The water-soluble calixarene p-hexasulfonato-calix[6]arene 1 was subjected
to voltammetric studies of its oxidation. At glassy carbon or platinum elec
trodes in aqueous electrolyte solutions, oxidation was observed at E > 0.7
V versus SCE in pH 2 solution. On glassy carbon, a stable derivatisation of
the electrode surface was inferred from the perturbation in the electroche
mistry of the anionic probe species Fe(CN)(6)(3-/4-) while the electrochemi
stry of the cationic probe Ru(NH3)(6)(3+ 2+) was unchanged. Investigation 6
of the electrochemistry of 1 as a function of pH (2 < pH < 10) showed the
expected dependence on the acid -base chemistry of 1 for the derivatisation
of the electrode surface. On platinum electrodes, the electrochemical deri
vatisation was less stable and less obvious than on carbon, indicating a we
akly adsorbed modifying layer. (C) 2001 Elsevier Science B.V. All rights re
served.