Polarized infrared spectra of highly oriented polyacetylenes

The polarization properties of the infrared bands of pure and halogendoped polyacetylene have been studied using highly oriented samples. In particular, the parallel polarization of the doping induced absorptions at low dopant levels is clearly detected from the spectra. At higher doping levels irreversible defects whose bands exhibit different polarization properties have also been identified.The vibrational assignment of pure trans and cis isomers is discussed on the basis of the present polarization data.