FTIR, FT Raman spectra and molecular structural confirmation of isoniazid

Isoniazid (INH) is a first-line anti-tuberculous medication used in the prevention and treatment of tuberculosis with molecular formula C 6H7N3O. The FTIR and FT Raman spectra of Isoniazid have been recorded in the region 4000 -400cm -1 and 3500 - 50 cm - 1, respectively. A detailed vibrational analysis has been made on the fundamental modes of vibration. The normal coordinate analysis has been carried out for INH following the Wilson’s FG matrix method on the basis of C 1 point group symmetry. A systematic set of potential constants has been evaluated using the method of kinetic constants and the evaluated potential constants have been compared with those of related molecules. To check whether the chosen set of vibrational frequencies contribute maximum to the potential energy associated with the normal coordinates of the molecule, potential energy distribution (PED) has been evaluated.