Nuclear magnetic resonance data for sulfur-33 nuclei in pure compounds are extremely sparse. Although the first observation of a 33S NMR signal was reported in 1951, it was not until 17 years later that additional data were published. Of the seven compounds investigated, only two, carbon disulfide and 1,2-ethanedithiol, can be considered organic; the chemical shift of the latter compound was not measured. The original objective of the present study, although not achieved, was to determine if a measurable chemical shift exists between the aromatic sulfur atom in thiophene and the nonaromatic one in tetrahydrothiophene. This is part of a more extensive investigation of the potential uses of new spectroscopic methods in studies of the structure of coals and related materials. The 33S NMR spectrum of thiophene and our unsuccessful attempt to observe the 33S resonance in tetrahydrothiophene are described in this note.
H. L. Retcofsky and R. A. Friedel, "Sulfur-33 Magnetic Resonance Spectrum of Thiophene," Appl. Spectrosc. 24, 379-380 (1970)