Raman and ab initio study of intermolecular interactions in aniline

Intermolecular interaction in liquid aniline is analyzed by methods of polarized Raman spectroscopy and ab initio quantum chemical simulation. Optimal geometry of a monomer, dimer, trimer and tetramer of aniline molecules, as well as their vibrational spectra were calculated by DFT method at B3LYP/6–311+G(2d,p) level of theory. The complexity of Raman bands at 996 and 1029 cm−1 is considered as an evidence of molecular aggregation in liquid aniline. The presence of molecular aggregates is confirmed by a high-frequency shift of the Raman band of C–N stretching vibrations.