Normal coordinate analysis and Nonlinear Optical Response of cross-conjugated system 4,4-Dimethyl Benzophenone

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 116; pp. 574 - 583
• Main Authors: Amalanathan, M., Xavier, T.S., Hubert Joe, I., Rastogi, V.K.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.12.2013
• Subjects: Benzophenones - chemistry; DFT; Hyperpolarizability; Methylation; Models, Molecular; NCA; Quantum Theory; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman; Vibrational spectra and THz spectra; Vibrational spectra and THz spectra; DFT; NCA; Hyperpolarizability
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2013.07.100

[Display omitted] •DFT calculations have been performed on the NLO crystal 4,4-Dimethyl Benzophenone (4DMBP).•The NCA was performed on 4DMBP to reproduce its experimental harmonic vibrational wavenumbers excellently.•The IR and Raman spectra of the compound were analyzed.•The calculated first order hyperpolarizability of 4DMBP calculated and is found to be 1.97×10−30e.s.u.•NBO, HOMO and LUMO analysis were also performed by DFT approach. FT-Raman and IR spectra of the nonlinear optical active crystal, 4,4-Dimethyl Benzophenone (4DMBP) have been recorded and analyzed The equilibrium geometry, harmonic vibrational wavenumbers of 4DMBP investigated with the help of density functional theory (DFT) method. The assignments of the vibrational spectra have been carried out with the help of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMFF). The calculated hyperpolarizability value shows the nonlinear optical activity of the molecule. The value of HOMO–LUMO energy, Mulliken and the natural charges are calculated and analyzed. The Natural bond orbital analysis confirms the occurrence of intramolecular charge transfer interaction.