AB-INITIO CALCULATED ENERGIES AND VIBRATIONAL FREQUENCIES OF 3-AZIDOPROPENE (ALLYLAZIDE)

Ab initio calculations on 3-azidopropene have been carried out using the TZP and TZ2P basis sets and MP2 electron correlation. Fully optimized geometries for the five possible conformations have been calculated at the SCF level. The calculations give the same order of conformer stability as obtained from electron diffraction and vibrational spectroscopy experiments: GG, SG, GG', SA and GA (the letters designate the conformation around the C-C and the C-N bonds, respectively). The ab initio calculated force constants were scaled and used in normal coordinate analyses for all the five conformers. The observed wavenumbers of the three most stable conformers GG, SG and Ge were used to derive common scale factors which were then applied to the force fields of the SA and GA conformers. The calculations suggest a few minor reassignments of the spectra. New Raman spectra of the liquid and crystalline states and infrared spectra in argon matrices are presented.