Molecular structure, homo-lumo analysis and vibrational spectroscopy of the cancer healing pro-drug temozolomide based on dft calculations

Abstract

The molecular structure and spectroscopic analysis of the Temozolomide molecule have been performed using the density functional theory in neutral and anion states as well as with the addition of DMSO solvent. The 6-311G(d) basis set was employed to optimize the molecular structure of the TMZ molecule using the DFT/B3LYP method. The HOMO-LUMO energies and MEP map were computed to determine the energy gap and probable sites of electrophilic and nucleophilic reactivity in the 6-311G+(d) basis set. The vibrational frequencies were calculated using a computational method and the major fundamental modes of vibration were assigned to their respective frequencies. The potential of the computational method to explain the vibrational modes was determined by comparing simulated spectra with experimental spectra. On isotope labeling of carbon, the frequency was shifted significantly.