Molecular assemblies and their electric properties

In this thesis I present a systematic discussion of large-area tunneling molecular junctions comprising self-assembled monolayers of conjugated molecules and using a liquid metal top-electrode of gallium-indium alloy at its eutectic composition. Diverse series of conjugated molecules were designed and synthesized in order to evaluate the effect of different backbones, conjugation paths, dipole moments, and electronic properties on the electric properties of assembled tunneling junctions. The obtained results were also compared to the performances of the investigated compounds in other experimental platforms, such as conductive probe AFM and STM break junctions, and in computational simulations. We investigated in detail the phenomenon of quantum interference: we reported for the first time the direct observation of destructive quantum interference in through-space transport and the preparation of a molecular memory device based on the redox properties of a self-assembled monolayer.