Knowledge Bank

The electronic spectrum of p-difluorobenzene vapor at 2700 {AA} has been the object of several studies in the $past1,2,3,4$. At this time, many of the basic features of the spectrum of the vibrationally and rotationally analyzed to some degree but there are still problems concerned with the fluorescence lifetime and intramolecular energy transfer aspects of this $molecule3,4$. We have taken high resolution and relatively high reciprocal dispersion photographs of this spectrum and of the perdeutero species from which improved vibrational analyses are possible, and we have also examined the apparent line widths of different bands of the spectrum of the perproto compound at varying theoretical resolutions. The onset of diffuseness and the line broadening of particular bands will be discussed, as these observations relate to the structure and energy transfer processes of this molecule.