Knowledge Bank

According to our present understanding of magnetic rotation $spectra,1$ (MRS) it is expected that transitions which are sensitive to a magnetic field either through a conventional Zeeman effect due to a magnetic moment coupled to the total angular momentum J or through a perturbation of the intensities of different magnetic sub-levels will exhibit magnetic rotation spectra. If this criterion is correct, the $3800\backslash AA$ bands of sulfur dioxide which have recently been analyzed as a singlet-triplet $transition2$ and exhibit a pronounced Zeeman $effect3$ would be expected to have a magnetic rotation spectrum. No MRS has been reported previously for the system. Furthermore, the $2900\backslash AA$ system of $SO2$ which has the structure of a singlet system and which $Douglas3$ found to exhibit no Zeeman effect, was shown by Kusch and $Loomis4$ to have an extensive MRS.