Knowledge Bank

The polymers of $CH2Se$ and $CD2Se$ were pyrolyzed at $700\circ C$ to yield monomeric selenoformaldehyde. Laser excitation spectra of these molecules were recorded. The origin of the weak singlet-singlet $A~1A2\leftarrow X~1Al$ system in $CD2Se$ was observed at $13631.5cm-1$ while that of $CH2Sc$ has been calculated to be at $13.555cm-1$. The much more extensive and intense singlet-triplet a3A2 - X1Al systems of CH2Se/CD2Se have origins at $12171.0/12262.7cm-1$. A double minimum potential energy function was used to fit the triplet state $V4$ inversion levels and was found to be similar to that observed for thioformaldehyde.