A series of four expanded pyridinium molecules were used to investigate the correlation between a single molecule conductance (electron transport) and redox (electron transfer) properties at the electrode vertical bar electrolyte interface. Quantum chemical calculations of the transmission functions using DFT and non-equilibrium Green's function approach confirmed LUMO. mediated electron transport in the break junction experiment. Single molecule conductance data can be rationalized within the framework of the non. resonant tunneling mechanism. More interestingly, a linear correlation was found between the conductance values and the apparent electron transfer rate constants for three molecules of this series. (C) 2018 Elsevier Ltd. All rights reserved.