Comparisons between reactivities of corresponding electrochemical and homogeneous redox processes

7 COMPARISONS BETWEEN REACTIVITIES OF CORRESPONDING ELECTROCHEMICAL AND HOMOGENEOUS REDOX PROCESSES 

Another simple relationship can be recovered for reactions where the outer-shell reorganization provides the only component of AG. If reactant electrode imaging can be neglected (so that R 1 - 0) and the internuclear distance, Rh, is equal to twice the reactant radius, then the quantity C in eqn. (43) equals AG, so that simply 

A similar relationship to eqn. (44) can also be derived for homogeneous heteronuclear , or cross, reactions (i.e. where the reaction partners are chemically distinct [76, 119] 

A number of tests of eqns. (44) and (46) have been made [64, 76, 97, 117a, 118,119], Although the work terms can yield sizeable uncertainties, broadly speaking the available data show reasonable agreement with eqn. (44), both for organic molecule-radical couples in aprotic solvents [118a, b] and for 

As for eqn. (46), this relation can be applied to chemically irreversible, as well as to reversible, electrochemical reactions since the influence of the reaction thermodynamics is cancelled out. Of the relatively few tests of eqn. (47) that have been made [64, 97, 116, 120], reasonable accordance with the experimental data has been obtained. 

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