Vibrational spectra of isomeric bromoxylenes

Abstract

The infrared (4000-250 cm −1) and Raman spectra (3500-100 cm −1) of 1-Br-2,3-dimethyl benzene, 1-Br-2,4-dimethyl benzene, 1-Br-2,5-dimethyl benzene and 1-Br-2,6-dimethyl benzene have been recorded using Perkin-Elmer (Model 621) double beam grating spectrophotometer and Argon ion laser respectively. The vibrational spectra have been analysed assuming C s point group for the first three and C 2v point group for the fourth isomer. The assignments for the fundamental vibrations, combination and overtone frequencies and the internal modes of vibrations of methyl group have been proposed. The vibration number in Wilson's notations for each mode of fundamental vibration has also been indicated.