Analysis of Quantum Chemical Vibrational Spectra and Normal Coordiante Analysis of 4’-(Trifluoromethyl) Acetophenone

Abstract

Infrared and Raman spectral investigation have contributed valuable and unique information about the nature and symmetry of vibrating molecules and ions, their hydrogen bonding, crystalline environments, their structure and vibrational interactions. Analysis of normal modes of vibrations using infrared and Raman spectra with quantum chemical computations offer a lot of scope for extracting unique information regarding the structural and bonding features of the molecule. The present work, quantum chemical analysis, vibrational spectra and normal coordinate analysis of 4’-(trifluoromethyl) acetophenone have completely been analysed. The FTIR and FT-Raman spectra of 4’-(trifluoromethyl) acetophenone were recorded in the region 4000–400 cm-1  and 3500–100 cm-1,respectively. Optimized geometrical parameters, harmonic vibrational frequencies, highest occupied molecular orbital and lowest unoccupied molecular orbital, electrostatic potential surface map have been calculated by the density functional theory (B3LYP) methods using cc-pVDZ and cc-pVTZ basis sets. The calculate HOMO – LUMO energies show that the charge transfer occurs within the molecule