Knowledge Bank

The excimer photolysis of $C6H5-N=S=O$ was expected to lead to seission photolysis of the precursor in a free jet expansion by probing its $B~3\Sigma +\leftrightarrow X~3\Sigma +$ transition. A rich LIF spectrum beginning at $19,500cm-1$ and extending beyond $20,500cm-1$ was also observed. The origin of the spectrum and two additional bands have been rotationally resolved. The rotational constants of 0.945 GHz (B) and 0.943 GHz (C) are irreconcilable with the carrier of the spectrum being phenyl nitrene. Rotational constants for the denterated molecule have also been obtained and support this argument. To aid in the identification of the photoproduct, we have performed ab initio calculations on phenyl nitrene and several other possible molecules that have been observed in solution and matrix studies of phenylnitrene (see figures, below). Of the calculated rotational constants and vibrational frequencies, only those for the carbene 3 are consistent with the experimental data. [FIGURE].