Electrochemistry at single-molecule sites

Abstract

A technique that permits compounds to be oxidized or reduced at electrode sites the size of single molecules has been developed by chemistry professor Marcin Majda and coworker Renata Bilewicz at the University of California, Berkeley [ J. Am. Chem. Soc. , 113 ,5464 (1991)]. In the technique, access to the electrode is restricted to a controlled number of single-molecule gate sites in a Langmuir-Blodgett film, a monomolecular film transferred from an air-water interface onto the electrode surface. film is composed of octadecanethiol and octadecyl alcohol, with just a trace amount of ubiquinone added. major components of the film passivate the surface—make it electrochemically inactive. Access is provided only by the ubiquinones, whose isoprenoid chains form channels that span the thickness of the monolayer. researchers say, The ability to channel access to the electrode surface through single-molecule gate sites ... opens new possibilities of designing monolayer assemblies in which chemical...