An approximate absolute 33S nuclear magnetic shielding scale

Sulfur-33 chemical shifts have been measured for a number of simple compounds, e.g. SF6, HFSO3, X2SO2, SO2, Cl2SO, CH3SH, H2S, and OCS, which have not been previously reported. Our results indicate that the range of 33S chemical shifts is approximately 1000 ppm, slightly less than that observed for 17O and approximately one half the range reported for 77Se. Using the 33S nuclear spin-rotation constant of OCS measured by molecular-beam electric resonance and Flygare's procedure, an absolute 33S shielding constant of 843 ± 12 ppm is calculated for OCS, permitting an approximate absolute shielding scale to be proposed for this nucleus.