Heterosupramolecular Chemistry: An Approach to Modulating Function in Molecular Devices

Abstract

AbstractLinked viologen‐anthraquinone molecules are attached to TiO2 nanocrystallites supported on a conducting glass substrate. The resulting assembly is incorporated as the working electrode in an electrochemical cell. Under opencircuit conditions, band‐gap excitation of the semiconductor nanocrystallite results in viologen‐mediated electron transfer to anthraquinone. Prior application of a negative potential step, which results in 2e−/2H+ reduction of anthraquinone, permits electron transfer only to viologen. At positive applied potentials, electron transfer following band‐gap excitation is largely suppressed. Some implications of these findings for modulation of function in molecular devices are considered.