High-resolution NMR spectroscopy in solids by truly magic-angle spinning

Right angles: In solid-state magic-angle spinning (MAS) NMR spectra, the line widths of carbonyl carbon atoms in polycryst. cholesteryl acetate are as narrow as 0.039 ppm if the magic angle is adjusted very accurately, i.e., within +-0.004 Deg. The line broadening obsd. for slightly miss-set angles is mostly due to residual chem. shift anisotropy (CSA) interactions. Long spin-echo life times up to T'2 = 3.6 s open the way to sophisticated NMR methods. [on SciFinder (R)]