The infrared spectra of 2,4 dimethylaniline have been recorded in the region 3600-100 cm−1. The Raman spectra with polarization measurements have been recorded and investigated for the first time in the region 3500-100 cm−1. New frequency assignments have been proposed assuming the molecule to possess an approximateC2 symmetry. Fifty normal modes of the molecule, out of a possible fifty four modes, have actually been observed and assigned including twenty seven hitherto unreported frequencies. The observed spectral changes give evidence of the presence of an intermolecular hydrogen bonding of an N−H...N type, and suggest a solid-solid phase transition between 223 and 123 K in the molecule.
