Frequency-swept solid-state 33S NMR of an organosulfur compound in an extremely low magnetic field

Abstract

Frequency-swept solid-state 33S nuclear magnetic resonance (NMR) spectra of a 33S-enriched organosulfur compound, [33S]-diphenyl disulfide, are presented. The NMR spectra were acquired at extremely low magnetic fields, 0.06 and 0.10T, which correspond to Larmor frequencies of 0.1959 and 0.3265MHz, respectively. The quadrupole coupling constant, CQ, and the asymmetry parameter, ηQ, for [33S]-diphenyl disulfide were found to be CQ=43.3±1.9MHz and ηQ=0.70±0.20, respectively. T1 measurements of [33S]-diphenyl disulfide were performed between 60 and 300K using nuclear quadrupole resonance signals, and a compromise observation temperature was found to be 300K. Quantum chemical calculations were performed and the results demonstrated that the quadrupole frequencies and CQ values were highly sensitive to the changes in dihedral angles of disulfide bonds.