Theoretical study of challenging properties of intramolecularly π-stacked oligo(dibenzofulvene) organic molecular semiconductors

摘要

It has been recently argued that poly(dibenzofulvene) displays different properties for inter- and intrachain charge transport processes in the hopping regime. The charge carrier path for intramolecular transport consists in a set of π-stacked fluorene rings attached as pendant groups to the main chain, which defines a set of increasingly longer oligomers of helical shape according to the number of fluorene rings. The all-pervasive non-covalent interactions, influencing the mutual orientation of the π-stacked fluorene rings, is accounted for by dispersion-corrected methods, which had to be previously assessed against some experimental values. The present theoretical study aims to rationalize the competition between the two processes (inter- vs. intrachain) through the accurate calculation of the molecular parameters governing charge transport along the intrachain path. Finally, we perform a computationally guided molecular engineering of a set of molecules, not yet synthesized, with extended face-to-face π-stacking, which is achieved by fusing benzene rings to terminal sides of the fluorene moieties. This allows us to anticipate the performance of this new set of related materials.