The Chemical Meaning of an Electrochemically Reversible Process

The well known ferrocene/ferrocenium oxidation possesses the features typical of electrochemical reversibility. This foreshadows the substantial maintenance of the original molecular geometry on passing from decamethylferrocene to decamethylferrocenium. As a matter 

The sandwich geometry is maintained upon one-electron removal, and only a slight elongation of the Fe-C bonding distances occurs. 

From a qualitative viewpoint this happens because the mass transport is specifically oriented towards the electrode surface, so that more amounts of species Ox reach the electrode surface in the unit time for unit area with respect to a planar electrode. This allows a steady-state condition to be reached (or the total depletion of Ox at the electrode 

Obviously, in order to obtain experimental conditions under which the radial diffusion might dominate over the linear diffusion (recall that in Chapter 1, Section 4.2.4, we have stated that at short times even at spherical, normal-sized electrodes linear diffusion holds), two requirements are needed  

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