Chemical shift anisotropy amplification

Abstract 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 ω 2 dimension with a sideband pattern in ω 1 in which the intensities mimic those for a sample spinning at a fraction of the rate ω r / N , and these sidebands result from an amplification by a factor N of the modulation caused by the CSA. Standard methods can be used to extract the principal tensor components from the ω 1 sideband patterns, and the nature of the experiment is such that the use of a large number of t 1 increments can avoided without compromising the resolution of different chemical sites. The new experiment is useful for accurately measuring narrow shift anisotropies.