Polarized infrared and Raman spectra and ab-initio calculations of benzotriazole

The i.r. spectra of benzotriazole have been measured from 4000 to 60 cm(-1): polarized spectra of single crystals have been also obtained. The Raman spectra of polycrystalline samples and solutions have been investigated. The structural parameters and vibrational frequencies have been determined from uh initio Hartree-Fock gradient calculations using the 6-31G* basis set; A detailed assignment of most of the observed bands has been proposed on the basis of the i.r. dichroism, Raman polarization data and frequency calculations.