Stark Effect in Gas-Phase Electron Resonance. The Dipole Moments of ClO, BrO, SH, and 1Δ SO

Abstract
We have studied the effects of electric fields on the electron resonance spectra of a number of diatomic free radicals in the gas phase. The use of high-frequency electric modulation has a number of advantages over conventional magnetic modulation, which are discussed. The theory of the Stark effect in molecules having Λ degeneracy or near degeneracy is developed and accounts quantitatively for our observations. We report determinations of the electric dipole moments of ClO, BrO, and SH in their electronic ground states, and SO in its 1Δ excited state.