Lattice dynamics and vibrational spectra of undoped and doped polyparaphenylene

Lattice dynamical calculations of undoped and doped polyparaphenylene are carried out and the results compared with the vibrational spectra presently available in the literature. The purpose of the work is to determine from vibrational spectra the extent of delocalization of π electrons along the chain. Moreover, it is suggested that the doping induced spectra are consistent with the formation of bipolarionic type defects.