Are magic angle spinning spectra indifferent to sense of spinning?

摘要

The apparent imperviousness of routine magic angle spinning (MAS) spectra to sense of spinning (clockwiseegative or counterclockwise/positive) is examined. Theoretical arguments, supported by simulations, reveal that the MAS signal depends on the spinning sense. However, this dependence is masked when appropriate symmetry of distribution of molecular orientations is present. Similar results are also found to be valid for signal arising from a 'total suppression of spinning sidebands' (TOSS) scheme. (C) 1998 John Wiley & Sons Ltd. [References: 15]