%0 Journal Article
%T Molecular Structure and Vibrational Analysis of 1-Bromo-2-Chlorobenzene Using ab initio HF and Density Functional Theory (B3LYP) Calculations
%A G. Shakila
%A S. Periandy
%A S. Ramalingam
%J Journal of Atomic and Molecular Physics
%D 2011
%R 10.1155/2011/512841
%X The FT-Raman and FT-IR spectra for 1-bromo-2-chlorobenzene (1B2CB) have been recorded in the region 4000¨C100£¿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. 1. Introduction Aromatic compounds such as benzene derivative compounds are commonly used for chronic inflammation treatment products in pharmaceutical products. Benzene is frequently used as an industrial solvent, especially for degreasing metal. Chlorobenzene is an important industrial solvent and a widely used intermediate in production of commodities such as herbicides, dyestuffs, and rubber [1]. The major use of Chlorobenzene is as an intermediate in the production of commodities such as herbicides, dyestuffs, and rubber. Chlorobenzene is also used as a high-boiling solvent in many industrial applications as well as in the laboratory. Bromobenzene can be used to prepare the corresponding Grignard reagent, phenyl magnesium bromide [2]. The combined Chlorobromobenzene is also used for the manufacture of some biological and industrial solvents. In recent years, chlorobromobenzene has been the frequent subject of experimental and theoretical work because of its significance in industry and environment. Literature survey reveals that to the best of our knowledge no ab initio HF/DFT with 6-31+G (d, p) and 6-311++G (d, p) basis sets calculations of 1-Br-2-CB have been reported so far. It is, therefore thought worthwhile to make a comprehensive vibrational analysis using both experimentally observed IR and Raman wavenumbers and theoretically calculated vibrational spectra. In this study, molecular geometry, optimized parameters, and vibrational frequencies are computed and the performance
%U http://www.hindawi.com/journals/jamp/2011/512841/