FT-IR, FT-Raman spectra and NBO analysis of 5-nitro-2-furoic acid: a DFT Method

The molecular structure and vibrational spectra of 5-Nitro-2-furoic Acid (NFC) have been investigated by combined theoretical and experimental approaches. The FT-IR and FT-Raman spectra of NFC was recorded in the range 4000 - 400cm(-1) and 3500 -50 cm(-1). Density functional method B3LYP with 6-31G** basis set was applied to carry out the quantum mechanical calculations of the geometrical structure and vibrational analysis of NFC. The spectra were interpreted with the aid of normal coordinate analysis (NCA) based on scaled quantum mechanical force field (SQM). Stability of the molecule arising from the hyper conjugative interactions, charge delocalization have been analyzed using natural bond analysis(NBO). The influence of the substituents on the geometry of the furan ring and its normal modes of vibration have been discussed.