Zeeman effects in the band System of sulfur dioxide

Abstract

Bands of the [Formula: see text] system of sulfur dioxide appear as structured absorption superimposed on an apparent continuum. A portion of this System between 3250 and 3000 Å has been recorded in a magnetic field and is found to exhibit a strong Zeeman effect, contrary to expectation for a singlet-singlet transition between bent states of an asymmetric rotor. Line shift and broadening is observed in relatively low fields (< 3 kG), and the spectra become diffuse in fields of ~ 10 kG. The possibility is considered that the magnetic moment in the à state results from rotational coupling of singlet electronic states but it appears unlikely that the angular momentum so developed is sufficient to account for the observations. The most probable explanation of the magnetic sensitivity is that the à state couples with a background of interacting vibrational levels of the ground state and low lying states of the triplet manifold.