Density functional theory study of infrared-active vibrational modes in doped poly(p-phenylene)

摘要

The absorption spectra of a poly(p-phenylene) film doped with FeCl_3 in the range from visible to infrared have been measured. The observation of two intra-gap electronic absorptions indicates the formation of positive polarons upon FeCl_3 doping. The observed doping-induced infrared spectrum is in good agreement with that calculated by the density functional theory method at the BLYP/6-31G* level for the radial cation of p-sexiphenyl. Although the infrared bands predicted by the effective conjugation coordinate theory have strong intensities, the infrared bands not predicted by this theory have considerable intensities.