Normal coordinate analysis and vibrational spectroscopy (FT-IR and FT-Raman) studies of
R Shahidha1, S Muthu2, E Elamurugu Porchelvi3
1Research and Development Centre, Bharathiar University, Coimbatore 641 046, India.
Abstract:
Vibrational spectral analysis of 5-methyl-N-[4-(trifluoromethyl) phenyl]-isoxazole-4-carboxamide is (5MN4TPI4C) molecule was carried out using FT-IR and FT-Raman spectroscopic techniques. The equilibrium geometry, harmonic vibrational wavenumbers, various bonding features have been computed using density functional B3LYP method with 6-311G(d,p) as basis set. The assignments of the vibrational spectra have been carried out with the aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMFFM). Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The non-linear optical (NLO) behavior of 5MN4TPI4C has been studied by determination of the electric dipole moment (μ) and hyperpolarizability (β) by using B3LYP/6-311G(d,p) method. The molecular orbital compositions and their contributions to the chemical bonding are studied by Total density of energy states (TDOS), sum of α and β electron (αβDOS) density of states. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures are calculated.
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