Surface anthraquinone coupling

B. Keita, I. Kawenoki, J. Kossanyi, D. Garreau, and L. Nadjo, Surface band energy shifts of ap-type Si electrode in the presence of redox couples, study of anthraquinone derivatives in the dark and under illumination, J. Electroanal. Chem. 145, 293, 1983. 

The surface CV of anthraquinone- or its derivative-adsorbed electrode shows a reversible 2-electron-transfer redox couple. For example. Figure 7.9(A) shows the surface CV of anthraquinone-carboxlyic-allyl ester (ACAE) adsorbed on a basal plane graphite electrode surface. The pH dependent of the peak potentials gives a slope of 57 mV pH , suggesting that the redox process involves two electrons and two protons. The surface reaction reactions on the electrode surface can be assigned as Reaction (7-VI) ... 

Consider the following example. Figure 9.27 shows a CV recorded on an n-Si electrode immersed in acetonitrile with two redox couples anthraquinone and its monoanion (AQ/AQ ) and ferrocene/ferrocenium (Fe(Cp)2/Fe(Cp)2 ). In this experiment, care was taken in the experimental set-up so that once the electrode was introduced into the cell, it was not further exposed to the external atmosphere. Thus, effects due to surface oxidation... 

Thicker layers can also be obtained from diazonium salt. Under usual conditions, the growth of the film stops because the electrons cannot reach the outer surface of the film to reduce new diazonium cations. This situation can be reversed if an electron carrier such as a reversible couple is imbedded in the film and activated. This was achieved during the formation of AuN02 when the potential of the electrode was maintained at a potential sufficient to reduce the nitrophenyl groups (Figure 3.40) a thickness of 86 nm was obtained [42]. High thickness films were also obtained with anthraquinone groups [276-277] and with a Ru(bipy)3 complex [95]. An important... 

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