Theoretical investigation of the molecular structure and vibrational spectra of rasagiline and its salts

Within the scope of this thesis, conformational analysis of parkinson's disease drug azilect's active ingredient rasagiline were performed with quantum mechanical DFT theory at the B3LYP/631++G(d,p) level using the Gaussian 03 package program.Seven conformers were found as true minimum on the potential energy surface scan (PES). Calculated harmonic and anharmonic vibrational frequencies for the lowest energy conformer were compared with experimental data. Vibrational assignments were made on the basis of total energy distribution (TED) calculated with scaled quantum mechanical (SQM) method.In order to ensure drug stability rasagiline molecule is in the form of salt. For the purpose of understanding the structure of the free form molecule in salt forms of rasagiline mesylate and rasagiline ethane disulfonate, whose crystal structure is known, geometric structures and harmonic vibrational frequencies were calculated with DFT/B3LYP/6-31++G(d,p) method and the results were interpreted.