Knowledge Bank

The spectra of several fluorobenzene cations have been generated by a corona discharge in a supersonic expansion. Rotational temperatures have been determined by computer simulation to be $80\circ K$. The band origin of $C6F6$ determined with high precision compares well with that obtained by laser excitation $studies.1,2,3$ trifluorobenzene cation spectra have been taken by the same technique and have been compared with matrix spectra. The rotatinal contour in the FT spectra are analyzed to identify the type of electronic transition.