Force field calculations for 2-amino-5-chloro- and 2-amino-5-bromo-benzotrifluorides

Force field calculations have been carried out for 2-amino-5-chloro- and 2-amino-5-bromo-benzotrifluorides using the earlier (Ref. of this article) reported IR and Raman spectra. As the frequencies of the corresponding modes for the C-Br and the C-Cl groups do not differ widely the two molecules are assumed to be isotopomers for the purpose of the force field calculations. The calculated and the observed frequencies match nicely for both the molecules. Consistent assignments have been proposed for the ring modes and the internal modes of the CF3 and the NH2 groups based on the potential energy distributions (PEDs), the IR and the Raman intensities and the depolarisation ratios of the Raman lines.