The gas-phase E.P.R. spectrum of diatomic sulphur molecules

The gas-phase E.P.R. spectrum of 32 S 2 molecules has been detected at spectrometer frequencies around 9 GHz. A single line from the mixed isotopic species 34 S 32 S has been detected by signal averaging. Neither the E.P.R. nor the radiofrequency-molecular beam spectra provide enough constraints separately to establish the molecular parameters uniquely, but by combining the E.P.R., molecular beam and some optical lines new values for the fine structure parameters and g-factors of the v = 0 level have been obtained. The preferred values are λ = 352·97 (±0·32) GHz, γ = -257 (±18) MHz, g r = -0·000031 (±0·000014), Δg′ = -0·0091 (±0·0017) (2σ limits). There is no evidence of discrepancy between the optical and microwave-radio-frequency values for the parameters.