Field-swept 33S NMR study of elemental sulfur

Field-swept 33S NMR spectra of a cyclic octaatomic molecule of elemental sulfur, α-S8, are presented. The spectra were acquired at a Larmor frequency of 16.2 MHz and using a superconducting magnet at between 6.32 and 0.50 T. Methods were developed for analyzing the field-swept 33S NMR spectra in which both Zeeman and quadrupole interactions were dominant. The quadrupole coupling constant, CQ, and the asymmetry parameter, ηQ, for α-S8 were found to be 43.68 MHz and 0.57, respectively. T1 measurements of α-S8 were conducted using the nuclear quadrupole resonance signals, and the activation energy was determined to be 54(1) kJ mol−1 from these T1 measurements. The molecular motion was assigned to ring-puckering of α-S8 molecules within the crystal structure.