| Given their inherent low detection sensitivity, 25Mg and 33S remain relatively understudied nuclei in solid-state nuclear magnetic resonance spectroscopy. With the use of an ultrahigh magnetic field of 21.1 T, magic-angle spinning, and the combination of various signal-enhancing techniques, the study of 25Mg and 33S SS-NMR has been made increasingly feasible. In this work, a series of magnesium-containing compounds with known crystal structure has been studied at natural abundance with the use of 25Mg SS-NMR. As well, a number of model anhydrous sulfate materials have been studied at natural abundance via 33S SS-NMR. First principles calculations implementing plane wave basis sets and pseudopotentials have been carried out on all compounds studied. Correlations between calculated NMR parameters and experimental results have given insight into the structural parameters. This work demonstrates that the chemical shift range of Mg in diamagnetic compounds may approach 200 ppm, although most commonly observed shifts are within the range of -15 to 25 ppm. The quadrupolar effects are shown to dominate 25Mg spectra in non-cubic environments and chemical shift anisotropy could only be detected in a handful of cases. For 33S in anhydrous sulfates, however, both the quadrupolar and shielding anisotropy interactions are shown to have an effect. With the use of calculation and experimental results, structural assessments were performed on existing anhydrous sulfate structures. |
