Abstract The mid-IR spectra of iodine doped polyazines is reported as a function of doping level. As the iodine content increases in this polymer, two new bands develop while the other peaks in the vibrational spectrum remain unchanged. A broad peak centered at 4000 cm -1 or above is assigned as an electronic transition to a low lying midgap state. This midgap state is probably associated with bipolaron formation. The second new band at 1505 cm -1 is narrow and is of vibrational origin. This band is assigned to a C=C or N=N double bond stretch. Correlation of the relative intensity of the 1505 cm -1 peak with the electrical conductivity as a function of iodine content suggests that the vibration associated with this band originates from the charge carrier.