PURE ROTATION SPECTRA OF SOME VIBRATIONAL EXCITED STATES OF SULFUR DIOXIDE

Abstract

The microwave spectra of the $\nu_{2}, 2\nu_{2}, 3\nu_{2},\nu_{1},\nu_{3},\nu_{1}+\nu_{2}$ and $\nu_{2} + \nu_{3}$ vibrational excited states of sulfur dioxide have been recorded. A careful analysis of the $\nu_{1},\nu_{2}, \nu_{3},$ and $2\nu_{2}$ states yielded the equilibrium distortion constants, from which the harmonic force field has been calculated. A few lines, which are slightly shifted from their calculated positions, cannot be explained without considering a weak resonance. In connection with that point, the frequency of the origin of the $2\nu_{2}$ vibration rotation band will be discussed.