Molecular structure, Vibrational Spectra, first-order hyperpolarizability and HOMO, LUMO studies of 3,4-dichlorobenzophenone

The vibrational frequencies of the molecule 3,4-dichlorobenzophenone (DclBP) have been obtained from the FT-IR
and Raman spectral data. The frequencies are also theoretically evaluated based on the density functional theory
(DFT) using the standard B3LYP/6-311+G(d, p) method and basis set combination. On the basis of potential energy
distribution calculated with MOLVIB program, the assignments for the various frequencies are attempted. To obtain
closer agreement between theoretical and experimental values, a scaling factor adjustment is also carried out. The final
analysis and assignments of the various vibrational modes are reported. The values of the electric dipole moment (μ)
and the first-order hyperpolarizability (β) of the investigated molecule were computed using ab initio quantum chemical
calculations. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. To
understand the intramolecular hyperconjugative interactions NBO analysis is carried out. Mulliken's net charges have
been calculated and compared with atomic natural charges.