Quantum interference effects in electron transport through nitrobenzene with pyridil anchor groups

We present density functional theory (DFT) based non-equilibrium Green’s function (NEGF) calculations for the conductance through a nitrobenzene molecule, which is anchored by pyridil-groups to Au electrodes. This work is building up on earlier theoretical studies where quantum interference effects have been identified both in qualitative tight-binding (TB) and in DFT descriptions for the same molecule with different chemical connections to the leads. The novelty in the current contribution is two-fold: i) the pyridil-anchors guarantee for the conductance to be determined by rather narrow peaks situated closely to the Fermi energy which maximizes the impact of quantum interferences on the I/V behaviour and helps to make them accessible to experiments, ii) a semi-quantitative comparison between TB models and DFT results for the investigated systems aims at facilitating the chemical design of nano-electronic devices based on quantum interference effects controlling the electron transport through single molecules.