Geometric and electronic structures of one-dimensionally polymerized coronene molecules

Abstract

On the basis of density functional theory, we studied the energetics, geometries, and electronic structures of dicoronylene molecules (coronene dimers) and one-dimensionally polymerized coronene molecules. Our calculations showed that the relative stability of the coronene dimers and polymers strongly depends on the mutual arrangement of molecules with respect to the polymer or dimer directions: the coronene dimer and the polymer with six-membered rings in the intermolecular bonds are the most stable structures among the three possible intermolecular arrangements. The dimer possesses a large energy gap between the highest occupied and lowest unoccupied states, which is narrower than that of the isolated coronene. The polymers are semiconductors with a moderate direct band gap and a large indirect gap for the polymers with six- and four-membered rings and that with five-membered rings, respectively, indicating the possibility of the electronic structure control of polymers via the intermolecular arrangement.