An electrochemical study on charge-transfer phenomenon between 7,7,8,8-tetracyanoquinodimethane and a self-assembled monolayer containing tetrathiafulvalene moiety using an indium-tin oxide electrode

A derivative of EDT-TTF (ethylenedithio-tetrathiafulvalene) with decylphosphonic acid was prepared and formed as its self-assembled monolayer (SAM) on the surface of indium-tin oxide (ITO) glass. The formation of the SAM was characterized by UV–vis and micro-Raman spectroscopies, cyclic voltammetry and atomic force microscopy. Cyclic voltammetry of the surface-modified ITO (SM-ITO) electrode showed two reversible peaks at E 1 / 2 1 = 0.658   V and E 1 / 2 2 = 0.944   V due to the redox processes of EDT-TTF moiety on the SAM. Cyclic voltammogram of TCNQ (7,7,8,8-tetracyanoquinodimethane) with the SM-ITO electrode shows two redox couples, one at E 1 / 2 1 = 0.287   V corresponding to the TCNQ/TCNQ− process and the other at E 1 / 2 2 = 0.963   V corresponding to the [EDT-TTF]/[EDT-TTF]+ one.