Sulfur-33 Hyperfine Interactions in the Gas-Phase Electron Resonance Spectra of Π 2SH and Δ 1SO

The gas-phase electron resonance spectra of Δ 331SO and Π 332SH have been observed in natural abundance. Since 33S has a nuclear spin of 32, the observed spectra have rich magnetic hyperfine and electric quadrupole structure. This structure has been analyzed to determine the following magnetic hyperfine and quadrupole constants: for Π 332SH—A1 = 71.1 ± 1.0 MHz, e2q0Q = 13.5 ± 2.0 MHz; for Δ 331SO—a = 145.1 ± 3.0 MHz, where the symbols are defined in the text. The Δ 331SO results are compared in a detailed way to similar hyperfine measurements in the Σ3 ground state of 33SO. The Π 332SH measurements are compared with the predictions of Hartree–Fock calculations on the ground state of SH.