Table of Contents
Journal of Atomic, Molecular, and Optical Physics
Volume 2011, Article ID 512841, 10 pages
Research Article

Molecular Structure and Vibrational Analysis of 1-Bromo-2-Chlorobenzene Using ab initio HF and Density Functional Theory (B3LYP) Calculations

1Department of Physics, Bharathidasan Government College for Women, Puducherry 605003, India
2Department of Physics, Tagore Arts College, Puducherry 605008, India
3Department of Physics, A.V.C. College, Mayiladuthurai, Tamilnadu 609305, India

Received 21 February 2011; Accepted 16 June 2011

Academic Editor: Amlan K. Roy

Copyright © 2011 G. Shakila et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The FT-Raman and FT-IR spectra for 1-bromo-2-chlorobenzene (1B2CB) have been recorded in the region 4000–100 cm−1 and compared with the harmonic vibrational frequencies calculated using HF/DFT (B3LYP) method by employing 6-31+G (d, p) and 6-311++G (d, p) basis set with appropriate scale factors. IR intensities and Raman activities are also calculated by HF and DFT (B3LYP) methods. Optimized geometries of the molecule have been interpreted and compared with the reported experimental values of some substituted benzene. The experimental geometrical parameters show satisfactory agreement with the theoretical prediction from HF and DFT. The scaled vibrational frequencies at B3LYP/6-311++G (d, p) seem to coincide with the experimentally observed values with acceptable deviations. The theoretical spectrograms (IR and Raman) have been constructed and compared with the experimental FT-IR and FT-Raman spectra. Some of the vibrational frequencies of the benzene are affected upon profusely with the halogen substitutions in comparison to benzene, and these differences are interpreted.