Chemistry and Molecular Electronics: New Molecules as Wires, Switches, and Logic Gates

The development of nanotechnology is driven in part by the ability of chemists to make elaborate molecules with functions that mimic the components of electrical circuits. The functions of these molecules range from the conceptually simple (molecular wires) via the more complex (molecular switches) to molecules that contain several integrated functions to give behavior characteristic of logic gates. This review surveys recent advances in these areas and looks at the advantages, limitations, and potential uses of the molecular components that have been prepared. Molecular wires can either transfer one electron at a time from one end to the other between two metal complex fragments, or transport electrons in bulk between two metal electrodes. A wide variety of molecular switches utilize stimuli such as structural or conformational changes, redox changes, or transient absorption of light to switch electron transfer through the molecules on or off, or even make the electron flow change direction. In molecular logic gates, the integration of two or more switchable properties allows the molecules to display behavior similar to that of electronic logic gates, suggesting a basis for future nanoscopic computing devices.See Correction to this article.