Flat – vertical transitions of fluoranthene molecules adsorbed on a mercury electrode

Abstract

The adsorption of fluoranthene from acetonitrile solution (containing 0.1 mol dm^–3 tetrabutylammonium perchlorate as background electrolyte) onto mercury electrodes has been studied. It is shown that potential-step chronoamperometry, at a rotating-disc electrode, allows the determination of the surface coverage of the adsorbed material. The latter is found to be dependent on the concentration of fluoranthene in bulk solution and it is inferred that when this is less than ca. 2 × 10^–4 mol dm^–3 the molecules are oriented flat on the electrode surface, whereas at higher concentrations they are vertically positioned. A.c. impedance measurements are also reported.