Electron resonance spectrum of gaseous SeO in its3Σ and1Δ states

The gas phase electron resonance spectrum of SeO in its 3Σ and 1Δ states has been studied. Values of the rotational constant B 0 and ‘spin-spin’ splitting parameter λ in the 3Σ state, previously determined from the ultraviolet spectrum, are shown to be consistent with the electron resonance results, and we are also able to estimate the spin-rotation interaction constant. In addition, the 3Σ spectrum shows 77Se hyperfine structure. The 1Δ spectrum yields values for the rotational constant (and hence bond length) and rotational g factor.