Experimental and Theoretical Spectroscopic Studies on Niacinamide

This study focuses on the experimental and theoretical spectroscopic characterization of niacinamide. Raman and FTIR spectroscopy were employed to identify the molecule’s vibrational modes. In the Raman spectrum, characteristic peaks corresponding to C-N stretching and NH bending were observed, along with vibrations from the aromatic ring and carbonyl group. FTIR analysis revealed distinct amide-related vibrational modes, affirming the presence and purity of niacinamide. The UV-Visible spectroscopy showed a prominent absorption peak at 265 nm, attributed to a π → π* electronic transition or n → π* transition from non-bonding electrons to anti-bonding orbitals, exhibiting a slight bathochromic shift. Time-Dependent Density Functional Theory (TDDFT) calculations predicted the absorption maximum at 280 nm, slightly overestimating the experimental value due to inherent approximations in electron correlation and exchange effects. Together, these findings provide comprehensive insights into the vibrational and electronic structure of niacinamide, enhancing the understanding of its molecular behavior for potential applications.