Spectroscopic (NMR, UV, FT-IR and FT-Raman) analysis and theoretical investigation of nicotinamide N-oxide with density functional theory

The spectroscopic properties of the nicotinamide N-oxide (abbreviated as NANO, C6H6N2O2) were examined by FT-IR, FT-Raman, NMR and UV techniques. FT-IR and FT-Raman spectra in solid state were observed in the region 4000–400 cm−1 and 3500–50 cm−1, respectively. The 1H and 13C NMR spectra were recorded in DMSO. The UV absorption spectrum of the compound that dissolved in water was recorded in the range of 200–800 nm. The structural and spectroscopic data of the molecule in the ground state were calculated by using Density Functional Theory (DFT) employing B3LYP methods with the 6-311++G(d,p) basis set. The geometry of the molecule was fully optimized, vibrational spectra were calculated and fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. The optimized structure of compound was interpreted and compared with the reported experimental values. The observed vibrational wavenumbers, absorption wavelengths and chemical shifts were compared with calculated values. As a result, the optimized geometry and calculated spectroscopic data show a good agreement with the experimental results.

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► Spectroscopic properties of NANO were examined by FT-IR, FT-Raman, NMR and UV techniques and DFT.
► All results were compared with experimental (FT-IR, FT-Raman, UV, 1H, 13C NMR) spectra.
► The electronic properties (such as HOMO and LUMO energies, absorption wavelength and excitation energies) were performed by DFT.