Vibrational analysis of pyrazinamide

Abstract

Pyrazinamide (PZA) is an anti-tubercular drug, with molecular formula C₅H₅N₃O. The FTIR and FT Raman spectra of PZA have been recorded in the region 4000-400cm⁻¹ and 3500–50cm⁻¹, respectively for molecular study. A detailed vibrational analysis has been made on the fundamental modes of vibration. A normal coordinate analysis has been carried out for PZA following the Wilson’s FG matrix method. A set of potential constants has been evaluated using the method of kinetic constants on the basis of C₁ point group symmetry. The evaluated potential constants have been compared with those of related molecules and are in the expected range to confirm the correctness of the assignments made. To check whether the chosen set of vibrational frequencies contributes maximum to the potential energy associated with the normal coordinates of the molecule, potential energy distribution (PED) has been evaluated.