Generating long supramolecular pathways with a continuous density of states by physically linking conjugated molecules via their end groups

Abstract

Self-assembled chains of conjugated 2,5-dialkoxy-phenylene-thienylene-based oligomers on epitaxial monolayer graphene exhibited a continuity in the electronic density of states across individual molecules physically linked by pi-pi-interactions of their end-groups. The use of graphene as substrate provided high sub-molecular resolution of electronic orbitals which were identied with the help of density functional theory calculations. We tentatively conclude that the combination of intra- and inter-molecular non-covalent interactions, together with a weak adsorption on the substrate, provided sucient stability of the molecular arrangement and so improved the conjugation of electrons along and even across molecules within a chain.