A four-state capacitance molecular switch based on a redox active tetrathiafulvalene self-assembled monolayer

An electroactive tetrathiafulvalene (TTF) self-assembled monolayer (SAM) on gold has been prepared and fully characterised by electrochemical impedance spectroscopy. Transfer rates of the same order were found for the two redox processes. Remarkably, the TTF SAM was successfully exploited as a 4-state electrochemical switch using the capacitance of the SAM as output signal.