Engineering the packing structure of thioether- and sulfone-substituted dibenzo[a,e]pentalenes by pentafluorophenyl substitution

Abstract

Dibenzo[a,e]pentalene derivatives as nonalternant conjugated hydrocarbons are attractive for use as ambipolar or n-type semiconductors in field-effect transistors. For organic semiconductors, not only the energy levels of the frontier molecular orbitals but also their solid-state packing is crucial for good charge transport abilities. The introduction of fluorine atoms into organic semiconductors can lead to a closer packing in the solid state, enabled through F⋯F, F⋯H, and F⋯π-interactions. We herein introduce pentafluorophenyl substituents into thioether- and sulfone-DBPs and demonstrate how these substituents not only further lower their LUMO energies to values down to −3.6 eV for the thioethers and −4.1 eV for the sulfone but also lead to a denser packing in the solid state due to fluorine-based interactions between the molecules.