The tuning by medium effect of the potential difference between the two consecutive electron transfers of dinickel bisfulvalene is qualitatively modeled by the Born solvation model and the Coulomb charge attraction/repulsion law. Calls are made for a better electrostatic understanding of the electrochemical experi-ment and for accurate modeling with theoretical chemistry. T he rationalization of the potential difference between consecutive electron transfers in redox-active molecules (ΔE 0 ′ value) stems from the birth of the field of molecular electrochemistry. 1−3 We have shown with model compounds in which electrophores are close enough to interact electrostati-cally that medium effects allow the ΔE 0 ′ value to be tuned over a wide potential range (ΔΔE 0 ′) on the order of nearly 1 V. 4 The most extensive amount of electrochemical data was collected for the potential separation between the two consecutive oxidations of dinickel bisfulvalene (1, Chart 1) to its dication. The required medium properties for a large tuning window of ΔE 0 ′ have been extensively discussed 4 and include the following incremental properties (considering as an example the generation of cations from a neutral analyte). The solvent should be of low polarity to favor ion-pairing. The solvent should be a poor donor to avoid specific stabilizing interactions with the analyte cations generated at the electrode. The size of the anion in the supporting salt can be changed from small and strongly ion-pairing (typically halides) to medium (e.g., tetrafluoroborate or hexafluorophosphate) to large and weakly coordinating (such as fluorinated tetraphenylborates) to vary the strength and effect of the resulting ion pair. A further refinement may be brought about by the rational choice of the size of the cation of the supporting salt, large or small, weakly or strongly ion pairing, to impact the competitive interaction of the generated cations with the supporting salt anions. Finally the concentration of the supporting salt may also be changed from low to high. Electrochemical measurements in solvents of high polarity (e.g., dimethyl sulfoxide) will also display the expected tunable potential window for ΔE