Electrochemistry of monolayers

Not surprisingly, similar to the case of monomeric derivatives, the adsorption of oligomers can lead to the formation of polymeric species (Fig. 5.16a). As an example, the polymerization of terthiophene on Ag surface has been reported [99]. 

Different mechanisms have been invoked to give a rationale to the charge transport, mainly ascribable to hopping and tunneling phenomena [3, 60, 104-106]. To a first approximation, the Arrhenius equation holds for hopping conduction mechanism  

Tunneling conduction mechanism is regulated by the Simmons equation  

The modification of surfaces with monolayers strongly modifies the electrochemical responses with respect to those recorded on a bare electrode [56, 109]. Once more, the most widely investigated systems in electrochemistry are based on alkylthiols adsorbed on Au. After anchoring a compact monolayer at a conductive 

Monolayers based on thiols are stable within quite a wide range of potential values (between ca. —0.8 V and +0.6 V vs. Saturated Calomel Electrode [SCE]) [110]. At more negative potentials, a reductive desorption takes place, according to the following reaction  

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