Synthesis, FTIR and FT-Raman spectral analysis and structure–activity relations of N-(4-bromophenyl)-2,2-dichloroacetamide by DFT studies

• The structural, vibrational and reactivity characteristics have been determined.
• The molecule has great electronegativity difference and charge is highly polarized.
• The atoms C2, C3, C5, C6, N7, O9 and C10 are more prone to nucleophilic attack.
• The LUMO of the molecule feature a larger number of nodes than the HOMO.
• The nN → π*CO interaction possess a strong stabilization of 64.21 kcal mol−1.

The FTIR and FT-Raman vibrational spectra of N-(4-bromophenyl)-2,2-dichloroacetamide molecule has been recorded and analysed the complete vibrational fundamental modes of the most stable geometry of the compound using the experimental FTIR and FT-Raman data on the basis of peak positions, relative intensities and quantum chemical studies. The observed vibrational frequencies were compared with the theoretical wavenumbers of the optimised geometry of the compound obtained from the DFT-B3LYP gradient calculations employing the high level 6-311++G** and cc-pVTZ basis sets. The effect of substituent Br in the amide moiety have been analysed and compared. The kinetic and thermodynamic stability and chemical reactivity descriptors of the molecule have been determined. The reactive centres are found from the molecular electrostatic potential and the atomic charges. The limits of electrostatic potential are −9.617e × 10−3 and +9.617e × 10−3. The molecule has great electronegativity difference, charge is very polarized, and there are significant differences in electron density in different regions of the molecule. The lone pair donor orbital, nN → π*CO interaction possess a strong stabilisation of 64.21 kcal mol−1.