ELECTRONIC-STRUCTURE OF POLYFLUORANTHENE LADDER POLYMERS

Fully unsaturated fluoranthene-type ladder polymers (PFA: polyfluorant hene) recently synthesized by Schluter et al. show a high. degree of p i-electron localization. Variation of the size of the two oligoacenic components separated by the characteristic five-membered ring, however , can lead to more delocalized structures with small (few tenths of an electronvolt) band gaps and can be used for engineering the electroni c properties. Charge transfer produces bipolaronic defect states in th ese polymers; sp(3) defects produce polaronic defects. Interpretation of the differences between the published absorption spectra for two me mbers of the PFA family is also given.