Knowledge Bank

Emission excitation spectra of the $A-x$ and $A-x$ and systems of $H2CS$ have been recorded at high resolution with jet cooling. Mononeric thiofornaldehyde was generated by pyrolysis in the throst of a continuous free jet1, yielding intense fluorescence and phosphorescence excitation spectre with rotational temperatures of 5-10 K. The spectra have been rotationally analyzed to obtain accurate band origins and rotational constants for a substantial number of upper state levels. In the triplet state, the major spin constants were determinable because transitions to the $F1,F2$, and $F3$ components are observed. Extensive perturbations are observed in the spectra due to the near-degeneracy of $\nu 5$ and $\nu 3$.