FT-IR, FT-Raman and DFT study of 3,3′-bis (trifluoromethyl) benzophenone and its biological activity with other halogen (Cl, Br) atoms

•3,3′-Bis (trifluoromethyl) benzophenone is studied using HF and B3LYP level of theory.•Experimental FT-IR and FT-Raman spectra recorded.•HOMO–LUMO energy gap, ESP and thermodynamic parameters were performed.

The FT-IR and FT-Raman spectra of 3,3′-bis (trifluoromethyl) benzophenone (TFMBP) were recorded and analyzed. Natural bond orbital analysis on TFMBP, 3,3′-bis (trichloromethyl) benzophenone (TCMBP) and 3,3′-bis (tribromomethyl) benzophenone (TBMBP) has been carried out for various intramolecular interactions that are responsible for the stabilization of the molecule. HOMO–LUMO energy gap of the halogen substitution (Cl, Br) has been computed with the help of density functional theory. The statistical thermodynamic functions (heat capacity, entropy, vibrational partition function and Gibbs energy) were obtained for the range of temperature 100–1000 K. The polarizability, first hyperpolarizability, anisotropy polarizability invariant has been computed using quantum chemical calculations. The infrared and Raman spectra were also predicted from the calculated intensities. Comparison of the experimental and theoretical spectra values provides important information about the ability of the computational method to describe the vibrational modes. UV–VIS spectral analyses of TFMBP have been researched by theoretical calculations. In order to understand electronic transitions of the compound, TD-DFT calculations on electronic absorption spectra in gas phase and solvent (DMSO and Chloroform) were performed. The calculated frontier orbital energies, absorption wavelengths (λ), oscillator strengths (ƒ) and excitation energies (E) for gas phase and solvent (water and methanol) are also illustrated.

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