The influence of electroactive solutes on the properties of electrochemically formed fullerene C60-based films

A study of simple redox solutes, ferrocene, N,N,N',N'-tetramethyl-1,4-phenylenediamine, decamethylferrocene, bis(i-propylcyclopentadienyl)iron(II), [Ru(phen)3](ClO4)2, [Fe(bpy)3](ClO4)2, [Co(bpy)3](ClO4)2, and iodine has been performed at electrodes modified with polymeric fullerene films. Fullerene-modified electrodes were prepd. by electropolymn. of C60 initiated by a trace amt. of dioxygen or by simultaneous electroredn. of fullerene and a palladium(II) acetate trimer. These two films affect the electrochem. behavior of reversible redox systems differently. For the film formed from C60 and O2, a significant decrease of electrochem. activity is obsd. upon repeated potential cycling. The electrochem. activity of the film is stabilized by the redox solute added to the growth soln. due to the catalytic oxidn. of the fullerene film by the oxidized form of the redox system. Pos. charged species can also be incorporated into the structure of the film during the electropolymn. process. The electrochem. behavior of redox-active solutes themselves becomes less reversible as the Pd/C60 film growth proceeds. This film incorporates also ferricinium ion, N,N,N',N'-tetramethyl-1,4-phenylenediamine cation, decamethylferricinium ion, and to a smaller degree [Co(bpy)3]n+