Rapid and Efficient Electrochemical Actuation in a Flexible Perylene Bisimide Dimer

The ability to reversibly alter molecular structures using an electrochemical stimulus is an area of great contemporary interest, where molecular design plays a key role in determining the efficiency and speed of the process. Although the choice of redox active center decides the threshold potential and energy efficiency of the process, selecting a backbone structure with a sufficiently low barrier to deformation ensures a fast response. We present a flexible perylene bisimide dimer that fulfills these criteria remarkably well and exhibits a rapid and very large conformational change at a much lower applied voltage than similar systems. A detailed investigation using cyclic voltammetry, spectroelectrochemistry, and EPR spectroscopy elucidates the mechanism of the actuation process.