Abstract
NCHAr substituted 3'-azido-3'-deoxythymidine derivative has been theoretically investigated by performing the B3LYP/6-31G** to obtain vibrational spectra as well as some important physical parameters. As a result of substitution total dipole moment is increased from 0.78 to 9.42 Debye; energy band gap is decreased from 5.51 to 1.92 eV; the molecular dimension increased from 10.34 to 14.78 angstrom. This physical data plus calculated thermodynamical parameters reflect the stability of the substituted AZT.