Click Chemistry: A Versatile Method for Tuning the Composition of Mixed Organic Layers Obtained by Reduction of Diazonium Cations

Postfunctionalization of glassy carbon electrodes previously modified by reduction of 4-azidobenzenediazonium was exploited to conveniently synthesize controlled mixed organic layers. Huisgen 1,3-dipolar cycloaddition was used to anchor functional entities to azide platform. By this way, ((4-ethynylphenyl)carbamoyl)ferrocene (phi-Fc) was coimmobilized with a set of acetylene derivatives: 1-ethynyl-4-nitrobenzene (phi-NO2), 4-ethynylaniline (phi-NH2) or ethylnylbenzene (phi). The composition of the resulting organic layers was tuned by adjusting the acetylene derivatives ratio in the postfunctionalization binary solution. Electronic properties of the substituents beared by the aromatic rings were found to have a strong impact on the cycloaddition kinetics toward the confined azide moieties. From this study, rules to prepare finely tuned bifunctional organic layers can be anticipated.