Solid state 33S NMR of inorganic sulfides

Solid state S-33 NMR spectra of a variety of inorganic sulfides have been obtained at magnetic field strengths of 4.7 and 17.6 T. Spectra acquired with magic angle spinning show considerable improvements in sensitivity and resolution when compared with static spectra. Multiple factors are considered when analyzing the spectral line widths, including; magnetic field inhomogeneity, dipolar coupling, chemical shift anisotropy, chemical shift dispersion (CSD), T-2 relaxation, and quadrupolar coupling. Quadrupolar coupling was expected to be the dominant line broadening mechanism. However, for most of the samples CSD was the prevailing line broadening mechanism. Thus, for many of the metal sulfides studied at a high magnetic field strength, the line widths were actually larger than those observed in the spectra at low field. This is atypical in solid state S-33 NMR. Solid state S-33 spin-lattice (T-1) and spin-spin (T-2) relaxation rates were measured for the first time and are discussed. This information will be useful in future efforts to use S-33 NMR in the compositional and structural analysis of sulfur containing materials. (C) 2003 Elsevier Science (USA). All rights reserved.