Molecular Structure, Vibrational Analysis and First Order Hyperpolarizability of 4-Methyl-3-Nitrobenzoic Acid Using Density Functional Theory (original) (raw)
2015, Optics and Photonics Journal
The Fourier Transform Infrared (FTIR) and FT-Raman spectra of 4-methyl-3-nitrobenzoic acid have been recorded in the range 4000-400 cm −1 and 3500-50 cm −1 , respectively. The optimized geometry of the molecule, its vibrational frequencies along with corresponding intensities have been computed using the Density Functional Theory (DFT) employing B3LYP/6-311++G basis set. The scaled values of harmonic vibrational frequencies obtained in the computations have been compared with their experimental counter parts. The scaling factors have been refined to reproduce the frequencies with an RMS error of 11.68 cm −1 between the experimental and computed frequencies. The theoretically constructed spectra agree satisfactorily with those of experimental spectra. First order hyperpolarizability constants have also been evaluated.
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