The S-containing molecules show a great affinity towards metal surfaces, particularly Au, Pt, Ag and Cu.  The interaction of the metal with the solution of these molecules gives rise to the formation of an adsorbed self assembled monolayer (SAM).  The preparation and structural characterization of monolayer assemblies supported on gold electrodes are of great interest in the study of the interfacial phenomena and in particular the direct electrochemistry of redox proteins.