From molecular to supramolecular electronics

Using individual molecules as conducting bridges for electrons offers opportunities when investigating quantum phenomena that are not readily accessible from experiments involving ensembles of molecules. The probing of single molecules has led, over the past few decades, to the rise of molecular electronics. Although single-supermolecule electronics is an emerging field, it is not yet a well-defined area of molecular electronics. There is little doubt, however, that single-supermolecule electronics is poised to have an impact on molecular electronics for the simple reason that non-covalent interactions between molecular components in complexes have a profound effect on electron conductivities. In this Review, we survey this emerging field from the standpoint of non-covalent interactions in mechanically interlocked molecules, as well as in supermolecules, and discuss the (super)structure–property relationship of four different interactions associated with (supra)molecular junctions. They are host–guest interactions, hydrogen bonding, π–π interactions, and non-covalent interactions present in mechanically interlocked molecules. We focus our attention on providing a supramolecular-level understanding of charge transport behaviour associated with each interaction, as well as demonstrating the theoretical background and experimental readiness of single-supermolecule electronics for potential applications, such as nucleic acid and peptide sequencing, and the design and production of quantum interference devices, random-access memories and integrated devices. Single-supermolecule electronics focuses not only on charge transport within individual supermolecules but also on the weak non-covalent interactions between components of supermolecules and mechanically interlocked molecules. This Review surveys the use of non-covalent interactions in the construction of electronic devices.