature of the experiment is such that a minimal number of t1 increments is required.