SPECTROSCOPIC STUDIES ON THE MONOBROMOTOLUENES

Liquid-phase Raman spectra and vapor-phase, near-ultraviolet absorptio n spectra of alpha-, o-, m-, and p-bromotoluenes have been studied. A number of new Raman features have been observed and assigned. Medium-r esolution UV spectra of the o- and m-isomers have been photographed fo r the first time, and that for p-bromotoluene, at considerably higher resolution than previously reported. The respective electronic band or igins for o-, m-, and p-bromotoluene lie at 36 841, 36 564, and 36 257 cm-1. The vibrational structure accompanying the pi <-- pi transitio n has been analyzed in detail to reveal a pattern similar to that obse rved for related substituted benzenes. The corresponding alpha-bromoto luene spectrum is diffuse.