Density functional study of structural and opto-electronical properties of fluoranthenopyracylene oligomers in their neutral and oxidized forms

We report a systematic characterization of recently prepared and electrochemically studied fluoranthenopyracylene oligomers with lateral phenylene rings connected to a π-conjugated ladder using density functional theory (DFT). Geometry optimizations have been performed for neutral ground state and oxidized forms. Geometrical changes on the ladder part after one- and two-electron oxidation were specified. The calculated time-dependent DFT electronic spectra and HOMO-LUMO gap values are in a good agreement with available experimental results for oligomers measured in solutions. The theoretical effective conjugation length was estimated to be 10 repeat units in agreement with experimental observations.